Search results for: contaminated soils
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1392

Search results for: contaminated soils

852 Optimized Cropping Calendar and Land Suitability for Maize through GIS and Crop Modelling

Authors: Marilyn S. Painagan, Willie Jones B. Saliling

Abstract:

This paper reports an optimized cropping calendar and land suitability for maize in North Cotabato derived from modeling crop productivity over time and space. Using Quantum GIS, eight representative soil types and 0.3o x 0.3o climate grids shapefiles were intersected to form thirty two pedoclimatic zones within the boundaries of the province. Surveys were done to ascertain crop performance and phenological properties on field. Based on these surveys, crop parameters were calibrated specific for a variety of maize. Soil properties and climatic data (daily precipitation, maximum and minimum temperatures) from pedoclimatic zones were loaded to the FAO Aquacrop Water Productivity Model along with the crop properties from field surveys to simulate yield from 1980 to 2010. The average yield per month was computed to come up with the month of planting having the highest and lowest probable yield in a year assuming that all lands were planted with maize. The yield attributes were visualized in the Quantum GIS environment. The study revealed that optimal cropping patterns varied across North Cotabato. Highest probable yield (8000 kg/ha) can be obtained when maize is planted on May and September (sandy clay-loam soils) in the northern part of the province while the lowest probable yield (1000 kg/ha) can be obtained when maize is planted on January, February and March (clay loam soils) at the northern part of the province. Yields are simulated on the basis of varieties currently planted by farmers of North Cotabato. The resulting maps suggest where and when maize is most suitable to achieve high yields. There is a need to ground truth and validate the cropping calendar on field.

Keywords: aquacrop, quantum GIS, maize, cropping calendar, water productivity

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851 Mongolian Water Quality Problem and Health of Free-Grazing Sheep

Authors: Yu Yoshihara, Chika Tada, Moe Takada, Nyam-Osor Purevdorj, Khorolmaa Chimedtseren, Yutaka Nakai

Abstract:

Water pollution from animal waste and its influence on grazing animals is a current concern regarding Mongolian grazing lands. We allocated 32 free-grazing lambs to four groups and provided each with water from a different source (upper stream, lower stream, well, and pond) for 49 days. We recorded the amount of water consumed by the lambs, as well as their body weight, behavior, white blood cell count, acute phase (haptoglobin) protein level, and fecal condition. We measured the chemical and biological qualities of the four types of water, and we detected enteropathogenic and enterohemorrhagic Escherichia coli in fecal samples by using a genetic approach. Pond water contained high levels of nitrogen and minerals, and well water contained high levels of bacteria. The odor concentration index decreased in order from pond water to upper stream, lower stream, and well. On day 15 of the experiment, the following parameters were the highest in lambs drinking water from the following sources: water intake (pond or lower stream), body weight gain (pond), WBC count (lower stream), haptoglobin concentration (well), and enteropathogenic E. coli infection rate (lower stream). Lambs that drank well water spent more time lying down and less time grazing than the others, and lambs that drank pond water spent more time standing and less time lying down. Lambs given upper or lower stream water exhibited more severe diarrhea on day 15 of the experiment than before the experiment. Mongolian sheep seemed to adapt to chemically contaminated water: their productivity benefited the most from pond water, likely owing to its rich mineral content. Lambs that drank lower stream water showed increases in enteropathogenic E. coli infection, clinical diarrhea, and WBC count. Lambs that drank well water, which was bacteriologically contaminated, had increased serum acute phase protein levels and poor physical condition; they were thus at increased risk of negative health and production effects.

Keywords: DNA, Escherichia coli, fecal sample, lower stream, well water

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850 Wetting Induced Collapse Behavior of Loosely Compacted Kaolin Soil: A Microstructural Study

Authors: Dhanesh Sing Das, Bharat Tadikonda Venkata

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Collapsible soils undergo significant volume reduction upon wetting under the pre-existing mechanically applied normal stress (inundation pressure). These soils exhibit a very high strength in air-dried conditions and can carry up to a considerable magnitude of normal stress without undergoing significant volume change. The soil strength is, however, lost upon saturation and results in a sudden collapse of the soil structure under the existing mechanical stress condition. The intrusion of water into the dry deposits of such soil causes ground subsidence leading to damages in the overlying buildings/structures. A study on the wetting-induced volume change behavior of collapsible soils is essential in dealing with the ground subsidence problems in various geotechnical engineering practices. The collapse of loosely compacted Kaolin soil upon wetting under various inundation pressures has been reported in recent studies. The collapse in the Kaolin soil is attributed to the alteration in the soil particle-particle association (fabric) resulting due to the changes in the various inter-particle (microscale) forces induced by the water saturation. The inundation pressure plays a significant role in the fabric evolution during the wetting process, thus controls the collapse potential of the compacted soil. A microstructural study is useful to understand the collapse mechanisms at various pore-fabric levels under different inundation pressure. Kaolin soil compacted to a dry density of 1.25 g/cc was used in this work to study the wetting-induced volume change behavior under different inundation pressures in the range of 10-1600 kPa. The compacted specimen of Kaolin soil exhibited a consistent collapse under all the studied inundation pressure. The collapse potential was observed to be increasing with an increase in the inundation pressure up to a maximum value of 13.85% under 800 kPa and then decreased to 11.7% under 1600 kPa. Microstructural analysis was carried out based on the fabric images and the pore size distributions (PSDs) obtained from FESEM analysis and mercury intrusion porosimetry (MIP), respectively. The PSDs and the soil fabric images of ‘as-compacted’ specimen and post-collapse specimen under 400 kPa were analyzed to understand the changes in the soil fabric and pores due to wetting. The pore size density curve for the post-collapse specimen was found to be on the finer side with respect to the ‘as-compacted’ specimen, indicating the reduction of the larger pores during the collapse. The inter-aggregate pores in the range of 0.1-0.5μm were identified as the major contributing pore size classes to the macroscopic volume change. Wetting under an inundation pressure results in the reduction of these pore sizes and lead to an increase in the finer pore sizes. The magnitude of inundation pressure influences the amount of reduction of these pores during the wetting process. The collapse potential was directly related to the degree of reduction in the pore volume contributed by these pore sizes.

Keywords: collapse behavior, inundation pressure, kaolin, microstructure

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849 Utilization of Silicon for Sustainable Rice Yield Improvement in Acid Sulfate Soil

Authors: Bunjirtluk Jintaridth

Abstract:

Utilization of silicon for sustainable rice cultivation in acid sulfate soils was studied for 2 years. The study was conducted on Rungsit soils in Amphoe Tanyaburi, Pathumtani Province. The objectives of this study were to assess the effect of high quality organic fertilizer in combination with silicon and chemical fertilizer on rice yield, chemical soil properties after using soil amendments, and also to assess the economic return. A Randomized Complete Block Design (RCBD) with 10 treatments and 3 replications were employed. The treatments were as follows: 1) control 2) chemical fertilizer (recommended by Land Development Department, LDD 3) silicon 312 kg/ha 4) high quality organic fertilizer at 1875 kg/ha (the recommendation rate by LDD) 5) silicon 156 kg/ha in combination with high quality organic fertilizer 1875 kg/ha 6) silicon at the 312 kg/ha in combination with high quality organic fertilizer 1875 kg/ha 7) silicon 156 kg/ha in combination with chemical fertilizer 8) silicon at the 312 kg/ha in combination with chemical fertilizer 9) silicon 156 kg/ha in combination with ½ chemical fertilizer rate, and 10) silicon 312 kg/ha in combination with ½ chemical fertilizer rate. The results of 2 years indicated the treatment tended to increase soil pH (from 5.1 to 4.7-5.5), percentage of organic matter (from 2.43 to 2.54 - 2.94%); avail. P (from 7.5 to 7-21 mg kg-1 P; ext. K (from 616 to 451-572 mg kg-1 K), ext Ca (from 1962 to 2042.3-4339.7 mg kg-1 Ca); ext Mg (from 1586 to 808.7-900 mg kg-1 Mg); but decrease the ext. Al (from 2.56 to 0.89-2.54 cmol kg-1 Al. Two years average of rice yield, the highest yield was obtained from silicon 156 kg/ha application in combination with high quality organic fertilizer 300 kg/rai (3770 kg/ha), or using silicon at the 312 kg/ha combination with high quality organic fertilizer 300 kg/rai. (3,750 kg/ha). It was noted that chemical fertilizer application with 156 and 312 kg/ha silicon gave only 3,260 และ 3,133 kg/ha, respectively. On the other hand, half rate of chemical fertilizer with 156 and 312 kg/ha with silicon gave the yield of 2,934 และ 3,218 kg/ha, respectively. While high quality organic fertilizer only can produce 3,318 kg/ha as compare to rice yield of 2,812 kg/ha from control. It was noted that the highest economic return was obtained from chemical fertilizer treated plots (886 dollars/ha). Silicon application at the rate of 156 kg/ha in combination with high quality organic fertilizer 1875 kg/ha gave the economic return of 846 dollars/ha, while 312 kg/ha of silicon with chemical fertilizer gave the lowest economic return (697 dollars/ha).

Keywords: rice, high quality organic fertilizer, acid sulfate soil, silicon

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848 Application of Neutron Activation Analysis Technique for the Analysis of Soil Samples from Farmlands of Yebrage Hawariat, East Gojjam, Ethiopia

Authors: Yihunie Hibstie Asres, Manny Mathuthu

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Farmers may not be conscious for their farmland’s nutrients, soil organic matter, water and air because they simply concerned only for their labor availability and soil fertility losses. The composition and proportion of these components greatly influence soil physical properties, including texture, structure, and porosity, the fraction of pore space in a soil. The soil of this farmland must be able to supply adequate amount of plant nutrients, in forms which can be absorbed by the crop, within its lifespan. Deficiencies or imbalances in the supply of any of essential elements can compromise growth, affecting root development, cell division, crop quality, crop yield and resistance to disease and drought. This study was conducted to fill this knowledge gap in order to develop economically vital and environmentally accepted nutrient management strategies for the use of soils in agricultural lands. The objective of this study is to assess the elemental contents and concentration of soil samples collected from farmlands of ‘Yebrage’ using Neutron Activation Analysis (NAA) techniques regardless of oxidation state, chemical form or physical locations. NAA is used to determine the elemental composition and concentrations present in a soil. The macro/micronutrient and organic matter deficiencies have been verified in agricultural soils through increased use of soil testing and plant analysis. The challenge for agriculture over the coming decades will meet the world’s increasing demands for food in a sustainable way. Current issues and future challenges point out that as long as agriculture remains a soil-based industry, major decreases in productivity likely to be attained ensuring that plants do not have adequate and balanced supply of nutrients.

Keywords: NAA, Yebrage, Chemoga, macro/micronutrient

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847 Health Risk Assessment and Source Apportionment of Elemental Particulate Contents from a South Asian Future Megacity

Authors: Afifa Aslam, Muhammad Ibrahim, Abid Mahmood, Muhammad Usman Alvi, Fariha Jabeen, Umara Tabassum

Abstract:

Many factors cause air pollution in Pakistan, which poses a significant threat to human health. Diesel fuel and gasoline motor vehicles, as well as industrial companies, pollute the air in Pakistan's cities. The study's goal is to determine the level of air pollution in a Pakistani industrial city and to establish risk levels for the health of the population. We measured the intensity of air pollution by chemical characterization and examination of air samples collected at stationary remark sites. The PM10 levels observed at all sampling sites, including residential, commercial, high-traffic, and industrial areas were well above the limits imposed by Pakistan EPA, the United States EPA, and WHO. We assessed the health risk via chemical factors using a methodology approved for risk assessment. All Igeo index values greater than one were considered moderately contaminated or moderately to severely contaminated. Heavy metals have a substantial risk of acute adverse effects. In Faisalabad, Pakistan, there was an enormously high risk of chronic effects produced by a heavy metal acquaintance. Concerning specified toxic metals, intolerable levels of carcinogenic risks have been determined for the entire population. As a result, in most of the investigated areas of Faisalabad, the indices and hazard quotients for chronic and acute exposure exceeded the permissible level of 1.0. In the current study, re-suspended roadside mineral dust, anthropogenic exhaust emissions from traffic and industry, and industrial dust were identified as major emission sources of elemental particulate contents. Because of the unacceptable levels of risk in the research area, it is strongly suggested that a comprehensive study of the population's health status as a result of air pollution should be conducted for policies to be developed against these risks.

Keywords: elemental composition, particulate pollution, Igeo index, health risk assessment, hazard quotient

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846 Experimental Field for the Study of Soil-Atmosphere Interaction in Soft Soils

Authors: Andres Mejia-Ortiz, Catalina Lozada, German R. Santos, Rafael Angulo-Jaramillo, Bernardo Caicedo

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The interaction between atmospheric variables and soil properties is a determining factor when evaluating the flow of water through the soil. This interaction situation directly determines the behavior of the soil and greatly influences the changes that occur in it. The atmospheric variations such as changes in the relative humidity, air temperature, wind velocity and precipitation, are the external variables that reflect a greater incidence in the changes that are generated in the subsoil, as a consequence of the water flow in descending and ascending conditions. These environmental variations have a major importance in the study of the soil because the conditions of humidity and temperature in the soil surface depend on them. In addition, these variations control the thickness of the unsaturated zone and the position of the water table with respect to the surface. However, understanding the relationship between the atmosphere and the soil is a somewhat complex aspect. This is mainly due to the difficulty involved in estimating the changes that occur in the soil from climate changes; since this is a coupled process where act processes of mass transfer and heat. In this research, an experimental field was implemented to study in-situ the interaction between the atmosphere and the soft soils of the city of Bogota, Colombia. The soil under study consists of a 60 cm layer composed of two silts of similar characteristics at the surface and a deep soft clay deposit located under the silky material. It should be noted that the vegetal layer and organic matter were removed to avoid the evapotranspiration phenomenon. Instrumentation was carried on in situ through a field disposal of many measuring devices such as soil moisture sensors, thermocouples, relative humidity sensors, wind velocity sensor, among others; which allow registering the variations of both the atmospheric variables and the properties of the soil. With the information collected through field monitoring, the water balances were made using the Hydrus-1D software to determine the flow conditions that developed in the soil during the study. Also, the moisture profile for different periods and time intervals was determined by the balance supplied by Hydrus 1D; this profile was validated by experimental measurements. As a boundary condition, the actual evaporation rate was included using the semi-empirical equations proposed by different authors. In this study, it was obtained for the rainy periods a descending flow that was governed by the infiltration capacity of the soil. On the other hand, during dry periods. An increase in the actual evaporation of the soil induces an upward flow of water, increasing suction due to the decrease in moisture content. Also, cracks were developed accelerating the evaporation process. This work concerns to the study of soil-atmosphere interaction through the experimental field and it is a very useful tool since it allows considering all the factors and parameters of the soil in its natural state and real values of the different environmental conditions.

Keywords: field monitoring, soil-atmosphere, soft soils, soil-water balance

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845 Shear Strength and Consolidation Behavior of Clayey Soil with Vertical and Radial Drainage

Authors: R. Pillai Aparna, S. R. Gandhi

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Soft clay deposits having low strength and high compressibility are found all over the world. Preloading with vertical drains is a widely used method for improving such type of soils. The coefficient of consolidation, irrespective of the drainage type, plays an important role in the design of vertical drains and it controls accurate prediction of the rate of consolidation of soil. Also, the increase in shear strength of soil with consolidation is another important factor considered in preloading or staged construction. To our best knowledge no clear guidelines are available to estimate the increase in shear strength for a particular degree of consolidation (U) at various stages during the construction. Various methods are available for finding out the consolidation coefficient. This study mainly focuses on the variation of, consolidation coefficient which was found out using different methods and shear strength with pressure intensity. The variation of shear strength with the degree of consolidation was also studied. The consolidation test was done using two types of highly compressible clays with vertical, radial and a few with combined drainage. The test was carried out at different pressures intensities and for each pressure intensity, once the target degree of consolidation is achieved, vane shear test was done at different locations in the sample, in order to determine the shear strength. The shear strength of clayey soils under the application of vertical stress with vertical and radial drainage with target U value of 70% and 90% was studied. It was found that there is not much variation in cv or cr value beyond 80kPa pressure intensity. Correlations were developed between shear strength ratio and consolidation pressure based on laboratory testing under controlled condition. It was observed that the shear strength of sample with target U value of 90% is about 1.4 to 2 times than that of 70% consolidated sample. Settlement analysis was done using Asaoka’s and hyperbolic method. The variation of strength with respect to the depth of sample was also studied, using large-scale consolidation test. It was found, based on the present study that the gain in strength is more on the top half of the clay layer, and also the shear strength of the sample ensuring radial drainage is slightly higher than that of the vertical drainage.

Keywords: consolidation coefficient, degree of consolidation, PVDs, shear strength

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844 Characterization of a Three-Electrodes Bioelectrochemical System from Mangrove Water and Sediments for the Reduction of Chlordecone in Martinique

Authors: Malory Jonata

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Chlordecone (CLD) is an organochlorine pesticide used between 1971 and 1993 in both Guadeloupe and Martinique for the control of banana black weevil. The bishomocubane structure which characterizes this chemical compound led to high stability in organic matter and high persistence in the environment. Recently, researchers found that CLD can be degraded by isolated bacteria consortiums and, particularly, by bacteria such as Citrobacter sp 86 and Delsulfovibrio sp 86. Actually, six transformation product families of CLD are known. Moreover, the latest discovery showed that CLD was disappearing faster than first predicted in highly contaminated soil in Guadeloupe. However, the toxicity of transformation products is still unknown, and knowledge has to be deepened on the degradation ways and chemical characteristics of chlordecone and its transformation products. Microbial fuel cells (MFC) are electrochemical systems that can convert organic matter into electricity thanks to electroactive bacteria. These bacteria can exchange electrons through their membranes to solid surfaces or molecules. MFC have proven their efficiency as bioremediation systems in water and soils. They are already used for the bioremediation of several organochlorine compounds such as perchlorate, trichlorophenol or hexachlorobenzene. In this study, a three-electrodes system, inspired by MFC, is used to try to degrade chlordecone using bacteria from a mangrove swamp in Martinique. As we know, some mangrove bacteria are electroactive. Furthermore, the CLD rate seems to decline in mangrove swamp sediments. This study aims to prove that electroactive bacteria from a mangrove swamp in Martinique can degrade CLD thanks to a three-electrodes bioelectrochemical system. To achieve this goal, the tree-electrodes assembly has been connected to a potentiostat. The substrate used is mangrove water and sediments sampled in the mangrove swamp of La Trinité, a coastal city in Martinique, where CLD contamination has already been studied. Electroactive biofilms are formed by imposing a potential relative to Saturated Calomel Electrode using chronoamperometry. Moreover, their comportment has been studied by using cyclic voltametry. Biofilms have been studied under different imposed potentials, several conditions of the substrate and with or without CLD. In order to quantify the evolution of CLD rates in the substrate’s system, gas chromatography coupled with mass spectrometry (GC-MS) was performed on pre-treated samples of water and sediments after short, medium and long-term contact with the electroactive biofilms. Results showed that between -0,8V and -0,2V, the three-electrodes system was able to reduce the chemical in the substrate solution. The first GC-MS analysis result of samples spiked with CLD seems to reveal decreased CLD concentration over time. In conclusion, the designed bioelectrochemical system can provide the necessary conditions for chlordecone degradation. However, it is necessary to improve three-electrodes control settings in order to increase degradation rates. The biological pathways are yet to enlighten by biologicals analysis of electroactive biofilms formed in this system. Moreover, the electrochemical study of mangrove substrate gives new informations on the potential use of this substrate for bioremediation. But further studies are needed to a better understanding of the electrochemical potential of this environment.

Keywords: bioelectrochemistry, bioremediation, chlordecone, mangrove swamp

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843 Effect of Cement Amount on California Bearing Ratio Values of Different Soil

Authors: Ayse Pekrioglu Balkis, Sawash Mecid

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Due to continued growth and rapid development of road construction in worldwide, road sub-layers consist of soil layers, therefore, identification and recognition of type of soil and soil behavior in different condition help to us to select soil according to specification and engineering characteristic, also if necessary sometimes stabilize the soil and treat undesirable properties of soils by adding materials such as bitumen, lime, cement, etc. If the soil beneath the road is not done according to the standards and construction will need more construction time. In this case, a large part of soil should be removed, transported and sometimes deposited. Then purchased sand and gravel is transported to the site and full depth filled and compacted. Stabilization by cement or other treats gives an opportunity to use the existing soil as a base material instead of removing it and purchasing and transporting better fill materials. Classification of soil according to AASHTOO system and USCS help engineers to anticipate soil behavior and select best treatment method. In this study soil classification and the relation between soil classification and stabilization method is discussed, cement stabilization with different percentages have been selected for soil treatment based on NCHRP. There are different parameters to define the strength of soil. In this study, CBR will be used to define the strength of soil. Cement by percentages, 0%, 3%, 7% and 10% added to soil for evaluation effect of added cement to CBR of treated soil. Implementation of stabilization process by different cement content help engineers to select an economic cement amount for the stabilization process according to project specification and characteristics. Stabilization process in optimum moisture content (OMC) and mixing rate effect on the strength of soil in the laboratory and field construction operation have been performed to see the improvement rate in strength and plasticity. Cement stabilization is quicker than a universal method such as removing and changing field soils. Cement addition increases CBR values of different soil types by the range of 22-69%.

Keywords: California Bearing Ratio, cement stabilization, clayey soil, mechanical properties

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842 The Effects of Some Organic Amendments on Sediment Yield, Splash Loss, and Runoff of Soils of Selected Parent Materials in Southeastern Nigeria

Authors: Leonard Chimaobi Agim, Charles Arinzechukwu Igwe, Emmanuel Uzoma Onweremadu, Gabreil Osuji

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Soil erosion has been linked to stream sedimentation, ecosystem degradation, and loss of soil nutrients. A study was conducted to evaluate the effect of some organic amendment on sediment yield, splash loss, and runoff of soils of selected parent materials in southeastern Nigeria. A total of 20 locations, five from each of four parent materials namely: Asu River Group (ARG), Bende Ameki Group (BAG), Coastal Plain Sand (CPS) and Falsebedded Sandstone (FBS) were used for the study. Collected soil samples were analyzed with standard methods for the initial soil properties. Rainfall simulation at an intensity of 190 mm hr-1was conducted for 30 minutes on the soil samples at both the initial stage and after amendment to obtain erosion parameters. The influence of parent material on sediment yield, splash loss and runoff based on rainfall simulation was tested for using one way analyses of variance, while the influence of organic material and their combinations were a factorially fitted in a randomized complete block design. The organic amendments include; goat dropping (GD), poultry dropping (PD), municipal solid waste (MSW) and their combinations (COA) applied at four rates of 0, 10, 20 and 30 t ha-1 respectively. Data were analyzed using analyses of variance suitable for a factorial experiment. Significant means were separated using LSD at 5 % probability levels. Result showed significant (p ≤ 0.05) lower values of sediment yield, splash loss and runoff following amendment. For instance, organic amendment reduced sediment yield under wet and dry runs by 12.91 % and 26.16% in Ishiagu, 40.76% and 45.67%, in Bende, 16.17% and 50% in Obinze and 22.80% and 42.35% in Umulolo respectively. Goat dropping and combination of amendment gave the best results in reducing sediment yield.

Keywords: organic amendment, parent material, rainfall simulation, soil erosion

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841 Molecular Characterization and Arsenic Mobilization Properties of a Novel Strain IIIJ3-1 Isolated from Arsenic Contaminated Aquifers of Brahmaputra River Basin, India

Authors: Soma Ghosh, Balaram Mohapatra, Pinaki Sar, Abhijeet Mukherjee

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Microbial role in arsenic (As) mobilization in the groundwater aquifers of Brahmaputra river basin (BRB) in India, severely threatened by high concentrations of As, remains largely unknown. The present study, therefore, is a molecular and ecophysiological characterization of an indigenous bacterium strain IIIJ3-1 isolated from As contaminated groundwater of BRB and application of this strain in several microcosm set ups differing in their organic carbon (OC) source and terminal electron acceptors (TEA), to understand its role in As dissolution under aerobic and anaerobic conditions. Strain IIIJ3-1 was found to be a new facultative anaerobic, gram-positive, endospore-forming strain capable of arsenite (As3+) oxidation and dissimilatory arsenate (As5+) reduction. The bacterium exhibited low genomic (G+C)% content (45 mol%). Although, its 16S rRNA gene sequence revealed a maximum similarity of 99% with Bacillus cereus ATCC 14579(T) but the DNA-DNA relatedness of their genomic DNAs was only 49.9%, which remains well below the value recommended to delimit different species. Abundance of fatty acids iC17:0, iC15:0 and menaquinone (MK) 7 though corroborates its taxonomic affiliation with B. cereus sensu-lato group, presence of hydroxy fatty acids (HFAs), C18:2, MK5 and MK6 marked its uniqueness. Besides being highly As resistant (MTC=10mM As3+, 350mM As5+), metabolically diverse, efficient aerobic As3+ oxidizer; it exhibited near complete dissimilatory reduction of As5+ (1 mM). Utilization of various carbon sources with As5+ as TEA revealed lactate to serve as the best electron donor. Aerobic biotransformation assay yielded a lower Km for As3+ oxidation than As5+ reduction. Arsenic homeostasis was found to be conferred by the presence of arr, arsB, aioB, and acr3(1) genes. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) analysis of this bacterium revealed reduction in cell size upon exposure to As and formation of As-rich electron opaque dots following growth with As3+. Incubation of this strain with sediment (sterilised) collected from BRB aquifers under varying OC, TEA and redox conditions revealed that the strain caused highest As mobilization from solid to aqueous phase under anaerobic condition with lactate and nitrate as electron donor and acceptor, respectively. Co-release of highest concentrations of oxalic acid, a well known bioweathering agent, considerable fold increase in viable cell counts and SEM-EDX and X-ray diffraction analysis of the sediment after incubation under this condition indicated that As release is consequent to microbial bioweathering of the minerals. Co-release of other elements statistically proves decoupled release of As with Fe and Zn. Principle component analysis also revealed prominent role of nitrate under aerobic and/or anaerobic condition in As release by strain IIIJ3-1. This study, therefore, is the first to isolate, characterize and reveal As mobilization property of a strain belonging to the Bacillus cereus sensu lato group isolated from highly As contaminated aquifers of Brahmaputra River Basin.

Keywords: anaerobic microcosm, arsenic rich electron opaque dots, Arsenic release, Bacillus strain IIIJ3-1

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840 Risk of Occupational Exposure to Cytotoxic Drugs: The Role of Handling Procedures of Hospital Workers

Authors: J. Silva, P. Arezes, R. Schierl, N. Costa

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In order to study environmental contamination by cytostatic drugs in Portugal hospitals, sampling campaigns were conducted in three hospitals in 2015 (112 samples). Platinum containing drugs and fluorouracil were chosen because both were administered in high amounts. The detection limit was 0.01 pg/cm² for platinum and 0.1 pg/cm² for fluorouracil. The results show that spills occur mainly on the patient`s chair, while the most referenced occurrence is due to an inadequately closed wrapper. Day hospitals facilities were detected as having the largest number of contaminated samples and with higher levels of contamination.

Keywords: cytostatic, contamination, hospital, procedures, handling

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839 Evaluation of Living Mulches Effectiveness in Weed Suppression, and Seed Yield of Black cumin (Nigella sativa L.) Under Salt Stress

Authors: Fatemeh Benakashani, Hossein Tavakoli, Elias Soltani

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To ensure the sustainability of crop cultivation and rural economies, it is imperative that we focus on cultivating resilient crops capable of withstanding salt stress. However, the effective management of weeds in salt-affected soils remains a significant challenge. This study investigates the impact of living mulches, specifically Berseem clover (Trifolium alexandrinum) and Barley (Hordeum vulgare), on weed control, as well as the quality and yield of Black cumin (Nigella sativa) in salt-affected soil. In our research, we employed a two-fold mowing strategy for the living mulches: once following crop establishment and once before the flowering stage. Notably, the weed-free plots demonstrated Black cumin's seed yield, and oil content (31.1% to 34.3%), consistent with previous studies, highlighting its potential for the reclamation and utilization of salt-affected lands. However, Black cumin exhibited limited competitiveness against prevalent weeds in the field, such as Amaranthus retroflexus, Chenopodium album, and Portulaca oleracea, which significantly diminished both the 1000 grain mass in plots where weeds were present. Interestingly, the introduction of living mulches led to improvements in seed yield and seed oil content when compared to both weed-free and weed-infested plots. Notably, Berseem clover exhibited greater biomass than Barley, indicating its heightened competitiveness against weeds. Nevertheless, it's worth noting that in the long term, Berseem clover also competed with the main crop, thereby limiting overall productivity. Consequently, we recommend relocating the Berseem clover living mulch following the establishment of Black cumin as a strategy for weed management in Black cumin fields situated in salt-affected soils.

Keywords: weed management, competition, clover, barley, medicinal plant

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838 The Relation between Urbanization and Forestry Policies in Turkey

Authors: Azize Serap Tuncer

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Turkey is one of the most outstanding figures among the Mediterranean countries from the natural and historical point at view. It is relatively rich country as regards the flora and vegetation. But at the same time as a result of improper and unplanned usage of the land for centuries, its forests and fertile soils have been exposed to great damages. While rapid and uncontrolled urbanization has important effects on the environment, urban development legislations, have become very unsufficient for the protection of these areas. Some of them have been completely eradicated, and some others have lost their fertility. Besides Turkey has a high main land with a rough surface and its soils areas exposed to heavy erosion. On the other hand as a developing country, it is not willing to endanger the goals of industrialization and avoid foreign direct investment by implementing strict environmental policies. Although this kind of pressure on forestland resources threatens the stability of forest land and land use management, in recent years, there has been an obvious increase in public concern about environmental problems like over global warming, environmental pollution, deforestation and their potential effects on natural resources. To protect the ecological balance and prevention of naturel resources from the unplanned intervention of human-beıng is only possible establishing conservation areas wıth co-operation at the national and the internatıonal levels. This study was carried out to evaluate the relation between urbanization and forestry policies in Turkey. While it elaborates the normative arrangements resulting in power conflicts, it also addresses which shortages and discrepancies are responsible for the said conflicts. The present urban reconstruction and transformation practices and their aesthetic and functional aspects were studied with some examples in a country level and evaluated within the assistance of literature researches, analyses, and observations. Atatürk Forest Farm and ODTU Forest examples were negotiated as two famous cases. Obtained findings were supported by charts and photos.

Keywords: deforestration, environmental policies, metropolitan, pollution, urbanization

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837 Relationship between Gully Development and Characteristics of Drainage Area in Semi-Arid Region, NW Iran

Authors: Ali Reza Vaezi, Ouldouz Bakhshi Rad

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Gully erosion is a widespread and often dramatic form of soil erosion caused by water during and immediately after heavy rainfall. It occurs when flowing surface water is channelled across unprotected land and washes away the soil along the drainage lines. The formation of gully is influenced by various factors, including climate, drainage surface area, slope gradient, vegetation cover, land use, and soil properties. It is a very important problem in semi-arid regions, where soils have lower organic matter and are weakly aggregated. Intensive agriculture and tillage along the slope can accelerate soil erosion by water in the region. There is little information on the development of gully erosion in agricultural rainfed areas. Therefore, this study was carried out to investigate the relationship between gully erosion and morphometric characteristics of the drainage area and the effects of soil properties and soil management factors (land use and tillage method) on gully development. A field study was done in a 900 km2 agricultural area in Hshtroud township located in the south of East Azarbijan province, NW Iran. Toward this, two hundred twenty-two gullies created in rainfed lands were found in the area. Some properties of gullies, consisting of length, width, depth, height difference, cross section area, and volume, were determined. Drainage areas for each or some gullies were determined, and their boundaries were drawn. Additionally, the surface area of each drainage, land use, tillage direction, and soil properties that may affect gully formation were determined. The soil erodibility factor (K) defined in the Universal Soil Loss Equation (USLE) was estimated based on five soil properties (silt and very fine sand, coarse sand, organic matter, soil structure code, and soil permeability). Gully development in each drainage area was quantified using its volume and soil loss. The dependency of gully development on drainage area characteristics (surface area, land use, tillage direction, and soil properties) was determined using correlation matrix analysis. Based on the results, gully length was the most important morphometric characteristic indicating the development of gully erosion in the lands. Gully development in the area was related to slope gradient (r= -0.26), surface area (r= 0.71), the area of rainfed lands (r= 0.23), and the area of rainfed tilled along the slope (r= 0.24). Nevertheless, its correlation with the area of pasture and soil erodibility factor (K) was not significant. Among the characteristics of drainage area, surface area is the major factor controlling gully volume in the agricultural land. No significant correlation was found between gully erosion and soil erodibility factor (K) estimated by the Universal Soil Loss Equation (USLE). It seems the estimated soil erodibility can’t describe the susceptibility of the study soils to the gully erosion process. In these soils, aggregate stability and soil permeability are the two soil physical properties that affect the actual soil erodibility and in consequence, these soil properties can control gully erosion in the rainfed lands.

Keywords: agricultural area, gully properties, soil structure, USLE

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836 An Evaluation of the Influence of Corn Cob Ash on the Strength Parameters of Lateritic SoiLs

Authors: O. A. Apampa, Y. A. Jimoh

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The paper reports the investigation of Corn Cob Ash as a chemical stabilizing agent for laterite soils. Corn cob feedstock was obtained from Maya, a rural community in the derived savannah agro-ecological zone of South-Western Nigeria and burnt to ashes of pozzolanic quality. Reddish brown silty clayey sand material characterized as AASHTO A-2-6(3) lateritic material was obtained from a borrow pit in Abeokuta and subjected to strength characterization tests according to BS 1377: 2000. The soil was subsequently mixed with CCA in varying percentages of 0-7.5% at 1.5% intervals. The influence of CCA stabilized soil was determined for the Atterberg limits, compaction characteristics, CBR and the unconfined compression strength. The tests were repeated on laterite cement-soil mixture in order to establish a basis for comparison. The result shows a similarity in the compaction characteristics of soil-cement and soil-CCA. With increasing addition of binder from 1.5% to 7.5%, Maximum Dry Density progressively declined while the OMC steadily increased. For the CBR, the maximum positive impact was observed at 1.5% CCA addition at a value of 85% compared to the control value of 65% for the cement stabilization, but declined steadily thereafter with increasing addition of CCA, while that of soil-cement continued to increase with increasing addition of cement beyond 1.5% though at a relatively slow rate. Similar behavior was observed in the UCS values for the soil-CCA mix, increasing from a control value of 0.4 MN/m2 to 1.0 MN/m2 at 1.5% CCA and declining thereafter, while that for soil-cement continued to increase with increasing cement addition, but at a slower rate. This paper demonstrates that CCA is effective for chemical stabilization of a typical Nigerian AASHTO A-2-6 lateritic soil at maximum stabilizer content limit of 1.5% and therefore recommends its use as a way of finding further application for agricultural waste products and achievement of environmental sustainability in line with the ideals of the millennium development goals because of the economic and technical feasibility of the processing of the cobs from corn.

Keywords: corn cob ash, pozzolan, cement, laterite, stabilizing agent, cation exchange capacity

Procedia PDF Downloads 275
835 Screening of Plant Growth Promoting Rhizobacteria in the Rhizo- and Endosphere of Sunflower (Helianthus anus) and Their Role in Enhancing Growth and Yield Attriburing Trairs and Colonization Studies

Authors: A. Majeed, M.K. Abbasi, S. Hameed, A. Imran, T. Naqqash, M. K. Hanif

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Plant growth-promoting rhizobacteria (PGPR) are free-living soil bacteria that aggressively colonize the rhizosphere/plant roots, and enhance the growth and yield of plants when applied to seed or crops. Root associated (endophytic and rhizospheric) PGPR were isolated from Sunflower (Helianthus anus) grown in soils collected from 16 different sites of sub division Dhirkot, Poonch, Azad Jammu & Kashmir, Pakistan. A total of 150 bacterial isolates were isolated, purified, screened in vitro for their plant growth promoting (PGP) characteristics. 11 most effective isolates were selected on the basis of biochemical assays (nitrogen fixation, phosphate solubilization, growth hormone production, biocontrol assay, and carbon substrates utilization assay through gas chromatography (GCMS), spectrophotometry, high performance liquid chromatography HPLC, fungal and bacterial dual plate assay and BIOLOG GN2/GP2 microplate assay respectively) and were tested on the crop under controlled and field conditions. From the inoculation assay, the most promising 4 strains (on the basis of increased root/shoot weight, root/shoot length, seed oil content, and seed yield) were than selected for colonization studies through confocal laser scanning and transmission electron microscope. 16Sr RNA gene analysis showed that these bacterial isolates belong to Pseudononas, Enterobacter, Azospirrilum, and Citobacter genera. This study is the clear evident that such isolates have the potential for application as inoculants adapted to poor soils and local crops to minimize the chemical fertilizers harmful for soil and environment

Keywords: PGPR, nitrogen fixation, phosphate solubilization, colonization

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834 Conservation Agriculture and Precision Water Management in Alkaline Soils under Rice-Wheat Cropping System: Effect on Wheat Productivity and Irrigation Water Use-a Case Study from India

Authors: S. K. Kakraliya, H. S. Jat, Manish Kakraliya, P. C. Sharma, M. L. Jat

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The biggest challenge in agriculture is to produce more food for the continually increasing world population with in the limited land and water resources. Serious water deficits and reducing natural resources are some of the major threats to the agricultural sustainability in many regions of South Asia. Food and water security may be gained by bringing improvement in the crop water productivity and the amount produced per unit of water consumed. Improvement in the crop water productivity may be achieved by pursuing alternative modern agronomics approaches, which are more friendly and efficient in utilizing natural resources. Therefore, a research trial on conservation agriculture (CA) and precision water management (PWM) was conducted in 2018-19 at Karnal, India to evaluate the effect on crop productivity and irrigation in sodic soils under rice-wheat (RW) systems of Indo-Gangetic Plains (IGP). Eight scenarios were compared varied in the tillage, crop establishment, residue and irrigarion management i.e., {First four scenarios irrigated with flood irrigation method;Sc1-Conventional tillage (CT) without residue, Sc2-CT with residue, Sc3- Zero tillage (ZT) without residue, Sc4-ZT with residue}, and {last four scenarios irrigated with sub-surface drip irrigation method; Sc5-ZT without residue, Sc6- ZT with residue, Sc7-ZT inclusion legume without residue and Sc8- ZT inclusion legume with residue}. Results revealed that CA-flood irrigation (S3, Sc4) and CA-PWM system (Sc5, Sc6, Sc7 and Sc8) recorded about ~5% and ~15% higher wheat yield, respectively compared to Sc1. Similar, CA-PWM saved ~40% irrigation water compared to Sc1. Rice yield was not different under different scenarios in the first year (kharif 2019) but almost half irrigation water saved under CA-PWM system. Therefore, results of our study on modern agronomic practices including CA and precision water management (subsurface drip irrigation) for RW rotation would be addressed the existing and future challenges in the RW system.

Keywords: Sub-surface drip, Crop residue, Crop yield , Zero tillage

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833 Experimental Studies on Stress Strain Behavior of Expanded Polystyrene Beads-Sand Mixture

Authors: K. N. Ashna

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Lightweight fills are a viable alternative where weak soils such as soft clay, peat, and loose silt are encountered. Materials such as Expanded Polystyrene (EPS) geo-foam, plastics, tire wastes, rubber wastes have been used along with soil in order to obtain a lightweight fill. Out of these, Expanded Polystyrene (EPS) geo-foam has gained wide popularity in civil engineering over the past years due to its wide variety of applications. It is extremely lightweight, durable and is available in various densities to meet the strength requirements. It can be used as backfill behind retaining walls to reduce lateral load, as a fill over soft clay or weak soils to prevent the excessive settlements and to reduce seismic forces. Geo-foam is available in block form as well as beads form. In this project Expanded Polystyrene (EPS) beads of various diameters and varying densities were mixed along with sand to study their lightweight as well as strength properties. Four types of EPS beads were used 1mm, 2mm, 3-7 mm and a mix of 1-7 mm. In this project, EPS beads were varied at .25%, .5%, .75% and 1% by weight of sand. A water content of 10% by weight of sand was added to prevent segregation of the mixture. Unconsolidated Unconfined (UU) tri-axial test was conducted at 100kPa, 200 kPa and 300 kPa and angle of internal friction, and cohesion was obtained. Unit weight of the mix was obtained for a relative density of 65%. The results showed that by increasing the EPS content by weight, maximum deviator stress, unit weight, angle of internal friction and initial elastic modulus decreased. An optimum EPS bead content was arrived at by considering the strength as well as the unit weight. The stress-strain behaviour of the mix was found to be dependent on type of bead, bead content and density of the beads. Finally, regression equations were developed to predict the initial elastic modulus of the mix.

Keywords: expanded polystyrene beads, geofoam, lightweight fills, stress-strain behavior, triaxial test

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832 The Effect of Multiple Environmental Conditions on Acacia senegal Seedling’s Carbon, Nitrogen, and Hydrogen Contents: An Experimental Investigation

Authors: Abdelmoniem A. Attaelmanan, Ahmed A. H. Siddig

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This study was conducted in light of continual global climate changes that projected increasing aridity, changes in soil fertility, and pollution. Plant growth and development largely depend on the combination of availing water and nutrients in the soil. Changes in the climate and atmospheric chemistry can cause serious effects on these growth factors. Plant carbon (C), nitrogen (N), and hydrogen (H) play a fundamental role in the maintenance of ecosystem structure and function. Hashab (Acacia senegal), which produces gum Arabic, supports dryland ecosystems in tropical zones by its potentiality to restore degraded soils; hence it is ecologically and economically important for the dry areas of sub-Saharan Africa. The study aims at investigating the effects of water stress (simulated drought) and poor soil type on Acacia senegal C, N, and H contents. Seven days old seedlings were assigned to the treatments in Split- plot design for four weeks. The main plot is irrigation interval (well-watered and water-stressed), and the subplot is soil types (silt and sand soils). Seedling's C%, N%, and H% were measured using CHNS-O Analyzer and applying Standard Test Method. Irrigation intervals and soil types had no effects on seedlings and leaves C%, N%, and H%, irrigation interval had affected stem C and H%, both irrigation intervals and soil types had affected root N% and interaction effect of water and soil was found on leaves and root's N%. Synthesis application of well-watered irrigation with soil that is rich in N and other nutrients would result in the greatest seedling C, N, and H content which will enhance growth and biomass accumulation and can play a crucial role in ecosystem productivity and services in the dryland regions.

Keywords: Acacia senegal, Africa, climate change, drylands, nutrients biomass, Sub-Saharan, Sudan

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831 Bioremediation of Sewage Sludge Contaminated with Fluorene Using a Lipopeptide Biosurfactant

Authors: X. Vecino, J. M. Cruz, A. Moldes

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The disposal and the treatment of sewage sludge is an expensive and environmentally complex problem. In this work, a lipopeptide biosurfactant extracted from corn steep liquor was used as ecofriendly and cost-competitive alternative for the mobilization and bioremediation of fluorene in sewage sludge. Results have demonstrated that this biosurfactant has the capability to mobilize fluorene to the aqueous phase, reducing the amount of fluorene in the sewage sludge from 484.4 mg/Kg up to 413.7 mg/Kg and 196.0 mg/Kg after 1 and 27 days respectively. Furthemore, once the fluorene was extracted the lipopeptide biosurfactant contained in the aqueous phase allowed the bio-degradation, up to 40.5 % of the initial concentration of this polycyclic aromatic hydrocarbon.

Keywords: fluorene, lipopeptide biosurfactant, mobilization, sewage sludge

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830 Multi-Residue Analysis (GC-ECD) of Some Organochlorine Pesticides in Commercial Broiler Meat Marketed in Shivamogga City, Karnataka State, India

Authors: L. V. Lokesha, Jagadeesh S. Sanganal, Yogesh S. Gowda, Shekhar, N. B. Shridhar, N. Prakash, Prashantkumar Waghe, H. D. Narayanaswamy, Girish V. Kumar

Abstract:

Organochlorine (OC) insecticides are among the most important organotoxins and make a large group of pesticides. Physicochemical properties of these toxins, especially their lipophilicity, facilitate the absorption and storage of these toxins in the meat thus possess public health threat to humans. The presence of these toxins in broiler meat can be a quantitative and qualitative index for the presence of these toxins in animal bodies, which is attributed to Waste water of irrigation after spraying the crops, contaminated animal feeds with pesticides, polluted air are the potential sources of residues in animal products. Fifty broiler meat samples were collected from different retail outlets of Bengaluru city, Karnataka state, in ice cold conditions and later stored under -20°C until analysis. All the samples were subjected to Gas Chromatograph attached to Electron Capture Detector(GC-ECD, VARIAN make) screening and quantification of OC pesticides viz; Alachlor, Aldrin, Alpha-BHC, Beta-BHC, Dieldrin, Delta-BHC, o,p-DDE, p,p-DDE, o,p-DDD, p,p-DDD, o,p-DDT, p,p-DDT, Endosulfan-I, Endosulfan-II, Endosulfan Sulphate and Lindane(all the standards were procured from Merck). Extraction was undertaken by blending fifty grams (g) of meat sample with 50g Sodium Sulphate anahydrous, 120 ml of n-hexane, 120 ml acetone for 15 mins, extract is washed with distilled water and sample moisture is dried by sodium sulphate anahydrous, partitioning is done with 25 ml petroleum ether, 10 ml acetonitrile and 15 ml n-hexane shake vigorously for two minutes, sample clean up was done with florosil column. The reconstituted samples (using n-hexane) (Merck chem) were injected to Gas Chromatograph–Electron Capture Detector(GC-ECD). The present study reveals that, among the fifty chicken samples subjected for analysis, 60% (15/50), 32% (8/50), 28% (7/50), 20% (5/50) and 16% (4/50) of samples contaminated with DDTs, Delta-BHC, Dieldrin, Aldrin and Alachlor respectively. DDT metabolites, Delta-BHC were the most frequently detected OC pesticides. The detected levels of the pesticides were below the levels of MRL(according to Export Council of India notification for fresh poultry meat).

Keywords: accuracy, gas chromatography, meat, pesticide, petroleum ether

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829 Lactate Biostimulation for Remediation of Aquifers Affected by Recalcitrant Sources of Chloromethanes

Authors: Diana Puigserver Cuerda, Jofre Herrero Ferran, José M. Carmona Perez

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In the transition zone between aquifers and basal aquitards, DNAPL-pools of chlorinated solvents are more recalcitrant than at other depths in the aquifer. Although degradation of carbon tetrachloride (CT) and chloroform (CF) occurs in this zone, this is a slow process, which is why an adequate remediation strategy is necessary. The working hypothesis of this study is that the biostimulation of the transition zone of an aquifer contaminated by CT and CF can be an effective remediation strategy. This hypothesis has been tested in a site on an unconfined aquifer in which the major contaminants were CT and CF of industrial origin and where the hydrochemical background was rich in other compounds that can hinder natural attenuation of chloromethanes. Field studies and five laboratory microcosm experiments were carried out at the level of groundwater and sediments to identify: i) the degradation processes of CT and CF; ii) the structure of microbial communities; and iii) the microorganisms implicated on this degradation. For this, concentration of contaminants and co-contaminants (nitrate and sulfate), Compound Specific Isotope Analysis, molecular techniques (Denaturing Gradient Gel Electrophoresis) and clone library analysis were used. The main results were: i) degradation processes of CT and CF occurred in groundwater and in the lesser conductive sediments; ii) sulfate-reducing conditions in the transition zone were high and similar to those in the source of contamination; iii) two microorganisms (Azospira suillum and a bacterium of the Clostridiales order) were identified in the transition zone at the field and lab experiments that were compatible with the role of carrying out the reductive dechlorination of CT, CF and their degradation products (dichloromethane and chloromethane); iv) these two microorganisms were present at the high starting concentrations of the microcosm experiments (similar to those in the source of DNAPL) and continued being present until the last day of the lactate biostimulation; and v) the lactate biostimulation gave rise to the fastest and highest degradation rates and promoted the elimination of other electron acceptors (e.g. nitrate and sulfate). All these results are evidence that lactate biostimulation can be effective in remediating the source and plume, especially in the transition zone, and highlight the environmental relevance of the treatment of contaminated transition zones in industrial contexts similar to that studied.

Keywords: Azospira suillum, lactate biostimulation of carbon tetrachloride and chloroform, reductive dechlorination, transition zone between aquifer and aquitard

Procedia PDF Downloads 157
828 Reduction Study of As(III)-Cysteine Complex through Linear Sweep Voltammetry

Authors: Sunil Mittal, Sukhpreet Singh, Hardeep Kaur

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A simple voltammetric technique for on-line analysis of arsenite [As (III)] is reported. Owing to the affinity of As (III) with thiol group of proteins and enzymes, cysteine has been employed as reducing agent. The reduction study of As(III)-cysteine complex on indium tin oxide (ITO) electrode has been explored. The experimental parameters such as scan rate, cysteine concentration, pH etc. were optimized to achieve As (III) determination. The developed method provided dynamic linear range of detection from 0.1 to 1 mM with a detection limit of 0.1 mM. The method is applicable to environmental monitoring of As (III) from highly contaminated sources such as industrial effluents, wastewater sludge etc.

Keywords: arsenite, cysteine, linear sweep voltammetry, reduction

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827 Assessment of the State of Hygiene in a Tunisian Hospital Kitchen: Interest of Mycological and Parasitological Samples from Food Handlers and Environment

Authors: Bouchekoua Myriam, Aloui Dorsaf, Trabelsi Sonia

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Introduction Food hygiene in hospitals is important, particularly among patients who could be more vulnerable than healthy subjects to microbiological and nutritional risks. The consumption of contaminated food may be responsible for foodborne diseases, which can be severe among hospitalized patients, especially those immunocompromised. The aim of our study was to assess the state of hygiene in the internal catering department of a Tunisian hospital. Methodology and major results: A prospective study was conducted for one year in the Parasitology-Mycology laboratory of Charles Nicolle Hospital. Samples were taken from the kitchen staff, worktops, and cooking utensils used in the internal catering department. Thirty one employees have benefited from stool exams and scotch tape in order to evaluate the degree of infestation of parasites. 35% of stool exams were positive. Protozoa were the only parasites detected. Blastocystis sp was the species mostly found in nine food handlers. Its role as a human pathogen is still controversial. Pathogenic protozoa were detected in two food handlers (Giardia intestinalis in one person and Dientamoeba fragilis in the other one. Non-pathogenic protozoa were found in two cases; among them, only one had digestive symptoms without a statistically significant association with the carriage of intestinal parasites. Moreover, samples were performed from the hands of the staff in order to search for a fungal carriage. Thus, 25 employees (81%) were colonized by fungi, including molds. Besides, mycological examination among food handlers with a suspected dermatomycosis for diagnostic confirmation concluded foot onychomycosis in 32% of cases and interdigital intertrigo in 26%. Only one person had hand onychomycosis. Among the 17 samples taken from worktops and kitchen utensils, fungal contamination was detected in 13 sites. Hot and cold equipment were the most contaminated. Molds were mainly identified as belonging to five different genera. Cladosporium sp was predominant. Conclusion: In the view of the importance of intestinal parasites among food handlers, the intensity of fungi hand carriage among these employees, and the high level of fungal contamination in worktops and kitchen utensils, a reinforcement of hygiene measures is more than essential in order to minimize the alimentary contamination-risk.

Keywords: hospital kitchen, environment, intestinal parasitosis, fungal carriage, fungal contamination

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826 Surface Water Flow of Urban Areas and Sustainable Urban Planning

Authors: Sheetal Sharma

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Urban planning is associated with land transformation from natural areas to modified and developed ones which leads to modification of natural environment. The basic knowledge of relationship between both should be ascertained before proceeding for the development of natural areas. Changes on land surface due to build up pavements, roads and similar land cover, affect surface water flow. There is a gap between urban planning and basic knowledge of hydrological processes which should be known to the planners. The paper aims to identify these variations in surface flow due to urbanization for a temporal scale of 40 years using Storm Water Management Mode (SWMM) and again correlating these findings with the urban planning guidelines in study area along with geological background to find out the suitable combinations of land cover, soil and guidelines. For the purpose of identifying the changes in surface flows, 19 catchments were identified with different geology and growth in 40 years facing different ground water levels fluctuations. The increasing built up, varying surface runoff are studied using Arc GIS and SWMM modeling, regression analysis for runoff. Resulting runoff for various land covers and soil groups with varying built up conditions were observed. The modeling procedures also included observations for varying precipitation and constant built up in all catchments. All these observations were combined for individual catchment and single regression curve was obtained for runoff. Thus, it was observed that alluvial with suitable land cover was better for infiltration and least generation of runoff but excess built up could not be sustained on alluvial soil. Similarly, basalt had least recharge and most runoff demanding maximum vegetation over it. Sandstone resulted in good recharging if planned with more open spaces and natural soils with intermittent vegetation. Hence, these observations made a keystone base for planners while planning various land uses on different soils. This paper contributes and provides a solution to basic knowledge gap, which urban planners face during development of natural surfaces.

Keywords: runoff, built up, roughness, recharge, temporal changes

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825 Evaluation of the Physico-Chemical and Microbial Properties of the Compost Leachate (CL) to Assess Its Role in the Bioremediation of Polyaromatic Hydrocarbons (PAHs)

Authors: Omaima A. Sharaf, Tarek A. Moussa, Said M. Badr El-Din, H. Moawad

Abstract:

Background: Polycyclic aromatic hydrocarbons (PAHs) pose great environmental and human health concerns for their widespread occurrence, persistence, and carcinogenic properties. PAHs releases due to anthropogenic activities to the wider environment have led to higher concentrations of these contaminants than would be expected from natural processes alone. This may result in a wide range of environmental problems that can accumulate in agricultural ecosystems, which threatened to become a negative impact on sustainable agricultural development. Thus, this study aimed to evaluate the physico-chemical, and microbial properties of the compost leachate (CL) to assess its role as nutrient and microbial source (biostimulation/bioaugmentation) for developing a cost-effective bioremediation technology for PAHs contaminated sites. Material and Methods: PAHs-degrading bacteria were isolated from CL that was collected from a composting site located in central Scotland, UK. Isolation was carried out by enrichment using phenanthrene (PHR), pyrene (PYR) and benzo(a)pyrene (BaP) as the sole source of carbon and energy. The isolates were characterized using a variety of phenotypic and molecular properties. Six different isolates were identified based on the difference in morphological and biochemical tests. The efficiency of these isolates in PAHs utilization was assessed. Further analysis was performed to define taxonomical status and phylogenic relation between the most potent PAHs-utilizing bacterial strains and other standard strains, using molecular approach by partial 16S rDNA gene sequence analysis. Results indicated that the 16S rDNA sequence analysis confirmed the results of biochemical identification, as both of biochemical and molecular identification of the isolates assigned them to Bacillus licheniformis, Pseudomonas aeruginosa, Alcaligenes faecalis, Serratia marcescens, Enterobacter cloacae and Providenicia which were identified as the prominent PAHs-utilizers isolated from CL. Conclusion: This study indicates that the CL samples contain a diverse population of PAHs-degrading bacteria and the use of CL may have a potential for bioremediation of PAHs contaminated sites.

Keywords: polycyclic aromatic hydrocarbons, physico-chemical analyses, compost leachate, microbial and biochemical analyses, phylogenic relations, 16S rDNA sequence analysis

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824 Solar Heating System to Promote the Disinfection

Authors: Elmo Thiago Lins Cöuras Ford, Valentina Alessandra Carvalho do Vale

Abstract:

It presents a heating system using low cost alternative solar collectors to promote the disinfection of water in low income communities that take water contaminated by bacteria. The system consists of two solar collectors, with total area of 4 m² and was built using PET bottles and cans of beer and soft drinks. Each collector is made up of 8 PVC tubes, connected in series and work in continuous flow. It will determine the flux the most appropriate to generate the temperature to promote the disinfection. Will be presented results of the efficiency and thermal loss of system and results of analysis of water after undergoing the process of heating.

Keywords: disinfection of water, solar heating system, poor communities, PVC

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823 Metal Contents in Bird Feathers (Columba livia) from Mt Etna Volcano: Volcanic Plume Contribution and Biological Fractionation

Authors: Edda E. Falcone, Cinzia Federico, Sergio Bellomo, Lorenzo Brusca, Manfredi Longo, Walter D’Alessandro

Abstract:

Although trace metals are an essential element for living beings, they can become toxic at high concentrations. Their potential toxicity is related not only to the total content in the environment but mostly upon their bioavailability. Volcanoes are important natural metal emitters and they can deeply affect the quality of air, water and soils, as well as the human health. Trace metals tend to accumulate in the tissues of living organisms, depending on the metal contents in food, air and water and on the exposure time. Birds are considered as bioindicators of interest, because their feathers directly reflects the metals uptake from the blood. Birds are exposed to the atmospheric pollution through the contact with rainfall, dust, and aerosol, and they accumulate metals over the whole life cycle. We report on the first data combining the rainfall metal content in three different areas of Mt Etna, variably fumigated by the volcanic plume, and the metal contents in the feathers of pigeons, collected in the same areas. Rainfall samples were collected from three rain gauges placed at different elevation on the Eastern flank of the volcano, the most exposed to airborne plume, filtered, treated with HNO₃ Suprapur-grade and analyzed for Fe, Cr, Co, Ni, Se, Zn, Cu, Sr, Ba, Cd and As by ICP-MS technique, and major ions by ion chromatography. Feathers were collected from single individuals, in the same areas where the rain gauges were installed. Additionally, some samples were collected in an urban area, poorly interested by the volcanic plume. The samples were rinsed in MilliQ water and acetone, dried at 50°C until constant weight and digested in a mixture of 2:1 HNO₃ (65%) - H₂O₂ (30%) Suprapur-grade for 25-50 mg of sample, in a bath at near-to-boiling temperature. The solutions were diluted up to 20 ml prior to be analyzed by ICP-MS. The rainfall samples most contaminated by the plume were collected at close distance from the summit craters (less than 6 km), and show lower pH values and higher concentrations for all analyzed metals relative to those from the sites at lower elevation. Analyzed samples are enriched in both metals directly emitted by the volcanic plume and transported by acidic gases (SO₂, HCl, HF), and metals leached from the airborne volcanic ash. Feathers show different patterns in the different sites related to the exposure to natural or anthropogenic pollutants. They show abundance ratios similar to rainfall for lithophile elements (Ba, Sr), whereas are enriched in Zn and Se, known for their antioxidant properties, probably as adaptive response to oxidative stress induced by toxic metal exposure. The pigeons revealed a clear heterogeneity of metal uptake in the different parts of the volcano, as an effect of volcanic plume impact. Additionally, some physiological processes can modify the fate of some metals after uptake and this offer some insights for translational studies.

Keywords: bioindicators, environmental pollution, feathers, trace metals, volcanic plume

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