Search results for: diisopropyldithiocarbamate sodium salt

Authors: H. Al-Jabli

Abstract:

Using the freeze-melting process for the disposing of high saline brines was the aim of the paper by confirming the performance estimation of the treatment system. A laboratory bench scale freezing technique test unit was designed, constructed, and tested at Doha Research Plant (DRP) in Kuwait. The principal unit operations that have been considered for the laboratory study are: ice crystallization, separation, washing, and melting. The applied process is characterized as “the secondary-refrigerant indirect freezing”, which is utilizing normal freezing concept. The high saline brine was used as definite feed water, i.e. average TDS of 250,000 ppm. Kuwait desalination plants were carried out in the experimental study to measure the performance of the proposed treatment system. Experimental analysis shows that the freeze-melting process is capable of dropping the TDS of the feed water from 249,482 ppm to 56,880 ppm of the freeze-melting process in the two-phase’s course, whereas overall recovery results of the salt passage and salt rejection are 31.11%, 19.05%, and 80.95%, correspondingly. Therefore, the freeze-melting process is encouraging for the proposed application, as it shows on the results, which approves the process capability of reducing a major amount of the dissolved salts of the high saline brine with reasonable sensible recovery. This process might be reasonable with other brine disposal processes.

Keywords: high saline brine, freeze-melting process, ice crystallization, brine disposal process

Procedia PDF Downloads 249

Authors: Vinod Kumar Tewari, Mazhar Husain, Hari Kishan Das Gupta

Abstract:

Background: Primary or secondary brain death is also accompanied with vasospasm of the perforators other than tissue disruption & further exaggerates the anoxic damage, in the form of neuropraxia. In normal conditions the excitatory impulse propagates as anterograde neurotransmission (ANT) and at the level of synapse, glutamate activates NMDA receptors on postsynaptic membrane. Nitric oxide (NO) is produced by Nitric oxide Synthetase (NOS) in postsynaptic dendride or cell body and travels backwards across a chemical synapse to bind to the axon terminal of a presynaptic neuron for regulation of ANT this process is called as the retrograde neurotransmission (RNT). Thus the primary function of NO is RNT and the purpose of RNT is regulation of chemical neurotransmission at synapse. For this reason, RNT allows neural circuits to create feedback loops. The haem is the ligand binding site of NO receptor (sGC) at presynaptic membrane. The affinity of haem exhibits > 10,000-fold excess for NO than Oxygen (THE 10,000 FOLD EFFECT). In pathological conditions ANT, normal synaptic activity including RNT is absent. NO donors like sodium nitroprusside (SNP) releases NO by activating NOS at the level of postsynaptic area. NO now travels backwards across a chemical synapse to bind to the haem of NO receptor at axon terminal of a presynaptic neuron as in normal condition. NO now acts as impulse generator (at presynaptic membrane) thus bypasses the normal ANT. Also the arteriolar perforators are having Nitric Oxide Synthetase (NOS) at the adventitial side (outer border) on which sodium nitroprusside (SNP) acts; causing release of Nitric Oxide (NO) which vasodilates the perforators causing gush of blood in brain’s tissue and reversal of brain death. Objective: In brain death cases we only think for various transplantations but this study being a pilot study reverses some criteria of brain death by vasodilating the arteriolar perforators. To study the effect of intrathecal sodium nitroprusside (IT SNP) in cases of brain death in which: 1. Retrograde transmission = assessed by the hyperacute timings of reversal 2. The arteriolar perforator vasodilatation caused by NO and the maintenance of reversal of brain death reversal. Methods: 35 year old male, who became brain death after head injury and has not shown any signs of improvement after every maneuver for 6 hours, a single superfusion done by SNP via transoptic canal route for quadrigeminal cistern and cisternal puncture for IV ventricular with SNP done. Results: He showed spontaneous respiration (7 bouts) with TCD studies showing start of pulsations of various branches of common carotid arteries. Conclusions: In future we can give this SNP via transoptic canal route and in IV ventricle before declaring the body to be utilized for transplantations or dead or in broader way we can say that in near future it is possible to revert back from brain death or we have to modify our criterion.

Keywords: brain death, intrathecal sodium nitroprusside, TCD studies, perforators, vasodilatations, retrograde transmission, 10, 000 fold effect

Procedia PDF Downloads 379

Authors: Esther Eduzor, Charles A. Negbenebor, Helen O. Agu

Abstract:

Smoking of meat enhances the taste and look of meat, it also increases its longevity, and helps preserve the meat by slowing down the spoilage of fat and growth of bacteria. The Lean meat from the forequarter of beef carcass was obtained from the Maiduguri abattoir. The meat was cut into four portions with weight ranging from 525-545 g. The meat was cut into bits measuring about 8 cm in length, 3.5 cm in thickness and weighed 64.5 g. Meat samples were washed, cured with various concentration of sodium chloride, sodium nitrate, citric acid and clove for 30 min, drained and smoked in a smoking kiln at a temperature range of 55-600°C, for 8 hr a day for 3 days. The products were stored at ambient temperature and evaluated microbiologically and organoleptically. In terms of processing and storage there were increases in pH, free fatty acid content, a decrease in water holding capacity and microbial count of the cured smoked meat. The panelists rated control samples significantly (p < 0.05) higher in terms of colour, texture, taste and overall acceptability. The following organisms were isolated and identified during storage: Bacillus specie, Bacillus subtilis, streptococcus, Pseudomonas, Aspergillus niger, Candida and Penicillium specie. The study forms a basis for new product development for meat industry.

Keywords: citric acid, cloves, smoked meat, bioengineering

Procedia PDF Downloads 422

Authors: Santos Maza, Enzo Aldoradin, Carlos Pariona, Eliud Arpi, Maria Rosales

Abstract:

The objective of this study was to investigate the effect of flaying then bleeding anchovy (Engraulis ringens) immersed within a sodium citrate solution. Anchovy is a pelagic fish that readily deteriorates due to its high content of polyunsaturated fatty acids. As such, within the Peruvian food industry, the shelf life of frozen anchovy is explicitly 6 months, this short duration imparts a barrier to use for direct consumption human. Thus, almost all capture of anchovy by the fishing industry is eventually used in the production of fishmeal. We offer this an alternative to its typical production process in order to increase shelf life. In the present study, 100 kg of anchovies were captured and immediately mixed with ice on ship, maintaining a high quality sensory metric (e.g., with color blue in back) while still arriving for processing less than 2 h after capture. Anchovies with fat content of 3% were immediately flayed (i.e., reducing subcutaneous fat), beheaded, gutted and bled (i.e., removing hemoglobin) by immersion in water (Control) or in a solution of 2.5% sodium citrate (treatment), then subsequently frozen at -30 °C for 8 h in 2 kg batches. Subsequent glazing and storage at -25 °C for 14 months completed the experiments parameters. The peroxide value (PV), acidity (A), fatty acid profile (FAP), thiobarbituric acid reactive substances (TBARS), heme iron (HI), pH and sensory attributes of the samples were evaluated monthly. The results of the PV, TBARS, A, pH and sensory analyses displayed significant differences (p<0.05) between treatment and control sample; where the sodium citrate treated samples showed increased preservation features. Specifically, at the beginning of the study, flayed, beheaded, gutted and bled anchovies displayed low content of fat (1.5%) with moderate amount of PV, A and TBARS, and were not rejected by sensory analysis. HI values and FAP displayed varying behavior, however, results of HI did not reveal a decreasing trend. This result is indicative of the fact that levels of iron were maintained as HI and did not convert into no heme iron, which is known to be the primary catalyst of lipid oxidation in fish. According to the FAP results, the major quantity of fatty acid was of polyunsaturated fatty acid (PFA) followed by saturated fatty acid (SFA) and then monounsaturated fatty acid (MFA). According to sensory analysis, the shelf life of flayed, beheaded and gutted anchovy (control and treatment) was 14 months. This shelf life was reached at laboratory level because high quality anchovies were used and immediately flayed, beheaded, gutted, bled and frozen. Therefore, it is possible to maintain the shelf life of anchovies for a long time. Overall, this method displayed a large increase in shelf life relative to that commonly seen for anchovies in this industry. However, these results should be extrapolated at industrial scales to propose better processing conditions and improve the quality of anchovy for direct human consumption.

Keywords: citrate sodium solution, heme iron, polyunsaturated fatty acids, shelf life of frozen anchovy

Procedia PDF Downloads 273

Authors: Akbar Rahmani Nejad, Pejman Rahmani Nejad, Ahmad Rahmani Nejad

Abstract:

we proposed the arresting of atmospheric lightning and passing the electrical current of lightning-bolts through underground water tanks to produce Hydrogen and restoring Hydrogen in reservoirs to be used later as clean and sustainable energy. It is proposed to implement this method for storage of extra electrical power (instead of lightning energy) during low energy demand periods to produce hydrogen as a clean energy source to store in big reservoirs and later generate electricity by burning the stored hydrogen at an appropriate time. This method prevents the complicated process of changing the output power of nuclear power plants. It is possible to pass an electric current through sodium chloride solution to produce chlorine and sodium or human waste to produce Methane, etc. however atmospheric lightning is an accidental phenomenon, but using this free energy just by connecting the output of lightning arresters to the output of power plant during low energy demand period which there is no significant change in the design of power plant or have no cost, can be considered completely an economical design

Keywords: hydrogen gas, lightning energy, power plant, resistive element

Procedia PDF Downloads 119

Authors: Syfur Rahman, Mohammad J. Khattak

Abstract:

Every year a huge quantity of recycling concrete aggregate (RCA) is generated in the United States of America. Utilization of RCA can solve the storage problem, prevent environmental pollution, and reduce the construction cost. However, due to the overall low strength and durability characteristics of RCA, its usages are limited to a certain area like a landfill, low strength base material, replacement of a few percentages of virgin aggregates in Portland cement concrete, etc. This study focuses on the improvement of the strength and durability characteristics of RCA by introducing the concept of roller-compacted geopolymer concrete. In this research, developed roller-compacted geopolymer concrete (RCGPC) and roller-compacted cement concrete (RCC) mixtures containing 100% recycled concrete aggregate were evaluated and compared. Several selected RCGPC mixtures were investigated to find out the effect of mixture variables, including sodium hydroxide (NaOH) molar concentration, sodium silicate (Na₂SiO₃), to sodium hydroxide (NaOH) ratio on the strength, stiffness and durability characteristics of the developed RCGPC. Sodium hydroxide (NaOH) and sodium silicate (Na₂SiO₃) were mixed in different ratios to synthesize the alkali activator. American Concrete Pavement Association (ACPA) recommended RCC gradation was used with a maximum nominal aggregate size of 19 mm with a 4% fine particle passing 0.075 mm sieve. The mixtures were made using NaOH molar concentration of 8M and 10M along with, Na₂SiO₃ to NaOH ratio of 0 and 1 by mass and 15% class F fly ash. Optimum alkali content and moisture content were determined for each RCGPC and RCC mixtures, respectively, using modified proctor test. Compressive strength, semi-circular bending beam strength, and dynamic modulus test were conducted to evaluate the mechanistic characteristics of both mixtures. To determine the optimum curing conditions for RCGPC, effects of different curing temperature and curing duration on compressive strength were also studied. Sulphate attack and freeze-thaw tests were also carried out to assess the durability properties of the developed mixtures. X-ray diffraction (XRD) was used for morphology and microstructure analysis. From the optimum moisture content results, it was found that RCGPC has high alkali content, which was mainly due to the high absorption capacity of RCA. It was found that the mixtures with Na₂SiO₃ to NaOH ratio of 1 yielded about 60% higher compressive strength than the ratio of 0. Further, the mixtures using 10M NaOH concentrations and alkali ratio of 1 produced about 28 MPa of compressive strength, which was around 33% higher than 8M NaOH mixtures. Similar results were obtained for elastic and dynamic modulus of the mixtures. On the other hand, the semi-circular bending beam strength remained the same for both 8 and 10 molar NaOH geopolymer mixtures. Formation of new geopolymeric compounds and chemical bonds in the newly formed novel RCGPC mixtures were also discovered using XRD analysis. The results of mechanical and durability testing further revealed that RCGPC performed similarly to that of RCC mixtures. Based on the results of mechanical and durability testing, the developed RCGPC mixtures using 100% recycled concrete could be used as a cost-effective solution for the construction of pavement structures.

Keywords: roller compacted concrete, geopolymer concrete, recycled concrete aggregate, concrete pavement, fly ash

Procedia PDF Downloads 122

Authors: A. Bachrata, N. Marie, F. Bertrand, J. B. Droin

Abstract:

The in-depth understanding of severe accident propagation in Generation IV of nuclear reactors is important so that appropriate risk management can be undertaken early in their design process. This paper is focused on model improvements in the SIMMER code in order to perform studies of severe accident mitigation of Sodium Fast Reactor. During the design process of the mitigation devices dedicated to extraction of molten fuel from the core region, the molten fuel propagation from the core up to the core catcher has to be studied. In this aim, analytical as well as the complex thermo-hydraulic simulations with SIMMER-III code are performed. The studies presented in this paper focus on physical phenomena and associated physical models that influence the corium relocation. Firstly, the molten pool heat exchange with surrounding structures is analysed since it influences directly the instant of rupture of the dedicated tubes favouring the corium relocation for mitigation purpose. After the corium penetration into mitigation tubes, the fuel-coolant interactions result in formation of debris bed. Analyses of debris bed fluidization as well as sinking into a fluid are presented in this paper.

Keywords: corium, mitigation tubes, SIMMER-III, sodium fast reactor

Procedia PDF Downloads 361

Authors: Mohammed Omar

Abstract:

Using Chenopodium murale leaf, gold nanoparticles (Au NP's) were biosynthesized effectively in an amicable strategy. The casting process was used to create composite layers of sodium alginate and polyvinyl pyrrolidone. Gold nanoparticles were incorporated into the polyvinyl pyrrolidone (PVP)/ sodium alginate (NaAlg) polymer blend by casting technique. Before and after exposure to different doses of gamma irradiation (2, 4, 6 Mrad), thin films of synthesized nanocomposites were analyzed. XRD revealed the amorphous nature of polymer blends (PVP/ NaAlg), which decreased by both Au NP's embedding and consecutive doses of irradiation. FT-IR spectra revealed interactions and differences within the functional groups of their respective pristine components and dopant nano-fillers. The optical properties of PVP/NaAlg – Au NP thin films (refractive index n, energy gap Eg, Urbach energy Eu) were examined before and after the irradiation procedure. Transmission electron micrographs (TEM) demonstrated a decrease in the size of Au NP’s and narrow size distribution as the gamma irradiation dose was increased. Gamma irradiation was found to influence the electrical conductivity of synthesized composite films, as well as dielectric permittivity (ɛ′) and dielectric losses (ε″).

Keywords: PVP, SPR, γ-radiations, XRD

Procedia PDF Downloads 83

Authors: Ayodele Adelusi Oyedeji

Abstract:

The study was carried out under a controlled environment with the aim of examining remediation of crude oil polluted soil. The germination rate, heights and girths, number of leaves and nodulation was determined following standard procedures. Some physicochemical (organic matter, pH, nitrogen, phosphorous, potassium, calcium, magnesium and sodium) characteristics of soil used were determined using standard protocols. Results showed that at varying concentration of crude oil i.e 0 ml, 25 ml, 50 ml, 75 ml and 100 ml, Leuceana leucocephala had germination rate of 92%, 90%, 84%, 62% and 56% respectively, mean height of 73.70cm, 58.30cm, 49.50cm, 46.45cm and 41.80cm respectively after 16 weeks after planting (WAP), mean girth of 0.54mm, 0.34mm, 0.33mm, 0.21mm and 0.19mm respectively at 16 WAP, number of nodules 18, 10, 10, 6 and 2 respectively and number of leaves 24.00, 16.00, 13.00, 10.00 and 6.00 respectively. The organic matter, pH, nitrogen, phosphorous, potassium, calcium, magnesium, and sodium decreased with the increase in the concentration of crude oil. Furthermore, as the concentration of crude oil increased the germination rate, height, girth, and number of leaves and nodules decreased, suggesting the effect of crude oil on Leuceana leucocephala. The plant withstands the varying concentration of the crude oil means that it could be used for the remediation of crude oil contaminated soil in the Niger Delta region of Nigeria.

Keywords: ecosystem conservation, Leuceana leucocephala, phytoremediation, soil pollution

Procedia PDF Downloads 89

Authors: Zermina Q., Wasif Y., Naeem S., Urooj S., Sajid R. A.

Abstract:

Land degradation, a leading environemtnal problem and a decrease in the quality of land has become a major global issue, caused by human activities. By land degradation, more than half of the world’s drylands are affected. The worldwide scope of main saline soils is approximately 955 M ha, whereas inferior salinization affected approximately 77 M ha. In irrigated areas, a total of 58% of these soils is found. As most of the vegetation types requires fertile soil for their growth and quality production, salinity causes serious problem to the production of these vegetation types and agriculture demands. This research aims to identify the salt affected areas in the selected part of Indus Delta, Sindh province, Pakistan. This particular mangroves dominating coastal belt is important to the local community for their crop growth. Object based image analysis approach has been adopted on Landsat TM imagery of year 2011 by incorporating different mathematical band ratios, thermal radiance and salinity index. Accuracy assessment of developed salinity landcover map was performed using Erdas Imagine Accuracy Assessment Utility. Rain factor was also considered before acquiring satellite imagery and conducting field survey, as wet soil can greatly affect the condition of saline soil of the area. Dry season considered best for the remote sensing based observation and monitoring of the saline soil. These areas were trained with the ground truth data w.r.t pH and electric condutivity of the soil samples. The results were obtained from the object based image analysis of Keti bunder and Kharo chan shows most of the region under low saline soil.Total salt affected soil was measured to be 46,581.7 ha in Keti Bunder, which represents 57.81 % of the total area of 80,566.49 ha. High Saline Area was about 7,944.68 ha (9.86%). Medium Saline Area was about 17,937.26 ha (22.26 %) and low Saline Area was about 20,699.77 ha (25.69%). Where as total salt affected soil was measured to be 52,821.87 ha in Kharo Chann, which represents 55.87 % of the total area of 94,543.54 ha. High Saline Area was about 5,486.55 ha (5.80 %). Medium Saline Area was about 13,354.72 ha (14.13 %) and low Saline Area was about 33980.61 ha (35.94 %). These results show that the area is low to medium saline in nature. Accuracy of the soil salinity map was found to be 83 % with the Kappa co-efficient of 0.77. From this research, it was evident that this area as a whole falls under the category of low to medium saline area and being close to coastal area, mangrove forest can flourish. As Mangroves are salt tolerant plant so this area is consider heaven for mangrove plantation. It would ultimately benefit both the local community and the environment. Increase in mangrove forest control the problem of soil salinity and prevent sea water to intrude more into coastal area. So deforestation of mangrove should be regularly monitored.

Keywords: indus delta, object based image analysis, soil salinity, thematic mapper

Procedia PDF Downloads 595

Authors: Asselah Amel, Affif Chaouche M'yassa, Toudji Amira, Tazerouti Amel

Abstract:

This study covers two aspects ; the biodegradability and the performances in corrosion inhibition of a series of synthetized surfactants namely Φ- sodium methyl ester sulfonates (Φ-MES: C₁₂-MES, C₁₄-MES and C₁₆-MES. The biodegradability of these organic compounds was studied using the respirometric method, ‘the standard ISO 9408’. Degradation was followed by analysis of dissolved oxygen using the dissolved oxygen meter over 28 days and the results were compared with that of sodium dodecyl sulphate (SDS). The inoculum used consists of activated sludge taken from the aeration basin of the biological wastewater treatment plant in the city of Boumerdes-Algeria. In addition, the anticorrosive performances of Φ-MES surfactants on a carbon steel "X70" were evaluated in an injection water from a well of Hassi R'mel region- Algeria, known as Baremian water, and are compared to sodium dodecyl sulphate. Two technics, the weight loss and the linear polarization resistance corrosion rate (LPR) are used allowing to investigate the relationships between the concentrations of these synthetized surfactants and their surface properties, surface coverage and inhibition efficiency. Various adsorption isotherm models were used to characterize the nature of adsorption and explain their mechanism. The results show that the MES anionic surfactants was readily biodegradable, degrading faster than SDS, about 88% for C₁₂-MES compared to 66% for the SDS. The length of their carbon chain affects their biodegradability; the longer the chain, the lower the biodegradability. The inhibition efficiency of these surfactants is around 78.4% for C₁₂-MES, 76.60% for C₁₄-MES and 98.19% for C₁₆-MES and increases with their concentration and reaches a maximum value around their critical micelle concentrations ( CMCs). Scanning electron microscopy coupled to energy dispersive X-ray spectroscopy allowed to the visualization of a good adhesion of the protective film formed by the surfactants to the surface of the steel. The studied surfactants show the Langmuirian behavior from which the thermodynamic parameters as adsorption constant (Kads), standard free energy of adsorption (〖∆G〗_ads^0 ) are determined. Interaction of the surfactants with steel surface have involved physisorptions.

Keywords: corrosion, surfactants, adsorption, adsorption isotherems

Procedia PDF Downloads 78

Authors: Khalifa Alatresh, Mirac Aydin

Abstract:

This research explores the impacts of irrigation by treated wastewater (TWW) on the mineralogical and chemical attributes of sandy calcareous soils in the Southern region of Misurata. Soil samples obtained from three horizons (A, B, and C) of six TWW-irrigated pedons (29years) and six other pedons from nearby non-irrigated areas (dry-control). The results demonstrated that the TWW-irrigated pedons had significantly higher salinity (EC), sodium adsorption ratio (SAR), exchangeable sodium percentage (ESP), cation exchange capacity (CEC), available phosphor (AP), total nitrogen (TN), and organic matter (OM) relative to the control pedons. Nonetheless, all the values of interest (EC < 4000 µs/cm < SAR < 13, pH < 8.5 and ESP < 15) remained lower than the thresholds, showing no issues with sodicity or salinity. Irrigated pedons contained significantly higher amounts of total clay and showed an altered distribution of particle sizes and minerals identified (quartz, calcite, microcline, albite, anorthite, and dolomite) within the profile. The observed results included the occurrence of Margarite, Anorthite, Chabazite, and Tridymite minerals after the application of TWW in small quantities that are not enough to influence soil genesis and classification.0,51 cm.

Keywords: treated wastewater, sandy calcareous soils, soil mineralogy, and chemistry

Procedia PDF Downloads 96

Authors: Baigts-Allende Diana, Klojdová Iveta, Kozlu Ali, Metri-ojeda Jorge

Abstract:

Emulsion gels are constituted by a colloidal system (emulsion) stabilized by a polymeric gel matrix. These systems are more homogeneous and stable than conventional emulsions and can behave as either gel-like or soft-solid. Protein-based emulsion gels (PEG) have been used as carrier systems of bioactive compounds and as food structuring to improve the texture and consistency, mainly in producing low-fat content products. This work studied the effect of protein: polysaccharide ratio 0.75:1.25, 1:1, and 1.25:0.75 (levels -1, 0, and +1) and pH values (2-9) on the stability of protein-based emulsion gels using soy protein isolate and sodium alginate. Protein emulsion capacity was enhaced with increased pH (6,7,8 and 9) compared to acid pH values. The smaller particle size for PEG was at pH 9 (~23µm); however, with increasing protein ratio (level +1), higher particle size was observed (~23µm). The same trend was observed for rheological measurements; the consistency index (K) increased at pH 9 for level -1 (1.17) in comparison to level +1 (0.45). The studied PEG showed good thermal stability at neutral and pH 9 (~98 %) for all biopolymer ratios. Optimal conditions in pH and biopolymer ratios were determined for PEG using soy protein and sodium alginate ingredients with potential use in elaborating stable systems for broad application in the food sector.

Keywords: emulsion gels, food structuring, biopolymers, food systems

Procedia PDF Downloads 52

Authors: Asif Jamal, Samia Sakindar, Ramla Rehman

Abstract:

Biosurfactants are amphiphilic surface active compounds obtained from natural resources such as plants and microorganisms. Because of their diverse physicochemical characteristics biosurfactant are replacing synthetic compounds in various commercial applications. In present study, a strain of P. aeruginosa was isolated from crude oil contaminated soil as efficient biosurfactant producers. The biosurfactant production was analyzed as a function of surface tension reduction, oil spreading capacity, emulsification index and hemolysis assay. This bacterial strain showed excellent emulsion activity of EI24 85%, surface tension reduction up to 28.6 mNm-1 and 7.0 mm oil displacement zone. Physicochemical and biological properties of extracted rhamnolipid were also investigated in current study. The chemical composition of product from strain PSS was analyzed by FTIR spectroscopy. The results revealed that extracted biosurfactant was rhamnolipid type in nature having RL-1 and RL-2 homologues. The surface behavior of rhamnolipid in aqueous phase was investigated varying extreme pH, temperature, salt conditions and with various hydrocarbons. The results indicated that biosurfactant produced by strain PSS Which showed stability during high temperature up to 121 C, salt concentrations up to 20% and pH range between (4—14). The emulsification activity with different hydrocarbons was also remarkable. It was concluded that rhamnolipid biosurfactant produced by strain PSS has excellent potential as emulsifying/remediation agent for broad range of hydrophobic pollutants.

Keywords: P. aeruginosa, bioremediation, rhamnolipid, surfactants

Procedia PDF Downloads 257

Authors: Seyedeh Zeinab Peighambarzadeh, Mehdi Tavana

Abstract:

Cataract is the most common cause of blindness worldwide and its incidence will increase as the World’s population ages. Even in modern ophthalmology, there is no effective medical treatment for cataract except surgery. Development of a drug which could prevent or delay the onset of cataract will lessen this burden and reduce the number of blind patients waiting for cataract surgery. This study was undertaken to evaluate the protective effect of vitamin E on Selenite-induced Cataract in Sprague-dawely rats. Cataracts were induced in rats by administration of sodium selenite. On postpartum day ten, in group I, saline was injected subcutaneously. Group II rat pups received subcutaneous injection of vitamin E (60mg/kg B.W.) at day 8 postpartum and every other day thereafter. Group III and IV rat pups received a subcutaneous injection of sodium selenite (13mg/kg B.W.) at day 10 postpartum. Group IV also received subcutaneous injection of vitamin E (60mg/kg B.W.) at day 8 postpartum and every other day thereafter. The development of cataract in rats was assessed clinically by slit-lamp biomicroscope from day 14 up to postpartum day 28. After sacrifice, extricated pup lenses were analyzed for total and soluble protein concentrations and eletrophoretic pattern (SDS-PAGE). There was no opacification of lens in Group I and II. There was mature cataract in 95% of Group III. In group IV, 55% of rats developed sub capsular or cortical cataract. Cataractous and biochemical changes of the crystalline lens proteins due to selenite can be retard or prevented by vitamin E.

Keywords: preventive effect, selenite-induced cataract, vitamin E, rat

Procedia PDF Downloads 358

Authors: Zhaoyang Liu, Detao Qin, Darren Delai Sun

Abstract:

The onshore production of oil and gas (for example, shale gas) generates large quantities of wastewater, referred to be ‘produced water’, which contains high contents of oils and salts. The direct discharge of produced water, if not appropriately treated, can be toxic to the environment and human health. Membrane filtration has been deemed as an environmental-friendly and cost-effective technology for treating oily wastewater. However, conventional polymeric membranes have their drawbacks of either low salt rejection rate or high membrane fouling tendency when treating oily wastewater. Recent years, forward osmosis (FO) membrane filtration has emerged as a promising technology with its unique advantages of low operation pressure and less membrane fouling tendency. However, until now there is still no report about FO membranes specially designed and fabricated for treating the oily and salty produced water. In this study, a novel nanocomposite FO membrane was developed specially for treating oil- and salt-polluted produced water. By leveraging the recent advance of nanomaterials and nanotechnology, this nanocomposite FO membrane was designed to be made of double layers: an underwater oleophobic selective layer on top of a nanomaterial infused polymeric support layer. Wherein, graphene oxide (GO) nanosheets were selected to add into the polymeric support layer because adding GO nanosheets can optimize the pore structures of the support layer, thus potentially leading to high water flux for FO membranes. In addition, polyvinyl alcohol (PVA) hydrogel was selected as the selective layer because hydrated and chemically-crosslinked PVA hydrogel is capable of simultaneously rejecting oil and salt. After nanocomposite FO membranes were fabricated, the membrane structures were systematically characterized with the instruments of TEM, FESEM, XRD, ATR-FTIR, surface zeta-potential and Contact angles (CA). The membrane performances for treating produced waters were tested with the instruments of TOC, COD and Ion chromatography. The working mechanism of this new membrane was also analyzed. Very promising experimental results have been obtained. The incorporation of GO nanosheets can reduce internal concentration polarization (ICP) effect in the polymeric support layer. The structural parameter (S value) of the new FO membrane is reduced by 23% from 265 ± 31 μm to 205 ± 23 μm. The membrane tortuosity (τ value) is decreased by 20% from 2.55 ± 0.19 to 2.02 ± 0.13 μm, which contributes to the decrease of S value. Moreover, the highly-hydrophilic and chemically-cross-linked hydrogel selective layer present high antifouling property under saline oil/water emulsions. Compared with commercial FO membrane, this new FO membrane possesses three times higher water flux, higher removal efficiencies for oil (>99.9%) and salts (>99.7% for multivalent ions), and significantly lower membrane fouling tendency (<10%). To our knowledge, this is the first report of a nanocomposite FO membrane with the combined merits of high salt rejection, high oil repellency and high water flux for treating onshore oil/gas produced waters. Due to its outstanding performance and ease of fabrication, this novel nanocomposite FO membrane possesses great application potential in wastewater treatment industry.

Keywords: nanocomposite, membrane, polymer, graphene oxide

Procedia PDF Downloads 237

Authors: Mohammad Khattak, Bikash Adhikari, Sambodh Adhikari

Abstract:

This research deals with the physical, microstructural, mechanical, and shrinkage characteristics of flyash-based soil-geopolymer mixtures. Medium and high plastic soils were obtained from local construction projects. Class F flyash was used with a mixture of sodium silicate and sodium hydroxide solution to develop soil-geopolymer mixtures. Several mixtures were compacted, cured at different curing conditions, and tested for unconfined compressive strength (UCS), linear shrinkage, and observed under scanning electron microscopy (SEM). The results of the study demonstrated that the soil-geopolymer mixtures fulfilled the UCS criteria of cement treated design (CTD) and cement stabilized design (CSD) as recommended by the department of transportation for pavement base and subbase layers. It was found that soil-geopolymer demonstrated either similar or better UCS and shrinkage characteristics relative to conventional soil-cement mixtures. The SEM analysis revealed that microstructure of soil-geopolymer mixtures exhibited development and steady growth of geopolymerization during the curing period. Based on mechanical, shrinkage, and microstructural characteristics it was suggested that the soil-geopolymer mixtures, has an immense potential to be used as pavement subgrade, subbase, and base layers.

Keywords: soil-geopolymer, pavement base, soil stabilization, unconfined compressive strength, shrinkage, microstructure, and morphology

Procedia PDF Downloads 164

Authors: Ayman El Sabagh, SobhySorour, AbdElhamid Omar, Adel Ragab, Mohammad Sohidul Islam, Celaleddin Barutçular, Akihiro Ueda, Hirofumi Saneoka

Abstract:

Salinity is one of the major factors limiting crop production in an arid environment. What adds to the concern is that all the legume crops are sensitive to increasing soil salinity. So it is implacable to either search for salinity enhancement of legume plants. The exogenous of osmoprotectants has been found effective in reducing the adverse effects of salinity stress on plant growth. Despite its global importance soybean production suffer the problems of salinity stress causing damages at plant development. Therefore, in the current study we try to clarify the mechanism that might be involved in the ameliorating effects of osmo-protectants such as proline and glycine betaine and compost application on soybean plants grown under salinity stress. Experiments were carried out in the greenhouse of the experimental station, plant nutritional physiology, Hiroshima University, Japan in 2011- 2012. The experiment was arranged in a factorial design with 4 replications at NaCl concentrations (0 and 15 mM). The exogenous, proline and glycine betaine concentrations (0 mM and 25 mM) for each. Compost treatments (0 and 24 t ha-1). Results indicated that salinity stress induced reduction in all growth and physiological parameters (dry weights plant-1, chlorophyll content, N and K+ content) likewise, seed and quality traits of soybean plant compared with those of the unstressed plants. In contrast, salinity stress led to increases in the electrolyte leakage ratio, Na and proline contents. Thus tolerance against salt stress was observed, the improvement of salt tolerance resulted from proline, glycine betaine and compost were accompanied with improved membrane stability, K+, and proline accumulation on contrary, decreased Na+ content. These results clearly demonstrate that could be used to reduce the harmful effect of salinity on both physiological aspects and growth parameters of soybean. They are capable of restoring yield potential and quality of seed and may be useful in agronomic situations where saline conditions are diagnosed as a problem. Consequently, exogenous osmo-protectants combine with compost will effectively solve seasonal salinity stress problem and are a good strategy to increase salinity resistance in the drylands.

Keywords: compost, glycine betaine, proline, salinity tolerance, soybean

Procedia PDF Downloads 353

Authors: Laura Dembovska, Ina Pundiene, Diana Bajare

Abstract:

Alkali-activated aluminium-silicate composites (AASC) can be used in the production of innovative materials with a wide range of properties and applications. AASC are associated with low CO₂ emissions; in the production process, it is possible to use industrial by-products and waste, thereby minimizing the use of a non-renewable natural resource. This study deals with the preparation of heat-resistant porous AASC based on chamotte for high-temperature applications up to 1200°C. Different fillers, aluminium scrap recycling waste as pores forming agent and alkali activation with 6M sodium hydroxide (NaOH) and potassium hydroxide (KOH) solution were used. Sodium hydroxide (NaOH) is widely used for the synthesis of AASC compared to potassium hydroxide (KOH), but comparison of using different activator for geopolymer synthesis is not well established. Changes in chemical composition of AASC during heating were identified and quantitatively analyzed by using DTA, dimension changes during the heating process were determined by using HTOM, pore microstructure was examined by SEM, and mineralogical composition of AASC was determined by XRD. Lightweight porous AASC activated with NaOH have been obtained with density in range from 600 to 880 kg/m³ and compressive strength from 0.8 to 2.7 MPa, but for AAM activated with KOH density was in range from 750 to 850 kg/m³ and compressive strength from 0.7 to 2.1 MPa.

Keywords: alkali activation, alkali activated materials, elevated temperature application, heat resistance

Procedia PDF Downloads 164

Authors: Ziyad Abunada, Abir Al-tabbaa

Abstract:

The current work is investigating the effectiveness of combined mixed materials mainly modified bentonites and organoclay in treating contaminated groundwater. Sodium bentonite was manufactured with a quaternary amine surfactant, dimethyl ammonium chloride to produce organoclay (OC). Inorgano-organo bentonite (IOB) was produced by intercalating alkylbenzyd-methyl-ammonium chloride surfactant into sodium bentonite and pillared with chlorohydrol pillaring agent. The materials efficiency was tested for both TEX compounds from model-contaminated water and a mixture of organic contaminants found in groundwater samples collected from a contaminated site in the United Kingdom. The sorption data was fitted well to both Langmuir and Freundlich adsorption models reflecting the double sorption model where the correlation coefficient was greater than 0.89 for all materials. The mixed materials showed higher sorptive capacity than individual material with a preference order of X> E> T and a maximum sorptive capacity of 21.8 mg/g was reported for IOB-OC materials for o-xylene. The mixed materials showed at least two times higher affinity towards a mixture of organic contaminants in groundwater samples. Other experimental parameters such as pH and contact time were also investigated. The pseudo-second-order rate equation was able to provide the best description of adsorption kinetics.

Keywords: modified bentobite, groundwater, adsorption, contaminats

Procedia PDF Downloads 208

Authors: Muhammad Randhawa, Muhammad Nadeem

Abstract:

Guava (Psidium guajava L.) is a vital source of minerals, vitamins, dietary fiber and antioxidants. Owing to highly perishable nature and proning towards chilling injury, diseases, insect-pests and physical damage the main drawbacks of guava after harvesting, present study was designed. Due to its delicacy in physiology, economic importance, effects of pre and postharvest factors and maturity indices, guava fruits should be given prime importance for good quality attributes. In this study guava fruits were stored at 10°C with 80% relative humidity after treating with different levels of sulphate salt of magnesium followed by dipping in cellulose based edible coating hydroxy propyl methyl cellulose (HPMC). The main objective of this coating was to enhance the shelf life of guava by inhibiting the respiration and also by binding the dissolved solids with salt application. Characterization for quality attributes including physical, physiological and bio chemical analysis was performed after every 7 days interval till the fruit remains edible during the storage period of 4 weeks. Finally, data obtained was subjected to statistical analysis. It was concluded on statistical basis that Surahi variety (treated with 5% MgSO4) showed best storage stability and kept its original quality up to almost 23 days during storage.

Keywords: edible coating, guava cultivars, physicochemical attributes, storage

Procedia PDF Downloads 303

Authors: Djamil Guettiche, Ahmed Mekki, Tighilt Fatma-Zohra, Rachid Mahmoud

Abstract:

The aim of this study was to synthesize and characterize conducting polymer composites of polypyrrole and graphene, including pristine and surface-treated graphene (PPy/GO, PPy/rGO, and PPy/rGO-ArCOOH), for use as sensitive elements in a homemade chemiresistive module for on-line detection of nitrogen oxides vapors. The chemiresistive module was prepared, characterized, and evaluated for performance. Structural and morphological characterizations of the composite were carried out using FTIR, Raman spectroscopy, and XRD analyses. After exposure to NO and NO₂ gases in both static and dynamic modes, the sensitivity, selectivity, limit of detection, and response time of the sensor were determined at ambient temperature. The resulting sensor showed high sensitivity, selectivity, and reversibility, with a low limit of detection of 1 ppm. A composite of polypyrrole and graphene functionalized with aryl 4-carboxy benzene diazonium salt was synthesized and characterized using FTIR, scanning electron microscopy, transmission electron microscopy, UV-visible, and X-ray diffraction. The PPy-rGOArCOOH composite exhibited a good electrical resistance response to NO₂ at room temperature and showed enhanced NO₂-sensing properties compared to PPy-rGO thin films. The selectivity and stability of the NO₂ sensor based on the PPy/rGO-ArCOOH nanocomposite were also investigated.

Keywords: conducting polymers, surface treated graphene, diazonium salt, polypyrrole, Nitrogen oxide sensing

Procedia PDF Downloads 56

Authors: Patrícia Severino, Luciana Nalone, Daniele Martins, Marco Chaud, Classius Ferreira, Cristiane Bani, Ricardo Albuquerque

Abstract:

Hydrogels produced with polymers have been used in the development of dressings for wound treatment and tissue revitalization. Our study on polymer nanocomposites containing silver nanoparticles shows antimicrobial activity and applications in wound healing. The effects are linked with the slow oxidation and Ag⁺ liberation to the biological environment. Furthermore, bacterial cell membrane penetration and metabolic disruption through cell cycle disarrangement also contribute to microbial cell death. The silver antimicrobial activity has been known for many years, and previous reports show that low silver concentrations are safe for human use. This work aims to develop a hydrogel using natural polymers (sodium alginate and gelatin) combined with silver nanoparticles for wound healing and with antimicrobial properties in cutaneous lesions. The hydrogel development utilized different sodium alginate and gelatin proportions (20:80, 50:50 and 80:20). The silver nanoparticles incorporation was evaluated at the concentrations of 1.0, 2.0 and 4.0 mM. The physico-chemical properties of the formulation were evaluated using ultraviolet-visible (UV-Vis) absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and thermogravimetric (TG) analysis. The morphological characterization was made using transmission electron microscopy (TEM). Human fibroblast (L2929) viability assay was performed with a minimum inhibitory concentration (MIC) assessment as well as an in vivo cicatrizant test. The results suggested that sodium alginate and gelatin in the (80:20) proportion with 4 mM of AgNO₃ in the (UV-Vis) exhibited a better hydrogel formulation. The nanoparticle absorption spectra of this analysis showed a maximum band around 430 - 450 nm, which suggests a spheroidal form. The TG curve exhibited two weight loss events. DSC indicated one endothermic peak at 230-250 °C, due to sample fusion. The polymers acted as stabilizers of a nanoparticle, defining their size and shape. Human fibroblast viability assay L929 gave 105 % cell viability with a negative control, while gelatin presented 96% viability, alginate: gelatin (80:20) 96.66 %, and alginate 100.33 % viability. The sodium alginate:gelatin (80:20) exhibited significant antimicrobial activity, with minimal bacterial growth at a ratio of 1.06 mg.mL⁻¹ in Pseudomonas aeruginosa and 0.53 mg.mL⁻¹ in Staphylococcus aureus. The in vivo results showed a significant reduction in wound surface area. On the seventh day, the hydrogel-nanoparticle formulation reduced the total area of injury by 81.14 %, while control reached a 45.66 % reduction. The results suggest that silver-hydrogel nanoformulation exhibits potential for wound dressing therapeutics.

Keywords: nanocomposite, wound healing, hydrogel, silver nanoparticle

Procedia PDF Downloads 86

Authors: Min-Hae Park, Ju-Na Hwang, Cheong-won Seo, Ji-Ho Kim, Kee-Joe Lim

Abstract:

Polymeric insulators are high hardness, corrosion resistant, lightweight and also good dielectric strength in electric equipment. For such reasons, the amount of polymeric insulators is increased consistently abroad. The current outdoor insulators are replaced by polymeric insulators. Silicone rubber of polymeric insulators is widely used in insulation materials for outdoor application since it has excellent electrical characteristics and high surface hydrophobic. However, it can be evade exposure to pollutant on surface using at outdoor. It also improve the pollution for dust and smoke due to the large are increasing, because most of the industrial area in which the electric power loads are concentrated are located at the coastal area with salt attack. Thus it is important to detect the main cause of the deterioration for outdoor insulation materials. But there has no standards for valuation to apply reliably and determine accurately deterioration under DC, still lacks DC characteristic researches in proportion to AC. In addition, a lot of ATH was added to improve tracking resistivity of silicone rubber, although the problem has been brought up about falling sharply mechanical properties. Therefore, we might compare surface resistivities of silicone rubber compounding of three kinds of filler. In this paper, specimens of silicone rubber composite usable as outdoor insulators were prepared. Micro-silica (SiO2), nano- alumina (Al2O3) and nano-ATH (Al(OH)3) were used in additives. The study aims to investigate properties of DC surface insulation on silicone rubber composite which were filled with various fillers from surface resistivity measurement and salt-fog test.

Keywords: composite, silicone rubber, surface insulation, HVDC

Procedia PDF Downloads 391

Authors: Krasimira N. Zhilkova, Mariya K. Kyulavska, Roza P. Mateva

Abstract:

The anionic polymerization of -caprolactam (CL) with bifunctional activators has been extensively studied as an effective and beneficial method of improving chemical and impact resistances, elasticity and other mechanical properties of polyamide (PA6). In presence of activators or macroactivators (MAs) also called polymeric activators (PACs) the anionic polymerization of lactams proceeds rapidly at a temperature range of 130-180C, well below the melting point of PA-6 (220C) permitting thus the direct manufacturing of copolymer product together with desired modifications of polyamide properties. Copolymers of PA6 with an elastic polypropylene glycol (PPG) middle block into main chain were successfully synthesized via activated anionic ring opening polymerization (ROP) of CL. Using novel PACs based on PPG polyols (with differ molecular weight) the anionic ROP of CL was realized and investigated in the presence of a basic initiator sodium salt of CL (NaCL). The PACs were synthesized as N-carbamoyllactam derivatives of hydroxyl terminated PPG functionalized with isophorone diisocyanate [IPh, 5-Isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane] and blocked then with CL units via an addition reaction. The block copolymers were analyzed and proved with 1H-NMR and FT-IR spectroscopy. The influence of the CL/PACs ratio in feed, the length of the PPG segments and polymerization conditions on the kinetics of anionic ROP, on average molecular weight, and on the structure of the obtained block copolymers were investigated. The structure and phase behaviour of the copolymers were explored with differential scanning calorimetry, wide-angle X-ray diffraction, thermogravimetric analysis and dynamic mechanical thermal analysis. The crystallinity dependence of PPG content incorporated into copolymers main backbone was estimate. Additionally, the mechanical properties of the obtained copolymers were studied by notched impact test. From the performed investigation in this study could be concluded that using PPG based PACs at the chosen ROP conditions leads to obtaining well-defined PA6-b-PPG-b-PA6 copolymers with improved impact resistance.

Keywords: anionic ring opening polymerization, caprolactam, polyamide copolymers, polypropylene glycol

Procedia PDF Downloads 393

Authors: Nafisa Komilova, Plamena Angelova, Andrey Abramov, Ulugbek Mirkhodjaev

Abstract:

Parkinson’s disease (PD) is a progressive neurodegenerative disorder which is induced by the loss of dopaminergic neurons in the midbrain. The mechanism of neurodegeneration is associated with the aggregation of misfolded proteins, oxidative stress, and mitochondrial disfunction. Considering this, the process of removal of unwanted organelles or proteins by autophagy is vitally important in neurons, and activation of these processes could be protective in PD. Short-time acidification of cytosol can activate mitophagy and autophagy, and here we used sodium pyruvate and sodium lactate in human fibroblasts with PD mutations (Pink1, Pink1/Park2, α-syn triplication, A53T) to induce changes in intracellular pH. We have found that both lactate and pyruvate in millimolar concentrations can induce short-time acidification of cytosol in these cells. It induced activation of mitophagy and autophagy in control and PD fibroblasts and protected against cell death. Importantly, the application of lactate to acute brain slices of control and Pink1 knockout mice also induced a reduction of pH in neurons and astrocytes that increase the level of mitophagy. Thus, acidification of cytosol by compounds which play important role in cell metabolism also can activate mitophagy and autophagy and protect cells in the familial form of PD.

Keywords: Parkinson's disease, mutations, mitophagy, autophagy

Procedia PDF Downloads 173

Authors: Pedro B. Antunes, Paulo J. Ramísio

Abstract:

Road runoff is a linear source of diffuse pollution that can cause significant environmental impacts. During rainfall events, pollutants from both stationary and mobile sources, which have accumulated on the road surface, are dragged through the superficial runoff. Road runoff in coastal zones may present high levels of salinity and chlorides due to the proximity of the sea and transported marine aerosols. Appearing to be correlated to this process, organic matter concentration may also be significant. This study assesses this phenomenon with the purpose of identifying the relationships between monitored water quality parameters and intrinsic site variables. To achieve this objective, an extensive monitoring program was conducted on a Portuguese coastal highway. The study included thirty rainfall events, in different weather, traffic and salt deposition conditions in a three years period. The evaluations of various water quality parameters were carried out in over 200 samples. In addition, the meteorological, hydrological and traffic parameters were continuously measured. The salt deposition rates (SDR) were determined by means of a wet candle device, which is an innovative feature of the monitoring program. The SDR, variable throughout the year, appears to show a high correlation with wind speed and direction, but mostly with wave propagation, so that it is lower in the summer, in spite of the favorable wind direction in the case study. The distance to the sea, topography, ground obstacles and the platform altitude seems to be also relevant. It was confirmed the high salinity in the runoff, increasing the concentration of the water quality parameters analyzed, with significant amounts of seawater features. In order to estimate the correlations and patterns of different water quality parameters and variables related to weather, road section and salt deposition, the study included exploratory data analysis using different techniques (e.g. Pearson correlation coefficients, Cluster Analysis and Principal Component Analysis), confirming some specific features of the investigated road runoff. Significant correlations among pollutants were observed. Organic matter was highlighted as very dependent of salinity. Indeed, data analysis showed that some important water quality parameters could be divided into two major clusters based on their correlations to salinity (including organic matter associated parameters) and total suspended solids (including some heavy metals). Furthermore, the concentrations of the most relevant pollutants seemed to be very dependent on some meteorological variables, particularly the duration of the antecedent dry period prior to each rainfall event and the average wind speed. Based on the results of a monitoring case study, in a coastal zone, it was proven that SDR, associated with the hydrological characteristics of road runoff, can contribute for a better knowledge of the runoff characteristics, and help to estimate the specific nature of the runoff and related water quality parameters.

Keywords: coastal zones, monitoring, road runoff pollution, salt deposition

Procedia PDF Downloads 220

Authors: Allen Yushark Fosu, Ndue Kanari, James Vaughan, Alexandre Changes

Abstract:

Spodumene is a lithium-bearing mineral of great interest due to increasing demand of lithium in emerging electric and hybrid vehicles. The conventional method of processing the mineral for the metal requires inevitable thermal transformation of α-phase to the β-phase followed by roasting with suitable reagents to produce lithium salts for downstream processes. The selection of appropriate reagent for roasting is key for the success of the process and overall lithium recovery. Several researches have been conducted to identify good reagents for the process efficiency, leading to sulfation, alkaline, chlorination, fluorination, and carbonizing as the methods of lithium recovery from the mineral.HSC Chemistry is a thermochemical software that can be used to model metallurgical process feasibility and predict possible reaction products prior to experimental investigation. The software was employed to investigate and explain the various reagent characteristics as employed in literature during spodumene roasting up to 1200°C. The simulation indicated that all used reagents for sulfation and alkaline were feasible in the direction of lithium salt production. Chlorination was only feasible when Cl2 and CaCl2 were used as chlorination agents but not NaCl nor KCl. Depending on the kind of lithium salt formed during carbonizing and fluorination, the process was either spontaneous or nonspontaneous throughout the temperature range investigated. The HSC software was further used to simulate and predict some promising reagents which may be equally good for roasting the mineral for efficient lithium extraction but have not yet been considered by researchers.

Keywords: thermochemical modelling, HSC chemistry software, lithium, spodumene, roasting

Procedia PDF Downloads 145

Authors: Joshua Chima Chizoba, Wisdom Izuchukwu Uzoma, Elizabeth Ifeyiwa Okoyeh

Abstract:

Water cannot be optimally used and sustained unless the quality is periodically assessed. The study area Umunneochi and environs are located in south eastern part of Nigeria. It stretches geographically from latitudes 50501N to 60000N and longitudes 70201E to 70301. The major geologic formations in the area include the Asu River group, Nkporo Shale, and Ajali Sandstone. The aim of this study is to evaluate the hydrochemical characteristics of surface and ground water sources in parts of Umunneochi and environs in order to establish portability of the water sources for drinking, domestic and irrigation purposes. A total of 15 samples were collected randomly from streams, springs and wells. The samples were analyzed for physicochemical parameters and heavy metals using handheld digital kits, photometer, titration method and Atomic Absorption Spectrophotometer (AAS) following acceptable standards. The obtained analytical data were interpreted, and results were compared with World Health Organization (WHO) standard. The concentration of pH, SO42-and Cl- range from 5.81 mg/l – 6.07 mg/l, 41.93 mg/l – 142.95 mg/l and 20.00 mg/l – 111 mg/l respectively, while Pb and Zn revealed a relative low mean concentration of 0.14 mg/l and 0.40 mg/l, which are all within (WHO) permissible limits except pH. About 27% of the samples are moderately hard. This is attributed to the mining activities in the areas. The abundance of cations and anions in the area are in the order of K+>Na+>Mg2+>Ca2+ and SO4->Cl->HCO3->NO3-, respectively. Chloride, bicarbonate, and nitrate are all within the permissible limits. 13.33% of the total samples contain Sulphate above the standard permissible limits. The values of calculated Water Quality Index (WQI) are less than 50 indicating excellent water. The predominant water-type in the study area is Na-Cl water type and mixed Ca-Mg-Cl water type based on the sample plots on the Piper diagram. The Sodium Absorption Ratio (SAR) calculations showed excellent water for consumption and also good water for irrigation purpose with low sodium and alkalinity ratio respectively. Government water projects are recommended in the area for sustainable domestic and agricultural water supply to ease the stress of water supply problems.

Keywords: groundwater, hydrochemical, physichochemical, water-type, sodium adsorption ratio

Procedia PDF Downloads 113

Authors: M. Kamil, Rahber Husain Khan

Abstract:

In the present study, the Interaction of anionic polymer, sodium carboxymethylcellulose (NaCMC), with cationic gemini surfactants 2,2[(oxybis(ethane-1,2-diyl))bis(oxy)]bis(N-hexadecyl1-N,N-[di(E2)/tri(E3)]methyl1-2-oxoethanaminium)chloride (16-E2-16 and 16-E3-16) and conventional surfactant (CTAC) in aqueous solutions have been studied by surface tension measurement of binary mixtures (0.0- 0.5 wt% NaCMC and 1 mM gemini surfactant/10 mM CTAC solution). Surface tension measurements were used to determine critical aggregation concentration (CAC) and critical micelle concentration (CMC). The maximum surface excess concentration (Ґmax) at the air-water interface was evaluated by the Gibbs adsorption equation. The minimum area per surfactant molecule was evaluated, which indicates the surfactant-polymer Interaction in a mixed system. The effect of changing surfactant chain length on CAC and CMC values of mixed polymer-surfactant systems was examined. From the results, it was found that the gemini surfactant interacts strongly with NaCMC as compared to its corresponding monomeric counterpart CTAC. In these systems, electrostatic interactions predominate. The lowering of surface tension with an increase in the concentration of surfactants is higher in the case of gemini surfactants almost 10-15 times. The measurements indicated that the Interaction between NaCMC-CTAC resulted in complex formation. The volume of coacervate increases with an increase in CTAC concentration; however, above 0.1 wt. % concentration coacervate vanishes.

Keywords: anionic polymer, gemni surfactants, tensiometer, CMC, interaction

Procedia PDF Downloads 70