Search results for: metal pollution

Authors: Benjamin Anabaraonye

Abstract:

Our environment is our entitlement, and it is our duty to guard it for the safety of our society. It is, therefore, in our best interest to explore the necessary tools required to tackle the issues of environmental pollution which are major causes of climate change. Poetry has been discovered through our study as a valuable tool for tackling climate change and environmental pollution. This study explores the science of poetry and how important it is for scientists and engineers to develop their creativity to obtain relevant skills needed to tackle these global challenges. Poetry has been discovered as a great tool for climate change education which in turn brings about climate change adaptation and mitigation. This paper is, therefore, a clarion and urgent call for us to rise to our responsibility for a sustainable future.

Keywords: climate change, education, environment, poetry

Procedia PDF Downloads 206

Authors: Angelo Lanzilotto, Martin Kuss-Petermann, Catherine E. Housecroft, Edwin C. Constable, Oliver S. Wenger

Abstract:

We recently described the synthesis of a new tetraphenylporphyrinatozinc(II)-conjugated 2,2':6',6"-terpyridine (1) in which the tpy domain enables the molecule to act as a metalloligand. The synthetic route to 1 has been optimized, the importance of selecting a particular sequence of synthetic steps will be discussed. Three homoleptic complexes have been prepared, [Zn(1)₂]²⁺, [Fe(1)₂]²⁺ and [Ru(1)₂]²⁺, and have been isolated as the hexafluoridophosphate salts. Spectroelectrochemical measurements have been performed and the spectral changes ascribed to redox processes are partitioned on either the porphyrin or the terpyridine units. Compound 1 undergoes a reversible one-electron oxidation/reduction. The removal/gain of a second electron leads to a further irreversible chemical transformation. For the homoleptic [M(1)₂]²⁺ complexes, a suitable potential can be chosen at which both the oxidation and the reduction of the {ZnTPP} core are reversible. When the homoleptic complex contains a redox active metal such as Fe or Ru, spectroelectrochemistry has been used to investigate the metal to ligand charge transfer (MLCT) transition. The latter is sensitive to the oxidation state of the metal, and electrochemical oxidation of the metal center suppresses it. Detailed spectroelectrochemical studies will be presented.

Keywords: homoleptic complexes, spectroelectrochemistry, tetraphenylporphyrinatozinc(II), 2, 2':6', 6"-terpyridine

Procedia PDF Downloads 220

Authors: Kriengsak Damampai, Skulrat Pichaiyut, Amit Das, Charoen Nacason

Abstract:

The curing of epoxidized natural rubber (ENR) was performed by using metal ions (Ferric chloride, FeCl₃). Two different mole% of epoxide were used there are 25 mole% (ENR-25) and 50 mole% (ENR-50) epoxizied natural rubber. The main aim of this work was investigated the influence of metal ions on the coordination reaction of epoxidized natural rubber. Also, cure characteristics and mechanical properties of the rubber compounds were investigated. It was found that the ENR-50 compounds indicated superior modulus and tensile strength than the ENR-25 compounds. This was attributed to higher the cross-linking in the rubber via coordination linkages between the oxidation groups in ENR molecule and FeCl₃of metal ions. Various quantities of FeCl3 were also investigated. It is seen that the ENR-25 and 50 mole% compounds with FeCl₃ of more than 3 mmol exhibited higher modulus and tensile strength compare to the pure ENR. Furthermore, the FTIR spectra was used to confirm the cross-linked of ENR with FeCl₃.

Keywords: Epoxidized natural rubber, Ferric chloride, cross-linking, Coordination

Procedia PDF Downloads 82

Authors: Olga A. Krysiak, Grzegorz Cichowicz, Wojciech Hyk, Michal Cyranski, Jan Augustynski

Abstract:

Metal oxides are known electrocatalyst in water oxidation reaction. Due to the fact that it is desirable for efficient oxygen evolution catalyst to contain numerous redox-active metal ions to guard four electron water oxidation reaction, mixed metal oxides exhibit enhanced catalytic activity towards oxygen evolution reaction compared to single metal oxide systems. On the surface of fluorine doped tin oxide coated glass slide (FTO) deposited (doctor blade technique) mixed metal oxide layer composed of nickel, iron, and chromium. Oxide coating was acquired by heat treatment of the aqueous precursors' solutions of the corresponding salts. As-prepared electrodes were photosensitive and acted as an efficient oxygen evolution catalyst. Our results showed that obtained by this method electrodes can be activated which leads to achieving of higher current densities. The recorded current and photocurrent associated with oxygen evolution process were at least two orders of magnitude higher in the presence of oxide layer compared to bare FTO electrode. The overpotential of the process is low (ca. 0,2 V). We have also checked the activity of the catalyst at different known photoanodes used in sun-driven water splitting. Herein, we demonstrate that we were able to achieve efficient oxygen evolution catalysts using relatively cheap precursor consisting of earth abundant metals and simple method of preparation.

Keywords: chromium, electrocatalysis, iron, metal oxides, nickel, oxygen evolution

Procedia PDF Downloads 211

Authors: V. Khosravi, F. D. Ardejani, A. Aryafar, M. Sedighi

Abstract:

Heavy metals have a damaging impact for the environment, animals and humans due to their extreme toxicity and removing them from wastewaters is a very important and interesting task in the field of water pollution control. Biosorption is a relatively new method for treatment of wastewaters and recovery of heavy metals. In this study, a continuous fixed bed study was carried out by using Bacillus thuringiensis as a biosorbent for the removal of Cu and Mn ions from Sarcheshmeh Acid Mine Drainage (AMD). The effect of operating parameters such as flow rate and bed height on the sorption characteristics of B. thuringiensis was investigated at pH 6.0 for each metal ion. The experimental results showed that the breakthrough time decreased with increasing flow rate and decreasing bed height. The data also indicated that the equilibrium uptake of both metals increased with decreasing flow rate and increasing bed height. BDST, Thomas, and Yoon–Nelson models were applied to experimental data to predict the breakthrough curves. All models were found suitable for describing the whole dynamic behavior of the column with respect to flow rate and bed height. In order to regenerate the adsorbent, an elution step was carried out with 1 M HCl and five adsorption-desorption cycles were carried out in continuous manner.

Keywords: acid mine drainage, bacillus thuringiensis, biosorption, cu and mn ions, fixed bed

Procedia PDF Downloads 404

Authors: Farideh Gheitasi, Amir Hossain Jaberansari, Payam Abedini

Abstract:

The World Health Organization (WHO) Manifesto for Safe Communities states that "All human beings have an equal right to health and safety". The purpose of a safe Community is to minimize the damages threatening people. It seems that not sufficient attention has been given to relate environment and objectives of the safe Community. The reason for that can be assigned to the lack of enough information about environmental parameters and their relation with indices of the safe community like type and effect time of damages resulting from air pollution. Air pollution can be characterized as one of main environmental problems of Tehran. This problem is mostly due to the special geographic and climate situation, high population density and irregular growth in the number of vehicles. This paper is aimed at investigating the necessity of considering environmental factors to obtain a safe community through determining the effects of environmental pollution, particularly air pollution, on 490000 elders (+65) of Tehran. The methodology used in this study was on the basis of Random sampling and social surveying. The number of questionnaires was determined to be 321 through using Cochran method and the questionnaires were filled out by elders during personal interviews. The analysis of obtained results indicated that elders believe the major effects of air pollution include heart and respiratory diseases, obligation to stay at home on polluted days and its associated mental problems. Moreover, it was found that there is direct link between the number of polluted days and mortality frequency of elders. Having an environmental view may have an appreciable influence on the qualitative and quantitative development of activities and also facilitate obtaining the goals of the Safe Communities. In addition to reduce damages caused by pollutions, this view will encourage friends of the environment to cooperate with authorities of the safe community.

Keywords: air pollution, elderly people, environment, waste management

Procedia PDF Downloads 482

Authors: M. S. Mrudula, M. R. Gopinathan Nair

Abstract:

In order to utilize the natural rubber for developing new green polymeric materials for specialty applications, we have prepared natural rubber and polyethylene oxide based polymeric networks by two shot method. The polymeric networks thus formed have been used as chelating exchanger for metal ion binding. Chelating exchangers are, in general, coordinating copolymers containing one or more electron donor atoms such as N, S, O, and P that can form coordinate bonds with metals. Hydrogels are water- swollen network of hydrophilic homopolymer or copolymers. They acquire a great interest due to the facility of the incorporation of different chelating groups into the polymeric networks. Such polymeric hydrogels are promising materials in the field of hydrometallurgical applications and water purification due to their chemical stability. The current study discusses the swelling response of the polymeric networks as a function of time, temperature, pH and [NaCl] and sorption studies. Equilibrium swelling has been observed to depend on both structural aspects of the polymers and environmental factors. Metal ion sorption shows that these polymeric networks can be used for removal, separation, and enrichment of metal ions from aqueous solutions and can play an important role for environmental remediation of municipal and industrial wastewater.

Keywords: block copolymer, adsorption, chelating exchanger, swelling study, polymer, metal complexes

Procedia PDF Downloads 342

Authors: Lamia L. G. Al-Mahamad, Benjamin R. Horrocks, Andrew Houlton

Abstract:

Hydrogels based on metal coordination polymers of nucleosides and a range of metal ions (Au, Ag, Cu) have been prepared and characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible absorption spectroscopy, and powder X-ray diffraction. AFM images of the xerogels revealed the formation of extremely long polymer molecules (> 10 micrometers, the maximum scan range). This result is also consistent with TEM images which show a fibrous morphology. Oxidative doping of the Au-nucleoside fibres produces an electrically conductive nanowire. No sharp Bragg peaks were found at the at the X-ray diffraction pattern for metal ions hydrogels indicating that the samples were amorphous, but instead the data showed broad peaks in the range 20 < Q < 40 and correspond to distances d=2μ/Q. The data was analysed using a simplified Rietveld method by fitting a regression model to obtain the distance between atoms.

Keywords: hydrogel, metal ions, nanowire, nucleoside

Procedia PDF Downloads 265

Authors: Tayyaba Bibi, Jenny Ronan, Robert Hernan, Kathleen O’Rourke, Brendan McHugh, Evin McGovern, Michelle Giltrap, Gordon Chambers, James Wilson

Abstract:

Sediment contamination is a major source of ecosystem stress and has received significant attention from the scientific community. Both the Water Framework Directive (WFD) and Marine Strategy Framework Directive (MSFD) require a robust set of tools for biological and chemical monitoring. For the MSFD in particular, causal links between contaminant and effects need to be assessed. Appropriate assessment tools are required in order to make an accurate evaluation. In this study, a range of recommended sediment bioassays and chemical measurements are assessed in a number of potentially impacted and lowly impacted locations around Ireland. Previously, assessment indices have been developed on individual compartments, i.e. contaminant levels or biomarker/bioassay responses. A number of assessment indices are applied to chemical and ecotoxicological data from the Seachange project (Project code) and compared including the metal pollution index (MPI), pollution load index (PLI) and Chapman index for chemistry as well as integrated biomarker response (IBR). The benefits and drawbacks of the use of indices and aggregation techniques are discussed. In addition to this, modelling of raw data is investigated to analyse links between contaminant and effects.

Keywords: bioassays, contamination indices, ecotoxicity, marine environment, sediments

Procedia PDF Downloads 228

Authors: S. Cheragh Dar, M. Saljooghi, A. Babrgir

Abstract:

In the last couple of decades researchers' attitudes were focused on developing and enhancing heat transfer processes by using new components or cellular solids that divide into stochastic structures and periodic structures. Open-cell metal foams are part of stochastic structures families that they can be considered as an avant-garde technology and they have unique properties, this porous media can have tremendous achievements in thermal processes. This paper argues and surveys postulating possible in industrial thermal issues which include: compact electronic cooling, heat exchanger, aerospace, fines, turbo machinery, automobiles, crygen tanks, biomechanics, high temperature filters and etc. Recently, by surveying exponential rate of publications in thermal open-cell metal foams, all can be demonstrated in a holistic view which can lead researchers to a new level of understanding in different industrial thermal sections.

Keywords: heat transfer, industrial thermal, cellular solids, open cell metal foam

Procedia PDF Downloads 292

Authors: Roman Marsalek

Abstract:

In this paper, snow samples containing dust particles from several sampling points around the city of Ostrava were analyzed. The pH values of sampled snow were measured and solid particles analyzed. Particle size, zeta potential and content of selected heavy metals were determined in solid particles. The pH values of most samples lay in the slightly acid region. Mean values of particle size ranged from 290.5 to 620.5 nm. Zeta potential values varied between -5 and -26.5 mV. The following heavy metal concentration ranges were found: copper 0.08-0.75 mg/g, lead 0.05-0.9 mg/g, manganese 0.45-5.9 mg/g and iron 25.7-280.46 mg/g. The highest values of copper and lead were found in the vicinity of busy crossroads, and on the contrary, the highest levels of manganese and iron were detected close to a large steelworks. The proportion between pH values, zeta potentials, particle sizes and heavy metal contents was established. Zeta potential decreased with rising pH values and, simultaneously, heavy metal content in solid particles increased. At the same time, higher metal content corresponded to lower particle size.

Keywords: dust, snow, zeta potential, particles size distribution, heavy metals

Procedia PDF Downloads 368

Authors: S. Hosseini, M. Ahmadi Najafabadi, M. Akhlaghi

Abstract:

The health of the journal bearings is very important in preventing unforeseen breakdowns in rotary machines, and poor lubrication is one of the most important factors for producing the bearing failures. Hydrodynamic lubrication (HL), mixed lubrication (ML), and boundary lubrication (BL) are three regimes of a journal bearing lubrication. This paper uses acoustic emission (AE) measurement technique to correlate features of the AE signals to the three lubrication regimes. The transitions from HL to ML based on operating factors such as rotating speed, load, inlet oil pressure by time domain and time-frequency domain signal analysis techniques are detected, and then metal-to-metal contacts between sliding surfaces of the journal and bearing are identified. It is found that there is a significant difference between theoretical and experimental operating values that are obtained for defining the lubrication regions.

Keywords: acoustic emission technique, pressure fed journal bearing, time and frequency signal analysis, metal-to-metal contact

Procedia PDF Downloads 155

Authors: Tanya Kaur Bedi, Shankha Pratim Bhattacharya

Abstract:

The US Environmental Protection Agency defines indoor air pollution as “The air quality within and around buildings, especially as it relates to the health and comfort of building occupants”. According to the 2021 report by the Energy Policy Institute at Chicago, Indian residents, a country which is home to the highest levels of air pollution in the world, lose about 5.9 years from life expectancy due to poor air quality and yet has numerous dwellings dependent on natural ventilation. Currently the urban population spends 90% of the time indoors, this scenario raises a concern for occupant health and well-being. This study attempts to demonstrate the causal relationship between the indoor air pollution and its determining aspects. Detailed indoor air pollution audits were conducted in residential buildings located in Kolkata, India in the months of December and January 2021. According to the air pollution knowledge assessment city program in India, Kolkata is also the second most polluted mega-city after Delhi. Although the air pollution levels are alarming year-long, the winter months are most crucial due to the unfavourable environmental conditions. While emissions remain typically constant throughout the year, cold air is denser and moves slower than warm air, trapping the pollution in place for much longer and consequently is breathed in at a higher rate than the summers. The air pollution monitoring period was selected considering environmental factors and major pollution contributors like traffic and road dust. This study focuses on the relationship between the built environment and the spatial-temporal distribution of air pollutants in and around it. The measured parameters include, temperature, relative humidity, air velocity, particulate matter, volatile organic compounds, formaldehyde, and benzene. A total of 56 rooms were audited, selectively targeting the most dominant middle-income group in the urban area of the metropolitan. The data-collection was conducted using a set of instruments positioned in the human breathing-zone. The study assesses the relationship between indoor air pollution levels and factors determining natural ventilation and air pollution dispersion such as surrounding environment, dominant wind, openable window to floor area ratio, windward or leeward side openings, and natural ventilation type in the room: single side or cross-ventilation, floor height, residents cleaning habits, etc.

Keywords: indoor air quality, occupant health, air pollution, architecture, urban environment

Procedia PDF Downloads 107

Authors: Mahesh Kumar Farejiya, Anil Kumar Dikshit

Abstract:

The toxic metal contamination and their biomagnification in marine fishes is a serious public health concern specially, in the coastal areas and the small islands. In the present study, concentration of toxic heavy metals like zinc (Zn), cadmium (Cd), lead (Pb), nickel (Ni), cobalt (Co), chromium (Cr) and mercury (Hg) were determined in the tissues of tunas (T. albacores) caught from the area near to Lakshdweep Islands. The heavy metals are one of the indicators for the marine water pollution. Geochemical weathering, industrialization, agriculture run off, fishing, shipping and oil spills are the major pollutants. The presence of heavy toxic metals in the near coastal water fishes at both western coast and eastern coast of India has been well established. The present study was conducted assuming that the distant island will not have the metals presence in a way it is at the near main land coast. However, our study shows that there is a significant amount of the toxic metals present in the tissues of tuna samples. The gill, lever and flash samples were collected in waters around Lakshdweep Islands. They were analyzed using ICP–AES for the toxic metals after microwave digestion. The concentrations of the toxic metals were found in all fish samples and the general trend of presence was in decreasing order as Zn > Al > Cd > Pb > Cr > Ni > Hg. The amount of metals was found to higher in fish having more weight.

Keywords: toxic metals, marine tuna fish, bioaccumulation, biomagnifications

Procedia PDF Downloads 355

Authors: Meimei Wen, Chang Nyung Kim

Abstract:

In the current study, three-dimensional liquid metal (LM) magneto-hydrodynamic (MHD) flows in a manifold with three sub-channels under a uniform magnetic field are numerically investigated. In the manifold, the electrical current can cross channel walls, thus having influence on the flow distribution in each sub-channel. A case with various arrangements of electric conductivity for different parts of channel walls is considered, yielding different current distributions as well as flow distributions in each sub-channel. Here, the imbalance of mass flow rates in the three sub-channels is addressed. Meanwhile, predicted are detailed behaviors of the flow velocity, pressure, current and electric potential of LM MHD flows with three sub-channels. Commercial software CFX is used for the numerical simulation of LM MHD flows.

Keywords: CFX, liquid metal, manifold, MHD flow

Procedia PDF Downloads 344

Authors: Yang Luo, Chang Nyung Kim

Abstract:

This study numerically analyzes a steady-state, three-dimensional liquid-metal magnetohydrodynamic flows in a conduit with multiple channels under a uniform magnetic field. The geometry of the conduit is of a four-parallel-channels system including one inflow channel and three outflow channels. The liquid-metal flows in the inflow channel, then turns 1800 in the transition segment, finally flows into three different outflow channels simultaneously. This kind of channel system can induce counter flow and co-flow, which is rarely investigated before. The axial velocity in the side layer near the first partitioning wall, which is located between the inflow channel and the first outflow channel, is the highest. ‘M-shaped’ velocity profiles are obtained in the side layers of the inflow and outflow channels. The interdependency of the current, fluid velocity, pressure, electric potential is examined in order to describe the electromagnetic characteristics of the liquid-metal flows.

Keywords: liquid-metal, multiple channels, magnetic field, magnetohydrodynamic

Procedia PDF Downloads 281

Authors: S. Meziane, H. I. Faraoun, C. Esling

Abstract:

Transition metal dichalcogenides have potential applications in power generation devices that convert waste heat into electric current by the so-called Seebeck and Hall effects thus providing an alternative energy technology to reduce the dependence on traditional fossil fuels. In this study, the thermoelectric properties of 1T and 2HTaX2 (X= S or Se) dichalcogenide superconductors have been computed using the semi-classical Boltzmann theory. Technologically, the task is to fabricate suitable materials with high efficiency. It is found that 2HTaS2 possesses the largest value of figure of merit ZT= 1.27 at 175 K. From a scientific point of view, we aim to model the underlying materials properties and in particular the transport phenomena as mediated by electrons and lattice vibrations responsible for superconductivity, Charge Density Waves (CDW) and metal/insulator transitions as function of temperature. The goal of the present work is to develop an understanding of the superconductivity of these selected materials using the transport properties at the fundamental level.

Keywords: Ab initio, High efficiency, Power generation devices, Transition metal dichalcogenides

Procedia PDF Downloads 197

Authors: Selda Uzal Seyfi, Levent Seyfi

Abstract:

The technological devices are more often being used days by day. Thus, electro magnetic pollution is being more important now than last decades. Especially mobile phones and their base stations are subject to assessment in respect of all living beings health as well as of human beings. In this context, it is worth to evaluate the situation of electromagnetic radiation exposing living beings such as animals. In this study, electromagnetic radiation levels to which sheep are exposed in Konya/Turkey are presented. The electromagnetic radiation is measured at 1800 MHz for GSM base stations. 1085 sheep farms are determined in areas of Konya center region (Selçuklu, Meram, and Karatay) in which sheep and goat breeding is widely carried out. In this study, 790 sheep and goat farms, 10.8 % for total farms in Konya region (7276), having more than 100 animals are assessed. Then, the data obtained are depicted. As a conclusion, the results should be evaluated together with the future measurements to determine the exact effect on health of sheep and their productivity.

Keywords: electromagnetic pollution, sheep housing, sheep and goat farm, environmental pollution

Procedia PDF Downloads 489

Authors: S. Jahani, V. Choopankareh

Abstract:

Many people lost their life caused by environmental pollution every year. The negative effects of environmental crises appear to be much higher in Asian countries. The most important environmental issue in the developing countries and especially in Tehran, to our best knowledge, is air pollution that has affected many aspects of life in society. Environmental topics related to technology’s development have been salient issues among the main concerns of designers. Green facades are the most considerable solutions which designers and architectures are focused on, all over the world. But there are lots of behavioral and psychological problems about this point. In this line, this excavation has tried to reveal the cultural and psychological influences of green façade in developing countries like Tehran. Green façades in developing countries are so useless, although they are so expensive. As a matter of fact, users consider green facade as a decorative item. This research is an attempt to recognize the reasons which show green façades as worthless element. Also, some solutions are presented to promote green façades in the developing countries as an intrinsic solution. There are so many environmental threats, especially about air pollution, for a city as Tehran, which might be solved by green facades.

Keywords: air pollution, developing countries, effects, green facades

Procedia PDF Downloads 276

Authors: Orish E. Orisakwe, Chinna N. Orish, Anthonet N. Ezejiofor

Abstract:

African mesquite has been recognized for its antimicrobial, anti-inflammatory, and potential anticarcinogenic activities. However, its neuroprotective benefits against heavy metal-induced neurotoxicity remain largely unexplored. Therefore, the objective of this study was to investigate the neuroprotective properties of African mesquite in the hippocampus and olfactory bulb against common environmental pollutants, including Cd, As, Hg, and Pb. Thirty-five albino Sprague Dawley rats were divided into five groups for the experiment. Group 1 served as the control and did not receive either the heavy metal mixture (HMM) or African mesquite. Group 2 was orally administered HMM, consisting of PbCl2 (20 mg/kg), CdCl2 (1.61 mg/kg), HgCl2 (0.40 mg/kg), and NaAsO3 (10 mg/kg), for 960 days. Meanwhile, groups 3, 4, and 5 were treated with HMM along with African mesquite at doses of 500 mg/kg, 1000 mg/kg, and 1500 mg/kg, respectively. African mesquite reduced heavy metal accumulation in the hippocampus and olfactory bulb. Additionally, Sprague Dawley rats exhibited improved performance in the Passive avoidance and Cincinnati Maze tests. Furthermore, treatment with African mesquite significantly alleviated inflammation macromolecules peroxidation. It also restored the concentrations of SOD, CAT, GSH, GPx, Hmox-1, and reduced the activity of AChE, NRF2 and NFkB and improved histopathological findings. African mesquite exhibits a multifaceted neuroprotective effect with the potential to mitigate various aspects of heavy metal-induced neurotoxicity.

Keywords: African mesquite, heavy metal mixture;, neurotoxicity;, chemoprevention

Procedia PDF Downloads 72

Authors: Ashish Mahalle, Kishore Borakhade

Abstract:

High porosity metal foams are excellent for heat dissipation. There use has been widened to include heat removal from high density microelectronics circuits. Other important applications have been found in compact heat exchangers for airborne equipment, regenerative and dissipative air cooled condenser towers, and compact heat sinks for power electronic. The low relative density, open porosity and high thermal conductivity of the cell edges, large accessible surface area per unit volume, and the ability to mix the cooling fluid make metal foam heat exchangers efficient, compact and light weight. This paper reports the thermal performance of metal foam for high heat dissipation. In experimentation metal foam samples of different pore diameters i.e. 35 µ, 20 µ, 12 µ, are analyzed for varying velocities and heat inputs. The study investigate the effect of various dimensionless no. like Re,Nu, Pr and heat transfer characteristics of basic flow configuration.

Keywords: pores, foam, effective thermal conductivity, permeability

Procedia PDF Downloads 311

Authors: Gulnur Arabaci

Abstract:

Heavy metals are one of the major groups of contaminants in the environment and many of them are toxic even at very low concentration in plants and animals. However, some metals play important roles in the biological function of many enzymes in living organisms. Metals such as zinc, iron, and cooper are important for survival and activity of enzymes in plants, however heavy metals can inhibit enzyme which is responsible for defense system of plants. Polyphenol oxidase (PPO) is a copper-containing metalloenzyme which is responsible for enzymatic browning reaction of plants. Enzymatic browning is a major problem for the handling of vegetables and fruits in food industry. It can be increased and effected with many different futures such as metals in the nature and ground. In the present work, PPO was isolated and characterized from green leaves of red poppy plant (Papaver rhoeas). Then, the effect of some known antibrowning agents which can form complexes with metals and metals were investigated on the red poppy PPO activity. The results showed that glutathione was the most potent inhibitory effect on PPO activity. Cu(II) and Fe(II) metals increased the enzyme activities however, Sn(II) had the maximum inhibitory effect and Zn(II) and Pb(II) had no significant effect on the enzyme activity. In order to reduce the effect of heavy metals, the effects of metal-antibrowning agent complexes on the PPO activity were determined. EDTA and metal complexes had no significant effect on the enzyme. L-ascorbic acid and metal complexes decreased but L-ascorbic acid-Cu(II)-complex had no effect. Glutathione–metal complexes had the best inhibitory effect on Red poppy leaf PPO activity.

Keywords: inhibition, metal, red poppy, poly phenol oxidase (PPO)

Procedia PDF Downloads 328

Authors: Shabnam, Jagdeep Kumar

Abstract:

Because of the impact of their greater surface area and smaller quantum sizes in comparison with other metal atoms or bulk metals, metal nanoparticles, such as those formed of gold, exhibit a variety of unusual chemical and physical properties. The size- and shape-dependent properties of gold nanoparticles (GNPs) are particularly notable. Metal nanoparticles have received a lot of attention due to their unique properties and exciting prospective uses in photonics, electronics, biological sensing, and imaging. The latest developments in GNP synthesis are discussed in this review. Green chemistry measures were used to assess the production of gold nanoparticles, with a focus on Process Mass Intensity (PMI). Based on these measurements, opportunities for improving synthetic approaches were found. With PMIs that were often in the thousands, solvent usage was found to be the main obstacle for nanoparticle synthesis, even ones that were otherwise considered to be environmentally friendly. Since ligated metal nanoparticles are the most industrially relevant but least environmentally friendly, their synthesis by arrested precipitation was chosen as the best chance for significant advances. Gold nanoparticles of small sizes and bio-stability are produced biochemically, and they are used in many biological applications.

Keywords: gold, nanoparticles, green synthesis, AuNP

Procedia PDF Downloads 83

Authors: Farrin Nayebzadeh, Mohammadreza Eslami Amirabadi

Abstract:

According to technological progress and urban development, the cities of the world are growing to become metropolitans, living in which can be enthusiastic, entertaining and accessibility to the facilities like education, economic factors, hygiene and welfare is high. On the other hand, there are some problems that have been ignored in planning for such high quality of life, most important of which, is human health. Two aspects of human health are physical health and mental health, that are closely associated. Human mental health depends on two important factors: Biological factor and environmental factor. Air pollution is one of the most important environmental risk factors that affects mental health. Psychological and toxic effects of air pollution can lead to psychiatric symptoms, including anxiety and changes in mood, cognition, and behavior, depression and also children's mental disorders like hyperactivity, aggression and agitation. Increased levels of some air pollutants are accompanied by an increase in psychiatric admissions and emergency calls and, in some studies, by changes in behavior and a reduction in psychological well-being. Numerous toxic pollutants interfere with the development and adult functioning of the nervous system. Psychosocial stress can cause symptoms similar to those of organic mental disorders. These factors can cause resonance of psychiatric disorders. So, in cities of developing countries, people challenge with mental health problems due to environmental factors especially air pollution that have not been forecasted in urban planning.

Keywords: air pollution, environmental factors, mental health, psychiatric disorder

Procedia PDF Downloads 504

Authors: Sarabjeet Singh Sidhu, Ajay Batish, Sanjeev Kumar

Abstract:

This paper reports the optimal process conditions for machining of three different types of metal matrix composites (MMCs): 65vol%SiC/A356.2; 10vol%SiC-5vol%quartz/Al and 30vol%SiC/A359 using PMEDM process. Metal removal rate (MRR), tool wear rate (TWR), surface roughness (SR) and surface integrity (SI) were evaluated after each trial and contributing process parameters were identified. The four responses were then collectively optimized using the technique for order preference by similarity to ideal solution (TOPSIS) and optimal process conditions were identified for each type of MMCS. The density of reinforced particles shields the matrix material from spark energy hence the high MRR and SR was observed with lowest reinforced particle. TWR was highest with Cu-Gr electrode due to disintegration of the weakly bonded particles in the composite electrode. Each workpiece was examined for surface integrity and ranked as per severity of surface defects observed and their rankings were used for arriving at the most optimal process settings for each workpiece.

Keywords: metal matrix composites (MMCS), metal removal rate (MRR), surface roughness (SR), surface integrity (SI), tool wear rate (TWR), technique for order preference by similarity to ideal solution (TOPSIS)

Procedia PDF Downloads 291

Authors: Minbale Aschale, Bitew K. Dessie, Endaweke Assegide, Yosef Abebe, Tena Alamirew, Claire L. Walsh, Gete Zeleke

Abstract:

The upper Awash Basin faces pollution challenges due to urbanization, population growth, and expanding industries. It receives various pollutants from its catchments. The study aimed to assess the impact of wastewater irrigation on vegetables and inform stakeholders about pollution challenges and consequences. Eighty-two composite samples of matured vegetables were randomly collected from twenty-one agricultural farm sites. These samples were analyzed for potentially toxic elements, including Cd, Pb, Cr, Hg, As, Ni, Sr, B, Co, Cu, Mn, Fe, Zn, and Se. The results indicated significant variations in concentrations across different sites, with localized contributions from various contaminants. Cr, Cd, and Pb concentrations in most vegetables exceeded recommended levels. Pollution levels varied with metals and vegetable types. Different vegetables contribute differently to health risks. The relative contributions of Ethiopian kale, cabbage, red beet, lettuce, Swiss chard, Gurage cabbage, tomato, zucchini, carrot, onion, watermelon, and potato to the aggregated risk were 12.69%, 12.25%, 11.83%, 11.20%, 10.21%, 9.91%, 8.49%, 5.66%, 3.96%, 3.35%, 3.10%, and 2.72%, respectively. Comparison with permissible standards revealed inadequate environmental management by relevant regulatory bodies and industries. Despite good laws and standards at the federal and regional levels, they are ineffectively implemented or enforced to prevent environmental pollution. Mitigation measures are urgently recommended to address the potential health implications of toxic substances.

Keywords: pollution, upper Awash Basin, health risk, Ethiopia

Procedia PDF Downloads 51

Authors: Kalyani Mer

Abstract:

Hydrogen peroxide (H₂O₂) is one of the most efficient and commonly used oxidants in in-situ chemical oxidation (ISCO) of organic contaminants. In the present study, we investigated the activation of H₂O₂ by heavy metal (nickel and lead metal ions) loaded biochar for phenol degradation in an aqueous solution (concentration = 100 mg/L). It was found that H₂O₂ can be effectively activated by biochar, which produces hydroxyl (•OH) radicals owing to an increase in the formation of persistent free radicals (PFRs) on biochar surface. Ultrasound treated (30s duration) biochar, chemically activated by 30% phosphoric acid and functionalized by diethanolamine (DEA) was used for the adsorption of heavy metal ions from aqueous solutions. It was found that modified biochar could remove almost 60% of nickel in eight hours; however, for lead, the removal efficiency reached up to 95% for the same time duration. The heavy metal loaded biochar was further used for the degradation of phenol in the absence and presence of H₂O₂ (20 mM), within 4 hours of reaction time. The removal efficiency values for phenol in the presence of H₂O₂ were 80.3% and 61.9%, respectively, by modified biochar loaded with nickel and lead metal ions. These results suggested that the biochar loaded with nickel exhibits a better removal capacity towards phenol than the lead loaded biochar when used in H₂O₂ based oxidation systems. Meanwhile, control experiments were set in the absence of any activating biochar, and the removal efficiency was found to be 19.1% when only H₂O₂ was added in the reaction solution. Overall, the proposed approach serves a dual purpose of using biochar for heavy metal ion removal and treatment of organic contaminants by further using the metal loaded biochar for H₂O₂ activation in ISCO processes.

Keywords: biochar, ultrasound, heavy metals, in-situ chemical oxidation, chemical activation

Procedia PDF Downloads 135

Authors: Kevlin Govender, Anthony Walker, Glen Bright

Abstract:

Mass customization is an area of increased importance and the development of rapid tooling applications is pivotal to the success of mass customization. This paper presents a laminated object manufacturing (LOM) process for rapid tooling. The process is termed 3D metal laminate printing and utilizes domestic-grade aluminum foil and epoxy for layered manufacturing. A detailed explanation of the process is presented to produce complex metal laminated composite parts. Aluminum-epoxy composite specimens were manufactured from 0.016mm aluminum and subjected to tensile tests to determine the mechanical properties of the manufactured composite in relation to solid metal specimens. The fracture zone of the specimens was analyzed under scanning electron microscopy (SEM) in order to characterize the fracture mode and study the interfacial bonding of the manufactured laminate specimens.

Keywords: 3D metal laminate printer, aluminum-epoxy composite, laminated object manufacturing, rapid tooling

Procedia PDF Downloads 290

Authors: Xiao L Dai, Wen X Wei, Shuo Wang, Jia B Li, Yan Wei

Abstract:

Heavy oil pollution generated from both natural and anthropogenic sources could cause significant damages to the ecological environment, due to the toxicity of some of its constituents. Nowadays, microbial remediation is becoming a promising technology to treat oil pollution owing to its low cost and prevention of secondary pollution; microorganisms are key players in the process. Compared to the free microorganisms, immobilized microorganisms possess several advantages, including high metabolic activity rates, strong resistance to toxic chemicals and natural competition with the indigenous microorganisms, and effective resistance to washing away (in open water system). Many immobilized microorganisms have been successfully used for bioremediation of heavy oil pollution. Considering the broad choices, low cost, simple process, large specific surface area and less impact on microbial activity, modified zeolite were selected as a bio-carrier for bacteria immobilization. Three strains of heavy oil-degrading bacteria Bacillus sp. DL-13, Brevibacillus sp. DL-1 and Acinetobacter sp. DL-34 were immobilized on the modified zeolite under mild conditions, and the bacterial load (bacteria /modified zeolite) was 1.12 mg/g, 1.11 mg/g, and 1.13 mg/g, respectively. SEM results showed that the bacteria mainly adsorbed on the surface or punctured in the void of modified zeolite. The heavy oil degradation efficiency of immobilized bacteria was 62.96%, higher than that of the free bacteria (59.83%). The heavy oil degradation process of immobilized bacteria accords with the first-order reaction equation, and the reaction rate constant is 0.1483 d⁻¹, which was significantly higher than the free bacteria (0.1123 d⁻¹), suggesting that the immobilized bacteria can rapidly start up the heavy oil degradation and has a high activity of heavy oil degradation. The results suggested that immobilized bacteria are promising technology for bioremediation of oil pollution.

Keywords: heavy oil pollution, microbial remediation, modified zeolite, immobilized bacteria

Procedia PDF Downloads 150

Authors: Nurul Hidayati

Abstract:

Increasing public awareness of environmental pollution influences the search and development of technologies that help in clean up of organic and inorganic contaminants such as metals. Sludge waste of paper industries as toxic and hazardous material from specific source contains Pb, Zn, and Cu metal from waste soluble ink. An alternative and eco-friendly method of remediation technology is the use of biosurfactants and biosurfactant-producing microorganisms. Soil washing is among the methods available to remove heavy metal from sediments. The purpose of this research is to study effectiveness of biosurfactant with concentration = CMC for the removal of heavy metals, lead, zinc and copper in batch washing test under four different biosurfactant production by microbial origin. Pseudomonas putida T1(8), Bacillus subtilis 3K, Acinetobacter sp, and Actinobacillus sp was grown on mineral salt medium that had been already added with 2% concentration of molasses that it is a low cost application. The samples were kept in a shaker 120 rpm at room temperature for 3 days. Supernatants and sediments of sludge were separated by using a centrifuge and samples from supernatants were measured by atomic absorption spectrophotometer. The highest removal of Pb was up to 14,04% by Acinetobacter sp. Biosurfactant of Pseudomonas putida T1(8) have the highest removal for Zn and Cu up to 6,5% and 2,01% respectively. Biosurfactants have a role for removal process of the metals, including wetting, contact of biosurfactant to the surface of the sediments and detachment of the metals from the sediment. Biosurfactant has proven its ability as a washing agent in heavy metals removal from sediments, but more research is needed to optimize the process of removal heavy metals.

Keywords: biosurfactant, removal of heavy metals, sludge waste, paper industries

Procedia PDF Downloads 331