Removal of Arsenic From Wastewater Using Bentonite (original) (raw)
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Toxicological & Environmental Chemistry, 2014
This study evaluated the feasibility of integrating amorphous magnesite and bentonite clay (composite) as an alternative technology for removing arsenic from industrial effluents. The removal of arsenic from industrial effluents by using magnesiteÀbentonite clay composite was carried out in batch mode. The effects of equilibration time, adsorbent dosage, adsorbate concentration, and pH on removal of arsenic were investigated. The experiments demonstrated that %100% arsenic removal is optimum at 30 minutes of agitation, 2 g of adsorbent dosage (2 g: 100 mL, S/L ratio), and 20 mg L ¡1 of arsenic concentration. The adsorption data fitted well to both Langmuir and Freundlich adsorption models, hence proving monolayer and multilayer adsorption. The kinetic studies revealed that the data fitted better to a pseudo-second-order reaction than to a pseudo-first-order reaction, hence proving chemisorption. At optimized conditions, the composite was able to remove arsenic to below World Health Organization water quality guidelines, hence depicting that the composite is effective and efficient in removing arsenic from contaminated water. Based on that, this comparative study proves that the composite is a promising adsorbent with high adsorption capacity for arsenic and can be a suitable substitute for the conventional treatment methods.
Arsenic ِAdsorption on Bauxite Mineral Using Batch Equilibrium Test
American Journal of Applied Sciences, 2009
Problem statement: Study suggested a solution to remove arsenic contamination from contaminated water. Approach: Bauxite, which is a mineral, was proposed as natural remediation material used in this study. Bauxite was collected from Johor mining company in Teluk Ramunia, Johor Bharu, Malaysia. Batch equilibrium test was performed in accordance to different initial concentrations, shaking time and different initial pH values. Results: Results showed that mineral bauxite has high Cation Exchange Capacity (CEC) and Specific Surface Area (SSA), with the values range from 23.9-32.6 meq/100 g and 18.5-22.09 m 2 g −1 , respectively. Sample of bauxite mineral is slightly acidic with pH values ranging from 5.06-5.35. Percentage of organic matter and carbonate content in bauxite are very low with the values of 3.78-4.57 and 2.435-2.5% respectively. For batch adsorption, results showed that bauxite has high adsorption capacity for arsenic and it can remove more than 99% of arsenic from contaminated water. The highest amount of arsenic adsorbed (q) was 4996.6 mg kg −1 in 500 ppm of arsenic concentration after 48 h of the test in pH 7.6. The lowest was 4554.7 mg kg −1 in 500 ppm of arsenic at 24 h of shaking time in pH 10. Conclusion: Results indicated that bauxite can be used as a natural material for the removal of arsenic from contaminated water.
Environmental Science and Pollution Research, 2019
The natural clay is an abundant, accessible, and low-cost material that has the potential for use in the water and wastewater industry. In this paper, Iranian natural clay and clay/Fe-Mn composite were used to remove toxic arsenic from the liquid environment. The natural clay and clay/Fe-Mn composite were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray (EDX), X-ray diffractometry (XRD), thermo-gravimetric analysis (TGA), and atomic force microscopy (AFM) techniques. The effects of parameters (initial pH, temperature, sorption dose, and contact time) on the efficiency and behavior of the arsenic(V) adsorption process were studied. Freundlich (R 2 = 0.945 and 0.989), Langmuir (R 2 = 0.922 and 0.931), modified Langmuir (R 2 = 0.921 and 0.929), and Dubinin-Radushkevich (R 2 = 0.706 and 0.723) models were fitted to evaluate the equilibrium data of arsenic(V) adsorption process by natural clay and clay/Fe-Mn composite, respectively. The Langmuir adsorption capacity of arsenic(V) by the natural clay and clay/Fe-Mn composite was determined to be 86.86 mg/g and 120.70 mg/g, respectively. The arsenic(V) adsorption process followed the pseudo-second-order model. Negative values of ΔG°and ΔH°showed that the arsenic(V) sorption by the studied materials is thermodynamically spontaneous and exothermic. According to the findings, the natural clay and clay/Fe-Mn are suitable and recyclable sorbents for arsenic(V) adsorption from aqueous solutions. Also, the composite of clay with iron and manganese can improve the efficiency of clay in the removal of arsenic.
Removal Of Arsenic From Potable Water By Adsorptive Media Treatment Techniques
Journal of the Chemical Society of Pakistan, 2012
This study was conducted to investigate the arsenic removal efficiency of different adsorptive media from water. Different naturally occurring materials such as bauxite, plastic clay, plaster of Paris, lime, alum, and alumina etc. were used for the development of media to remove arsenic As +5 present in the artificially contaminated water. Different ratios of the selected materials were combined and ignited at 900 0 C to enhance its arsenic removing efficiency. It was found that the media bauxite, plastic clay, lime (1:1:1) has a maximum removal (99%) of As +5 species from aqueous media and can be used on-site to reduce the arsenic contamination of potable water. Furthermore, the materials used in this experiment were cheaply and abundantly available within the country. The method is very simple and economically viable, for removal of arsenic from potable water.
Efficiency of Different Indigenous Raw Materials for Removal of Arsenic from Aqueous Solution
Biomedical Journal of Scientific & Technical Research
This study was carried out to investigate arsenic removing efficiency of different indigenous materials. The materials used were including bauxite, plaster of paris, alum, activated alumina, limestone, and plastic clay. Different ratios of these raw materials were grinded, mixed thoroughly in a motor and enough water was added to the mixture to form thick slurry. The mixture is preferably calcined and is reafter converted into granular form. Removal of as from the aqueous system is readily accomplished by contacting the aqueous system with the media until the arsenic is substantially removed from the aqueous solution and their efficiency towards removal of arsenic from water was studied through atomic absorption spectrophotometer. It was found that when these materials were used individually the results showed that bauxite removed 97.5% arsenic from standard solution, alum individually removed 37%, plaster of paris 72.8%, Activated Alumina (AA) removed 40% arsenic from standard-solution and plastic clay did not show any affiliation for adsorption of arsenic. It had only 2% removal efficiency when used alone. Lime is quite effective for arsenic removal. It has 99 % efficiency for arsenic removal. Different media were developed after mixing the above said indigenous materials in different ratios. These different media showed different removal efficiencies. After conducting several experiments, it was concluded that the media developed after mixing of limestone, bauxite and plastic clay (1:1:1) showed maximum (100%) removal of arsenic from drinking water. It is an excellent media in terms of adsorbing and removal of arsenic.
Journal of Applied Geology, 2015
Arsenic (As) is a toxic element found in both natural and anthropogenic sources. High concentration of this element was recently uncovered in the groundwater of Sumbawa Island, Indonesia. To mitigate this problem, As adsorption potential of natural geological materials like lignite, bentonite, shale, and iron sand obtained in Indonesia were evaluated by batch experiments. Arsenic adsorption onto these materials was investigated as a function of solution pH, particle sizes of adsorbents and coexisting sulfate concentration. In addition, batch leaching experiments were performed to elucidate the stability of geogenic As present in all adsorbents at different pHs. The results showed that among these natural materials tested, lignite was the most effective adsorbent of As(V) followed by bentonite, shale and then iron sand, and that the amounts of As(III) adsorbed onto all adsorbents were lower than those of As(V).This indicates that As(III) is more mobile in comparison to As(V). The ads...
REMOVAL OF ARSENIC FROM SYNTHETIC WASTE WATER USING ADSORPTION PROCESS
Environmental pollution particularly from heavy metals and minerals in the waste water is the most serious problem in India. Arsenic is viewed as being synonymous with toxicity. Dangerous arsenic concentration in natural water is now a worldwide problem. Existing overviews of arsenic removal technology that has traditionally been used: Adsorption. Adsorption process being very simple, economical effective and versatile has become the most preferred methods for removal of toxic contaminants from wastewater. In this project we use the iron acetate coated activated alumina (IACAA) and activated alumina (AA) as a adsorbents. The adsorption potential of IACAA for removal of arsenic [As (III)] as arsenite by batch sorption technique gives more effective results in comparision to AA. Percentage adsorption on IACAA and AA were determined as a function of contact time and adsorption dose. IACAA was characterized by EDAX (energy dispersive x-rays analysis) and SEM (scanning electron microscope). The impact of the amount of impregnated iron acetate in activated alumina on arsenic adsorption capacities was investigated in this study. In this study we also described the preparation of iron acetate and coating of iron acetate on activated alumina.
Removal Of Arsenic In Aqueous Solution By Low Cost Adsorbent: A Short Review
International Journal of ChemTech Research
The presence of arsenic in waters, especially groundwater, has become a worldwide problem in the past decades. High arsenic concentrations have been reported recently from the Argentina,. Among 21 th countries in different parts of the world affected by groundwater arsenic contamination, the largest population at risk is in Bangladesh followed by West Bengal in India. There are numbers of arsenic removal methods, which include coagulation followed by precipitation, membrane separation, anion exchange, etc.Arsenic pollution has emerged as a serious public health concern in Pakistan also. The use of low-cost adsorbent obtained from an environmentally friendly materials, has been investigated as a replacement for the current expensive methods of removing arsenic from solution. Some low-cost adsorbents are superior including treated slags, carbons developed from agricultural waste, biosorbents, goethite and some commercial adsorbents, which include resins, gels, silica, treated silica t...
Remediation of Arsenic Contaminated Water by a Novel Carboxymethyl Cellulose Bentonite Adsorbent
Applied Ecology and Environmental Research, 2019
Suitability of bentonite clay modified with sodium carboxymethyl cellulose (Na-CMC) for the removal of arsenic(III) ions from aqueous solution was tested in batch adsorption studies and complemented by theoretical modeling with Langmuir, Freundlich and Temkin isotherm models. The effects of various factors, such as the initial adsorbate concentrations, pH, and temperature of the solutions were investigated in series of experiments. FTIR analysis was used to detect functional groups typical for cellulose and bentonite. Scanning electron microscope was used to analyze the surface morphology of the composites. It was established that the removal process was fast in the beginning and adsorption equilibrium was attained in around 20 minutes with good fittings to both Langmuir and Freundlich model. Maximum adsorption capacity (Qmax) obtained from experiments was 9.4 mg/g. No influence of solution pH and temperature on the sorption was noticed. The series of conducted experiments showed that synthesized composites are suitable for the removal of arsenic from wastewaters by adsorption as efficient and low-cost technique.
Algerian natural montmorillonites for arsenic(III) removal in aqueous solution
International Journal of Environmental Science and Technology, 2013
The adsorption of As(III) from aqueous solutions using naturally occurring and modified Algerian montmorillonites has been investigated as a function of contact time, pH, and temperature. Kinetic studies reveal that uptake of As(III) ions is rapid within the first 3 h, and it slows down thereafter. Equilibrium studies show that As(III) shows the highest affinity toward acidic montmorillonite even at very low concentration of arsenic. The kinetics of As(III) adsorption on all montmorillonites used is well described by a pseudo-secondorder chemical reaction model, which indicates that the adsorption process of these species is likely to be chemisorption. Adsorption isotherms of As(III) fitted the Langmuir and Freundlich isotherm models well. The adsorption of As(III) is pH-dependent obtaining an optimal adsorption at pH 5. From the thermodynamic parameters, it is concluded that the process is exothermic, spontaneous, and favorable. The results suggest that M 1 , M 2, and acidic-M 2 could be used as low-cost and effective filtering materials for removal of arsenic from water.