• Proceedings of the PSK Conference
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• 2003.04a
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• pp.163.1-163.1
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• 2003

Arsenic is a ubiquitous element that ranks 20th in abundance in the earth's crust, 14th in the sea water, and is a component of several hundred minerals. Arsenic and its compounds are mobile in the environment. Groundwater contamination by arsenic is a serious threat to mankind all over the world and it can also enter food chain. Humans are exposed to this toxic arsenic from air, food and water. (omitted)

• International Journal of Advanced Culture Technology
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• v.8 no.2
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• pp.283-288
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• 2020

This study investigated the purification process of groundwater contaminated with zinc and arsenic using a permeable reactive barrier with a zero-valent iron/pumice mixture. We determined the removal rates of the contaminants for 30 days. In this study, column reactor filled with the zero-valent iron/pumice reactive mixture was used. Experimental results showed that the mixture exhibited an almost complete removal of the zinc and arsenic ions. Arsenic was removed via co-precipitation and adsorption processes while zinc ions were asorbed in active sites.The purification process of water from the metal ionscontinued for 30 days with constant hydraulic conductivity because of the enhanced porosity of the pumice and interparticle distance between the zero-valent iron and pumice. Contaminants removal rates and the remediation mechanism for each reactive system are described in this paper.

• Environmental Engineering Research
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• v.18 no.3
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• pp.163-168
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• 2013

In this study, an innovative media, iron mixed ceramic pellet (IMCP) has been developed for arsenic (As) removal from groundwater. A porous, solid-phase IMCP (2-3 mm) was manufactured by combining clay soil, rice bran, and Fe(0) powder at $600^{\circ}C$. Both the As(III) and As(V) adsorption characteristics of IMCP were studied in several batch experiments. Structural analysis of the IMCP was conducted using X-ray absorption fine structure (XAFS) analysis to understand the mechanism of As removal. The adsorption of As was found to be dependent on pH, and exhibited strong adsorption of both As(III) and As(V) at pH 5-7. The adsorption process was described to follow a pseudo-second-order reaction, and the adsorption rate of As(V) was greater than that of As(III). The adsorption data were fit well with both Freundlich and Langmuir isotherm models. The maximum adsorption capacities of As(III) and As(V) from the Langmuir isotherm were found to be 4.0 and 4.5 mg/g, respectively. Phosphorus in the water had an adverse effect on both As(III) and As(V) adsorption. Scanning electron microscopy results revealed that iron(III) oxides/hydroxides are aggregated on the surface of IMCP. XAFS analysis showed a partial oxidation of As(III) and adsorption of As(V) onto the iron oxide in the IMCP.

• Journal of Soil and Groundwater Environment
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• v.16 no.2
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• pp.6-11
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• 2011

In this report, we provide experimental evidence that heavy metal ions could be removed using Pachymeniopsis sp., particularly soluble arsenic in leachate from soil contaminated by arsenic. We performed pilot scale of soil washing process based on our results. The adsorption of arsenic by Pachymeniopsis sp. indicated that it could be described with the Langmuir Model and the maximum adsorption capacity increased with decreasing pH (pH 3: 102.48 mg/g, pH 5: 98.32 mg/g, pH 7: 57.70 mg/g, pH 9: 43.34 mg/g) and increasing temperature (10$^{\circ}C$ : 60.38 mg/g, 20$^{\circ}C$ : 76.39 mg/g, 30$^{\circ}C$ : 112.12 mg/g). Our results revealed that soluble arsenic in leachate was removed from 24.03 mg/L to 0.6 ${\pm}$ 0.1 mg/L by Pachymeniopsis sp. for 48hours on pilot scale of soil washing process.

• Journal of Korean Society on Water Environment
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• v.31 no.2
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• pp.209-215
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• 2015

The purpose of this study is to evaluate the characteristic of the iron oxide carrier for removing arsenic contained in the groundwater. 4 types of iron oxide carrier used in the study is iron oxide coated sand carrier (IOCSC), iron oxide coated zeolite carrier (IOCZC), iron oxide plasticity carrier (IOPC) and platinum iron oxide plasticity carrier (PIOPC). The results of this study, IOPC is showed high arsenic adsorption strength and the maximum amount of adsorption than the IOCC. Based on the results of the arsenic adsorption characteristic, by using IOCC was conducted to column test. As a result, PIOPC is showed a high arsenic adsorption amount than IOPC, it was found that the time required to reach the breakthrough point is also extended. Therefore it is determined that stably compliance with water quality standards enhanced drinking water when using the PIOPC.

• Journal of Wetlands Research
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• v.24 no.2
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• pp.142-154
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• 2022

Arsenic (As) contamination in groundwater is one of the main problems in Bangladesh. As toxicity causes serious human health problems such as edema, skin cancer, bladder cancer, lung cancer, hyperkeratosis, premature birth, and black foot disease. As contamination in groundwater mainly originates from the geological characteristics of the area due to the influence of anthropogenic activities. Since most of the people in Bangladesh rely on tube well for drinking water, it is necessary to investigate the current status of As pollution and identify the treatment technologies that can be used to provide arsenic-free drinking water in water-scarce areas. A total of 92 papers were reviewed in this study to present a complete overview of the recent status of groundwater As contamination in Bangladesh and different low-cost remediation technologies. A method for evaluating the relative feasibility of different treatment technologies was also utilized to determine the most appropriate technologies for groundwater As treatment in Bangladesh. The districts with the highest groundwater As contamination include Brahamanbariya, Tangail, Barisal, Pabna, Patuakhali, Kurigram, Magura, and Faridpur, with concentrations exceeding 0.05 mg/L. Only six districts had relatively low groundwater arsenic concentrations (0.01 mg/L), including Kushtia, Khagrachari, Jessore, Dinajpur, Meherpur, and Munshiganj. There were a number of technologies used for treating As in water, but aerated electrocoagulation, Mg-Fe-based hydrotalcite-like compound, and electro-chemical As remediation (ECAR) reactor were found to be the most feasible treatment methods for As. Overall, the investment, operational, and maintenance costs, availability of materials, and expertise requirements should be considered when selecting the most appropriate treatment method for As in water.

• Journal of Korean Society on Water Environment
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• v.33 no.3
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• pp.334-340
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• 2017

A pilot-scale electrodialysis system was designed and constructed to treat groundwater polluted with arsenic and manganese. Synthetic groundwater, in which some amount of arsenic and manganese was added to make 500 mg/L of Mn and $50{\mu}g/L$ of As, was used as a feed for the ED system. The limiting current density, linear water velocity, applied voltage, and membrane surface area were investigated to obtain efficient and economic operation of the ED system. The linear water velocity was increased 0.74 cm/s to 11 cm/s based on evaluation of limiting current density. The water quality of diluate for 85 minutes of operation was satisfied with water quality criteria for drinking water using the ED system with 14 pairs of ion exchange membranes. The increased membrane pairs to 21 and 42 pairs were very effective to reduce conductivities of the diluate. The operation cost of the ED system was assessed using specific energy consumption, which was $1.065{\sim}1.2kWh/m^3$. Considering low salt concentrations of the groundwater, improvement of the ED system are required to increase current utilization and to apply low voltage while the ED system was applicable to produce drinking water.

• Journal of Soil and Groundwater Environment
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• v.24 no.4
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• pp.1-10
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• 2019

Recently, groundwater contamination by mixed occurrence of arsenic (As) and nitrate ($NO_3{^-}$) has been a serious environmental issue all around world. In this study, we investigated the microbial As(III) oxidation characteristic under denitrification process to examine the feasibility of the microbial consortia in wetland sediment to simultaneously treat these two contaminants. The detail objectives of this study were to investigate the effects of $NO_3{^-}$ on the oxidation of As(III) in anaerobic environments and observe the microbial community change during the As oxidation under denitrification process. Results showed that the As(III) was completely and simultaneously oxidized to As(V) under denitrification process, however, it occurred to a much less extent in the absence of sediment or $NO_3{^-}$. In addition, the significant increase of As(III) oxidation rate in the presence of $NO_3{^-}$ suggested the potential of As oxidation under denitrification by indigenous microorganisms in wetland sediment. Genera Pseudogulbenkiania, and Flavisolibacter were identified as predominant microbial species driving the redox process. Conclusively, this study can provide useful information on As(III) oxidation under denitrifying environment and contribute to develop an effective technology for simultaneous removal of As(III) and $NO_3{^-}$ in groundwater.

• Environmental Analysis Health and Toxicology
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• v.24 no.4
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• pp.293-301
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• 2009

This study was conducted to investigate the distribution of the concentrations of selected trace metals and inorganic anions in five types of drinking water samples (mineral spring water, well water, small community water, municipal tap water, and commercial mineral water) collected from Chuncheon, Gangwon-do in 2007. Forty four samples were analyzed for five metals and five anions using an atomic absorption spectrometer and an ion chromatograph, respectively. Arsenic (As) and nitrate (${NO_3}^-$) concentrations in some groundwater samples did not meet the future (10 ${\mu}g/L$) and current (44 mg/L) Korean drinking water standards, respectively. On the other hand, any municipal tap water samples, the sources of which were lake surface water, satisfied the Korean standards. Human health risk assessment results showed that arsenic in all types of water, especially groundwater including commercial mineral water, may pose both noncarcinogenic and carcinogenic effects on the residents. It is concluded that groundwater is not safe drinking water any longer and that a national survey and follow-up measures need to be taken.

• Journal of Soil and Groundwater Environment
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• v.26 no.6
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• pp.65-73
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• 2021

Since the amount of red mud, generated from aluminum smelting process as a by-product, has increased worldwide, the recycle and metal resource recovery from the red mud is becoming more important. In this study, in order to recycle the red mud as a soil stabilizer to remediate arsenic contaminated soils, neutralization of red mud was investigated. Red mud was neutralized by washing with distilled water and NaCl, CaCl₂, FeCl₃, and HCl solutions and heating at 200-800℃, and arsenic stabilization characteristics in soils were evaluated with the neutralized red mud. Although washing with distilled water was not effective in neutralizing red mud, the application of the washed red mud to soils lowered the soil pH compared to the application of untreated red mud. Among NaCl, CaCl₂, FeCl₃, and HCl solutions, washing with FeCl₃ showed the most effective in lowering pH of the red mud from pH 10.73 to pH 4.26. Application of the neutralized red mud in soils resulted in quite different arsenic stabilization efficiency depending on soil samples. In M1 soil, which showed relatively high arsenic stabilization efficiency by untreated red mud, the neutralization of red mud resulted in little effect on arsenic stabilization in soil. On the other hand, in M2 soil, which showed low arsenic stabilization efficiency by untreated red mud, the neutralization of red mud increased arsenic stabilization significantly. Soil characteristics such as clay minerals and pH buffering capacity seemed to affect reactions between red mud and soils, which resulted in different effects of the red mud application on soil pH and arsenic stabilization efficiencies.