Halim Md. Abdul, Kyushu University, Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan, Tel: +81-92-642-3298, Fax: +81-92-642-3295, Email address: hyd09@civil.kyushu-u.ac.jp
Razzak Abdur, Kyushu University, Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan, Tel: +81-92-642-3298, Fax: +81-92-642-3295
Oda Keita, Kyushu University, Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan, Tel: +81-92-642-3298, Fax: +81-92-642-3295
Hiroshiro Yoshinari, Kyushu University, Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan, Tel: +81-92-642-3297, Fax: +81-92-642-3295
Jinno Kenji, Kyushu University, Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan, Tel: +81-92-642-3295, Fax: +81-92-642-3295

Arsenic is now a major concern on a global scale due to its severe toxicity effect for the human body. The identification of release mechanisms may assist in designing safe and effective remediation strategies. In this regards, experiments were carried out to observe the release of As from soil to water under anaerobic condition. The concentrations of total As and arsenate (As(V)) measured in soil was same and it was 9.4 mg kg-1 that indicated As remained primarily as As(V) in soil. The concentrations of As, Fe, Mn, Mg, Ca and NO3- were measured by the inductively coupled plasma and mass spectrometry (ICP-MS) and ion chromatography (IC), respectively in effluents of soil column, and also physical properties were measured during the experiment to find out their interrelationships. It was observed that As concentration increased with decreasing oxidation reduction potential (ORP). Arsenic concentrations demonstrated negative covariation with the concentrations of NO3- but strongly correlated with Fe and dissolve organic carbon (DOC) concentrations. These relationships suggest that As may mobilized from soil to water by reductive dissolution of Fe oxyhydroxide with microbial reduction of organic matter under anaerobic environment. A numerical simulation of arsenic transport model, coupled with bacteria mediated biogeochemical processes was also applied to verify this hypothesis.    

Arsenic Contamination in Groundwater of Vietnam

Sunbaek Bang, International Environmental Research Center (IERC), Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712, Korea , Tel: 82-62-970-3368, Fax: 82-62-970-3394 
Kyoung-Woong Kim, International Environmental Research Center (IERC), Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712, Korea , Tel: 82-62-970-3391, Fax: 82-62-970-3394
Van Anh Nguyen, Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712, Korea , Tel: 82-62-970-3399, Fax: 82-62-970-2434
Hung Viet Pham, Center for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science , T3, 334 Nguyen Trai, Thanh Xuan, Hanoi , Vietnam
Tel: 84-4-858-7964, Fax: 84-4-858-8152

The groundwater of Vietnam was characterized and the potential risks from groundwater were investigated in Vietnam . Arsenic contamination in groundwater was found in Ha Nam province in the northern part of Vietnam . Since groundwater has been used as one of the main drinking water sources in this region, groundwater (n=40) and hair (n=54) samples were collected in four districts in Ha Nam province. As(III) and As(V) species in groundwater were separated with disposable arsenic speciation cartridge at site. The concentrations of arsenic in groundwater ranged from less than 1 to 582 µg/L. According to the results of arsenic speciation, approximately 90% of arsenic in groundwater existed as As(III) species. Average concentrations of iron and manganese were 18 and 0.7 mg/L, respectively. Most samples exceeded the Vietnamese drinking water standard of 10 µg/L for arsenic. However, a real intake of arsenic to human is less than analyzed arsenic concentration because sand filtration units is used to remove iron and arsenic in groundwater in this region. After treatment, arsenic concentrations decreased from <1 to 82 µg/L. The concentrations of arsenic in hair samples and treated groundwater were compared. Arsenic concentrations in hair sample and treated groundwater had significantly positive correlation.

Arsenic Contamination of Ground Water in some parts of Eastern India and its Remedial Measures

Gopal Pathak, Ph.D, Professor & Head ,Environmental Science & Engineering Group, Birla Institute of Technology, Mesra, Ranchi., India

Arsenic contamination of ground water has led to a massive epidemic of arsenic poisoning in many districts of eastern India . The same type of problem has been observed in neighboring country like Bangladesh . The arsenic in the ground water is of natural origin & is released from the sediments into the ground water due to anoxic conditions of the subsurface. Arsenic has a tendency to get accumulated in body tissues to cause arsenicosis. It affects liver & heart and is carcinogenic .Its permissible limit in potable water supply is 0.05 mg/lit.

The present paper deals with the arsenic contamination situation in some parts of eastern India . Health impacts on humans residing in these areas have been discussed. Special emphasis has been given on the remedial measures.

Applicability of Biological Techniques for the Remediation of Arsenic Contaminated Soils

Nymphodora Papassiopi, National Technical University of Athens, School of Mining and Metallurgical Engineering, Iroon Polytexneiou 9 157 80, Zografou, Athens, Greece, Tel: +30-210-7722298, Email: papasiop@metal.ntua.gr
Katerina Vaxevanidou, National Technical University of Athens, School of Mining and Metallurgical Engineering, Iroon Polytexneiou 9 157 80, Zografou, Athens, Greece, Tel: +30-210-7722275, Email: vaxevank@central.ntua.gr

Arsenic is a common and highly toxic pollutant of soils, emanating from several industrial activities. It occurs mainly in the form of anions which are strongly bound on the Fe(III)-oxides of soil. The biological reduction of Fe(III)-oxides has been often reported as the most important mechanism contributing in the release of associated As and the subsequent contamination of aquifers. Present study investigates whether this natural biogeochemical process can be used for remediation purposes, i.e. for obtaining the removal of As from contaminated soils.

The effectiveness of this treatment was evaluated on two soil samples with different characteristics. The first sample, originating from Lavrion , Greece , is a calcareous soil very poor in organic matter, i.e. 0.76% and contaminated with As up to 1000 mg As/kg, due to past mining activities. The second soil originates from Auzon , France , it has high organic carbon content, i.e. 8%, and it is contaminated with As up to 4500 mg As/kg due to wood preservation activities. The biological treatment of the soils was conducted under anaerobic conditions using the Fe(III)-reducing microorganism Desulfuromonas palmitatis. To enhance the reductive dissolution of Fe(III)-oxides and avoid the reprecipitation of As(V) with biogenic Fe(II) in the form of ferrous arsenates, some of the experiments were carried out in the presence of EDTA.

Simple biological treatment with D. palmitatis was not able to enhance the mobilization of As neither from Lavrion, nor from Auzon soil. Addition of EDTA in the aqueous solution has greatly stimulated the Fe(III) reducing activity of D. palmitatis and resulted in removing up to 90% of As from Lavrion soil and 70% from Auzon soil. Moreover, in the case of Auzon soil it was found that it is possible to obtain the removal of As by simply stimulating the biological activity of endogenous bacteria. Control experiments that were carried out on Auzon soil, using nutrients and EDTA but without addition of D. palmitatis, resulted in removing the same percentage of As, i.e. 70%, though with a much slower kinetics, i.e. after 60 days of treatment compared to 10 days with D. palmitatis. No endogenous bacterial activity was observed with Lavrion soil, probably due to the very low content of organic matter.

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