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Arsenic and iron removal from water using constructed soil filter—a novel approach
Author(s) -
Nemade Pravin,
Kadam Avinash M.,
Shankar Hariharan S.
Publication year - 2008
Publication title -
asia‐pacific journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.348
H-Index - 35
eISSN - 1932-2143
pISSN - 1932-2135
DOI - 10.1002/apj.173
Subject(s) - arsenic , chemistry , environmental chemistry , adsorption , groundwater , wastewater , manganese , filtration (mathematics) , ion exchange , environmental engineering , environmental science , ion , geology , statistics , geotechnical engineering , mathematics , organic chemistry
Arsenic poisoning is a global problem. It is known that groundwater in Bangladesh and West Bengal predominantly contains As(III) and concentrations of Fe(II) which are often too low for removal of arsenic in optimum quantities. To eliminate arsenic from drinking water, several basic methods such as coagulation, adsorption, ion exchange, filtration, membrane processes, are reported. To deal with this issue on a small to large scale, we present a novel approach to remove arsenic and iron from water by constructed soil filter (CSF). In CSF, As (III) is oxidized to As(V) by media via natural oxidation and subsequently, arsenic is co‐precipitated with iron. Here water containing arsenic, iron, and phosphate is passed through the CSF media at the rate of 100 ml/min. Results show a mean residence time of 8.6 min and a holdup of 1.85 l. Results of six runs show that with initial As(III) of 300 µg/l and iron concentration of 5–10 mg/l, residual arsenic levels below 10 ppb and residual iron < 0.30 mg/l in water can be achieved. In CSF, no chemicals are needed for the oxidation of As(III) to As(V). The oxidation takes place due to the presence of various oxides such as iron, manganese, aluminum, and the microbial diversity in the media of soil bioreactor. Such a novel technology is also applied for purification of water and wastewater. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.