TY - JOUR
T1 - A practical soil washing method for use in a Cd-contaminated paddy field, with simple on-site wastewater treatment
AU - Makino, Tomoyuki
AU - Maejima, Yuji
AU - Akahane, Ikuko
AU - Kamiya, Takashi
AU - Takano, Hiroyuki
AU - Fujitomi, Shinichi
AU - Ibaraki, Toshiyuki
AU - Kunhikrishnan, Anitha
AU - Bolan, Nanthi
N1 - Funding Information:
We gratefully acknowledge the useful suggestions of Dr. T. Arao and T. Nishio, National Institute for Agro-Environmental Sciences. This work was supported in part by a Grant-in-Aid from the Ministry of Agriculture, Forestry and Fisheries of Japan (Research Project for Ensuring Food Safety from Farm to Table AC-1211).
Publisher Copyright:
© 2016 Published by Elsevier B.V.
PY - 2016/5/15
Y1 - 2016/5/15
N2 - Heavy metal contamination in rice paddies is a serious problem in monsoon Asia, and these fields require appropriate restoration measures. Although soil washing is a promising remediation technology, high cost for the treatment on soil washing leachate (wastewater) is one of the critical problems. This study sought to develop a simple method for the restoration of paddy fields by soil washing, with simplified wastewater treatment. Ferric chloride solution (FeCl3) was used as a washing chemical to extract Cd from a soil, which produced the wastewater containing Cd and other metals. Three alkali materials (NaOH, MgO, and CaCO3) were tested to treat the wastewater and determined MgO is optimal. In an on-site experiment, the target pH for wastewater treatment was controlled between 8 and 9 by using MgO. All metals in the wastewater could be effectively removed, reaching levels substantially lower than those permitted by Japanese standards. The treated wastewater could be discharged to agricultural canal. Therefore, our novel simplified method effectively removed heavy metals from the wastewater produced by on-site soil washing and contribute drive down the cost.
AB - Heavy metal contamination in rice paddies is a serious problem in monsoon Asia, and these fields require appropriate restoration measures. Although soil washing is a promising remediation technology, high cost for the treatment on soil washing leachate (wastewater) is one of the critical problems. This study sought to develop a simple method for the restoration of paddy fields by soil washing, with simplified wastewater treatment. Ferric chloride solution (FeCl3) was used as a washing chemical to extract Cd from a soil, which produced the wastewater containing Cd and other metals. Three alkali materials (NaOH, MgO, and CaCO3) were tested to treat the wastewater and determined MgO is optimal. In an on-site experiment, the target pH for wastewater treatment was controlled between 8 and 9 by using MgO. All metals in the wastewater could be effectively removed, reaching levels substantially lower than those permitted by Japanese standards. The treated wastewater could be discharged to agricultural canal. Therefore, our novel simplified method effectively removed heavy metals from the wastewater produced by on-site soil washing and contribute drive down the cost.
KW - Heavy metal contamination
KW - Paddy soil
KW - Soil treatment
KW - Soil washing
KW - Wastewater treatment
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U2 - 10.1016/j.geoderma.2016.01.006
DO - 10.1016/j.geoderma.2016.01.006
M3 - Article
AN - SCOPUS:84976253121
VL - 270
SP - 3
EP - 9
JO - Geoderma
JF - Geoderma
SN - 0016-7061
ER -