Effects of manganese oxide-modified biochar composites on arsenic speciation and accumulation in an indica rice (Oryza sativa L.) cultivar.
A pot experiment was used to investigate arsenic (As) speciation and accumulation in rice, as well as its concentration in both heavily contaminated and moderately contaminated soils amended with manganese oxide-modified biochar composites (MBC) and biochar alone (BC). In heavily As-contaminated soil, application of BC and MBC improved the weight of above-ground part and rice root, whereas in moderately As-contaminated soil, the application of MBC and low rate BC amendment increased rice root, grain weight and the biomass of the plant. Arsenic reduction in different parts of rice grown in MBC-amended soils was greater than that in plants cultivated in BC-amended soils. Such reduction can be attributed to the oxidation of arsenite, As(III), to arsenate, As(V), by Mn-oxides, which also had a strong adsorptive capacity for As(V). MBC amended to As-contaminated soil had a positive effect on amino acids. The Fe and Mn levels in the iron-manganese plaque that formed on the rice root surface differed among the treatments. MBC addition significantly increased Mn content (p < 0.05); the application of 2.0% MBC increased Mn content 36- and 10-fold compared to the control in heavily and moderately As-contaminated soils, respectively. The results indicate that application of Mn oxide-modified biochar to As-contaminated paddy soil could effectively remediate contaminated soil and reduce As accumulation in edible parts of rice.
Agro-environmental Protection Institute, Ministry of Agriculture, Key Laboratory of Production Environment Quality, Ministry of Agriculture of China, Tianjin 300191, China.
Zhihong
Z
Yu
The New Zealand Institute for Plant and Food Research Limited, Private Bag 4704, Christchurch 8140, New Zealand.
Weiwen
W
Qiu
Agro-environmental Protection Institute, Ministry of Agriculture, Key Laboratory of Production Environment Quality, Ministry of Agriculture of China, Tianjin 300191, China.
Fei
F
Wang
College of Resource and Environment, Hunan Agricultural University, Changsha 410128, China.
Ming
M
Lei
Agro-environmental Protection Institute, Ministry of Agriculture, Key Laboratory of Production Environment Quality, Ministry of Agriculture of China, Tianjin 300191, China.
Di
D
Wang
Agro-environmental Protection Institute, Ministry of Agriculture, Key Laboratory of Production Environment Quality, Ministry of Agriculture of China, Tianjin 300191, China. Electronic address: forestman1218@163.com.
Zhengguo
Z
Song
D000327:Adsorption; D000596:Amino Acids / Q000032:analysis; D001151:Arsenic / Q000032:analysis*; D018533:Biomass; D002606:Charcoal / Q000737:chemistry*; D007501:Iron / Q000378:metabolism; D008345:Manganese / Q000032:analysis; D017895:Manganese Compounds / Q000032:analysis / Q000737:chemistry*; D009930:Organic Chemicals / Q000032:analysis; D012275:Oryza / Q000187:drug effects*; D010087:Oxides / Q000737:chemistry*; D018515:Plant Leaves / Q000187:drug effects; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D018547:Plant Stems / Q000187:drug effects; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*
D000596:Amino Acids; D017895:Manganese Compounds; D009930:Organic Chemicals; D010087:Oxides; D012987:Soil; D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal; D008345:Manganese; C027424:manganese oxide; D007501:Iron; D001151:Arsenic
Arsenic; Brown rice; Manganese oxide-biochar composites; Paddy soil