Yin Daixia, Wang Xin, Peng Bo, Tan Changyin, Ma Lena Q
College of Resources and Environmental Science, Hunan Normal University, Changsha, Hunan 410081, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China.
College of Resources and Environmental Science, Hunan Normal University, Changsha, Hunan 410081, China.
Chemosphere. 2017 Nov;186:928-937. doi: 10.1016/j.chemosphere.2017.07.126. Epub 2017 Jul 26.
In this study, the effects of biochar derived from rice-straw (biochar) and iron-impregnated biochar (Fe-biochar) on Cd and As mobility in rice rhizosphere and transfer from soil to rice were investigated with different application rates. 1-3% biochar reduced porewater Cd in rhizosphere but elevated soluble As, resulting in 49-68% and 26-49% reduction in the root and grain Cd, with a simultaneous increase in root As. Unlike biochar, 0.5% Fe-biochar decreased porewater As throughout rice growth, resulting in reduced root As, which, however, increased Cd uptake by root. Biochar-induced soil As mobilization was probably through competitive desorption and Fe-biochar-induced soil Cd mobilization was probably via soil acidification. The results suggested that biochar and Fe-biochar was effective in reducing Cd and As uptake by rice, respectively, so they may be used as emergency measures to cope with single Cd or As contamination in paddy soils.
在本研究中，研究了不同施用量下稻草生物炭（生物炭）和铁浸渍生物炭（铁生物炭）对水稻根际镉和砷的迁移以及从土壤向水稻转移的影响。1 - 3%的生物炭降低了根际孔隙水中的镉，但提高了可溶性砷，导致根和籽粒中的镉分别降低了49 - 68%和26 - 49%，同时根中的砷增加。与生物炭不同，0.5%的铁生物炭在水稻整个生长过程中降低了孔隙水中的砷，导致根中的砷减少，然而，这却增加了根对镉的吸收。生物炭诱导的土壤砷活化可能是通过竞争性解吸，而铁生物炭诱导的土壤镉活化可能是通过土壤酸化。结果表明，生物炭和铁生物炭分别有效降低了水稻对镉和砷的吸收，因此它们可作为应对稻田土壤单一镉或砷污染的应急措施。
