改性纳米碳黑用于重金属污染土壤改良的研究

采用培养试验,研究了添加改性纳米碳黑对江西贵溪污染土壤中有效态Cu和Zn含量的影响,并对比研究了包施和混施效果差异,同时还通过温室盆栽试验研究了改性纳米碳黑对黑麦草生物量和黑麦草对Cu和Zn的吸收量以及土壤Cu和Zn形态的影响.结果表明,添加改性纳米碳黑可以降低土壤中有效态Cu和Zn的含量.与对照相比,培养60d后,添加1%、3%和5%改性纳米碳黑的土壤有效态Cu含量分别降低了47.3%、72.0%和80.9%,有效态Zn含量分别降低了3.0%、17.7%和43.6%.同等材料用量下包施不如混施的钝化效果好,且所用时间要长,但包施具有将所施材料和被吸附的重金属移出土壤体系的优点.土壤中添加改性碳黑可以促进黑麦草的生长,降低Cu和Zn在黑麦草地上部的积累量同时降低了土壤中Cu和Zn交换态和碳酸盐结合态,而增加有机物及硫化物结合态含量.

Application of modified nano-particle black carbon for the remediation of soil heavy metal pollution

A modified nano-particle carbon black (nano-CB) was used as amendment for controlling the bioavailability of Cu and Zn in soil by cultivation experiment. The nano-CB significantly reduced the bioavailability of soil Cu and Zn. Compared with the control, the bioavailable soil Cu concentration decreased about 47.3%, 72.0% and 80.89% after 60days of cultivation with 1%, 3%, and 5% nano-CB, respectively; bioavailable soil Zn concentration decreased by 3.0%, 17.7% and 43.6%, respectively. The treatment of packet application was not better than mixed application and needed more time for equilibrium, but the CB which adsorbed heavy metal from soil could be easily taken out. Nano-CB amendment significantly increased biomass of ryegrass and reduced the uptake of Cu and Zn concentration in ryegrass. Application of nano-CB reduced exchangeable and cabonate-bound soil Cu and Zn in ryegrass rhizosphere, and increased the proportion of organic/sulphide fractions.