Remediation effects of biochar on soil co-contaminated by copper, lead and cadmium

In this paper, two corn straw derived biochars prepared at 400益(BC400) and 700益(BC700) were added into soil co-contaminated by copper, lead, and cadmium to study the effectiveness of biochars incorporation on ameliorating co -contaminated soil by soil incubation experiment and pot experiment of pakchoi. The results showed that soil pH increased by 0.14-0.52 and 0.27-0.78 after BC400 and BC700 addition respectively. Both biochars had the ability to prompt the inactivation of heavy metals in soil, and reduce metals content of edible part and root of pakchoi. The effect of decreasing bioavailability of metals in soil enhanced as the application rate of biochar rose. The reducing bioavailability of metals by different biochar amendments was in the following order: BC700>BC400. At a given biochar content, compared with BC700, soil amended with BC400 resulted in elevated biomass dry weight of edible part of pakchoi. Meanwhile, compared with BC700, greater microbial biomass increase was observed with the BC400 application.