生物质炭对小白菜吸收多环芳烃的影响

Effects of biochar on polycyclic aromatic hydrocarbons(PAHs) bioaccumulation in Chinese cabbage

选取小麦秸秆、污泥、猪粪三种原料制备的生物质炭为研究材料,通过盆栽试验,探究不同原料生物质炭对PAHs污染土壤中小白菜生长情况及对PAHs吸收积累的影响。结果表明:三种生物质炭对小白菜吸收PAHs均有一定的抑制作用,与对照相比,施用生物质炭小白菜对PAHs的吸收量降低14.53%~49.41%,三种生物质炭的抑制能力依次为麦秸炭>猪粪炭>污泥炭;相对于1%的施用量,施用2%的麦秸炭与猪粪炭小白菜中PAHs含量分别显著降低32.02%和21.40%,而污泥炭不同施用量对小白菜中PAHs总含量的影响无明显差异;生物质炭对小白菜吸收2~3环的低分子量PAHs的降低率为0~30.81%,对4~6环的高分子量PAHs吸收的降低率为30.72%~68.07%;施用2%的麦秸炭和猪粪炭,使小白菜的生物量显著提高20.03%和22.28%。因此,施用生物质炭可作为一种降低污染土壤中作物吸收PAHs,同时保障作物产量的有效技术途径。

Biochar technology provides a potential approach to mitigate soil pollution in agricultural production. However, limited studies have focused on the effects of different kinds of biochar on polycyclic aromatic hydrocarbons（PAHs）bioaccumulation. To address this issue, three kinds of biochar including wheat straw biochar（WBC）, sludge biochar（SBC） and pig manure biochar（PBC） were prepared through the technology of oxygen limited pyrolysis, and a spot experiment was conducted to assess the mitigation effects of three kinds of biochar with the application rates of 1% and 2% on PAH transfer from contaminated urban soil to Chinese cabbage. The results showed that addition of different kinds of biochar significantly reduced the concentrations of all PAHs by 14.53%-49.41% in the Chinese cabbage compared to the control soil（P0.05）, and the mitigation effectiveness was observed in order of WBCPBCSBC. Compared with the 1% application rate, the concentrations of PAHs were decreased by 32.02% and 21.40% under 2% WBC and 2% PBC amendments, respectively,though no significant difference was observed between the application rates of SBC. For different PAHs, the 2-3 rings and 4-6 rings PAHs bioaccumulation were reduced by 0-30.81% and 30.72%-68.07% under biochar application. In addition, the production of Chinese cabbage was significantly increased by 20.03% and 22.28% under 2% WBC and PBC, respectively. Therefore, biochar amendments could be an effective approach to reduce crop uptake of PAHs while ensuring crop yield in contaminated soil.