热解油基钻屑/橘皮钝化修复铜铅污染土壤

Pyrolytic oil-based drilling cuttings/orange peel for remediation of copper-lead contaminated soil

摘要:

探究热解油基钻屑（OBDC）/橘皮（OB）生物炭资源化用于钝化修复铜铅污染土壤的效果及其对土壤微生物的影响，将热解OBDC/OB生物炭（OBDCs-OB）加入到Cu（Ⅱ）和Pb（Ⅱ）污染土壤中进行为期83 d的钝化修复实验。结果表明，OBDCs-OB表面具有—OH、—COOH等官能团、碳酸盐岩和黏土矿物等矿物组成以及多孔结构，可作为吸附剂使用；对比空白土壤，加入OBDCs-OB后，土壤阳离子交换容量（CEC）增加18.29 cmol/kg，维持pH在6.80左右；土壤中可酸溶态Cu（Ⅱ）和Pb（Ⅱ）浓度分别降低18.21%和20.07%；Cu和Pb的潜在浸出毒性分别降低52.8%和92.8%，有效钝化了Cu（Ⅱ）和Pb（Ⅱ）；土壤微生物菌落总数最大值为8.6×1010 cfu/g，土壤脱氢酶与脲酶活性最大值为127.10 μgTPE/(g·6 h)和167.10 mg/NH3-N/(kg·24 h)，增加土壤微生物群落多样性和丰富度，促进土壤微生物生长。

Abstract:

The effects of pyrolytic oil-based drilling cuttings (OBDC)/ orange bark (OB) biochar on passivation and remediation of Cu (Ⅱ) and Pb (Ⅱ) contaminated soil and its effects on soil microorganisms were investigated. The pyrolytic OBDC/OB biochar (OBDCs-OB) was added to Cu (Ⅱ) and Pb (Ⅱ) contaminated soil for 83 days of passivation and remediation experiments were reported. The results show that OBDCs-OB has functional groups such as —OH and —COOH, mineral compositions such as carbonate rocks and clay minerals, and porous structure, which can be used as adsorbent. Compared with the blank soil, after adding OBDCs-OB, the cation exchange capacity (CEC) of soil increased by 18.29 cmol/kg, and the pH was maintained at about 6.80. Acid-soluble Cu (Ⅱ) and Pb (Ⅱ) concentrations in soil decreased by 18.21% and 20.07%, respectively, and changed to reducible state. The potential leaching toxicity of Cu and Pb decreased by 52.8% and 92.8%, respectively, which effectively passivated Cu (Ⅱ) and Pb (Ⅱ). The maximum value of soil microbial population was 8.6×1010 cfu/g, and the maximum value of soil dehydrogenase and urease activities was 127.10 μgTPE/(g·6 h) and 167.10 mgNH3-N/(kg·24 h), which increased the diversity and richness of soil microbial community and promoted the growth of soil microbial community. In conclusion, OBDCs-OB can deactivate heavy metals in the remediation of heavy metal contaminated soil, promote the growth of soil microorganisms, and increase the diversity and richness of microbial community, which has practical application potential and provides basis for OBDC resource utilization.