PDF(Pubmed)
Abstract：
Organochlorine pesticides (OCPs) were typical persistent organic pollutants that posed great hazards and high risks in soil. In this study, a peanut shell biochar-loaded nano zero-valent iron (BC/nZVI) material was prepared in combination with soil indigenous microorganisms to enhance the degradation of α-hexachlorocyclohexane(α-HCH) and γ-hexachlorocyclohexane(γ-HCH) in water and soil. The effects of BC/nZVI on indigenous microorganisms in soil were investigated based on the changes in redox potential and dehydrogenase activity in the soil. The results showed as follows: (1) The specific surface area of peanut shell biochar loaded with nano-zero-valent iron was large, and the nano-zero-valent iron particles were evenly distributed on the peanut shell biochar; (2) peanut shell BC/nZVI had a good degradation effect on α-HCH and γ-HCH in water, with degradation rates of 64.18% for α-HCH and 91.87% for γ-HCH in 24 h; (3) peanut shell BC/nZVI also had a good degradation effect on α-HCH and γ-HCH in soil, and the degradation rates of α-HCH and γ-HCH in the 1% BC/nZVI reached 55.2% and 85.4%, second only to 1% zero-valent iron. The degradation rate was the fastest from 0 to 7 days, while the soil oxidation-reduction potential (ORP) increased sharply. (4) The addition of BC/nZVI to the soil resulted in a significant increase in dehydrogenase activity, which further promoted the degradation of HCHs; the amount of HCHs degradation was significantly negatively correlated with dehydrogenase activity. This study provides a remediation strategy for HCH-contaminated sites, reducing the human health risk of HCHs in the soil while helping to improve the soil and increase the activity of soil microorganisms.
摘要：
有机氯农药(OCPs)是典型的持久性有机污染物,在土壤中危害大、风险高。在这项研究中,将花生壳生物炭负载的纳米零价铁（BC/nZVI）材料与土壤土著微生物结合制备，以增强水和土壤中α-六氯环己烷（α-HCH）和γ-六氯环己烷（γ-HCH）的降解。根据土壤氧化还原电位和脱氢酶活性的变化，研究了BC/nZVI对土壤土著微生物的影响。结果表明:(1)负载纳米零价铁的花生壳生物炭的比表面积较大,纳米零价铁颗粒均匀分布在花生壳生物炭上;(2)花生壳BC/nZVI对水中的α-HCH和γ-HCH具有良好的降解效果,24h内α-六氯环己烷降解率为64.18%,γ-六氯环己烷降解率为91.87%;(3)花生壳BC/nZVI对土壤中α-六氯环己烷和γ-六氯环己烷也有较好的降解效果,1%BC/nZVI中α-HCH和γ-HCH的降解率分别达到55.2%和85.4%，仅次于1%的零价铁。0～7天降解速度最快，而土壤氧化还原电位（ORP）急剧增加。(4)向土壤中添加BC/nZVI导致脱氢酶活性显著增加,进一步促进了HCHs的降解;HCHs的降解量与脱氢酶活性呈显著负相关。这项研究为六氯环己烷污染的场地提供了补救策略，降低HCHs在土壤中的人类健康风险，同时有助于改善土壤和增加土壤微生物的活性。
