Abstract：
This study assessed for the first time the bioremediation potential of an organic horse amendment in soils contaminated with solid wastes of the obsolete pesticide lindane (α-hexachlorocyclohexane (α-HCH) = 80 mg kg-1, β-HCH = 40 mg kg-1, γ,δ,ε-HCH≈10 mg kg-1) searching for a self-sufficient bio-based economy. Four treatments were implemented: polluted (PS, ΣHCHs = 130 mg kg-1) and control (CS, ΣHCHs = 1.24 mg kg-1) soils and the respective amended soils (APS and ACS). A commercial amendment, coming from organic wastes, was used for soil biostimulation (5% dry weight), and the temporal evolution of the enzymatic activity (dehydrogenase, β-glucosidase activity, phenoloxidase, arylamidase, phosphatase, and urease) and HCHs concentration of the soils was evaluated over 55 days under controlled humidity and temperature conditions. The horse amendment positively influenced the physicochemical properties of the soil by reducing pH (from 8.3 to 8) and increasing the organic matter (TOC from 0.5 to 3.3%) and nutrient content (P and NH4+ from 24.1 to 13.7 to 142.1 and 41.2 mg kg-1, respectively). Consequently, there was a notable enhancement in the soil biological activity, specifically in the enzymatic activity of dehydrogenase, phenol-oxidase, phosphatase, and urease and, therefore, in HCH degradation, which increased from <1 to 75% after the incubation period. According to the chlorine position on the cyclohexane ring, the following ranking has been found for HCHs degradation: β-HCH (46%) < ε-HCH (57%) < α-HCH (91%) ≈ δ-HCH (91%) < γ-HCH (100%). Pentachlorocyclohexene (PCCH) and 1,2,4-trichlorobenzene (1,2,4-TCB) were identified as HCHs degradation metabolites and disappeared at the end of the incubation time. Although further research is required, these preliminary findings suggest that organic amendments represent a sustainable, harmless, and cost-effective biostimulation approach for remediating soils contaminated with recalcitrant HCHs, boosting the circular economy.
摘要：
这项研究首次评估了有机马改良剂在被废弃农药林丹（α-六氯环己烷（α-HCH）=80mgkg-1，β-HCH=40mgkg-1，γ，δ,ε-HCH≈10mgkg-1）寻求自给自足的生物经济。实施了四种处理：污染(PS，ΣHCHs=130mgkg-1)和对照(CS，ΣHCHs=1.24mgkg-1）土壤和相应的改良土壤（APS和ACS）。商业修正案，来自有机废物，用于土壤生物刺激(5%干重)，和酶活性的时间演变(脱氢酶，β-葡萄糖苷酶活性，酚氧化酶,芳基酰胺酶,磷酸酶和脲酶）和土壤中的HCHs浓度在受控的湿度和温度条件下进行了55天的评估。马改良剂通过降低pH（从8.3到8）并增加有机质（TOC从0.5到3.3％）和养分含量（P和NH4从24.1到13.7到142.1和41.2分别对土壤的理化性质产生了积极影响。mgkg-1）。因此,土壤生物活性显著增强，特别是在脱氢酶的酶活性中，酚氧化酶，磷酸酶和脲酶，因此,在六氯环己烷降解中，在潜伏期后从<1增加到75％。根据环己烷环上的氯位置，六氯环己烷降解的排序如下:β-六氯环己烷(46%)<ε-六氯环己烷(57%)<α-六氯环己烷(91%)≈δ-六氯环己烷(91%)<γ-六氯环己烷(100%)。五氯环己烯（PCCH）和1,2,4-三氯苯（1,2,4-TCB）被鉴定为HCHs降解代谢产物，并在孵育时间结束时消失。虽然还需要进一步的研究,这些初步发现表明，有机修正案代表了一种可持续的，无害,和具有成本效益的生物刺激方法，用于修复被顽固的六氯环己烷污染的土壤，推动循环经济。
