Abstract：
Sediment, as the destination of marine pollutants, often bears much more serious petroleum pollution than water. Biochar is increasingly utilized for remediating organic pollutant-laden sediments, yet its long-term impacts on oil-contaminated sediment remain poorly understood. In this study, simulation experiments adding 2.5 wt% biochars (corn straw and wood chips biochar at different pyrolysis temperatures) were conducted. The effects on petroleum hydrocarbon attenuation, enzyme activities, and microbial community structure were systematically investigated. Results showed enhanced degradation of long-chain alkanes in certain biochar-treated groups. Biochar species and PAH characteristics together lead to the PAHs\' attenuation, with low-temperature corn straw biochar facilitating the degradation of phenanthrene, fluorene, and chrysene. Initially, biochars reduced polyphenol oxidase activity but increased urease and dehydrogenase activities. However, there was a noticeable rise in polyphenol oxidase activity for a long time. Biochars influenced bacterial community succession and abundance, likely due to nutrient release stimulating microbial activity. The structural equations model (SEM) reveals that DON affected the enzyme activity by changing the microbial community and thus regulated the degradation of PAHs. These findings shed light on biochar\'s role in bacterial communities and petroleum hydrocarbon degradation over extended periods, potentially enhancing biochar-based remediation for petroleum-contaminated sediments.
摘要：
沉积物,作为海洋污染物的目的地，石油污染往往比水严重得多。生物炭越来越多地用于修复富含有机污染物的沉积物，然而，它对石油污染沉积物的长期影响仍然知之甚少。在这项研究中,进行了添加2.5wt％生物炭（不同热解温度下的玉米秸秆和木屑生物炭）的模拟实验。对石油烃衰减的影响，酶活性，系统研究了微生物群落结构。结果表明，在某些生物炭处理组中，长链烷烃的降解增强。生物炭种类和PAH特性共同导致PAHs衰减，低温玉米秸秆生物炭有利于菲的降解,芴,还有Chrysene.最初，生物炭降低了多酚氧化酶的活性，但增加了脲酶和脱氢酶的活性。然而,长期以来，多酚氧化酶活性显着上升。Biochars影响细菌群落的演替和丰度，可能是由于营养释放刺激微生物活动。结构方程模型（SEM）表明DON通过改变微生物群落影响酶活性，从而调节PAHs的降解。这些发现揭示了生物炭在细菌群落和石油烃降解中的作用。可能增强基于生物炭的石油污染沉积物修复。
