摘要

重金属的积累和抗生素抗性基因（ARGs）在接受长期施肥的土壤中的加速传播引起了全世界的关注。在本研究中，使用 Mg(OH)2 修饰的生物炭 (Mg(OH)2/BC) 从猪粪中回收 N 和 P 获得的鸟粪石支持的生物炭复合材料 (MAP/BC) 被用作修复的新改良剂Cu 和 ARG 污染的农业土壤。同时研究了MAP/BC对Cu固定化、ARG分布和土壤中细菌群落的影响。结果表明，MAP/BC 固定铜的机制包括形成磷酸铜沉淀和表面复合物。 10% MAP/BC 改性后，土壤中酸溶性铜含量在第 56 天下降了 0.47 倍，而残留铜含量增加了 1.41 倍。同时，大多数目标ARGs（tetX、tetT、tetW、tetG、ermB、sulI、sulII和intlI）的丰度降低了11.35-99.95%，总ARGs的丰度降低了30.69%。冗余分析表明，生物可利用的铜含量在 ARGs 和细菌群落的变化中起着至关重要的作用。网络分析进一步表明土壤 ARG 的潜在宿主主要是厚壁菌门和放线菌。上述结果表明，MAP/BC 的应用可以减轻粪肥土壤中的 Cu 和 ARG 污染。

 The accumulation of heavy metals and the accelerated dissemination of antibiotic-resistance genes (ARGs) in soil receiving long-term manure application are causing worldwide concern. In this study, struvite-supported biochar composite (MAP/BC) obtained by N and P recovery from pig slurry with Mg(OH)2-modified biochar (Mg(OH)2/BC) was used as a novel amendment for the remediation of Cu- and ARG-contaminated agricultural soil. The effects of MAP/BC on Cu immobilization, ARG distribution, and the bacterial community in the soil were investigated simultaneously. The results showed that the mechanisms involved in the immobilization of Cu by MAP/BC included the formation of copper-phosphate precipitation and a surface complex. With a 10% MAP/BC modification, the acid-soluble Cu content in soil decreased by 0.47-fold at day 56 while the residual Cu content increased 1.41-fold. Meanwhile, the abundances of most of the target ARGs (tetX, tetT, tetW, tetG, ermB, sulI, sulII, and intlI) were reduced by 11.35–99.95%, and the abundance of total ARGs was reduced by 30.69%. The redundancy analysis indicated that the bio-available Cu content played a crucial role in the variations of both ARGs and bacterial communities. The network analysis further suggested that potential hosts of soil ARGs were mainly Firmicutes and Actinobacteria. The above results suggested that the application of MAP/BC can mitigate Cu and ARG pollution in manured soil.

  https://www.sciencedirect.com/science/article/abs/pii/S0048969720318076