摘要
      本研究制备了通过从沼液中回收营养物获得的鸟粪石负载沸石（SZ），并将其用作土壤改良剂，以处理微塑料污染土壤中Cu、四环素（TC）和抗生素抗性基因（ARGs）的联合污染。采用分批实验研究了SZ、环境微塑料和土壤颗粒对Cu和TC的吸附。Langmuir等温线模型很好地拟合了Cu和TC在SZ上的等温吸附，最大吸附容量分别为103 mg g−1和158 mg g−2，远高于EM和土壤颗粒的相应吸附容量。3%SZ改良剂使1%EM污染土壤中的生物可利用Cu和TC分别降低了73.0%和71.3%以上。同时，ARGs的总相对丰度降低了76.2–80.3%。冗余分析和网络分析表明，大多数ARGs（如sul1、tetG、tetX和intl1）的相对丰度与土壤中的生物有效Cu和TC显著相关。在SZ存在的情况下，较低的污染物积累减轻了EMs上ARGs的选择压力。结构方程模型进一步表明，SZ通过改变污染物的生物利用度、土壤性质和土壤微生物群落，间接抑制了ARG在微塑料污染土壤中的增殖。这些结果表明，SZ改良剂可以有效缓解微塑料污染土壤中重金属、抗生素和ARGs的联合污染。
Abstract
In this study, struvite-loaded zeolite (SZ) obtained by nutrient recovery from biogas slurry was prepared and used as a soil amendment to treat the combined pollution of Cu, tetracycline (TC) and antibiotic resistance genes (ARGs) in microplastic-contaminated soil. The adsorption of Cu and TC by SZ, environmental microplastics (EMs) and soil particles was investigated using batch experiments. Isothermal adsorption of Cu and TC onto SZ was well fitted by the Langmuir isotherm model, with maximum adsorption capacities of 103 mg g−1 and 158 mg g−1, respectively, which were much higher than the corresponding sorption capacities of EMs and soil particles. Three % SZ amendment reduced bioavailable Cu and TC by more than 73.0% and 71.3%, respectively, in 1% EMs contaminated soil. At the same time, the total relative abundance of ARGs was reduced by 76.2–80.3%. Redundancy analysis and network analysis showed that the relative abundance of most ARGs such as sul1, tetG, tetX and intl1 were significantly correlated to bio-available Cu and TC in soil. In presence of SZ, lower pollutant accumulation alleviated the selection pressure for ARGs on EMs. Structure equation models further indicated that SZ indirectly abated ARG proliferation in microplastic-contaminated soil by altering pollutant bioavailability, soil properties and soil microbe communities. These results demonstrate that SZ amendment could effectively alleviate the combined pollution of heavy metals, antibiotics and ARGs in microplastic-contaminated soil.

https://www.sciencedirect.com/science/article/abs/pii/S1385894721020647