Zhang Zhaoxin, Li Jiake, Li Yajiao, Wang Dongqi, Zhang Jingyu, Zhao Lingzhi
State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China; Shaanxi Provincial Land Engineering Construction Group Co., Ltd., Xi'an 710075, China.
State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an 710048, China.
Ecotoxicol Environ Saf. 2021 Nov 11;228:112957. doi: 10.1016/j.ecoenv.2021.112957.
Bioretention system is one of the most used green stormwater infrastructures (GSI), and its media is a key factor in reducing runoff water volume and purifying water quality. Many studies have investigated media improvement to enhance the pollutant removal capacity. However, the long-term cumulative effect and microbial effect of pollutants in the modified-media bioretention system is less known. This study investigated the cumulative effect of pollutants and their influence on microbial characteristics in conventional and modified media bioretention system. The addition of modifiers increased the background content of pollutants in the media, and the accumulation of pollutants in planting soil (PS) and bioretention soil mixing + water treatment residuals (BSM+WTR) was relatively higher after the simulated rainfall experiment. The accumulation of pollutants led to a decrease in dehydrogenase activity, and an increase in urease and invertase activities. Ten dominant bacterial species at the phylum level were found in all bioretention systems. The relative abundances of the bacteria with good viability under low nutritional conditions decreased, while the species which could live in the pollutant-rich environment increased. The accumulation of pollutants in the bioretention system led to the extinction of some functional microorganisms. The better the effects of modified media on pollutant removal showed, the more obvious effect on the media micro-ecosystem was. To ensure the long-term efficient and stable operation of the modified-media bioretention system, we recommend balancing the pollutant removal efficiency and cumulative effect in modified-media bioretention systems.
生物滞留系统是最常用的绿色雨水基础设施（GSI）之一，其介质是减少径流量和净化水质的关键因素。许多研究都对介质改良进行了调查，以提高污染物去除能力。然而，改性介质生物滞留系统中污染物的长期累积效应和微生物效应却鲜为人知。本研究调查了传统介质和改性介质生物滞留系统中污染物的累积效应及其对微生物特性的影响。改性剂的添加增加了介质中污染物的背景含量，模拟降雨试验后，种植土（PS）和生物滞留土混合+水处理残渣（BSM+WTR）中污染物的积累相对较高。污染物的积累导致脱氢酶活性降低，脲酶和转化酶活性增加。在所有生物滞留系统中均发现了10种门水平的优势细菌物种。在低营养条件下具有良好生存能力的细菌相对丰度降低，而能够在富含污染物的环境中生存的物种增加。生物滞留系统中污染物的积累导致一些功能微生物灭绝。改性介质对污染物去除的效果越好，对介质微生态系统的影响就越明显。为确保改性介质生物滞留系统长期高效稳定运行，建议在改性介质生物滞留系统中平衡污染物去除效率和累积效应。
