摘要
      污水处理厂的污水作为补充水排入河流，这可能会导致生态风险。本研究比较了污水处理厂污水和天然地表水（NSW）的元素组成和微生物群落，揭示了污水处理站污水排放的潜在生态风险。选择了中国郑州市最近升级的20座污水处理厂和3座相对较大的水库。污水处理厂出水中N、P、S、K、Ca、Mg、B、Si、Na、Fe、Mn、Co、Ni和Sn的含量显著高于新南威尔士州，而Mo、V、Pb和Cd的含量显著低于新南威尔士州。相对于IV类地表水质量标准（中国大多数河流的控制标准），污水处理厂出水和新南威尔士州的元素不平衡指数（IMI）（代表元素比例的不平衡程度）没有显著差异。污水处理厂污水中相对于Hoagland公式的常量营养素IMI显著低于新南威尔士州，而新南威尔士州污水处理厂的污水排放可能显著降低这一指数；这可能是初级生产力爆炸的一个重要原因。污水处理厂废水中的微生物多样性明显高于新南威尔士州。污水处理厂废水中移动遗传元素和氧化应激耐受表型的预测相对丰度显著高于新南威尔士州，而革兰氏阴性表型的丰度显著较低，潜在致病表型的丰度略低。升级污水处理厂的污水表现出病原体扩散的低风险，但抗生素耐药性基因扩散的高风险。在评估污水处理厂污水排放的生态风险时，应考虑元素组成和微生物群落。
Abstract
Wastewater treatment plant (WWTP) effluent is discharged into rivers as supplemental water, which may result in ecological risk. This study compares the element composition and microbial community of WWTP effluent and natural surface water (NSW) and reveals the potential ecological risk of WWTP effluent discharge. Twenty recently upgraded WWTPs and three relatively large reservoirs in Zhengzhou city, China, were selected. The contents of N, P, S, K, Ca, Mg, B, Si, Na, Fe, Mn, Co, Ni and Sn were significantly higher in WWTP effluent than in NSW, while those of Mo, V, Pb and Cd were significantly lower. There was no significant difference between WWTP effluent and NSW in terms of the element imbalance index (IMI) (representing the extent of imbalance of element proportions) relative to the class IV surface water quality standard (the control standard for most Chinese rivers). The macronutrient IMI relative to the Hoagland formula was significantly lower in WWTP effluent than in NSW, and WWTP effluent discharge could significantly lower this index in NSW; this may be an important cause of primary productivity explosion. The microbial diversity was significantly higher in WWTP effluent than in NSW. The predicted relative abundances of mobile genetic elements and oxidative-stress-tolerant phenotypes were significantly higher in WWTP effluent than in NSW, whereas the abundance of gram-negative phenotypes was significantly lower, and that of potential pathogenic phenotypes was slightly lower. The effluent from upgraded WWTPs exhibited a low risk of pathogen diffusion but a high risk of antibiotic resistance gene diffusion. The element composition and microbial community should be considered when evaluating the ecological risk of WWTP effluent discharge.

https://www.sciencedirect.com/science/article/abs/pii/S0301479722019715