以永定河( 北京段) 为研究对象, 开展不同再生水占比景观水体连续 24 d 的水质监测实验, 监测指标包括化学 需氧量、氨氮、溶解氧、pH、电导率及土壤微生物多样性等。结果分析表明: 相同实验条件下永定河上游山峡段河岸 带土壤微生物多样性明显好于下游沙质断流河岸带土壤, 而二者混合形成的沙土有利于丰富土壤微生物多样性; 高 再生水占比水体对于环境更加敏感, 更容易因为外部因素引起水质变化, 在高温下水质恶化速率更快; 根据实验所 监测的多项水质指标与生态效应综合分析, 静止景观水体再生水占比在超过 75% 以后水质持续恶化, 推荐永定河 实际景观河道再生水占比控制在 75% 以下。

Taking Yong ding Riv er ( Beijing sectio n) as the research object, we monito red the chang es of wat er qualit y in land2 scape w ater bodies w ith different ratios of reclaimed w ater for 24 co nsecutive day s. The monito ring indicato rs included chemical ox yg en demand, ammo nia nitr og en, dissolved o xy gen, pH, co nductivity , and soil micro bial diversity. The r esults show ed that: The micr obial diversity in t he upstream riparian soil of the Yo ngding Riv er is sig nificantly better than that in the dow nstr eam ri2 parian so il. The sand formed by the combination of the two is conducive to enriching so il micr obial diversity. T he wat er body wit h a high ratio o f r eclaimed w ater is mor e sensitive to envir onmental changes. Its w ater qualit y is mo re prone t o changes when influenced by exter nal factors, and deterior at es fast er at high temper atur e. Accor ding to the com pr ehensive analysis of v arious water qualit y indicators monito red by the ex periment , the w ater quality of impounded landsca pe water bodies will deteriorat e co nt inuously if t he ratio of reclaimed water ex ceeds 75% . It is recommended that the r atio of reclaimed w ater in Yongding River be contr olled below 75% .

国家水环境治理重大专项( 2018ZX07101005204) ; 国家自然科学基金资助项目( 41771305; 41530858)