厌/缺氧水体COD降解及氮转化规律小试研究

Organic degradation and nitrogen transformation in oxygen deficient water

采用取自市区河道的河水,对有无流动两种工况下厌/缺氧水体(DO≤0.50mg/L)COD降解和氮转化规律进行了小试研究。结果表明,无流动工况下COD<60.0mg/L时,即使DO≤0.50mg/L,NH4+-N亦可依靠大气复氧发生缓慢氧化,并有TN损失,其可能途径是厌氧氨氧化;流动工况下,虽然DO≤0.50mg/L,但COD和NH4+-N均能依靠大气复氧进行有氧降解,TN依然有损失。根据小试研究结果,认为在低DO条件下(≤0.50mg/L)进行河道水质模拟时,需要考虑NH4+-N的氧化和TN的减少。

Concentration profiles of COD and nitrogen species were obtained for an oxygen deficient river water sample （DO≤0.50 mg/L） in the batch reactor which was operated with and without agitation to simulate a stagnant or flowing river. At a COD〈60.0 mg/L and without agitation, DO from surface re-aeration resulted in slow COD degradation and nitrification and that de-nitrification taking place later resulted in a reduction in total nitrogen. Agitation allowed more oxygen transferred into the liquid phase and thereby enhanced both COD degradation and nitrification although DO was still lower than 0.50 mg/L and that de-nitrification taking place earlier resulted in a more rapid loss in total nitrogen. It is therefore necessary to consider ammonium oxidation and total nitrogen loss in water quality simulation for an oxygen deficient river segment with a DO≤0.50 mg/L.