不同类型氮组成对异养硝化好氧反硝化体系中氮转化的影响

Effects of Different Nitrogen Compositions on Nitrogen Transformation in Heterotrophic Nitrification Aerobic Denitrification System

工业大规模固氮、农业大面积使用氮素等行为引发了严重的水污染问题,污染水体中氮的转化成为水体治理的重点研究领域。凭借新的独特技术优势,好氧反硝化生物脱氮技术自提出以来,受到国内外环境领域学者的广泛关注。本文通过建立一种异养硝化-好氧反硝化(HN-AD)体系模拟自然水生生态系统,考察了不同初始浓度、氮源种类、不同氮组成比例对HN-AD体系中氮转化的影响。研究结果表明,NO3--N和NO2--N的介入加速NH4+-N的降解,氨氮的降解率从30%分别提高到65%和55%;NH4+-N和NO2--N的介入对NO3--N的降解有抑制作用;NH4+-N与NO3--N的介入会造成NO2--N的累积和降解率的降低。因此,在自然水生生态系统中经常发生并造成氮的损失,而培养良好的HN-AD沉积物可能是修复富营养化水体的有用生物工具。

Large-scale nitrogen fixation in industry and large-scale use of nitrogen in agriculture have caused serious water pollution problems,and nitrogen conversion in polluted water bodies has become a key research field of water body treatment.With the new unique technical advantages,aerobic denitrification biological denitrification technology has been widely concerned by environmental scholars at home and abroad since it was proposed.In this paper,a heterotrophic nitrification-aerobic denitrification(HN-AD)system was established to simulate natural aquatic ecosystems,and the effects of different initial concentrations,types of nitrogen sources,and different nitrogen composition ratios on nitrogen conversion in the HN-AD system were investigated.The results showed that the intervention of NO3--N and NO2--N accelerated the degradation of NH4+-N,and the degradation rate of ammonia nitrogen increased from 30%to 65%and 55%,respectively.The intervention of NH4+-N and NO2--N inhibited the degradation of NO3--N.The intervention of NH4+-N and NO3--N will increase the accumulation of NO2--N and reduce the degradation rate of NO2--N.Thus,nitrogen loss occurs and results in natural aquatic ecosystems,and cultured good HN-AD sediments may be a useful biological tool for remediation of eutrophic waters.