水循环周期对生态床内氮形态转化过程的影响

构建复合生态床修复北方景观水体,通过控制出水循环周期,研究不同循环速率下水体氮在系统内的转换及不同转换过程之间的关系,深入分析复合基质生态床修复景观水的过程及作用机理.结果表明,当循环周期为1 h和1.5 h时,溶解氧经首次循环由7提高至11左右,并始终保持较高水平;C/N由进水时4～6提高至出水时6～10,C/N的升高说明系统中N的相对去除率高于C,循环促进了氮及有机物的去除.出水循环提高了NH⁺₄-Ｎ、NO^-₂-Ｎ及TN的去除率, 且循环速率的提高使得硝化作用进行得更加迅速和彻底,补充了氮从系统中去除的好氧反硝化途径.当循环周期为1.5 h和1 h时,NH⁺₄-Ｎ与NO^-₂-Ｎ去除过程间的相关系数值分别为0.885 3和0.968 5;NO^-₂-Ｎ与TN去除过程间的相关系数随循环速率加快而增加,最高为0.942 4.当循环速率加快,NH⁺₄-Ｎ的氧化与NO^-₂-Ｎ的氧化2个过程间的传递更加迅速, 缩短了氮在系统中的转化途径,且循环速率越快,整个转化越迅速.

Effect of Effluent Recycling on Nitrogen Transition in Ecology Filter

Ecological filter was constructed to remedy Northern water in landscaping function. Nitrogen transition and its course in different recycling rate were studied by controlling the period. The action mechanism of landscaping water treated by compound substrate was analyzed deeply. Data showed that DO was improved from 7 to 11 and kept high when the recycling period was 1 hours and 1.5 hours. C/N was improved from 4-6 to 6-10. Removal ratios of NH4+ -N, NO2- -N and TN increased with recycling rate improving. Transition coefficients of NH4+ -N and NO2- -N were 0.885 3 and 0.968 5 under 1 hours and 1.5 hours period. The highest coefficient of NH4+ -N and NO2- -N was 0.942 4. Improving of recycling rate made the nitrification more rapidly and completely, and the transition approach of nitrogen was shortened. More rapid the recycling rate was, more direct was the transition.