阳澄湖养殖水体COD降解动力学研究

Degradation kinetics of COD in aquaculture waters in Yangcheng lake

2008年5月到2009年5月,从苏州市阳澄湖中湖的河蟹养殖区采集水样,在不同温度和起始浓度下进行化学需氧量（COD）生化降解试验。依据COD降解动力学理论,计算不同条件下COD降解速率系数。结果表明,阳澄湖COD生化降解动力学符合一级反应动力学模式,其降解速率系数k值介于0.028~0.086 d-1之间;试验水温与COD降解速率系数密切相关,在试验水温10~28℃之间,k值随温度升高而增大。初步估算表明,阳澄湖COD降解产生的净化容量约为11.8 t.d-1。

Water sampling was conducted from May 2008 to May 2009 in the crab culture area,located in the middle of Yangcheng lake in Suzhou,and the biochemical degradation of chemical oxygen demand（COD） was monitored under different temperature and initial concentrations.The degradation rate coefficients for COD under different conditions were determined based on the theory of COD degradation kinetics.The results indicated that the biochemical degradation kinetics for COD in the lake fitted for the characteristic model of first-order reaction kinetics,and the degradation rate coefficients,k value,varied between 0.028 and 0.086 d-1.The test water temperatures were found to be closely related to COD degradation rate coefficients,and when the water temperature ranged from 10℃ to 28℃,the k value increased with the increasing of temperature.It was estimated that the purification capacity up to about 11.8 t·d-1 could be achieved by COD degradation in Yangcheng lake.