纳污海水中COD生化降解过程的模拟试验研究

1995年5－11月期间，采取渤海湾海水，控制不同的试验水温和不同的有机物起始浓度，采用试验室模拟方法，测定COD生化降解曲线。依据COD降解动力学理论，得出不同环境条件下的COD生化降解动力学参数。经过归纳综合，建立了纳污海水中COD的生化降解动力学参数方程式。试验结果显示，渤海湾天津近岸排海污水COD生化降解过程符合一级反应动力学模型，其降解速率系数足值介于0．023－O．076d-1之间。k值受温度变化的影响较大，温度越高，k值越大。

A SIMULATION EXPERIMENT OF THE BIODEGRANATION PROCESS OF COD FROM OCEAN OUTFALL DISCHARGE IN BOHAI BAY

The Bohai Bay is an important semi-enclosed coastal sea in China. Over the last decades the Bay has been polluted by large amount of municipal and industrial wastewater from the cities around the Bay. Many researches had been studied on the water quality pollution of the Bay. However, most of the researches focused on the physical diffusion and dilution of pollutants. In this paper the biodegradation pattern of chemical oxygen demand (COD) in the seawater was investigated under laboratory conditions. The COD biodegradation were measured at different temperatures and initial COD concentrations. According to the first order reaction kinetics, the optimum values of degradation coefficient which satisfied the reaction equation for the set of experimental data were estimated. The experimental results show that COD first-order reaction kinetic coefficient (k) was from 0.023 to 0.076 d^-1. The relationship between k and sea water temperature was established based on the experimental data. The values of k were proportional to the sea water temperature when it was from 10 to 28 °C. When the initial concentration of COD was from 4 to 9 mg/L, it had little influence on the kinetic coefficient. The COD concentration of sea water was in equilibrium after sewage had been discharged into the sea water for about eight days. The equation of COD degradation kinetics that was obtained in this research could be used in the water quality models for the Bohai Bay.