纳污海水中COD生化降解过程的模拟试验研究

A SIMULATION EXPERIMENT OF TIIE BIODEGRADATION PROCESS OF COD FROM OCEAN OUTFALLDISCHARGE IN BOHAI BAY

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。

Th Bohai Bay is an impodrit 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 cihes around the Bay. bo researehes had been studied on the wator quality pollution of the Bay-However, most of the researehes focused on the physical diffusion and dilution of pollutants. In this paper the biodegradation pahem of chendcal oxygen demand (CoD) in the seawater was inveshgatod Undr labofatory condihons. The COD biodegradaon were measared at different temperabes and ihihal COD concentrations. According to the first order reashon kinehcs, the optimum values of degradaon coefficient which satisfied the reachon equaon for the set of experimental data were eshmated. The experimental results show tha COD first-order reaction Kinetic coefficient (k) was from 0.023 to 0.076 d-1. The relationship between k and sea warer temperabe was estabished based on the experimental dare. The values of k were proportional to the sea warer temperature when it was from 10 to 28℃. Whn the initial concentration of COD was from 4 to 9 mg / L, ithad litile influence on the kinehc coefficient The COD conceIhaon of sea water was in equllibrium after sewage had been discharged into the sea water for about eight days. The equaon of COD degradation kinetics that was obtained in thes researeh could be used in the water quality models for the Bohai Bay.