混合污水脱氮除碳工艺优化运行试验

Optimization Experiment on Nitrogen and Carbon Removal Process of Mixed Wastewater

来自无害化厂的粪便污水混入城市污水后,因高浓度污染物的冲击,广州大坦沙污水厂等单位出水脱氮除碳效果下降。针对该问题,文章以实际混合污水为进水,采用大坦沙污水厂倒置A2/O工艺的模拟反应器,通过正交试验优化运行工况,并据单因子试验结果,探讨了水力停留时间、溶解氧、污泥回流比和混合液回流比对污染物去除的作用规律。结果表明,水力停留时间是影响混合污水处理效果的最显著因素,其延长对除污有利。当水温为28~35℃、粪便污水与城市污水以0.33%比例混合、SRT为20 d时,最优运行工况是：水力停留时间为8h、溶解氧为2.0mg/L、污泥回流比为80%、混合液回流比为150%。此时,COD、NH3-N和TN平均去除率分别为85.5%、98.5%和63.7%,出水可稳定达标排放。

Effect of denitrification and carbon removal from the effluent of a wastewater treatment plant（WTTP）,Guangzhou was reduced due to deep-processing factory feces from urban wastewater intermingled with high concentration of pollutants.With the actual mixed wastewater as influent,using inverted A2/O process simulation reactor of the WTTP,the orthogonal experiment was done for the optimal operating conditions,and rule of HRT,DO,R and r on pollutant removal was discussed.Results showed that HRT was the key factor for the removal efficiency,and prolong of HRT would be helpful for the removal.In conditions of water temperature 28～35 ℃,mixed ratio of nightsoil wastewater and municipal wastewater 1：300 and SRT 20 d,the optimum operation parameters were HRT 8 h,DO 2.0 mg/L,R 80% and r 150%.In this condition,COD,ammonia and nitrogen removal rate was 85.5%,98.5% and 63.7% respectively,with the effluent satisfactory to national standard.