生态塘深度处理石化废水尾水的效果及影响因素

采用由兼氧塘、好氧塘和水生植物塘串联而成的生态塘系统处理石化废水尾水,在中型试验装置上考察其处理效果及影响因素。结果表明:经处理后,污水的COD降低率为25%~50%,系统出水的COD稳定在40~50mg/L范围内,达到GB 18918—2002《城镇污水处理厂污染物排放标准》中的一级A标准中对COD的要求,但石油类物质浓度指标略微超标;温度是影响生态塘系统处理效果的主要因素,净水效果呈季节性变化,温度较高时处理效果较好,其对总氮(TN)去除的影响大于COD和总磷(TP);光照对COD降低率、TP和TN去除率的影响较为相似,最高去除率均出现在16:00左右,夜间三者均出现一定程度的下降。

TREATING EFFICIENCY OF TAIL WATER OF PETROCHEMICAL WASTEWATER BY ECO-PONDS AND INFLUENCE FACTORS

A pilot scale eco-pond system, consisting of facultative pond, aerobic pond and hydrophyte pond, was used to test the efficiency and influence factors of tail water deep treatment of petrochemical wastewater. The results indicate that COD concentration in effluent ranges from 40 mg/L to 50 mg/L, equivalent to COD reduction rate of 25%-50%, and reaches the A level of class 1 standard for COD in“Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant” (GB 18918-2002), except the concentration index of petroleum substances, which is slightly overweight. Among influence factors, the temperature is the main one. The treatment efficiency changes with seasons. The influence of higher temperature on TN removal is higher than that on COD and TP, while the effect of illumination on COD, TP and TN removal is relatively similar. The highest removal rates for three pollutants occur at about 16:00 pm, and the removal rates decline in a certain degree at night.