海水曝气生物滤器污染物沿程转化规律的研究

以竹制空心生化球填料生物滤器处理海水养殖废水为对象,在水力负荷为0.58m3/m3(填料)×h]、氨氮负荷为(0.35~0.46)g/m3(填料)×h]、有机负荷约为11.58g/m3(填料)×h]、气水比3:1、pH值为7.8~8.0、DO浓度2.8~5.8mg/L的条件下,考察了有机物和总氨氮(TAN)的沿程转化规律,分析了污染物的空间分布特性.结果表明:在给定的运行条件下,CODMn的主要去除区间在滤器的0~10cm高度,其中CODMn和溶解性CODMn在此处的去除率分别为49.12%和34.88%;TAN的主要去除区间为0~30cm,其中10cm处TAN的去除率为18%,30cm处为55%;生物量和生物活性由下向上呈递减的分布趋势;生物滤器污染物的主要去除区间为0~30cm,受到水质、水量冲击时,较高层的填料(30~60cm)起到了缓冲作用,将下层生物膜未能降解的污染物去除.

A study on transformation of main pollutants along the wastewater flow in biological aerated filter

The performances of biological aerated filter (BAF) with hollow bamboo balls as filter media for wastewater treatment in marine aquaculture was investigated. The wastewater was conditioned at pH ranging from 7.8~8.0, DO ranging from 2.8~5.8mg/L, air-to-water ratio at 3, hydraulic load of 0.58m3/(m3×h), TAN load of 0.35~0.46g/(m3×h), and organic load of 1.58g/(m3×h). Transformation of organic substances and ammonia nitrogen along the water flow were evaluated to determine the spatial distribution characteristics of pollutants. Results showed that most CODMn was removed between 0~10cm height, with 49.12% CODMn removed and 34.88% soluble CODMn removed in this range, meanwhile most TAN removed between 0~30cm height, with 18% TAN removed at 10cm and 55% removed at 30cm. The biomass and microbial activity decreased from the bottom of the filter to the top. In conclusion, pollutants were mainly removed between the height of 0~30cm, and the left section of the filter always acted as a buffer to remove pollutants remained in the wastewater, in case of sudden waste load or hydraulic impact.