不同曝气工况对养殖污水处理效果的影响

The Effects of Different Aeration Conditions on the Treatment of Aquaculture Wastewater

设计了一套优化组合的水处理系统,主要由下行生物膜池、上行生物膜池、下行牡蛎壳滤池和上行牡蛎壳滤池4个单元串联构成,各单元底部均设置了曝气装置.设计了仅其中1个单元或者3个单元曝气的4种工况,来研究不同曝气工况对养殖污水处理效果的影响.结果表明:在系统进水总氨氮质量浓度为0.52～0.72 mg.L-1,亚硝酸盐氮质量浓度为0.15～0.72 mg.L-1,硝酸盐氮质量浓度为7.59～9.26 mg.L-1,活性磷酸盐质量浓度为1.81～2.40 mg.L-1,水温为15.3～20.4℃时,采用仅上行牡蛎壳滤池曝气工况时水处理效果最好,对总氨氮、亚硝酸盐氮、硝酸盐氮和活性磷酸盐的去除率分别达到(76.7±7.5)%、(94.9±3.6)%、(12.2±38.7)%和(17.8±17.4)%,各项指标的出水浓度分别为0.16、0.04、6.76、1.91 mg.L-1.其中:总氨氮和硝酸盐氮出水浓度分别达到国家GB 3838—2002《地表水环境质量标准》中的Ⅱ类和Ⅲ类水标准,亚硝酸盐氮出水浓度低于鳗鱼养殖安全浓度,但活性磷酸盐出水浓度高于国家GB 3838—2002《地表水环境质量标准》中的水质标准.

A set of good wastewater treatment system was designed, which consisted of downstream bio- film pool, upstream hiofilm pool, downstream oyster shell biofilter and upstream oyster shell biofilter, four u- nits connected in series and each unit with aeration equipment on the bottom. The effects of different aeration conditions were studied on the treatment of the aquaculture wastewater at aerating only one unit or three units of four kinds of aeration condition. The results showed that the best water treatment effect was on the condition of aerating upstream oyster shell hiofilter only, when the effluent concentrations of total ammonia nitrogen, ni- trite nitrogen, nitrate nitrogen and reactive phosphorus were 0. 52 -0. 72 mg·L-1 , 0. 15 -0. 72 mg·L-1, 7.59 -9.26mg·L-1 and 1.81 - 2. 40 mg·L-1 respectively, and the temperature was 15.3 - 20. 4 ℃. The removal rates of total ammonia nitrogen, nitrite nitrogen, nitrate nitrogen and reactive phosphorus were （76. 7 ± 7.5） %, （94.9 ± 3.6） %, （12. 2 ± 38.7） % and （ 17.8 ± 17.4） % respectively, and the corre- sponding effluent concentrations were 0. 16 mg·L-1 , 0. 04 mg·L-1 , 6. 76 mg·L-1and 1.91 mg·L-1 respectively. The total ammonia nitrogen and nitrate nitrogen concentration of effluent water fitted respective wa- ter quality standard Ⅱ and Ⅲ in ＂Environmental Quality Standards for Surface Water＂ （GB 3838--2002）. The nitrite nitrogen concentration was far lower than the safe concentration for eel farming. But the reactive phosphorus concentration of effluent water was much higher than the water quality standard of the national ＂Environmental Quality Standards for Surface Water＂ （GB 3838--2002）.