不同填料对曝气生物滤池除污效果的影响

采用臭氧/BAF组合工艺处理制革园区污水处理厂的二级生化出水,考察了不同填料BAF挂膜启动的运行情况,探讨了臭氧投加量为25 mg/L时不同填料BAF稳定运行的除污效果及机理。平行运行3个BAF,其填料分别为活性炭、陶粒、活性炭/陶粒(体积比为1∶1)。在挂膜启动期间,活性炭和混合填料BAF对COD的去除率表现为先下降再上升最后趋于稳定,32 d后出水COD<60 mg/L,而陶粒BAF对COD的去除效果不明显。稳定运行期间,进水COD、色度平均值分别为117 mg/L和112.5倍,活性炭BAF的出水值则降至50 mg/L和6倍,达到《城镇污水处理厂污染物排放标准》(GB 18918—2002)中的一级B标准。在此期间活性炭、混合填料和陶粒BAF中的生物量分别为30.69、25.87、15.18 nmol/g。

Impact of Different Medias on Pollutants Removal in Biological Aerated Filters

The combined process of ozone and biological aerated filter(BAF) was used to treat secondary biologically treated effluent from a tannery park wastewater treatment plant.The running performances of BAFs with different media were investigated during the biofilm growth period.The pollutants removal performance and mechanisms of BAFs with different media at ozone dosage of 25 mg/L were explored.Three BAFs operating in parallel were filled with activated carbon,ceramsite and mixture of activated carbon and ceramsite with 1 ∶ 1 volume ratio.The COD removal rates of BAF with activated carbon and BAF with the mixture first decreased,then increased and finally stabilized during the biofilm growth period.After 32 d,the effluent COD was below 60 mg/L in both reactors.The COD removal efficiency of the ceramsite BAF was not significant.During the steady state operation of the activated carbon BAF,the average COD and color were decreased from 117 mg/L and 112.5 times in the influent to 50 mg/L and 6 times in the effluent,which met the first level B criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 18918-2002).In the same period,biomasses in the activated carbon,mixture and ceramsite BAFs were 30.69 nmol/g,25.87 nmol/g and 15.18 nmol/g respectively.