生物转盘内部投加PAC化学除磷效果研究

Chemical Phosphorus Removal Efficiency of Rotating Biological Contactor with Addition of Polyaluminium Chloride

采用生物转盘工艺处理小城镇生活污水,研究生物转盘内部投加聚合氯化铝(PAC)的除磷效果以及对生物膜的影响。试验在已建生物转盘进行,处理水量为400m^3/d,TP平均浓度为2.11 mg/L,PAC投加量为60 mg/L。结果表明,在生物转盘投加PAC对TP的去除率明显高于使用管道混合器,这期间生物膜性状良好,对COD和氨氮的平均去除率分别为72.1%和82.2%;当加药点在生物转盘内部后端、转速为0.6 r/min时,TP去除率为82.5%,出水水质稳定达到一级A标准。可见,在生物转盘投加PAC可以实现高效除磷,并且对系统的处理能力和生物膜未造成影响。

Domestic wastewater in small town was treated by a rotating biological contactor(RBC),and the effects of adding polyaluminium chloride(PAC)inside the RBC on phosphorus removal and biofilm were explored.The experiment was carried out in an established RBC.The treatment capacity was 400 m^3/d,and the average TP and PAC dosage were 2.11 mg/L and 60 mg/L.The removal efficiency of TP by adding PAC to RBC was significantly higher than that of the pipeline mixer,properties of the biofilm were good during this period,and the average removal efficiencies of COD and NH4^+-N were 72.1%and 82.2%,respectively.When the dosing point was at backend of the RBC and the rotation speed was 0.6 r/min,the TP removal rate was 82.5%,and the effluent quality was better than the first class A specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant.The addition of PAC to RBC could achieve high phosphorus removal efficiency,and it had no adverse effect on the processing capacity of the system and biofilm.