预处理-MBR工艺去除养猪沼液中土霉素和四环素

Removal of Oxytetracycline and Tetracycline in Piggery Biogas Slurry via Pretreatment-MBR Process

针对养猪沼液水质复杂,主要表现在有机物及氮磷含量高、碳氮比低,传统污水处理工艺无法对其进行有效处理的情况,本研究采用化学絮凝-磷酸铵镁结晶方法作为预处理手段,构成预处理-MBR组合工艺对其进行处理并对组合工艺处理去除养猪沼液中的土霉素和四环素机理进行研究。结果表明,在75 h和60 h两种不同的水力停留时间(HRT)下,系统对COD的去除率均高于60%,对NH^+4-N的去除率均高于90%,出水水质均能够达到GB18596-2001规定的排放标准,且HRT=75 h的出水水质优于HRT=60h。预处理-MBR组合工艺对对土霉素与四环素抗生素的去除主要通过化学絮凝、磷酸铵镁结晶,生物降解与污泥吸附实现,其中化学絮凝和磷酸铵镁结晶起最主要作用,而生物降解作用最小。

In view of the complex water quality of the pig-raising biogas slurry, the high content of organic matter and nitrogen and phosphorus, and the low carbon-nitrogen ratio, the traditional sewage treatment process cannot effectively treat it. The chemical flocculation-magnesium ammonium phosphate(MAP) crystallization method was used to form a pretreatment-MBR combined process to treat it. The results showed that, COD removal rate was both more than 60% and NH4+-N removal was both more than 90% when HRT was set at 75 h and 60 h, respectively. The effluent quality reached the discharge standard of GB 18596-2001, and the effluent quality of HRT of 75 h was better than HRT of 60 h. The pretreatment-MBR combined process could remove oxytetracycline and tetracycline antibiotics mainly through chemical precipitation, MAP crystallization, biodegradation and sludge adsorption, of which chemical flocculation and MAP crystallization played the most important role, while biodegradation only made a small contribution.