贵州某规模化养猪场废水中抗生素的污染特征及去除效果

为了解贵州某规模化养猪场废水处理过程中抗生素的污染特征及废水处理工艺对抗生素的去除效果,使用固相萃取-液相色谱-串联质谱仪(SPE-LC-MS)技术,对2家规模化养猪场(猪场A和猪场B)废水处理工艺各处理单元进出水中10种兽用抗生素的去除进行调查研究.结果表明, 2家规模化养猪场废水处理工艺对常规污染物(COD、NH~+_4-N、TN和TP)的去除率在88.10%以上. 2家养猪场废水处理工艺各处理单元进出水中均有多种抗生素检出,检出浓度范围在ND～120 842.74 ng·L~(-1)之间.其中,主要的污染单体为磺胺间甲氧嘧啶(SMM)、磺胺对甲氧嘧啶(SMD)、土霉素(OTC)和氧氟沙星(OFL),最高单体污染浓度达120 842.74 ng·L~(-1)(SMM).调查的10种抗生素在处理工艺中的去除效果较好,总去除率为99.23%～100.00%,在猪场A的废水处理工艺中,"USR+2级A/O+消毒池+氧化塘"组合工段能有效去除废水中残留的抗生素,其中对SMM、SMD和OTC的总去除率达100.00%;在猪场B的废水处理工艺中,"超滤(UF)+纳滤(NF)"组合工段能有效去除废水中的抗生素,最终废水中99.23%以上的抗生素被去除.但最终出水中大部分抗生素的浓度高于欧盟水环境抗生素阈值(10 ng·L~(-1)).通过冗余分析发现废水中常规指标(COD、NH~+_4-N、TN、TP和pH)与部分抗生素的降解具有相关性.

Pollution Characteristics and Removal Effects of Antibiotics in Wastewater from Large-Scale Pig Farms in Guizhou

To understand the pollution characteristics and removal effect of antibiotics in the wastewater treatment process of large-scale pig farms in Guizhou, solid-phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS) was used to investigate the removal of ten veterinary antibiotics from the influent and effluent of each treatment unit during the wastewater treatment process in two large-scale pig farms (named Farm A and Farm B). The results showed that the removal rates of conventional pollutantsincluding chemical oxygen demand (COD), NH₄⁺-N, total nitrogen (TN), and total phosphorus (TP)] in Farm A and Farm B were above 88.10%. The antibiotics concentrations detected in the influent and effluent ranged from ND-120842.74 ng·L^-1. The main antibiotics were sulfamonomethoxine (SMM), sulfamethoxazole (SMD), oxytetracycline (OTC), and ofloxacin (OFL), and the SMM concentration was highest at 120842.74 ng·L^-1. The removal rate of the ten antibiotics was 99.23%-100.00% in Farm A and Farm B. In the wastewater treatment process of Farm A, the treatment section "USR+2A/O+disinfection pond+oxidation pond" removed antibiotics in wastewater effectively, with the total removal rate of SMM, SMD, and OTC reaching 100.00%. In the wastewater treatment process of Farm B, the treatment section "ultrafiltration (UF)+nanofiltration (NF)" removed antibiotics effectively by more than 99.23%. However, the concentrations of antibiotics investigated in the effluent were higher than the EU water environment antibiotic threshold (10 ng·L^-1). Finally, through redundancy analysis, it was found that conventional indicators (COD, NH₄⁺-N, TN, TP, and pH) in wastewater were related to the degradation of some antibiotics.