嘉兴市规模化养猪场沼液水质调查研究

Study on the Quality of Digested Piggery Wastewater in Large-Scale Farms in Jiaxing

以嘉兴市10家大型规模化养猪场为对象,开展了沼液水质调查,测试了COD、氮、磷和外源化学品（抗生素、重金属）的污染水平.结果表明,不同猪场之间水质差异很大,且同一猪场的沼液水质随时间波动很大.其中春季检测组的猪场沼液浓度普遍较高,COD、氨氮、TN和TP的浓度分别高于2000、1000、1000和60 mg·L^-1的猪场有7家,秋季和冬季检测组的沼液浓度稍低,夏季检测组最低.沼液碳氮比失衡严重,其中秋季检测组最低,仅为0.8-4.3.4类（四环素类、磺胺类、大环内酯类、喹诺酮类）共10种抗生素和6种重金属（铜、锌、铅、铬、镍和镉）在10家猪场沼液中均有检出.重金属以铜、锌为主,平均值分别为1.88 mg·L^-1和7.63 mg·L^-1.抗生素以四环素类（四环素、土霉素、金霉素）为主.10种抗生素总浓度的最低值为10.1μg·L-1,最高值为1090μg·L-1,远高于欧盟的水环境抗生素阈值（10 ng·L^-1）.猪场沼液不仅氮磷脱除难,而且重金属和抗生素污染严重,亟待开发低成本高效无害化处理与资源化利用技术.

Pollution characteristics of digested piggery wastewater（ DPW）,including not only the chemical oxygen demand（ COD）,nitrogen and phosphorus but also the veterinary antibiotics and heavy metals,were investigated in ten large-scale pig farms in Jiaxing City. Results showed that the water quality of DPW greatly varied with farms and seasons. DPW in the spring group showed the highest pollutant concentration,with seven of the ten pig farms demonstrating COD of over 2 000 mg·L^-1total nitrogen and ammonia nitrogen of over 1 000 mg·L^-1nd total phosphorus of over 60 mg·L^-1 Pollutant concentrations of DPW were lower in the autumn and winter groups,while the lowest was observed in the summer group. Unbalanced nutrient was observed in DPW,the carbon nitrogen ratio showed the lowest value of 0. 8-4. 3 in the autumn group. Four classes（ tetracyclines,quinolones,macrolides and sulfonamides） of ten antibiotics and six heavy metals（ Cu,Zn,Pb,Cd,Ni and Cr） were detectable in DPW from all the ten farms. Cu and Zn were the top two dominant heavy metals,with an average concentration of 1. 88 mg·L^-1nd 7. 63 mg·L^-1respectively. Tetracyclines（ including Tetracycline,Oxytetracycline and Chlortetracycline） were always the dominant antibiotics. The total concentration of the ten antibiotics was in the range of 10. 1 μg·L^- 1to 1090 μg·L- 1,far exceeding the antibiotics limit of 10 ng·L- 1in the water environment specified by EU. Efficient but low cost treatment technologies are in urgent need in order to deal with the pollution by DPW,a wastewater that is not only difficult to remove nitrogen and phosphorus,but also seriously polluted by heavy metals and antibiotics.