亚热带典型分散式养殖农区的环境污染特征研究

Study on Characteristics of Environmental Pollution in Rural Area with Typical Decentralized Animal Breeding in Subtropical Region

以我国亚热带丘陵区一个多年以生猪养殖业为主的农村环境为研究对象,通过监测地表水、地下水、土壤和蔬菜,综合评估养殖业对该地区环境污染的影响。结果表明:(1)地表水中氮磷污染严重,河水铵态氮和总磷的含量范围为4.89-18.20 mg/L和1.05-3.33 mg/L,受养殖废水直接排放的池塘水铵态氮和总磷最高分别为132.7、45.3 mg/L;地表水中铵态氮、总氮和总磷呈极显著正相关(p<0.01);(2)地下水主要受硝态氮污染,含量在5.44-44.82 mg/L之间;(3)土壤主要受重金属Cd和Cu污染,耕层土壤中,菜地土的Cd和Cu超标率均为100%,水稻土中Cd的超标率达87.5%;(4)蔬菜样品中Cd、Pb、Zn、Ni含量范围分别为0.29-1.94 mg/kg、0.52-4.25 mg/kg、50.66-209.47 mg/kg、1.61-9.11 mg/kg,均超过国家蔬菜安全标准。因此,改善研究区的生态环境,妥善解决养殖废弃物污染问题已迫在眉睫。

A rural area with typical decentralized animal breeding in subtropical hilly region was employed to investigate the situation of environmental pollution. Samples of surface water, groundwater, soil and vegetables were analyzed to evaluate environmental qualityin the study rural. The results indicated that the surface water samples were heavily contaminated ＋ by nitrogen （N） and phosphorus （P）. For river water, the contents of ammonia nitrogen （NH4^＋ -N） and total phosphorus （TP） were in the ranges of 4.89-18.20 mg/L and 1.05-3.33 mg/L, respectively. Meanwhile, the pond water directly receiving discharge of poultry breeding wastewater had the highest concentrations of 132.7 mg/L for NH4^＋-N and 45.3 mg/L for TP. There was significantly positive relationship between NH4^＋ -N, TN and TP. Nitrate was the most pollutant with the concentrations from 5.44 to 44.82 mg/L in the underground water below 50 m. The soils were always polluted by Cd and Cu, especially, all vegetable soils and 87.5% paddy soils in 0-20 cm surpassed the values of national environment quality standards. The contents of Cd, Pb, Zn and Ni in vegetable samples ranged in 0.29-1.94 mg/kg, 0.52-4.25 mg/kg, 50.66-209.47 mg/kg and 1.61-9.11 mg/kg, respectively, which exceeded the limit values of national safety standard for vegetables. It was clear that the study site had serious environmental pollution problem, and reducing the discharge of pollutants from the poultry farms was extremely urgent.