Hydrochemical Characteristics and Quality Assessment of Shallow Groundwater in Poultry Farming Sites in Suzhou City, China

In recent years, the impact of the excrement from large-scale poultry farms on the quality of shallow groundwater has attracted widespread attention. In the present study, the hydrogeochemical characteristics of shallow groundwater around poultry farming sites in the town of Zhuxianzhuang in Suzhou, Northern Anhui, China, were investigated using various statistical techniques, a Piper trilinear diagram, ion combination ratios, correlation analysis, and a fuzzy comprehensive evaluation method. The results show that the shallow groundwater in the area is dominantly of the HCO3-Ca type. The relative abundances of the major cations and anions in the groundwater are in the order Na+> Ca2+> Mg2+ > K+ and HCO3- > Cl-> SO42-> NO3-> F-, respectively. According to the concentrations and distribution of tri-nitrogen in the groundwater, pollution is mainly associated with domestic wastewater, followed by poultry farm waste. The most severe pollution involves NO2-N, and this adversely impacts the potability of the shallow groundwater. The leaching of rocks and silicate weathering are the principal processes responsible for the ionic composition of the shallow groundwater in the study area. Class I, II, and III waters account for 9.52%, 28.57%, and 61.90%, respectively, of the groundwater in the area. The shallow groundwater is suitable for high salinity-tolerant plants or soils associated with good leaching conditions. Future water management in the poultry farming area should prioritize the control of shallow groundwater nitrite pollution.