This study aimed to assess the heavy metal (Mn, Ni, Cu, Zn, Sr, Cd, Pb, and Cr) pollution characteristics, sources, and human health risks in shallow groundwater in the impact zones of urban and rural semi-intensive poultry farms in Suzhou City. Ordinary kriging interpolation showed that poultry farming contributed substantially to the pollution of shallow groundwater by Mn, Zn, and Cu. Positive matrix factorization was applied to identify the sources of heavy metals, and the health risks were assessed based on the hazard index and carcinogenic risks of the various sources. Heavy metal enrichment was closely related to anthropogenic activities. In addition, four sources were identified: poultry manure (29.33%), natural source (27.94%), industrial activities (22.29%), and poultry wastewater (20.48%). The main exposure route of carcinogenic and non-carcinogenic risks to adults and children was oral ingestion. The non-carcinogenic risk of oral ingestion in children was higher than that in adults; the carcinogenic risk was higher in adults than in children. Poultry manure (42.0%) was considered the largest contributor to non-carcinogenic risk, followed by poultry wastewater (21%), industrial activities (20%), and natural sources (17%). Industrial activity (44%) was the primary contributor to carcinogenic risk, followed by poultry wastewater (25%), poultry manure (19%), and natural sources (12%).

Long-term mining activities have changed the hydrogeochemical evolution process of groundwater and threatened the safe use of groundwater. By using the methods of hydrochemistry and multivariate statistical analysis, this study determined the hydrogeochemical evolution mechanism affecting the quality of karst groundwater by analyzing the conventional hydrochemistry data of the karst groundwater of the Carboniferous Taiyuan Formation in Hengyuan Coal Mine in the recent 12 years. The results show that, under the disturbance of mining, the quality of karst groundwater in Taiyuan Formation is poor, mainly because the contents of Na⁺+K⁺ and SO₄²⁻ are too high to allow usage as drinking water. The reason for the high content of SO₄²⁻ in karst groundwater lies in the dissolution of gypsum and the oxidation of pyrite, and the high content of Na⁺+K⁺ lies in the cation exchange. Influenced by the stratum grouting, the circulation of karst groundwater is improved, the cation exchange is weakened, and the desulfurization is enhanced. In the future, it is predicted that the hydrochemical type of karst groundwater in Taiyuan Formation in the study area will evolve from SO₄-Ca·Mg type to HCO₃-Ca Mg type.

Surface water is an indispensable water resource of drinking and irrigation, which plays important role on human health and quantity of grain production. Hydrogeochemical process as well as quality assessment of 31 representative surface water samples from 3 typical lakes around Fuli abandoned quarries area were carried out. The cation is dominated by Ca2+ and Mg2+, while the anion is dominated by HCO3 - and SO4 2-. The two leading hydrochemical type are SO4.HCO3-Ca.Mg (100%) in No. 1 lake, wheres HCO3.SO4-Ca.Mg (88.24%) and SO4.HCO3-Ca.Mg (11.76%) of No.2 and No.3 lake. The chemical composition of No.1 lake are mainly controlled by carbonate dissolution and ion-exchange, the chemical composition of No.2 and No.3 lake is mainly influenced by both ion-exchange and dissolution of carbonate and silicate minerals, among which rock weathering is the most important factor. The recharging of the lakes is mainly derived from atmospheric precipitation with the existence of evaporation. The surface water in the study area, in general, is suitable for drinking and irrigation. The outcomes of this research provide a better understanding of hydrochemical mechanism of surface water around quarries, and it will help to improve management and sustainable utilization of water resources for local government.

Years mining activities have changed the distribution characteristics of groundwater hydrochemical field, which may lead to the deterioration of groundwater quality and the occurrence of mine water inrush disasters. The study of groundwater hydrogeochemical evolution can provide a theoretical basis for the prevention of mine water inrush disaster and the rational utilization and protection of groundwater. Using the Piper trigram, Person correlation analysis matrix, Gibbs diagram, ion proportion coefficient diagram, and mineral saturation index to study the hydrogeochemical evolution mechanism of Taiyuan Formation limestone water before grouting (2010) and after grouting (2020) in this study. The results show that the concentrations of anion and cation in the limestone water of Taiyuan Formation have the same change trend before and after grouting in the study area, the anion concentration changes to SO4 2- >HCO3 - >Cl-, the cation concentration changes to Na++K+>Ca2+>Mg2+. The correlation coefficient between most ions of limestone water after grouting is reduced. The hydrogeochemical type is gradually transformed from Na++K+-SO4 2- type to Mg2+-SO4 2- type and Ca2+-SO4 2- type. Rock weathering and cation exchange are the main factors affecting the hydrogeochemical characteristics of limestone water. The higher concentration of SO4 2- is related to the dissolution of gypsum and the oxidation of pyrite.