ABSTRACT
The interface between Shengjin Lake and Yangtze River was selected as the study area. The water chemical composition and hydrogen and oxygen isotope values of different types of water bodies were tested, and their seasonal variation characteristics were analyzed to explore the sources of chemical ions in the surface and groundwater. Finally, the contribution of mixed water sources to chemical ions in groundwater was estimated. The results show the following â The concentration of chemical ions in the surface and groundwater of the study area is higher than that of atmospheric precipitation, and the physical and chemical parameters exhibit seasonal variation. â¡ Surface water mainly belongs to the Ca-HCO3 type, but the proportion of the Ca-SO4 type in summer is significantly lower than that in other seasons; Groundwater primarily belongs to Ca-HCO3 and Ca-SO4 types, with proportions of 46% and 27%, respectively, and the seasonal difference is not significant. ⢠Ca2+ and Mg2+ in the surface and groundwater mainly come from the dissolution of carbonate rocks, carbonic acid and sulfate ions participate in the dissolving process of carbonate minerals. Na+and Cl- are partly derived from atmospheric precipitation and partly sourced from agricultural fertilization and manure sewage. ⣠Mixed water sources is also an important source of chemical ions in groundwater, with the average contribution 28% to Cl-, showing a seasonal trend.
Subject(s)
Groundwater , Water Pollutants, Chemical , Environmental Monitoring , Lakes , Rivers , Water Pollutants, Chemical/analysisABSTRACT
In this study, the natural zeolite and rice husk biochar were mixed as a combination amendment for metal immobilization in a Cd, Pb, As, and W co-contaminated soil. A 90 day incubation study was conducted to investigate the effects of amendments on toxic metal in soil. Zeolite, biochar, and their combination application increased the soil pH and cation exchange capacity. A combination of amendments decreased the bioavailability of Cd, Pb, As, and W. Besides, the potential drawback of biochar application on As and W release was overcome by the combination agent. Zeolite, biochar, and combination treatment decreased total bioavailability toxicity from 335.5 to 182.9, 250.5, and 143.4, respectively, which means that combination was an optimum amendment for soil remediation. The results of the Community Bureau of Reference sequential extraction and scanning electron microscopy-energy-dispersive spectrometry images confirmed the Cd and Pb adsorption onto biochar. However, As and W immobilization was dominantly controlled by zeolite. It appears that the combination of amendments is an efficient amendment to remediate Cd, Pb, As, and W co-contamination in soil, although the combination of amendments has a lower stabilization rate for W than for zeolite.