Hydrochemical characteristics and functions of groundwater in southern Laizhou Bay based on the multivariate statistical analysis approach

Yang

et al. 2022

Preprint

Self Cite

The groundwater environment is important to human living in coastal plain. In this study, southern Laizhou Bay (SLB) is chosen as the study area and 47 groundwater samples are collected to analyze groundwater environmental effects and health risk assessment in saline-fresh water mixing zone (SFMZ) of coastal plain. Influenced by saline water intrusion (SWI), K+, Na+, Ca2+, Mg2+, Cl-, SO42- and HCO3- concentration values are exceeded WHO standard value seriously. High-F groundwater is the product in process of SWI, caused by cation exchange, weakly alkaline environment, evaporation and fluorite dissolution. Na+ concentration and a decrease in the Ca2+ concentration can promote further dissolution of fluorite and other F-containing minerals. Based on the health risk assessment method, the average HQ sequence in typical groundwater pollutants is Cl- > F- > NO3-N > Se > Mn > NO2-N > Cu > Pb > Zn > Fe, and the CR sequence caused by carcinogenic heavy metals is Cd > As > Cr. The greatest non-carcinogenic risk to adults and children in the study area is caused by Cl-. Cd is the most important indicator of carcinogenic risk, and its contribution to CR accounts for 74.531%. The regions with high health impacts of carcinogenic pollutants in groundwater are mainly concentrated in the central part of the study area, with the exceeding range of 35.373% for adults and 44.768% for children. Non-carcinogenic pollutants are enriched in SFMZ, which have greater impacts on human body and lead to higher health risks compared with carcinogenic pollutants.

Section: The Direct Effects Of Swisupporting

confidence: 70%

Section: Saline Water Intrusion (Swi)mentioning

confidence: 58%

Section: Introductionmentioning

confidence: 99%

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The groundwater environmental effects and health risk assessment in saline-fresh water mixing zone of coastal plain

Yang

et al. 2022

Preprint

Self Cite

“…As shown in Table , the Kaiser–Meyer–Olkin was 0.759, and Bartlett’s test of sphericity declined, indicating that the data were correlated, and the factor analysis was effective. With two principal components, the cumulative contribution rate was greater than 80%, and the information extraction rate of each variable was greater than 0.70. , The two principal components can better reflect most of the information of the original variables, and the effect of PCA is good. As shown in Table , ions of Na + , K + , Ca 2+ , Mg 2+ , Cl – , and HCO 3 – possessed high loading values in the PC 1 direction, whereas the ion of SO 4 2– had a high loading value in the PC 2 direction.…”

Section: Discussionmentioning

confidence: 99%

Research on Temporal Patterns of Water–Rock Interaction in the Coal Mine Underground Reservoir Based on the Dynamic Simulation Test

et al. 2023

The temporal pattern of water−rock interaction is significant in predicting the ion concentration of the effluent in coal mine underground reservoirs. This study used the roof-caved rock samples and main incoming water (mine water and fissure water) of the Daliuta coal underground reservoir as the research object and designed four groups of dynamic simulation experiments of the water−rock interaction. Based on the main ion concentrations in the water sample at different reaction times, Q-type hierarchical cluster analysis (HCA) was used to classify the stages of water− rock interaction. The types and intensities of water−rock interaction in each stage were identified by combining the ion ratio and principal component analysis (PCA). Q-type HCA shows that the dynamic simulation experimental water samples can be divided into three categories according to the reaction time, representing the early, middle, and late stages of the water−rock interaction process. The influence of water quality on the division of the water−rock interaction stage is greater than that of rock characteristics. The ion ratio and PCA show that the dissolution of pyrite minerals, cation exchange reaction, and mineral adsorption mainly occur in the early stage of water−rock interaction, in which the cation exchange reaction plays a leading role in the change of ions in water. In the middle stage, the cation exchange reaction and the dissolution of carbonate minerals, such as calcite and dolomite, mainly occur, in which mineral dissolution is the main. In the late stage, the water−rock interaction is relatively weak, and the change of ion concentration in water is not obvious. This study proves the temporal patterns of water−rock interaction between caved rock and mine water (or fissure water) and differences in the types and intensities of water−rock interaction in each stage. The results can provide a theoretical basis for the optimization of the operation cycle of coal mine underground reservoirs and the prediction of effluent ion concentration.

“…The research object in this study was a rural dump in the red bed area of northern Sichuan, China. Following that, statistical analysis, the ion ratio method, the Piper and Gibbs diagram method, and the isotope tracer method were used to assess the hydrochemical features of groundwater (Fan et al, 2020;Masoud and Abu, 2022;Peng et al, 2022;Wu et al, 2018). Furthermore, numerical models for modeling landfill leachate migration and diffusion in groundwater have been developed (Fandio et al, 2020;Mishra et al, 2019;Peter et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Assessment of landfill groundwater quality and regulating factors: a case study of northern Sichuan

Liu,

Zhang,

et al. 2024

Preprint

A total of 31 groundwater samples were obtained and analyzed in this research endeavor from a conventional rural landfill situated in the red-layer region of northern Sichuan. The Chemical characteristics, controlling factors and hydrogeochemical processes of the groundwater in the study area were elucidated through the application of multivariate statistical analysis and ionic ratio analysis. To predict the spreading range and concentration of the contaminants in the landfill, a groundwater flow model and a solute transport model were constructed using groundwater numerical simulation software. The Piper diagram revealed that the majority of the groundwater exhibited a chemical composition of HCO3-Na and SO4·Cl-Na, which is denoting neutral or weakly alkaline groundwater and belonged to the soft-fresh and hard-brackish water types, respectively. The concentrations of NH4-N in groundwater varied from 0.025 to 17.3 mg/L, with 51.61% of samples surpassing the limit of 0.5 mg/L established by the World Health Organization for drinking water. The groundwater chemistry in the studied area was primarily affected by cation exchange, human activities, and the weathering of carbonate rocks, according to the Gibbs plot, ionic ratio analysis, and SI calculations. According to the calculated weighted water quality index (EWQI), the majority of the groundwater quality indicators in the study area were classified as poor or very poor, with NH4-N concentration being the primary determinant. Numerical simulation results showed that the diffusion area of the NH4-N pollution plume in the horizontal plane along the direction of groundwater flow was 5618 m2, 10142 m2, and 11695 m2 for 1, 5, and 10 years of waste leachate leakage, respectively. In conclusion, the findings of this research offer a scientific basis for the remediation of groundwater attributable to the landfill situated in the red-layer region of northern Sichuan.