Assessment of heavy metal pollution in soils of Jebba Area, Nigeria: Concentrations, source analysis and implications for ecological and human health risks.

This comprehensive research investigates heavy metal contamination in the rapidly developing town of Jebba in north-central Nigeria, which is essential to the nation's economy due to its agro-allied and non-agro-allied businesses. The research focuses on soil samples, collecting and analyzing 137 surface soil samples to assess the presence of 25 distinct metals. After statistical analysis and simple mathematical models are applied to the data, the amounts of harmful metals and their probable causes are revealed. The study identifies geogenic and anthropogenic origins of toxic metals, with some elements exceeding average crustal concentrations. Non-homogeneous metal dispersion is shown in the region by spatial distribution maps. The geo-accumulation index reflects various amounts of contamination, with particular metals posing significant threats to the ecosystem. Additionally, the study compares results with worldwide studies, revealing distinct pollution patterns in Jebba. The research delves into weathering processes, employing chemical indices to quantify the level of soil weathering and uncovering a prominent role of geogenic activities in metal release. Bivariate correlation and principal component analysis indicate links and possibly common sources among heavy metals, emphasizing anthropogenic contributions. In addition, assessments of ecological and medical risks are conducted, indicating possible threats to human wellness and the ecosystem. Children, in particular, are regarded as especially vulnerable to non-carcinogenic health concerns, with various heavy metals posing potential threats through diverse exposure routes. The study emphasizes the need to implement remediation procedures to address the risks to public health and the environment related to metal pollution.

Natural carbon mineralization and its control on the geochemical evolution of coal-based aquifers in the Salt Range, Punjab, Pakistan.

Hydrochemical analysis of the Salt Range was conducted to understand carbon weathering and its impact on groundwater evolution within the complex geological framework of Punjab. Our results showed that groundwater samples were alkaline with a pH range of 7.0-8.6 and 7.8-8.8 for the eastern Salt Range (ESR) and Trans-Indus Salt Range (TSR), respectively, while that of the Central Salt Range (CSR) was acidic to moderately alkaline ranging between 5.7 and 7.5. The water types of Ca-Mg-HCO3, Ca-Mg-Cl, and Ca-Cl2 were the dominant hydro-chemical facies in ESR and CSR sites. However, groundwater of the TSR site falls under Ca-Mg-Cl, Ca-Cl2, and mixed types of Ca-Mg-SO4. Our new findings suggest that groundwater chemistry is primarily controlled by rock dominance and reverse ion exchange reaction, followed by evapotranspiration processes. The wells of ESR, CSR, and TSR were reported with higher levels of Fe and Zn. Regarding the suitability for irrigation, sodium adsorption ratio (SAR), magnesium adsorption ratio (MAR), sodium percentage (Na%), Kelley's ratio (KR), and potential salinity (PS) at all three sites (ESR, TSR, and CSR) had the potential to become a salinity hazard. The conceptual model of geochemical evolution shows that both local and regional salinization is driven by local geology and intensive coal mining activities. The neutralization capacity of the parent geological formation buffers the acidity and lowers the overall trace element enrichment. The potential of natural weathering could be further explored as a solution to coal mining's impact on the environment.

Microscopic Reservoir Characteristics of the Lacustrine Calcareous Shale: An Example from the Es4 s Shale of the Paleogene Shahejie Formation in Boxing Sag, Dongying Depression.

The Es4 s shale is taken as the main research object to understand and describe the reservoir characteristics in Boxing Sag, Dongying Depression. Through core observation, X-ray diffraction, thin section observation, field-emission scanning electron microscopy analysis, and low-pressure nitrogen gas adsorption experiment, the reservoir space of the Es4 s shale including pore types, pore size, and pore structure characteristics was elucidated. The study shows that the shale in the Boxing Sag has the following characteristics: (1) the reservoir space in the study area is diverse, with the development of inorganic pores, organic pores, and microfractures. The higher the content of calcite and organic matter, the more favorable the development of intergranular pores, dissolution pores, and organic matter pores and (2) complex pore structure. The average Barrett-Joyner-Halenda pore size of calcareous shale is 6.5-22.8 nm, and the Brunauer-Emmett-Teller cumulative specific surface area is 0.7588-4.744 m2/g. According to the morphological analysis of the adsorption and desorption curve, it is found that the shale samples in the target interval are mainly ink-bottle-shaped, cylindrical, and slit-shaped pores. The shale samples with relatively well-laminated intervals are mainly composed of ink-bottle-shaped and cylindrical pores, while the samples with relatively unlaminated intervals and high clay mineral content are mainly composed of slit-shaped pores. The contents of clay minerals and calcite are correlated with pore volume, specific surface area, and pore size, which further indicates the controlling effect of clay minerals and carbonate mineral components on pore structure parameters. This study not only helps us to understand the distribution of various micropores/nanopores in the lacustrine shale but also acts as a guiding note for the characterization of the shale oil reservoir, which ultimately offers a theoretical foundation for lacustrine shale oil exploration and development.