Abnormally high concentrations of metals including nickel (Ni) in soils result from high geochemical background (HB) or anthropogenic contamination (AC). Metal bioaccessibility in AC-soils has been extensively explored, but studies in HB-soils are limited. This study examined the Ni bioaccessibility in basalt and black shale derived HB-soils, with AC-soils and soils without contamination (CT) being used for comparison. Although HB- and AC-soils had similar Ni levels (123 ± 43.0 vs 155 ± 84.7 mg kg⁻¹), their Ni bioaccessibility based on the gastric phase of the Solubility Bioaccessibility Research Consortium (SBRC) in vitro assay was different. Nickel bioaccessibility in HB-soils was 6.42 ± 3.78%, 2-times lower than the CT-soils (12.0 ± 9.71%) and 6-times lower than that in AC-soils (42.6 ± 16.3%). Based on the sequential extraction, a much higher residual Ni fractionation in HB-soils than that in CT- and AC-soils was observed (81.9 ± 9.52% vs 68.6 ± 9.46% and 38.7 ± 16.0%). Further, correlation analysis indicate that the available Ni (exchangeable + carbonate-bound + Fe/Mn hydroxide-bound) was highly correlated with Ni bioaccessibility, which was also related to the organic carbon content in soils. The difference in co-localization between Ni and other elements (Fe, Mn and Ca) from high-resolution NanoSIMS analysis provided additional explanation for Ni bioaccessibility. In short, based on the large difference in Ni bioaccessibility in geochemical background and anthropogenic contaminated soils, it is important to base contamination sources for proper risk assessment of Ni-contaminated soils.

Excess exposure to fluoride causes substantive health burden in humans and livestock globally. However, few studies have assessed the distribution and controls of variability of ambient background concentrations of fluoride in soil. Ambient background concentrations of fluoride in soil were collated for Greater Melbourne, Greater Geelong, Ballarat and Mitchell in Victoria, Australia (n = 1005). Correlation analysis and machine learning techniques were used to identify environmental and anthropogenic influences of fluoride variability in soil. Sub-soils (>0.3 m deep), in some areas overlying siltstone and sandstone, and to a lesser extent, overlying basalt, were naturally enriched with fluoride at concentrations above ecological thresholds for grazing animals. Soil fluoride enrichment was predominantly influenced by parent material (mineralogy), precipitation (illuviation), leaching during palaeoclimates and marine inputs. Industrial air pollution did not significantly influence ambient background concentrations of fluoride at a regional scale. However, agricultural practices (potentially the use of phosphate fertilisers) were indicated to have resulted in added fluoride to surface soils overlying sediments. Geospatial variables alone were not sufficient to accurately model ambient background soil fluoride concentrations. A multiple regression model based on soil chemistry and parent material was shown to accurately predict ambient background fluoride concentrations in soils and support assessment of fluoride enrichment in the environment.

High concentration of fluoride (up to 20.9 mg/L) in groundwater with significant variation (p = 5.9E-128) among samples was reported from Birbhum district, an acknowledged fluoride endemic region in India. The groundwater samples (N = 368) were grouped based on their hydrochemical properties and aquifer geology for hydro-geochemical characterization. Friedman’s test showed p < 0.0001 confidence level which indicates that fluoride concentration among geological groups and water groups are independent. Bland-Altman plot was used to study the inter-relationships among the groups through bias value (∂) and limit of agreement (LoA). Among the geological groups, laterites and granite-gneiss groups exhibited statistically significantly difference in fluoride geochemistry; whereas the younger and older alluvium groups displayed similar characteristics. The fluoride concentration was found to be in the order Lateritic > Granite-gneiss > Older alluvium ≥ Younger alluvium. Dissolution of minerals (such as fluorite, biotite) in laterite sheeted basalt, and granite-gneiss is the main source of groundwater fluoride in the region. Fluoride concentration is also influenced by depth of water table. Hydrochemical study indicated that fluoride concentration was higher in Na–HCO₃ than in Ca–SO₄ and Ca–HCO₃ type of groundwater. The fluoride concentration were positively correlated with Na⁺ and pH and negatively correlated with the Ca²⁺ and Mg²⁺ signifying linkage with halite dissolution and calcite, dolomite precipitation. Geostatistical mapping of WQI through empirical bayesian kriging (EBK) with respect to regional optimal guideline value (0.73 mg/L) classified that groundwater in some parts of the district are unfit for drinking purpose. Health survey (N = 1767) based on Dean’s criteria for dental fluorosis indicated presence of slight to moderate dental hazard. Besides, providing baseline data for management of groundwater quality in the study area, the study demonstrated the applicability of Bland-Altman analysis and empirical bayesian kriging (EBK) in delineation and interpolation of fluoride contaminated region.

The effective approaches to eliminate impacts of ethanol on the biodegradation of benzene, toluene, ethylbenzene, and xylene (BTEX) are concerned in the bioremediation of groundwater contaminated with ethanol-blended gasoline. In situ chemical oxidation (ISCO) is a common technique widely used for the remediation of contaminated groundwater. However, the selectivity of ISCO for BTEX and ethanol removal is poorly understood. Therefore, a batch experiment was performed with different aquifer materials, including calcareous soil, basalt soil, granite soil, dolomite, and sand. Gasoline was used to provide dissolved BTEX and ethanol reagent was used as additive to improve the quality of gasoline and to reduce the possibility of air pollution caused by gasoline. Persulfate (PS) was used as a chemical oxidant to oxidize organic contaminants. The target concentrations of BTEX and ethanol were 20 mg/L and 1000 mg/L, respectively. The results showed that ethanol could be preferentially degraded in the absence of PS and inhibit BTEX biodegradation. However, BTEX could be preferentially removed prior to ethanol in all aquifer materials used at ambient temperature, when PS was added at a PS/BTEX molar ratio of 150. Over 94% BTEX in sand, dolomite, and granite soil was preferentially removed with the first-order decay rate constants of 0.890–2.703 day⁻¹ within the first ~ 10 days, followed by calcareous and basalt soil at the constants of 0.123–0.371 day⁻¹. Ethanol could compete with BTEX for sulfate radical at the first-order decay rate constants of 0.005–0.060 day⁻¹ for the first 25 days, which was slower than that of BTEX. The pH quickly decreased to < 2.5 in dolomite, sand, and granite soil, but maintained > 6.2 in calcareous soil. Rich organic matter in calcareous and basalt soil had an inhibition effect on BTEX oxidation by PS. The pH buffer in calcareous soil may imply the potential of PS oxidation combined with bioremediation in carbonate rock regions.

Uranium tailing ponds are a potential major source of radioactive pollution. Solidification treatment can control the diffusion and migration of radioactive elements in uranium tailings to safeguard the surrounding ecological environment. A literature review and field investigation were conducted in this study prior to fabricating 11 solidified uranium tailing samples with different proportions of PVA fiber, basalt fiber, metakaolin, and fly ash, and the weight percentage of uranium tailings in the solidified body is 61.11%. The pore structure, volume resistivity, compressive strength, radon exhalation rate variations, and U(VI) leaching performance of the samples were analyzed. The pore size of the solidified samples is mainly between 1 and 50 nm, the pore volume is between 2.461 and 5.852 × 10⁻² cm³/g, the volume resistivity is between 1020.00 and 1937.33 Ω·m, and the compressive strength is between 20.61 and 36.91 MPa. The radon exhalation rate is between 0.0397 and 0.0853 Bq·m⁻²·s⁻¹. The cumulative leaching fraction of U(VI) is between 2.095 and 2.869 × 10⁻² cm, and the uranium immobilization rate is between 83.46 and 85.97%. Based on a comprehensive analysis of the physical and mechanical properties, radon exhalation rates, and U(VI) leaching performance of the solidified samples, the basalt fiber is found to outperform PVA fiber overall. The solidification effect is optimal when 0.6% basalt fiber is added.

This study analysed the effectiveness of innovative (basalt meal, brown algae extract) and conventional (barley straw) substances which hypothetically alleviate the inhibiting effect of Cd²⁺ on biochemical properties of soil, with particular regard to the activity of arylsulfatase. An analysis of their potential was carried out based on the activity of arylsulfatase and the number of Pseudomonas sp. determined on the 25th and 50th days of the study. Cd²⁺ was applied in the following doses: 0, 4, 40, 80, 120, 160, 200 mg Cd²⁺ kg⁻¹ of DM soil, in the form of CdCl₂·2.5H₂O. A complex formulation of the issue was obtained from the presentation of biochemical properties using the RS (resistance of soil) index. Cadmium caused permanent adverse effects in the soil environment, inhibiting the activity of arylsulfatase and the yield of spring barley. The consequences of stress connected with increasing Cd²⁺ pollution were intensified by an elongation of the accumulation time of the tested metal in the soil. Chances for regeneration of the soil may be sought, most of all, with the application of straw and, to a lesser degree, with basalt meal. Brown algae did not meet the expectations for its potential. An increase in the studied parameters also resulted from sowing the soil with spring barley.

Geological barriers play an important role in preventing pollution of groundwater. Basalts are common geological media; however, there have not been any studies that report the effect of basalt type on the metal ion adsorption performance. In this study, we explored the metal ion (Zn²⁺ and Cd²⁺) adsorption ability of two kinds of weathering basalts, the origin weathering basalt (WB) and the eluvial deposit (ED), both of which were derived from same basaltic formation. Characteristics of the sediments were examined by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Barrett-Joyner-Halenda (BJH) measurement, and the rapid potentiometric titration (RPT) method. Batch experiments were performed to evaluate the Zn²⁺ and Cd²⁺ adsorption performance of WB and ED and how adsorption was affected by contact time, initial metal ion concentration, pH, and ionic strength. Despite WB and ED having similar chemical compositions, WB exhibited better adsorption than ED likely due to the fact that WB was rougher and had more small-sized spherical structures and stronger electrostatic forces. The adsorption process fits the Freundlich isotherm model well. The adsorption efficiency decreased with a decrease of pH (from 4 to 2) and with increasing ionic strength. These results suggest that a geological barrier composed of WB media might be able to effectively sequester metallic contaminants to prevent them from reaching groundwater.

This study aims to employ marble, pumice, and basalt combination for phosphate ions adsorption. Response surface methodology (RSM) was used to optimize the preparation method. The optimum mixture of marble, pumice, and basalt was used as an adsorbent for phosphate removal, where RSM optimized the adsorption process. The maximum removal efficiency was obtained when the combination was 0.5 marble: 0.25 pumice: 0.25 basalt. All the developed models (preparation, capacity, and removal efficiency models) were found to be significant and adequately precise to describe model space. The maximum removal efficiency reached 94% at pH 2, initial phosphate ions concentration of 10 mg/L, and contact time of 60 min. The adsorption of phosphate ions onto the prepared adsorbent was found to follow the Freundlich isotherm and the pseudo-second-order model. The phosphate adsorption onto the prepared adsorbent was feasible and naturally spontaneous. At the end of the study, the adsorption of phosphate onto the rock combinations was realized successfully and the generation of second-order pollutants was prevented since the prepared adsorbent can be utilized in the soil enrichment.

The exploitation of volcanic rock quarries generates enormous waste, which causes the problem of disposal, leading to rising dust levels in quarries and depositions on nearby farms by runoffs. To address this issue, the development of sustainable solution for their valorization in construction industries is required. The present investigation aims to valorize granite (GW) and basalt (BW) quarry waste powders as partial replacement (up to 20 wt.%) of iron-rich aluminosilicates in the synthesis of geopolymer binders. Both synthesized series of samples were sealed and cured at 7, 14, and 28 days at room temperature before subjecting to various analytical techniques, including the mechanical properties, XRD, FT-IR, TG/DTG, and SEM–EDS. The results showed that both GW and BW powders are efficient to produce sufficient amounts of geopolymer binder, with ensure good cohesion and connectivity between different components within the final matrices. The values of compressive strength were 7.5–35.9 MPa and 6.2–39.7 MPa for laterite/granite and laterite/basalt geopolymer composites, denoted LGA and LBA, respectively. Moreover, the coexistence of the amorphous Na-aluminosilicate, Ca-aluminosilicate, and Na-polyferrosialate species is responsible for the mechanical properties development of the end-products. Based on the findings, the selected quarry wastes appeared to be sustainable and cost-effective materials for the synthesis of low-energy consumption binder, suitable for the production of construction materials.

The present study is focused on seasonal variation in groundwater quality, hydrochemistry, and associated human health risk in the Shivganga river basin, Western Maharashtra, India, to promote sustainable development of groundwater resources of this semi-arid region. The qualitative geochemical analysis, contamination levels, and human health risk assessment (HHRA) of groundwater are integral steps in groundwater management in the Deccan Plateau basalt flow region of India. Representative groundwater samples (n = 68) collected from the Shivganga River basin area of Pune district, Maharashtra, during pre-monsoon (PRM) and post-monsoon (POM) seasons in 2015 were analyzed for major cations and anions. According to the World Health Organization (WHO, 2017) drinking standards, EC, total dissolved solids, hardness, bicarbonate, calcium, and magnesium surpassed the desirable limit. Boron and fluoride content exceeded the prescribed desirable limit of the WHO. The pollution and drinking suitability were assessed by computing pollution index of groundwater (PIG), groundwater quality index (GWQI), and HHRA particularly for boron and fluoride toxicity. PIG values inferred that about 6% of groundwater samples has moderate, 24% has low, and 70% has insignificant pollution in the PRM season, while only 1 sample (3%) showed high pollution, 6% showed low, and 91% showed insignificant pollution in the POM season. GWQI classification demonstrated that 27% and 15% samples are within the poor category, and only 15% and 18% of the samples fall into excellent water category in the PRM and the POM seasons, respectively. Total hazard index (THI) revealed that 88% of children, 59% of adults, and about 38% of infants are exposed to non-carcinogenic risk, as THI values (>1) were noted for the PRM season, while 62% of children, 47% of adults, and 24% of infants are vulnerable to non-carcinogenic health hazard during the POM period.