Springer Science and Business Media LLC

Geochemical analysis is a useful tool in hydrogeological assessment, particularly in constructing a conceptual model of a hydrogeological system. In this study, major ion concentrations of 53 groundwater samples from the coal-bearing aquifer in the Qidong coal mine, northern Anhui Province of China have been processed by statistical analysis for understanding either hydro-chemical characteristics or hydrological evolution, which will be useful for the safety of coal mining. The results suggest that most of the samples are Na–SO4 and Na–HCO3 types, and their hydro-chemical compositions are mainly controlled by dissolution of more soluble minerals (e.g. calcite) and weathering of silicate minerals (e.g. plagioclase). Two groups of samples have been subdivided by quantile and scatter plots of factor scores, one is related to different degrees of water–rock interactions and another is related to groundwater mixing. Moreover, four end members have been identified and the mixing calculation suggests that the groundwater samples affected by mixing have 20–100 % contribution from the loose layer aquifer (LA), and therefore, groundwater from the LA in the coal mine should be taken seriously during coal mining. The study demonstrated that statistical analysis is useful for connecting the hydrochemistry of groundwater with hydrological evolution of the aquifer.

This study comprises the comparative evaluation of floating (Azolla filiculoides) and submerged (Hydrilla verticillata) macrophytes for potential biosorption of Cu(II), Cr(VI), As(III) and Pb(II) from aqueous solution in a multi-component study. Statistically valid Plackett–Burman design of experiments was employed with four heavy metals at two different levels by varying their initial concentration in the range 10-50 mg L−1 for both the macrophytes. The maximum removal efficiency for Pb(II) was obtained for both the biosorbents, i.e., Azolla sp. (81.4%) and Hydrilla sp. (84.3%) within 4 h of the experimental runs, with an initial concentration of 10 mg L−1 of all the heavy metals. Followed by Pb(II) removal, a declining trend for the removal (%) for Cu(II), As(III) and Cr(VI) was obtained, for all the experimental runs. Also, the minimum removal (%) for all the experimental runs was attained at 25 mg L−1 (maximum) for all the heavy-metal concentration level. The removal efficiency (%) trends follow the order: Pb(II) > Cu(II) > As(III) > Cr(VI) for both the biosorbents. Analysis of variance and Student’s t test of the metal bioremoval revealed that main (individual) effect due to the metals was highly significant (P value < 0.05) on each other’s removal. Student’s t test results revealed that both Pb(II) and Cu(II) strongly inhibited both Cu(II) removal (P value < 0.01), while Cr(VI) has only inhibitory effect on Pb(II) removal. Henceforth, all these results simultaneously depicted good potential of the aquatic macrophytes for the biosorption capability of heavy metal and the effect of individual metals on each other’s removal in the multi-component system.

In response to rising concerns about the effect of sulfate on water quality, human health, and agriculture, many jurisdictions around the world are imposing tighter regulations for sulfate discharge. This is driving the need for environmental compliance in industries like mining, metal processing, pulp and paper, sewage treatment, and chemical manufacturing. The sulfate removal from synthetic water by high cross-linked polystyrene divinylbenzene resin was studied at batch experiments in this study. The effect of pH, contact time, sulfates concentration, and adsorbent dose on the sulfate sequestration was investigated. The optimum conditions were studied on Saline water as a case study. The results showed that with increasing of the absorbent amount; contact time, and pH improve the efficiency of sulfate removal. The maximum sulfates uptake was obtained in pH and contact time 3.0 and 120 min, respectively. Also, with increasing initial concentration of sulfates in water, the efficiency of sulfate removal decreased. The obtained results in this study were matched with Freundlich isotherm and pseudo-second-order kinetic. The maximum adsorption capacity (Qm) and constant rate were found 0.318 (mg/g) and 0.21 (mg/g.min), respectively. This study also showed that in the optimum conditions, the sulfate removal efficiency from Saline water by 0.1 mg/L sulfates was 65.64 %. Eventually, high cross-linked polystyrene divinylbenzene resin is recommended as a suitable and low cost absorbent to sulfate removal from aqueous solutions.

Groundwater samples from alluvial aquifers of Bathinda district, southwest Punjab were measured for physicochemical parameters as well as major ion chemistry to evaluate the groundwater suitability for drinking and irrigation purposes and to present the current hydrochemical status of groundwater of this district. Temporal variations were analyzed by comparing the pre- and post-monsoon groundwater chemistry. Most of the samples showed contamination: F− (72 %), Mg2+ (22 %), SO4 2− (28 %), TH (25 %), NO3 − (22 %), HCO3 − (22 %) and TDS (11 %) during pre-monsoon and F− (50 %), Mg2+ (39 %), SO4 2− (22 %), TH (28 %), NO3 − (22 %) and TDS (28 %) during post-monsoon above permissible limits for drinking, while rest of the parameters fall within the limits. Irrigation suitability was checked using sodium absorption ratio (SAR), residual sodium carbonate (RSC), percent sodium (Na%) and permeability index (PI). Most of the samples fall under good to suitable category during pre-monsoon period, but fall under doubtful to unsuitable category during post-monsoon period. Presence of high salt content in groundwater during post-monsoon season reflects leaching of salts present in the unsaturated zone by infiltrating precipitation. Hydrochemical data was interpreted using Piper’s trilinear plot and Chadha’s plot to understand the various geochemical processes affecting the groundwater quality. The results indicate that the order of cation dominance is Na+ > Mg2+ > Ca2+, while anion dominance is in the order Cl− > HCO3 − > SO4 2−. The geochemistry of groundwater of this district is mainly controlled by the carbonate and silicate mineral dissolution and ion exchange during pre-monsoon and leaching from the salts deposited in vadose zone during post-monsoon. The main sources of contamination are soluble fertilizers and livestock wastes. This study is significant as the surface water resources are limited and the quality and quantity of groundwater are deteriorating with time due to anthropogenic inputs.

This study investigates how land use and climate changes affect water yield ecosystem service (ES) in the Sirvan River basin, located in Iran’s Kurdistan and Kermanshah provinces. By detecting land-use and climatic parameter changes in the past, their future evolution were modeled by scenario making. For this purpose, we developed two land-use scenarios (low and high urbanization) and two climatic scenarios (Representative Concentration Pathway 2.6 and RCP 8.5). The implemented scenarios showed how the amount of water yield in the basin and sub-basins changes in the future based on climate and land-use changes. The results showed that, concerning land use, the forest has decreased from 2013 to 2019, and built-up areas have increased. Also, the results showed that precipitation has been declining in the long term, and the temperature has been rising. Finally, the Water yield in 2019 was higher than in 2013 and lower in the future based on forecast scenarios. This trend will continue until 2040. In addition, it was found that the t effects of these factors on water yield ES are a complex process, and based on the results, the impact of climatic factors is more significant than the one of land-use change. We could conclude that this region will face more environmental problems in the future.

Soil wearing away or erosion is a chief agent of land loss in agricultural land and is regarded worldwide as a serious environmental hazard. This study performed watershed prioritization using morphometric parameters based on fuzzy best worse method (F-BWM) and GIS integration for Gusru Watershed, India. This study prioritizes sub-watersheds of the study area from viewpoint of soil erosion using five major parameters i.e., stream frequency (Fs), relative relief (Rr), length of overland flow (Lo), relief ratio (Rh) and drainage density (Dd). Fuzzy based Best Worse Multi-Criteria Decision-Making (F-BWM) Method was used to assigning weights to used criteria and combining them to achieve erosion susceptibility for each sub-watershed. Results showed that sub-watersheds 9, 14, and 5 were most susceptible to soil erosion and sub-watershed 3 was the least from the viewpoint of soil erosion ranking.