Hydrogeochemical understanding of groundwater is essential for the effective management of groundwater. This study has been carried out to have concrete data for the seasonal variations in hydrogeochemistry of groundwater in central Tamilnadu forming a complex geological terrain with a varied lithology. A total of 244 groundwater samples were collected during four different seasons, viz, southwest monsoon (SWM), summer (SUM), postmonsoon (POM), and northeast monsoon (NEM) from bore wells. The physical parameters such as pH, temperature, TDS, ORP, humidity, and electrical conductivity (EC) were measured insitu, whereas major ions were analyzed in the lab adopting standard procedures. Overall, higher EC and NO₃ values were observed and exceeded the WHO permissible limit irrespective of seasons, except for NO₃ in SWM. Na and HCO₃ are the dominant cation and anion in the groundwater irrespective of seasons. The highest average values of Na (65.06 mg L⁻¹) and HCO₃ (350.75 mg L⁻¹) were noted during SWM. Statistical analysis was carried out to elucidate the hydrogeochemistry of the region. Initially, to understand the ionic relationship, correlation matrix was used followed by factor analysis for determination of major geochemical control and later factor scores were derived to understand the regional representations. An attempt has also been made to identify the samples influenced by multiple geochemical processes and to understand their spatial variation in the study period. Correlation of geochemical parameters reveals a excellent positive correlation between Ca and NO₃ in SUM, SWM, and NEM due to the dominant of anthropogenic sources and minor influence of weathering process. Strongly loaded factor scores are found to be mostly in the following order POM > NEM > SWM > SUM. Principal component analysis of different seasons indicates the interplay of natural weathering and anthropogenic factors. Overall, the predominant geochemical processes in this region, irrespective of seasons are weathering and, ion exchange and anthropogenic activities.

Coal mining causes serious ecological and environmental damage. The crushed gangue is backfilled into underground goaf, which not only inhibits mining-induced subsidence but also reduces accumulation of waste on the ground: however, the effects of backfilling with gangue backfill materials in goaf are affected by a combination of multiple factors. To predict compression-induced deformation (CID) of gangue backfill materials, key factors influencing compression and deformation characteristics of gangue backfill materials in an underground confined space (lithology, particle size distribution, lateral stress and lateral loading times) were determined. Moreover, two key factors, namely, lithology and particle size distribution of gangue backfill materials, were quantified. Based on orthogonal test design, the compression characteristics of gangue backfill materials were measured under different stress levels and coupling effects of the four key factors by utilising a self-made bidirectional loading test system for bulk materials. Furthermore, through regression, the relationships of the four key factors and axial strain were determined as well as undetermined parameters in axial stress-axial strain equations and axial stress. Based on this, an equation for predicting stress-strain relationship during compression-induced deformation of gangue backfill materials under multi-factor coupling effects was established. Comparison with the orthogonal test results shows that this equation can predict compression-induced deformation of gangue backfill materials in goaf. This is beneficial to providing a basis for predicting strata movement and surface subsidence and guidance for designing backfilling process, thus protecting the surface environment.

Multivariate statistical techniques and geostatistical methods are among the important tools used in surface water quality management. They are widely used in interpreting data, identifying the pollution sources, understanding the spatial variation of parameters, and determining the places of monitoring stations. Therefore, in this study, spatial variation of water quality and pollutants in the Anzali Wetland water (Iran) was evaluated using multivariate statistical and Kriging methods. The values of different water quality parameters measured in six stations in the wetland water were subjected to cluster analysis (CA) and principal component analysis (PCA). Cluster analysis reduced the number of stations from six to four. The results of PCA showed that industrial and agricultural pollution sources could be responsible for the Anzali Wetland water quality. Then, the spatial variation maps of the PCA scores were generated using Kriging geostatistical method in the geographical information system (GIS) to investigate the pollution sources affecting the wetland parts. These maps illustrated that a great part of the wetland body was under the effect of agricultural sources, while the industrial sources affected the outlet and central parts. Finally, a comparison between two models (multiple linear regression (MLR) and Kriging) was made to assess their ability in predicting water quality parameters in the study area. The results showed the improvement of prediction using MLR, which was by 25%–97%, compared with Kriging. The results of the present study can be effectively used in the planning and implementation of future monitoring networks in the Anzali Wetland and other similar aquatic systems.

Dynamic oil release from oil-contaminated sediment to seawater was investigated in kinetic and factor experiments. Oil-release kinetic was described using a two-compartment first-order equation with rapid- and slow-release steps. The rapid-desorption-fraction rate (kᵣ) was not affected by the ratio of solid-liquid, but significantly affected by sediment pollution level and salinity. The slow-desorption-fraction rate constant (kₛ) was affected by sediment pollution level, the ratio of solid-liquid, and salinity. Desorption efficiencies were 1.09–4.04%, increasing as the sediment pollution level and salinity increased and the ratio of solid-liquid decreased. Oil desorption was critically affected by sediment suspension (or lack of). The desorption kinetics curves were unaffected with the shear force for unsuspended sediment, and the desorption efficiency and kᵣ were increasing with the shear force for suspended sediment, and no significant correlations were found between kₛ and hydrodynamic conditions. The results provide a theoretical basis for evaluating ecological risks posed by oil in sediment.

Trimethylamine (TMA) is an odorous volatile organic compound emitted by industries. Algal-based biotechnologies have been proven as a feasible alternative for wastewater treatment, although their application to abate polluted air emissions is still scarce. This work comparatively assessed the removal of TMA in a conventional bacterial bubble column bioreactor (BC) and a novel algal-bacterial bubble column photobioreactor (PBC). The PBC exhibited a superior TMA abatement performance compared to the conventional BC. In this sense, the BC reached a removal efficiency (RE) and an elimination capacity (EC) of 78% and 12.1 g TMA m⁻³ h⁻¹, respectively, while the PBC achieved a RE of 97% and a EC of 16.0 g TMA m⁻³·h⁻¹ at an empty bed residence time (EBRT) of 2 min and a TMA concentration ~500 mg m⁻³. The outstanding performance of the PBC allowed to reduce the operating EBRT to 1.5 and 1 min while maintaining high REs of 98 and 94% and ECs of 21.2 and 28.1 g m⁻³·h⁻¹, respectively. Moreover, the PBC improved the quality of the gas and liquid effluents discharged, showing a net CO₂ consumption and decreasing by ~ 30% the total nitrogen concentration in the liquid effluent via biomass assimilation. A high specialization of the bacterial community was observed in the PBC, Mumia and Aquamicrobium sp. being the most abundant genus within the main phyla identified. GraphicalAbstract

Climate change has become a threatening issue for major field crops of Pakistan, especially rice. A 2 years’ (2014 and 2015) field trial was conducted on fine, coarse, and hybrid rice at Research Area, Department of Agronomy, University of Agriculture, Faisalabad following the split-plot design. Data of growth, yield, and yield components were collected to calibrate and evaluate the CERES-Rice model under Decision Support System for Agro-technology Transfer (DSSAT). Two cultivars of each type of fine, coarse, and hybrid rice were transplanted with interval of fortnight from May to September during 2014 and 2015. The model was calibrated with non-stressed sowing data during the year 2014 and evaluated with the data of 2015. Climate change scenarios were generated for mid-century (2040–2069) under representative concentration pathway (RCP8.5) using different general circulation models (GCMs) (baseline, cool dry, hot dry, cool wet, hot wet, and middle) were using different General Circulation Models (GCMs). CERES-Rice calibration and evaluation results were quite good to simulate impacts of climate change and to formulate adaptations during 2040–2069 (mid-century). Simulations of all GCMs showed an average increase of 3 °C in average temperature as compared to baseline (1980–2010). Likewise, there would be an average increase of 107.6 mm in rainfall than baseline. The future rise in temperature will reduced the paddy yield by 10.33% in fine, 18–54% in coarse and 24–64% in hybrid rice for mid-century under RCP8.5. To nullified deleterious effects of climate change, some agronomic and genetics adaptation strategies were evaluated with CERES-rice during mid-century. Paddy yield of fine rice was increased by 15% in cool dry and 5% in hot dry GCM. Paddy yield of coarse rice was improved by 15% and 9% under cool dry and hot dry climatic conditions, respectively, with adaptations. For hybrid rice, paddy yield was enhanced by 15% and 0.3% with cool wet and hot dry climatic conditions, respectively. Hot dry climatic conditions were the most threatening for rice crop in rice producing areas of Punjab, Pakistan.

Evaluation of geogenic carbon fluxes between solid Earth and its atmosphere is essential to understand the global geological carbon cycle. Some of the key geogenic CO₂ suppliers are the magmatic mantle and metamorphic degassing from active and quiescent volcanoes, fault zones, geothermal systems and CO₂ rich groundwater. Indian Himalayan geothermal field hosts about 340 geothermal springs in natural as well as artesian condition that eject hot waters and volatiles with varied temperature and chemical composition. These sites provide an opportunity to analyse tectonically driven gas emissions and their impact on regional and global climate. Here we adopt a method for direct measurement of Dissolved Inorganic Carbon (DIC ≈ HCO₃) concentration in the geothermal springs to estimate geogenic CO₂ flux from an active region based on water discharge and area of geothermal system between the tectonic boundaries of the Main Central Thrust (MCT) and Main Boundary Thrust (MBT) of the Garhwal (Northwest) Himalaya. In the study area, geothermal spring water contain high δ¹³CDIC ratio (− 8.5‰ to + 4.0‰ VPDB), and among the major ions, bicarbonate (HCO₃⁻) varies by an order of magnitude from 1697 to 21,553 μEq/L; chloride and sodium vary from 90 to 19,171 μEq/L and 436 to 23181 μEq/L. The elevated concentration of Cl⁻ and Na⁺ in geothermal spring waters suggests affinity towards their deeper origin. These geothermal springs cover a large area of nearly 10,000 km² of the Garhwal region showing a significant discharge of CO₂ rich water with an estimated carbon dioxide degassing flux of ~7.2 × 10⁶ mol/year to the atmosphere. Considering widespread occurrences of geothermal springs in tectonically active areas worldwide, the proposed direct measurement of DIC may be used as a reliable tool to estimate CO₂ fluxes in different active orogenic settings within the Earth system. Results of stable isotopes of δ¹⁸O ₍VSMOW₎ and δD ₍VSMOW₎ in these geothermal spring waters follow the Global Meteoric Water Line (GMWL), suggesting affinity of their recharge through the meteoric origin.

Hepatocellular carcinoma (HCC), a common type of human malignancies, leads to increasing incidence and fairly high mortality. An increasing number of studies have verified that long noncoding RNAs (lncRNAs) played key roles in the development of multiple human cancers. As a biomarker, SLC16A1-AS1 has been reported in non-small cell lung cancer (NSCLC) and oral squamous cell carcinoma (OSCC). Thus, we decided to investigate whether SLC16A1-AS1 exerts its biological function in HCC. In this study, we discovered that SLC16A1-AS1 was obviously downregulated in HCC tissues and cells. Overexpression of SLC16A1-AS1 inhibited HCC cell proliferation, invasion, and epithelial-mesenchymal transition (EMT) process as well as promoted cell apoptosis. Moreover, SLC16A1-AS1 was confirmed to enhance the radiosensitivity of HCC cells. Molecular mechanism exploration suggested that SLC16A1-AS1 served as a sponge for miR-301b-3p and CHD5 was the downstream target gene of miR-301b-3p in HCC cells. Rescue assays implied that CHD5 knockdown could recover the effects of SLC16A1-AS1 overexpression on HCC cellular processes. In brief, our study clarified that SLC16A1-AS1 acted as a tumor suppressor in HCC by targeting the miR-301b-3p/CHD5 axis, which may be a promising diagnostic biomarker and provide promising treatment for HCC patients.

The composition of lipids in soil offers clues to soil degradation processes due their persistency and selectivity in soil, and close relation to long-term processes in the ecosystem, thanks to their role in cell membranes of organisms. Organic solvent-extractable compounds were recovered from soils collected at two sites differing in the degree of forest damage. Gas chromatography/mass spectroscopy and Fourier transform infrared spectroscopy were applied in order to characterize solvent-extractable lipids. Raman spectroscopy was also applied as it provides distinct advantages for determining the structural order of carbonaceous materials. The organic matter measurement techniques were combined with an established simultaneous multi-element measurement technique. Variations in individual soil horizons from the sites were reflected in the crystallinity of epicuticular waxes, presence of long-chain aliphatic hydrocarbons, concentrations of n-alkanes, saturated and unsaturated fatty acids, dicarboxylic acids, and in the content of aromatic structures, hydroxyl, ester, and carboxylic acid groups. The results are explained by differently transformed organic matter. The concentrations of elements in the soils were also affected by atmospheric depositions, including higher accumulations of arsenic and antimony, and lower contents of natural nutrients. These data have potential to be used as sensitive biogenic indicators of ecosystem damage by long-term atmospheric depositions.

Vanadium (V) pollution in soil has been widely noted, while knowledge about the effect of soil colloid on migration of V is scarce. Batch adsorption-desorption and transportation of the colloid-adsorbed V in columns packed with quartz sand under various environment conditions were carried out to explore the retention and transportation of V by colloidal kaolinite. Batch adsorption-desorption studies show that the adsorption of V by the colloidal kaolinite was mainly specific adsorption and redox played a limited role in the adsorption process. The maximum adsorption capacity of the colloidal kaolinite was 712.4 mg g⁻¹, and about 5.9–8.7% of the adsorbed V could be desorbed. Both the adsorption-desorption and migration of V with colloidal kaolinite were highly ambient condition dependent. The column studies show that V was highly mobile in the saturated porous media. An easier transfer of V with an increase in pH, IS, and velocity of flow was noted. However, the increase of IS lead to the blockage of the colloidal kaolinite transportation. The recovery rate of the colloidal kaolinite at pH 7 and 9 was 2.0 and 2.1 times that at pH 5, respectively. The migration of colloidal-adsorbed V in sand column preceded that of V ion, but more colloidal-bound V than V ion remained in the column. Lack of consideration of the combination and co-transportation of V and colloidal kaolinite will lead to an overestimation of the risk of V to deeper soil profiles and groundwater. Graphical abstract