Rajasthan is one of the main mineral potential state of India. During the last 30 years it has witnessed enormous expansion of mining industries, but mining of most of the minor minerals coupled with changing climate has posed serious problems to the environmental fabric in the state, apart from base metal beneficiation plants. Groundwater is also being polluted day-by-day by effluents generated from mineral wastes and beneficiation processes in the vicinity of mining sites such as Khetri. Pollutant concentrations were measured in groundwater at the vicinity of Khetri copper mining project, Rajasthan to investigate the influence of copper mining on environment. Pollutant concentrations in groundwater were investigated. Copper metal concentration in water samples were found above the maximum desirable limit in two sources: G4 and G5, due to washing away of mineral with water. Mining industry has deteriorated quality of groundwater resources in the state of Rajasthan, and these industries are becoming centers of pollution sources which need timely actions at government level so that natural resources such as groundwater can be protected.

A student-centric research education program with the active participation of undergraduate students is initiated. The aim is to imbibe ―responsible citizenship behavior‖ in them so that each member becomes conscious and well trained to take up environmental-related issues and challenges for long-term sustainability of the ecosystem. In this work, we report spectrophotometer-based estimation of hexavalent chromium (57-268 gL-1) and lead (34–158 gL-1) concentrations in different surface waters and groundwater samples in and around the city of Hyderabad, India. Our results indicate that the studied surface water bodies and aquifers are contaminated to variable degrees and pose a serious threat to the ecosystem. In view of low geochemical baseline values for chromium and lead, the origin of heavy metal pollution is inferred to be anthropogenic, mainly originating from industrial effluents. The toxicological data are integrated with health data for risk assessment and impending health hazard. Finally, the novelty of this student-centric research program is highlighted.

Climatic condition, geology, and geochemical processes in an area play a major role on groundwater quality. Impact of these on the fluoride content of groundwater was studied in three regions-part of Nalgonda district in Telangana, Pambar River basin, and Vaniyar River basin in Tamil Nadu, southern India, which experience semi-arid climate and are predominantly made of Precambrian rocks. High concentration of fluoride in groundwater above 4 mg/l was recorded. Human exposure dose for fluoride through groundwater was higher in Nalgonda than the other areas. With evaporation and rainfall being one of the major contributors for high fluoride apart from the weathering of fluoride rich minerals from rocks, the effect of increase in groundwater level on fluoride concentration was studied. This study reveals that groundwater in shallow environment of all three regions shows dilution effect due to rainfall recharge. Suitable managed aquifer recharge (MAR) methods can be adopted to dilute the fluoride rich groundwater in such regions which is explained with two case studies. However, in deep groundwater, increase in fluoride concentration with increase in groundwater level due to leaching of fluoride rich salts from the unsaturated zone was observed. Occurrence of fluoride above 1.5 mg/l was more in areas with deeper groundwater environment. Hence, practicing MAR in these regions will increase the fluoride content in groundwater and so physica or chemical treatment has to be adopted. This study brought out the fact that MAR cannot be practiced in all regions for dilution of ions in groundwater and that it is essential to analyze the fluctuation in groundwater level and the fluoride content before suggesting it as a suitable solution. Also, this study emphasizes that long-term monitoring of these factors is an important criterion for choosing the recharge areas.

Sewage treatment plants (STPs) are considered as “hotspots” for the emergence and proliferation of antibiotic resistance. However, the impact of heavy metals contamination on dispersal of antibiotic resistance in STPs is poorly understood. This study simultaneously investigated the effect of removal of metal and antibiotic resistance as well as mobile elements at different treatment units of STPs in Delhi, India. Results showed that treatment technologies used in STPs were inefficient for the complete removal of metal and antibiotic resistance, posing an ecological risk of co-selection of antibiotic resistance. The strong correlations were observed between heavy metals, metal and antibiotic resistance, and integrons, implying that antibiotic resistance may be exacerbated in the presence of heavy metals via integrons, and that metal and antibiotic resistance share a common or closely associated mechanism. We quantified an MRG rcnA, conferring resistance to Co and Ni, and identified that it was more abundant than all MRGs, ARGs, integrons, and 16S rRNA, suggesting rcnA could be important in antibiotic resistance dissemination in the environment. The associations between heavy metals, metal and antibiotic resistance, and integrons highlight the need for additional research to better understand the mechanism of co-selection as well as to improve the removal efficacy of current treatment systems.

Amoxicillin (AMO) and amikacin (AMK) are broad-spectrum antibiotics that are most preferably given post-delivery (normal and cesarian) in the maternity hospitals located in Sagar city (Madhya Pradesh), India. Both the antibiotics make their way through sewage/drainage systems into the environment in the form of metabolized and unmetabolized compounds. Growing concern about the contamination of wastewater by antibiotics requires fast, sensitive and eco-friendly techniques. Therefore a simple, rapid and environmental friendly chromatographic method has been developed for simultaneous determination of AMO and AMK in maternity hospital wastewater samples. A micellar liquid chromatographic (MLC) method was developed with a C₁₈ column (250 mm × 4.6 mm), sodium dodecyl sulphate (SDS; 0.15 M), 1-butanol (7%) as a modifier, pH 5 and photo diode detector (PDA) at 270 nm and 256 nm for AMO and AMK respectively. The method was fast with analysis time below 9 min. In the present MLC method, linearities (r > 0.998), limits of quantification in the range of 0.02–0.04 μg/mL, repeatabilities, and intermediate precision below 4.9% were adequate for the quantification of AMO and AMK. The proposed method can be utilized to detect and quantify both the antibiotics in various samples by hospitals, pharmaceutical companies, pollution control board, municipal corporations, etc.

Six years of data (2012–2017) at an urban site-Srinagar in the Northwest Himalaya were used to investigate temporal variability, meteorological influences, source apportionment and potential source regions of BC. The daily BC concentration varies from 0.56 to 40.16 μg/m³ with an inter-annual variation of 4.20–7.04 μg/m³ and is higher than majority of the Himalayan urban locations. High mean annual BC concentration (6.06 μg/m³) is attributed to the high BC observations during winter (8.60 μg/m³) and autumn (8.31 μg/m³) with a major contribution from Nov (13.88 μg/m³) to Dec (13.4 μg/m³). A considerable inter-month and inter-seasonal BC variability was observed owing to the large changes in synoptic meteorology. Low BC concentrations were observed in spring and summer (3.14 μg/m³ and 3.21 μg/m³), corresponding to high minimum temperatures (6.6 °C and 15.7 °C), wind speed (2.4 and 1.6 m/s), ventilation coefficient (2262 and 2616 m²/s), precipitation (316.7 mm and 173.3 mm) and low relative humidity (68% and 62%). However, during late autumn and winter, frequent temperature inversions, shallow PBL (173–1042 m), stagnant and dry weather conditions cause BC to accumulate in the valley. Through the observation period, two predominant diurnal BC peaks were observed at ⁓9:00 h (7.75 μg/m³) and ⁓21:00 h (6.67 μg/m³). Morning peak concentration in autumn (11.28 μg/m³) is ⁓2–2.5 times greater than spring (4.32 μg/m³) and summer (5.23 μg/m³), owing to the emission source peaks and diurnal boundary layer height. Diurnal BC concentration during autumn and winter is 65% and 60% higher than spring and summer respectively. During autumn and winter, biomass burning contributes approximately 50% of the BC concentration compared to only 10% during the summer. Air masses transport considerable BC from the Middle East and northern portions of South Asia, especially the Indo-Gangetic Plains, to Srinagar, with serious consequences for climate, human health, and the environment.