Identification of environmental stress parameters to study the natural colour change of water in highly saline inland Crater Lake at Lonar, India.

Lonar Lake is a highly saline inland water body created by a crater in Maharashtra, India. A rare occurrence of the colour change of lake water from green to brown and eventually to pinkish-red was observed in Lonar in June 2020. This phenomenon attracted the attention of researchers, academicians and interestingly legal fraternity to understand the causes of colour change. The literature studies coupled the phenomenon of colouration of water to three aspects: the presence of halophilic Halobacterium salinarum or an algal species of Dunaliella (Dunaliella salina) or oxidization of metals (Fe and Mn) present in water. A comprehensive study was done to understand and assess the change in the colour of Lonar Lake water. The green colour of the lake is primarily due to the dominance of chlorophyll-a pigment in the algae population. The stressed condition in June 2020 adversely affected the photosynthesis activity of Dunaliella sp. resulting in the red colouration of the species. This red colour of Dunaliella sp. is due to the formation of a pigment named carotenoid which is similar to that in halophilic bacteria. This pigment completely hides the green chloroplast, and water turns pinkish-red. This study describes detailed investigations of environmental and climatic parameters to determine possible causes of abiotic stress on the algae population of the lake. The major factors contributing to the stressed conditions are high dissolved solids, alkalinity and alkaline pH due to salts in the lake water due to evaporation losses and limited rainfall over the months. The study further verified whether the colour change is a cyclic event and predicted possible lake conditions for the event of colour change to occur in the future.

Evaluation of pathogen risks using QMRA to explore wastewater reuse options: A case study from New Delhi in India.

Selecting appropriate reuse for treated wastewater is a challenge. The current investigation outlines the utilization of quantitative microbial risk assessment (QMRA) to assist Effluent Treatment Plant (ETP) management to determine the best-possible reuse of treated wastewater from 11 ETPs in Delhi. Four representative pathogens: pathogenic Escherichia coli spp., Salmonella spp., Cryptosporidium spp. and Giardia spp. were selected to characterize microbial water quality. Reuse options selected based on the survey and interaction with ETP managers include crop irrigation, garden irrigation, toilet flush and industrial applications. The probability of infection was characterized for two exposure groups: workers and children. Water quality monitoring indicates the occurrence of pathogenic E. coli spp. (100%), Salmonella spp. (63%), Cryptosporidium spp. (81%) and Giardia spp. (45%) in the treated wastewater. QMRA reveals the annual median-probability of infection above acceptable limits for pathogenic E. coli spp., Cryptosporidium spp. and Salmonella spp. The probabilities of Giardia-associated infections were low. Adults showed a 1.24 times higher probability of infection compared to children. Sensitivity analysis indicated pathogen concentration as the most critical factor. The study highlights that the existing plans for chlorination-based treatment technology may prove insufficient in reducing the risk for selected reuse options; but, alternate on-site control measures and up-grading water reuse protocol may be effective.

A Review of Recently Developed LC-MS/MS Methods for the Analysis of Pharmaceuticals and Personal Care Products in Water.

BACKGROUND: Pharmaceuticals and personal care products (PPCPs) are present in the environment in trace concentrations. These compounds may cause health hazards to human beings and animals. The concerns related to their existence has led to development of a number of sensitive, accurate, and robust analytical methods. OBJECTIVE: This article aims to review the recently developed chromatography-MS-based methods for the analysis of PPCPs in varied aqueous matrices and also presents a brief overview of the current status of PPCPs in the Indian aquatic environment. METHODS: It demonstrates existing and recent trends in sampling, sample preparation techniques, and instrumentation methods for estimation of PPCPs in water. RESULTS: Solid-phase extraction is found to be the most commonly used sample preparation technique, and LC-tandem MS (MS/MS; with electrospray ionization) is the most extensively used instrumentation technique for the analysis of PPCPs. CONCLUSIONS: The analytical methods reviewed here provide a detailed overview of the procedures for detection and quantification of PPCPs in water. These methods are useful for monitoring these compounds in environmental matrices and facilitate risk assessment studies. HIGHLIGHTS: This paper reviews the analytical methods for estimation of PPCPs in aquatic environmental matrices and presents their comprehensive evaluation.

Nitrate in drinking water and vegetables: intake and risk assessment in rural and urban areas of Nagpur and Bhandara districts of India.

The study focuses on the estimation of health risk from nitrate present in the drinking water and vegetables in Nagpur and Bhandara districts in the state of Maharashtra, India. Drinking water samples from 77 locations from the rural as well as urban areas and 22 varieties of vegetable were collected and analyzed for the presence of nitrate for a period of 1 year (two seasons). The daily intake of nitrate from these water and vegetable samples was then computed and compared with standard acceptable intake levels to assess the associated health risk. The mean nitrate concentration of 59 drinking water samples exceeded the Bureau of Indian Standards limit of 45 mg/L in drinking water. The rural and urban areas were found to have mean nitrate concentration in drinking water as 45.69 ± 2.08 and 22.53 ± 1.97 mg/L, respectively. The estimated daily intake of drinking water samples from 55 study sites had nitrate concentration far below the safety margin indicating serious health risk. The sanitation survey conducted in 12 households reported contaminated source with positive E. coli count in 20 samples as the major factor of health risk. The average nitrate concentration was maximum in beetroot (1349.38 mg/kg) followed by spinach (1288.75 mg/kg) and amaranthus (1007.64 mg/kg). Among the samples, four varieties of the vegetables exceeded the acceptable daily intake (ADI) with an assumption of 0.5 kg consumption of vegetables for an average of a 60-kg individual. Therefore, irrigation of these locally grown vegetables should be monitored periodically for nitrogen accumulation by the crop above the ADI limit. The application of nitrogenous fertilizers should also be minimized in the rural areas to help protect the nitrate contamination in groundwater sources.

Access to Household Water Quality Information Leads to Safer Water: A Cluster Randomized Controlled Trial in india.

Household-specific feedback on the microbiological safety of drinking water may result in changes to water management practices that reduce exposure risks. We conducted a randomized, controlled trial in India to determine if information on household drinking water quality could change behavior and improve microbiological quality as indicated by Escherichia coli counts. We randomly assigned 589 participating households to one of three arms: (1) a messaging-only arm receiving messaging on safe water management ( n = 237); (2) a standard testing arm receiving the same messaging plus laboratory E. coli testing results specific to that household's drinking water ( n = 173); and (3) a test kit arm receiving messaging plus low-cost E. coli tests that could be used at the household's discretion ( n = 179). Self-reported water treatment increased significantly in both the standard testing arm and the test kit arm between baseline and follow-up one month later. Mean log10 E. coli counts per 100 mL in household stored drinking water increased in the messaging-only arm from 1.42 to 1.87, while decreasing in the standard testing arm (1.38 to 0.89, 65% relative reduction) and the test kit arm (1.08 to 0.65, 76% relative reduction). Findings indicate that household-specific water quality information can improve both behaviors and drinking water quality.

The risk of cancer as a result of elevated levels of nitrate in drinking water and vegetables in Central India.

The objective of the present study was to determine the effect of nitrates on the incidence of gastrointestinal (GI) cancer development. Nitrate converted to nitrite under reducing conditions of gut results in the formation of N-nitrosamines which are linked to an increased gastric cancer risk. A population of 234 individuals with 78 cases of GI cancer and 156 controls residing at urban and rural settings in Nagpur and Bhandara districts of India were studied for 2 years using a case-control study. A detailed survey of 16 predictor variables using Formhub software was carried out. Nitrate concentrations in vegetables and primary drinking water supplies were measured. The logistic regression model showed that nitrate was statistically significant in predicting increasing risk of cancer when potential confounders were kept at base level (P value of 0.001 nitrate in drinking water; 0.003 for nitrate in vegetable) at P < 0.01. Exposure to nitrate in drinking water at >45 mg/L level of nitrate was associated with a higher risk of GI cancers. Analysis suggests that nitrate concentration in drinking water was found statistically significant in predicting cancer risk with an odds ratio of 1.20.

Optimization of a Modified QuEChERS Method for Multiresidue Analysis of Pharmaceuticals and Personal Care Products in Sewage and Surface Water by LC-MS/MS.

A quick, sensitive multiresidue method was developed for the analysis of 19 multiclass pharmaceuticals and personal care products (PPCPs) in surface water and sewage water. The proposed modified QuEChERS method involved the extraction of water samples (10 mL) with acetonitrile (10 mL) after the addition of 1% acetic acid, 4 g magnesium sulfate, and 0.2 g ammonium acetate, and was validated in distilled water, surface water, and sewage water with respect to linearity, LOD and LOQ, precision, and accuracy. The LOD and LOQ varied within the ranges of 0.001-0.167 and 0.002-0.25 ng/mL, respectively. Recoveries of the target compounds ranged from 73 to 125%, with precision RSD values <27%. The method provided a precise estimation of PPCPs in field samples, and acetaminophen, atenolol, metformin, sulfamethoxazole, carbamazepine, methylparaben, and triclosan were detected in concentrations ranging from 0.10 to 1.40 and 0.10 to 3.4 ng/mL in surface water and sewage water, respectively. This is an innovative application of the QuEChERS approach for estimation of PPCPs from aqueous matrixes. The method provides significantly higher output (preparation of 25-30 samples a day) compared to conventional SPE-based methods (<10 samples a day).

Design and development of sustainable remediation process for mitigation of fluoride contamination in ground water and field application for domestic use.

Decentralised household chemo defluoridation unit (CDU) was developed and designed based on a combination of coagulation and sorption processes. Chemo-defluoridation process was optimised to reduce use of chemicals and increase acceptability among beneficiaries without affecting palatability of water. Chemical dose optimization undertaken in the laboratory using jar test revealed the optimum calcium salt to initial fluoride ratio of 60 for fluoride removal. Performance of CDU was evaluated in the laboratory for removal efficiency, water quality parameters, filter bed cleaning cycle and desorption of fluoride. CDU evaluation in the laboratory with spiked water (5 mg/L) and field water (~4.2 mg/L) revealed treated water fluoride concentration of less than 1mg/L. Seventy five CDUs were installed in households at Sakhara Village, Yavatmal District in Maharashtra State of India. Monthly monitoring of CDUs for one year indicated reduction of the raw water fluoride concentration from around 4 mg/L to less than 1mg/L. Post implementation survey after regular consumption of treated drinking water by the users for one year indicated user satisfaction and technological sustainability.

Healthcare facility effluents as point sources of select pharmaceuticals to municipal wastewater.

Effluents from four healthcare facilities were characterized for the concentration of 16 common active pharmaceutical ingredients. The sampled facilities included a hospital, nursing care, assisted living, and independent living facility located within a single municipal wastewater system in Texas. Eleven of the 16 monitored pharmaceuticals were detected in at least 1 healthcare facility effluent and 2 measured antibiotics (sulfamethoxazole and trimethoprim) were detected in all 4 facility effluents. Active pharmaceutical ingredient concentrations ranged from non-detectable levels for several corticosteroids in all facility effluents to 180 microg/L sulfamethoxazole in the nursing care wastewater effluent. The mass of active pharmaceutical ingredients discharged to the municipality's wastewater conveyance system was determined by combining individual facility concentration data and daily wastewater flow. The estimated daily mass loading of all 16 pharmaceuticals ranged from 0.16 g/day to 23 g/day in the assisted living facility and nursing wastewater effluents, respectively. The combined active pharmaceutical ingredient mass loading for all four facilities was 42.6 g/day. These findings provide source characterization data for 16 common pharmaceuticals in healthcare facility wastewater and provide a basis for risk assessment of pharmaceuticals present in healthcare facility wastewaters.

Advanced oxidation of alkylphenol ethoxylates in aqueous systems.

Alkylphenols and alkylphenol ethoxylates are ubiquitous wastewater contaminants. In this study the oxidation of nonylphenol ethoxylates (NPEO) and octylphenol ethoxylates (OPEO) by oxidant systems generating hydroxide radicals was evaluated. The reaction of each oxidant with a technical mixture of NPEO (Tergitol™) and OPEO (Triton X-100™) in ultrapure laboratory water and four aqueous environmental matrices was carried out in order to develop an understanding of reaction kinetics. The oxidation of APEOs was evaluated by hydroxyl radical generated by (1) hydrogen peroxide in the presence of ultraviolet light, (2) Fenton's reagent, and (3) a photo-Fenton's process. The second order kinetic rate constant for both NPEO and OPEO with hydroxyl radical was calculated to be 1.1×10¹° M⁻¹ s⁻¹. The efficacy of the AOPs within an aqueous environmental matrix was dependent on the rate of formation of hydroxyl radical and the scavenging capacity of the matrix. A model based on the hydroxyl radical formation, scavenging capacity and the kinetic rate constant of target APEO was developed from the existing literature and applied to predict the concentration of APEOs in solution during advanced oxidation in different aqueous environmental matrices.

Source characterization of nervous system active pharmaceutical ingredients in healthcare facility wastewaters.

Nervous system active pharmaceutical ingredients (APIs), including anti-depressants and opioids, are important clinically administered pharmaceuticals within healthcare facilities. This study provides source characterization data describing the composition and magnitude of nervous system APIs present in healthcare facility wastewaters. Concentrations and mass loadings of ten nervous system APIs and three nervous system API metabolites are reported for wastewaters from a hospital, nursing, assisted living, and independent living facility within a single municipality. Concentrations of nervous system APIs ranged from non-detectable levels for alprazolam in all four facility wastewaters to a high of 290 ng/L amitriptyline in nursing facility wastewater. The summed mean concentration of all thirteen analytes ranged from 402 ng/L in independent living facility wastewater to 624 ng/L in assisted living facility wastewater. Wastewater flow rates from each facility were combined with concentration data to estimate the daily mass loading of nervous system APIs leaving each facility through wastewater discharge to the municipal sewer system. The total mass loading of all thirteen analytes for the hospital, nursing, assisted living, and independent living facility was 228, 44, 29.5, and 28.1 mg/day, respectively. The total mass loading of nervous system APIs contributed to the municipality's wastewater from all four facilities was 330 mg/day.

Concentrations and mass loadings of cardiovascular pharmaceuticals in healthcare facility wastewaters.

Healthcare facilities are an under-characterized source of pharmaceuticals to municipal wastewaters. In this study, the composition and magnitude of sixteen cardiovascular active pharmaceutical ingredients (APIs) and two cardiovascular API metabolites in wastewater effluents from a hospital, nursing care, assisted living, and independent living facility are presented. Each cardiovascular API was detected in at least one facility's wastewater. The hospital's wastewater had the most detected cardiovascular APIs with thirteen of the eighteen measured compounds positively confirmed and quantified. Maximum mean analyte concentrations within each healthcare facility's wastewater were: 11.3 µg L(-1) atenolol for the independent living facility; 8.7 µg L(-1) valsartan for the assisted living facility; 2.7 µg L(-1) diltiazem for the nursing home facility; and 14.6 µg L(-1) valsartan for hospital facility. Daily wastewater flow was combined with individual concentrations to estimate the cardiovascular API mass loadings leaving each facility through wastewater discharges to the municipal sewer system. The estimated daily mass loading of all measured cardiovascular APIs ranged from 0.87 g per day at the assisted living facility to 12.5 g per day at the hospital. The combined loading for all four facilities was 16.2 g per day. This presented research informs the risk management process by providing source characterization data for healthcare facility wastewaters containing commonly prescribed cardiovascular APIs.