Assessing seasonal fluctuations in leachate chemical properties and leachate pollution index as contamination indicators.

Municipal solid waste (MSW) management practices that lack scientific rigor and use impromptu methods have produced massive leachate in urban complexes. Nowadays, the management of leachate has become an utmost concern worldwide. The MSW landfill site was a low-lying, open dump that operated in a non-engineered way. In this context, the physicochemical characterization of leachate has been carried out. Leachate sampling was done at the Bhandewadi dumpsite, Nagpur, for three seasons (summer, rainy, and winter). During analysis, parameters such as COD, BOD5, pH, TKN, TSS, sulfates, and chlorides were analyzed, and the obtained data was compared with the standard EPA 2003 and CPHEEO 2016 methods. Values of COD, BOD5, TKN, sulfates, and chlorides were in the range of 2500-16,000 mg/L, 495-2500 mg/L, 167-1900 mg/L, 240-900 mg/L, and 1400-5900 mg/L with respect to all three seasons, respectively. In conjunction with physicochemical analysis, the landfill leachate's leachate pollutant index (LPI) was assessed. The highest LPI values were observed for summer (14.323) as compared to rainy (12.301) and winter (11.348) data. This index reflects the hazardous character of MSW leachate and the total potential for leachate contamination. The results of this study showed seasonal variations in the observed data. Age and seasonal fluctuations therefore substantially influence the composition of the leachate.

Nutrient optimization for indigenous microbial consortia of a Bhagyam oil field: MEOR studies.

The microbial enhanced oil recovery (MEOR) method is an eco-friendly and economical alternative technology. The technology involves a variety of uncertainties, and its success depends on controlling microbial growth and metabolism. This study is one of a kind that showed successful tertiary recovery of crude oil through indigenous microbial consortia. In this study, a medium was optimized to allow ideal microbial growth under reservoir conditions through RSM. Once the nutrient recipe was optimized, the microbial metabolites were estimated through gas chromatography. The maximum amount of methane gas (0.468 mM) was produced in the TERIW174 sample. The sequencing data set showed the presence of Methanothermobacter sp. and Petrotoga sp. In addition, these established consortia were analyzed for their toxicity, and they appeared to be safe for the environment. Furthermore, a core flood study showed efficient recovery that was ~25 and 34% in TERIW70 and TERIW174 samples, respectively. Thus, both the isolated consortia appeared to be suitable for the field trials.

Emerging environmental contaminants: A global perspective on policies and regulations.

Emerging contaminants include many synthetic or natural substances, such as pharmaceuticals and personal care products, hormones, and flame retardants that are not often controlled or monitored in the environment. The consumption or use of these substances is on an ever-rising trend, which dangerously increases their prevalence in practically all environmental matrices. These contaminants are present in low environmental concentrations and cause severe effects on human health and the biota. The present review analyzed 2012-2022 years papers via PubChem, science direct, National Center for Biotechnology Information, web of science on the legislations and policies of emerging contaminants globally. A state-of-the-art review of several studies in the literature focus on examining and evaluating the emerging contaminants and the frameworks adopted by developed and developing countries to combat the release of emerging contaminants and form footprints towards water sustainability which includes water availability, usage patterns, generation and pollution management, the health of aquatic systems, and societal vulnerability. The paper aims to provide a comprehensive view of current global policies and framework regarding evaluating and assessing the chemicals, in light of being a threat to the environment and biota. The review also highlights the future global prospects, including current governmental activities and emerging contaminant policy measures. The review concludes with suggestions and way forward to control the inventory and disposal of emerging contaminants in the environment.

The occurrence, fate, toxicity, and biodegradation of phthalate esters: An overview.

Phthalate esters (PAEs) are a class of emerging xenobiotic compounds that are extensively used as plasticizers. In recent times, there has been an increasing concern over the risk of this pervasive pollution exposure causing endocrine disruption and carcinogenicity in humans and animals. The widespread use of PAEs in home and industrial applications has resulted in their discharge in aquatic bodies via leaching, volatilization, and precipitation. In this overview, the current state of PAE pollution, its potential origins, its fate, as well as its effects on the aquatic environment are discussed. A state-of-the-art review of several studies in the literature that focus on the biological degradation of PAEs is included in this study. The paper aims to provide a comprehensive view of current research on PAEs in the environment, highlighting its fate and alleviated risks on the aquatic biotas, their challenges, future prospects, and the need for good management and policies for its remediation. PRACTITIONER POINTS: Occurrence of phthalate esters was summarized in various environmental matrices along with its serious ecotoxicological implications on biota. Wastewater is the prime source of PAEs contamination. Lack of species-specific effects on biota due to dose, exposure route, and susceptibility. The predominant route to mineralization in PAEs is biodegradation. A critical analysis of worldwide PAE production and consumption identifies the necessity for global PAE production, consumption, and release policies.

Changes in HIV care continuum indicators among community-based samples of HIV-infected people who inject drugs and men who have sex with men across 21 cities in India.

Monitoring key populations' progress towards UNAIDS 90-90-90 targets is essential to achieving HIV/AIDS epidemic control. Using serial cross-sectional data, we evaluated changes in HIV care continuum among people who inject drugs(PWID) and men who have sex with men(MSM) in India. Cross-sectional baseline (2012/2013) and follow-up (2016/2017) samples were recruited using respondent-driven sampling across 21 cities. All participants were tested for HIV and RNA measured in HIV-positive participants. Linear regression was used to model temporal site-level changes in continuum indicators in MSM versus PWID. At baseline, we recruited 2,544 HIV-infected PWID and 1,086 HIV-infected MSM. At follow-up, we recruited 2,517 HIV-infected PWID and 1,763 HIV-infected MSM. At baseline, there were no significant differences in continuum indicators between MSM and PWID. At follow-up, compared to PWID, the proportion of MSM reaching each care continuum indicator-awareness of status, receipt of care, ART use, viral suppression-increased by 15-33 percentage points: 78% of MSM versus 49% of PWID were aware of their status (p < 0.01); 56% of MSM versus 32% of PWID were virologically suppressed (p = 0.05). MSM showed marked improvements across the care continuum, whereas PWID lagged and may require additional intervention. Differential improvement in HIV engagement may necessitate population-specific interventions and routine surveillance to facilitate HIV elimination.

HIV, hepatitis B & C in people who inject drugs in India: A systematic review of regional heterogeneity & overview of opioid substitution treatment.

BACKGROUND OBJECTIVES: This systematic review evaluates the human immunodeficiency virus (HIV), hepatitis C virus (HCV) and hepatitis B virus (HBV) burden among people who inject drugs (PWIDs) in India. In addition, we selectively examined research on opioid substitution treatment (OST)-related services due to their role in antiviral treatment uptake and adherence. METHODS: Data were sourced from peer-reviewed and government publications between 1991 and September 20, 2023, searched in MEDLINE, Scopus and EBSCOhost. English language studies reporting weighted prevalence or raw numbers and recruitment sites were included for review. Quality was assessed using the Joanna Briggs Institute tool. Data synthesis was done in graphs and tables. RESULTS: We included 50 reports, yielding 150 HIV, 68 HCV and 24 HBV prevalence estimates across India, revealing significant regional heterogeneity. Notably, 16 States had a single community-based HIV estimate, and 19 States had limited or no HCV data. The highest HIV and HCV prevalence was in Manipur (74.7% and 97.5%, respectively) in 1996. Recent spikes included 50.2 per cent HIV prevalence in Punjab (2010) and 73 per cent HCV in Uttar Pradesh (2021). Nationally, OST coverage in 2020 was under five per cent, with some northeast, north and central States exceeding this, but most others were falling below two per cent. No studies on the cost-effectiveness of directly observed treatment models for OST were identified. INTERPRETATION CONCLUSIONS: There is a lack of sufficiently granular and generalizable estimates for HIV prevalence and any estimates for HCV and HBV among PWIDs in large parts of the country. Community-based representative studies are required to quantify the prevalence and severity of these diseases and allocate resources.

Biodegradation of technical hexachlorocyclohexane by Cupriavidus malaysiensis.

Lindane (γ-Hexachlorocyclohexane) has been used extensively as a pesticide all over the world. The production of Lindane entails the formation of four major Hexachlorocyclohexane (HCH) isomers, that is, alpha, beta, gamma, and delta as muck. These have been used as Technical HCH in developing countries as an inexpensive alternate source. However, HCH isomers pose a severe environmental hazard due to their highly persistent nature and toxicity. In this study, the effect of HCH application on the soil microbial diversity was studied. The species which could persist even after prolonged exposure at high HCH concentration, was isolated, screened, and enriched as potential t-HCH degraders. The selected isolate could degrade 88.05%, 92.19%, 91.54%, and 82.85% of the alpha, gamma, beta, and delta isomers, respectively at 100 mg/L HCH concentration. Identification of the isolate by 16s rRNA sequencing was similar to Cupriavidus malaysiensis. To the best of the authors' knowledge, this is the first study to observe this particular strain's ability to simultaneously degrade the four isomers, especially the most recalcitrant beta isomer. Therefore, the degradative capability of this strain, as a sole carbon source at higher HCH concentration (100 mg/l), can be exploited for bioremediation of HCH contaminated sites.

Polybrominated diphenyl ethers (PBDEs) in Indian wastewater treatment plant: Occurrence, mass flow and removal.

Polybrominated diphenyl ethers (PBDEs) are categorized as a group of brominated flame retardants that cause hazardous health impacts but are still being used consistently worldwide. The studies on their occurrence and fate in wastewater treatment plants are scarce, and considering the Indian scenario, no study has been reported till date in this context. Therefore, in the present study, PBDE congeners of primary concern were investigated first time to assess the existence, dissemination and fate of PBDEs in the municipal wastewater treatment plant (MWTP) located in Nagpur city, Maharashtra, India. BDE 209 and 47 were detected as the predominant PBDE contaminants in all the analysed samples. The concentration of PBDEs was primarily found in the particulate phase of wastewater. According to mass loading analysis, 1297 mg/day concentration of PBDEs is disposed of at landfill sites in the form of sludge, while 77.46 mg/day is released via final effluent. The present investigation is the first of its kind of study conducted to evaluate the PBDE contamination in Indian MWTP, which reveals the presence of high PBDE concentration in Indian municipal sewage. The findings of the current study exhibit the need for appropriate action toward the sound surveillance of PBDEs in the Indian context.

Integrated soil washing and bioreactor systems for the treatment of hexachlorocyclohexane contaminated soil: A review on enhanced degradation mechanisms, and factors affecting soil washing and bioreactor performances.

Investigations about the remediation of Hexachlorocyclohexane (HCH), a persistent organic pollutant of global concern, have been extensively reported to treat the HCH contaminated soil. The difficulty arising due to desorption and long ageing procedures of this hydrophobic organic compound in the soil, make it necessary to exploit techniques like soil washing or addition of surfactants, for enhancing the mass transfer rate of hydrophobic compounds. However, this technique gives rise to the generation of a large quantity of waste solution containing the pollutant and various other toxic substances. Moreover, it is challenging to deal with the complex soil washing solution, and thus a follow-up treatment of such washing solution is essentially required before its discharge. This follow-up treatment could be the bioreactor system to efficiently treat the pollutant in the wash solution, thereby reducing the amount of contaminated soil that has to be treated. Among many suggested remediation methods and treatment technologies, integrated soil washing and post-treatment with the bioreactor system could be an environmentally viable method for the remediation of HCH contaminated sites. This review focuses on the soil washing procedures applied so far for the HCH contaminated soil and various factors affecting the efficiency of separation of the target pollutant. Furthermore, the environmental and reactor design-related factors are also discussed for degradation of HCH in the reactor system. Finally, advantages and environmental feasibility of this proposed combined technology and the challenges that need to be encountered are envisaged.

Occurrence of organic micropollutants in municipal landfill leachate and its effective treatment by advanced oxidation processes.

Landfilling is the most prominently adopted disposal technique for managing municipal solid waste across the globe. However, the main drawback associated with this method is the generation of leachate from the landfill site. Leachate, a highly concentrated liquid consisting of both organic and inorganic components arises environmental issues as it contaminates the nearby aquifers. Landfill leachate treatment by conventional methods is not preferred as the treatment methods are not much effective to remove these pollutants. Advanced oxidation processes (AOPs) based on both hydroxyl and sulfate radicals could be a promising method to remove the micropollutants completely or convert them to non-toxic compounds. The current review focuses on the occurrence of micropollutants in landfill leachate, their detection methods and removal from landfill leachate using AOPs. Pharmaceuticals and personal care products occur in the range of 10-1 to more than 100 µg L-1 whereas phthalates were found below the detectable limit to 384 µg L-1, pesticides in the order of 10-1 µg L-1 and polyaromatic hydrocarbons occur in concentration from 10-2 to 114.7 µg L-1. Solid-phase extraction is the most preferred method for extracting micropollutants from leachate and liquid chromatography (LC) - mass spectrophotometer (MS) for detecting the micropollutants. Limited studies have been focused on AOPs as a potential method for the degradation of micropollutants in landfill leachate. The potential of Fenton based techniques, electrochemical AOPs and ozonation are investigated for the removal of micropollutants from leachate whereas the applicability of photocatalysis for the removal of a wide variety of micropollutants from leachate needs in-depth studies.

Mixed industrial wastewater treatment by the combination of heterogeneous electro-Fenton and electrocoagulation processes.

Mixed industrial wastewater treatment efficiency of combined electro-Fenton (EF) and electrocoagulation (EC) processes was investigated in the present study. Alkali modified laterite soil was used as a heterogeneous EF catalyst and found superior performance than the raw laterite soil. Initially, the effect of catalyst dosage, initial pH, and applied voltage on the performance of EF process was carried out. A total of 54.57% COD removal was observed after 60 min of the EF treatment. Further treatment was carried out with EC process at different voltages. A total of 85.27% COD removal after 2 h treatment was observed by combining two electrochemical processes. Performance of EF followed by EC (EF + EC) process was compared with EC followed by EF (EC + EF) process. Even though efficiency is the same, EF + EC is a better strategy than EC + EF as it nullifies the neutralization requirement after EF process in addition to high mineralization efficiency, enhanced biodegradability, and lesser sludge generation.

Aerobic degradation of decabrominated diphenyl ether through a novel bacterium isolated from municipal waste dumping site: Identification, degradation and metabolic pathway.

In the present study, a novel bacterium capable of degrading BDE-209 aerobically was isolated from a municipal waste dumping site and identified as Bacillus tequilensis strain BDE-S1 through 16S rRNA gene sequencing. A correlation between BDE-209 and bromide concentration, COD, TOC, and cell biomass was established. 65% of 50 mg/L initial concentration of BDE-209 was degraded within eight days of incubation by BDE-S1 strain. Two hexa, two penta, one tetra-BDE congener, and benzamide were detected as metabolites. The bromide release, COD, TOC and cell biomass were found to be significantly correlated parameters with BDE-209 degradation. Based on the metabolite analysis, ortho and meta debromination, cleavage of diphenyl ether bond and ring-opening were suggested as possible degradation pathways. This is the first study demonstrating the use of indigenously isolated Bacillus tequilensis strain BDE-S1 for aerobic degradation of BDE-209, which could provide new comprehension for bioremediation of PBDEs from contaminated environments.

Awareness of and willingness to use pre-exposure prophylaxis (PrEP) among people who inject drugs and men who have sex with men in India: Results from a multi-city cross-sectional survey.

INTRODUCTION: Pre-exposure prophylaxis (PrEP) is effective in reducing HIV transmission among key populations. In India, where PrEP is not currently part of the national HIV program, little is known about PrEP awareness, willingness to use PrEP, and barriers to uptake among people who inject drugs (PWID) and men who have sex with men (MSM). METHODS: We used respondent-driven sampling to accrue PWID and MSM in 22 sites from August 2016 to May 2017. Participants were asked about awareness of PrEP, willingness to use PrEP (following a brief description) and reasons why they might not be willing to use PrEP. Participants were also queried on preferences for PrEP delivery modality (oral vs. injectable). Multi-level logistic regression models were used to determine participant correlates of willingness to use PrEP. Estimates were weighted for the sampling method. RESULTS: A total of 10,538 PWID and 8,621 MSM who self-reported being HIV-negative were included in the analysis. Only 6.1% (95% confidence interval [CI]: 5.9, 6.3) of PWID and 8.0% of MSM (95% CI: 7.7, 8.4) were aware of PrEP. However, willingness to use PrEP was substantially higher in both groups: 52.4% of PWID and 67.6% of MSM. Participants commonly cited a perceived low risk for acquiring HIV infection, being perceived by others as being HIV-positive, and side effects as reasons why they would be unwilling to use PrEP. Among PWID, sharing needles and hazardous alcohol use were associated with increased willingness to use PrEP. Among MSM, having a main male partner and injection drug use were associated with increased willingness to use PrEP. Preference for daily oral or monthly injectable PrEP was similar among MSM (39.6%% vs. 41.7%,), while PWID were more likely to prefer oral to injectable administration routes (56.3% vs. 31.1%). CONCLUSIONS: As India plans to roll-out of PrEP in the public sector, our multi-city survey of PWID and MSM highlights the need for key population-focused education campaigns about PrEP and self-assessment of risk.

Impact of Port and harbour activities on plankton distribution and dynamics: A multivariate approach.

Numerous researches have been conducted to study the impact of Port activities on water quality. However, investigation on the response of the inhabiting biota to Port related extrinsic factors is extremely limited. Using Canonical Correspondence Analysis, comprehensive assessment of plankton population dynamics and distribution corresponding to the spatial heterogeneity in physico-chemical characteristics of harbour and adjacent coastal water is conducted. The results revealed resource competition for nitrate, predator mediated co-existence of species favoured by active switching and Port influenced environmental filtering due to suspended solids, and oil and grease as the predominant factor to modulate the plankton community structure and succession in harbour. The higher heterogeneity in the measured environmental variables at coast revealed dispersion of nutrient and other pollutants from harbour into the adjacent coastal water during ebb tide. Our results indicate reengineering of Port infrastructures and efficient management policies including water quality standards to facilitate proper water circulation and minimize pollution with a long term goal to reconcile economic interest with ecosystem conservation.

An overview on combined electrocoagulation-degradation processes for the effective treatment of water and wastewater.

Electrocoagulation (EC) process is found as effective water and wastewater treatment method, as it can able to remove a variety of pollutants, treat various industrial wastewater, and able to handle fluctuations in pollutant quality and quantity. The performance of EC process can be improved significantly in combination with degradation processes. Different combinations of EC process with Fenton, electro-Fenton, photo-Fenton, photocatalysis, sonochemical treatment, ozonation, indirect electrochemical oxidation, anodic oxidation and sulfate radical based advanced oxidation process are found very effective for the treatment of water and wastewater. Enhanced performance of EC process in combination with degradation process was reported in most of the articles.

Conversion of sewage sludge into biochar: A potential resource in water and wastewater treatment.

Production of biochar from sewage sludge (SS) is consistent with the goal of sustainable resource recovery and promotes a wastewater-based circular economy. Thermochemical conversion of SS to biochar resolves two major issues simultaneously as it minimizes the cost of disposal and acts as a resource to eliminate the toxic contaminants from water and wastewater. The reusability and ready availability of the biochar, irrespective of the season, makes it an economically viable material for wastewater treatment. In this review, explicit insights into the production, modification and usage of SS derived biochar are provided including (i) the production yield, (ii) characteristic features such as physical, chemical, electrochemical and morphological aspects, and (iii) impact on contaminant removal through adsorption, catalytic and electrochemical processes. Particular attention is given to the use of SS derived biochar as an adsorbent for contaminants present in wastewaters, the potential use of biochar as a catalyst and support material in advanced oxidation processes and the use of biochars as an electrode material. The effect of pyrolysis conditions and co-pyrolysis with other materials on biochar properties is explored and insight is provided into the toxicity of biochar components present at different process conditions.

Pharmacological STING Activation Is a Potential Alternative to Overcome Drug-Resistance in Melanoma.

Melanoma is the most aggressive type of skin cancer and resistance to the conventional chemotherapy is the major cause for its poor prognosis. Metabolic perturbations leading to increased production of reactive oxygen species activate NRF2-dependent anti-oxidative responses to survive oxidative stress. This protective function of NRF2 is the primary cause for therapy resistance in cancer as anti-cancer agents such as BRAF inhibitors also induce NRF2-dependent antioxidative response. We had reported that type I interferons produced upon activation of STING, abrogates NRF2 function. Therefore, we investigated if STING agonists such as the newly developed dimeric aminobenzimidazole (diABZI) could sensitize melanoma cells to the clinically used BRAF inhibitors. Our results reveal that pharmacological activation of STING by diABZI, down regulates NRF2-dependent anti-oxidative responses and potentiates cell-death in melanoma cells when used in combination with BRAF inhibitors.

Synthesis and applications of various bimetallic nanomaterials in water and wastewater treatment.

Bimetallic nanoparticles are the complex combination of two different metal constituents in nanoscale. Water and wastewater treatment utilizing bimetallic particles is an emerging research area. When two metals are combined, it can show not only the properties of its constituents but also new and enhanced properties derived by the synergy of the combination. These properties of bimetallic nanoparticles inevitably depend on the size, structure, and morphology of the particles. Thus the adopting synthesis strategy is very crucial to achieve desired results. Here in this review, the various bimetallic synthesis strategies are compared. The bimetallic nanoparticles decontaminate water through adsorption and/or catalysis mechanism. The various degradation pathways, specifically, adsorption, reduction, oxidation, and advanced oxidation processes are discussed in detail in this review.

Eco-restoration approach for mine spoil overburden dump through biotechnological route.

The overburden dumps which are created during the process of mining are devoid of supportive and nutritive capacity for biomass development. Restoration of these overburden dumps requires the establishment of a self-sustaining soil-plant system, for which a restoration strategy is needed to accelerate the natural processes of ecosystem development. For eco-restoration of a coal mine spoil dump, National Environmental Engineering Research Institute developed an ecofriendly multidisciplinary approach to restore the fertility of the mine spoil overburden dump. In this regard, an experiment was conducted to restore the fertility of the overburden dump in an area of 20 ha at Durgapur in India. To reclaim the dump, the IBA (integrated biotechnological approach) was used. The integrated biotechnological approach involves the utilization of industrial waste ETP sludge (effluent treatment plant sludge) to support the nutritive capacity for vegetation establishment, inoculation, and isolation of Azotobacter, Bradyrhizobium, and VAM (vesicular arbuscular mycorrhiza) spores of Gigaspora and Glomus species along with suitable indigenous trees of ecological and economic importance. The findings of the experimental study revealed that amendment of the mine spoil with organic amendment at 50 t/ha improved the nutrient, microbiological, and physicochemical properties of the coal mine spoil and reduced the toxicity of heavy metals due to increased organic carbon content of the organic amendment effluent treatment plant sludge. Thus, amendment of the effluent treatment plant sludge and biofertilizer application provided better supportive material for the growth of different plant species which resulted into momentous biomass (aboveground biomass and belowground biomass) production thereby improving the productivity and fertility of the mine spoil dump in a short span. Thus, using IBA, the ecology and biodiversity of the area was conserved. It also helped to maintain the aesthetic environment surrounding the mine site.

Enhanced nodulation and higher germination using sludge ash as a carrier for biofertilizer production.

Sludge ash, a byproduct resulting from the combustion of the dewatered sludge generated in the sewage treatment plants, is recognized as a hazardous solid waste throughout the world. This solid waste, which is produced in behemoth volume, has very limited applications and is directly disposed to landfills. The present study aims to explore a novel strategy for utilizing this solid waste for the development of Rhizobium biofertilizer and thus reducing the burden on landfills. The Rhizobium inoculum was prepared and mixed with sludge ash to formulate Rhizobium biofertilizer, and shelf life of this formulation was evaluated by counting colony forming unit. The prepared formulation was applied on lentil seeds, and its effect was analyzed by assessing the plant growth along with other yield characteristics. Enhanced colony forming unit count (6487.78) was observed in sludge ash carrier combination with a better shelf life of five months in comparison to lignite carrier formulation from the beginning of the experiment (9.1%) till 150th day (69.8%). Lentil seeds treated with sludge ash based biofertilizer showed luxuriant growth with 19% enhanced root length, 42% in number of nodules, 10% in plant growth and 53.40% in seed yield as compared to conventional lignite formulations. Hence, biofertilizer produced from waste material sludge ash is not supposed to cause a hazard for the soil and plants when incorporated in defined amount and can prove to be a substitute for conventional lignite carrier in biofertilizer production.