Anaerobic oxidation of methane in landfill and adjacent groundwater environments: Occurrence, mechanisms, and potential applications.

Landfills remain the predominant means of solid waste management worldwide. Widespread distribution and significant stockpiles of waste in landfills make them a significant source of methane emissions, exacerbating climate change. Anaerobic oxidation of methane (AOM) has been shown to play a critical role in mitigating methane emissions on a global scale. The rich methane and electron acceptor environment in landfills provide the necessary reaction conditions for AOM, making it a potentially low-cost and effective strategy for reducing methane emissions in landfills. However, compared to other anaerobic habitats, research on AOM in landfill environments is scarce, and there is a lack of analysis on the potential application of AOM in different zones of landfills. Therefore, this review summarizes the existing knowledge on AOM and its occurrence in landfills, analyzes the possibility of AOM occurrence in different zones of landfills, discusses its potential applications, and explores the challenges and future research directions for AOM in landfill management. The identification of research gaps and future directions outlined in this review encourages further investigation and advancement in the field of AOM, paving the way for more effective waste stabilization, greenhouse gas reduction, and pollutant mitigation strategies in landfills.

Machine learning vs. statistical model for prediction modeling and experimental validation: Application in groundwater permeable reactive barrier width design.

Permeable reactive barrier (PRB) is an effective in-situ technology for groundwater remediation. The important factors in PRB design are the width and reactive material. In this study, the beaded coal mine drainage sludge (BCMDS) was employed as the filling material to adsorb arsenic pollutants in groundwater, aiming to design the width of PRB. The design methods involving traditional continue column experiments and empirical formulas, as well as machine learning (ML) predictions and statistical methods, which are compared with each other. Traditional methods are determined based on breakthrough curves under several conditions. ML method has advantages in predicting the width of mass transfer zone (WMTZ), which simultaneously consider the characteristics of material, pollutant, and environmental conditions, with data collected from articles. After data preprocessing and model optimizing, selected the XGBoost algorithm based on the high accuracy, which shows good prediction for WMTZ (R2 = 0.97, RMSE = 0.15). The experimentally derived WMTZ values were also used to validate the predictions, demonstrating the ML low error rate of 7.04 % and the feasibility. Subsequent statistical analysis of multiple linear regression (MLR) showed the error rate of 39.43 %, interpret superiority of ML due to the complexity of influencing factors and the insufficient precision of math regression. Compared to traditional width design methods, ML can improve design efficiency and save experimental time and manpower. Further expansion of the dataset and optimization of algorithms could enhance the accuracy of ML, overcoming existing limitations and gaining broader applications.

The contribution of decentralized water systems on water quality in Maniema province, DRC.

Decentralized water systems (DWS) distribute water in remote African areas. Throughout an intervention in Maniema, Congo, the influence of a DWS performing chlorination in the community's water quality was measured. Additionally, a socio-economic and WASH practices survey was conducted in the communities. Free residual chlorine (FRC) and microbiological contamination were measured; at the borehole, treatment site, distribution points, and households's water containers. In Big Five, water was collected from unimproved sources before DWS construction. Despite that, only 16,6% of households used efficient water treatment methods, resulting in 73% of water stored unsafe for consumption. After construction, household water quality drastically improved, regardless of FRC fluctuations; 93% of samples were classified as low health risk (safe). The renovation guaranteed continuous supply through electro-chlorinators in RVA, where chlorination was intermittent. Water from DWS with adequate chlorine levels prevented microbiological contamination in households for 12 hours. Although economically attractive, the system's sustainability will require future evaluation.

Identifying susceptible groundwater contamination zones in western Odisha of India using hydro-geochemical and geospatial approaches.

Nuapada is one of the most drought-affected and fluoride-contaminated districts in Odisha, India. The presence of various dissolved substances, evapotranspiration, and lowering water table during pre- and post-monsoon (PRM and POM) seasons are responsible for declining groundwater (GW) quality over the Nuapada region. To comprehend the contaminated GW zones over the Nuapada and Komna blocks of the northern Nuapada district during the seasons, integration of hydrogeochemistry and statistical approaches using GW sample data on a geospatial platform have been done. The analysis exhibits that the major source of groundwater contamination is mostly geogenic with little anthropogenic impact. The cumulative impact of fluoride (F-), iron (Fe2+), and nitrate (NO3-) contents are noticed in great-depth zones of the water table in the north and south parts of Nuapada and Komna blocks, respectively. The dominant hydro facies, such as Na-Cl (41.77%) and Ca-Cl (25.31%) types exist over both blocks during PRM and POM seasons, respectively. Demarcation of contaminant and susceptible zones over the study area using geospatial analysis and groundwater quality indices (GWQI) were done. About 3% of the total area, in the north and middle parts of the Nuapada and Komna blocks, falls under contamination zones and is unfit for drinking purposes, and about 35% of the region is susceptible to future contamination. The outcome of the result analysis will enhance the scope for researchers, policymakers, and water managers to regulate emerging health, agricultural, and industrial issues in the stressed aquifer system in India and the world.

Evaluation of uranium content and annual ingestion dose in the surface and ground water bodies of Chittorgarh, Rajasthan, India.

Uranium, naturally occurring radionuclide is chemotoxic and nephrotoxic beyond acceptable limit. The presence of uranium beyond acceptable limit in surface and ground water, adversely affecting people's health. In the present investigation, the uranium concentration in surface and ground water of Chittorgarh, Rajasthan was studied along with the physico-chemical parameters of water (n = 87). The ground water was further sub-categorised into well water, handpump water, and borewell water. The mean uranium concentration was observed at 2.5 ± 1.9 µgL-1 and 16.5 ± 1.4 µgL-1 in the surface and ground water samples, respectively. In sub-categories of ground water, the highest uranium concentration was found in borewell water (23.3 ± 17.0 µgL-1), followed by handpump water (13.5 ± 9.1 µgL-1) and well water (6.0 ± 5.5 µgL-1). The uranium concentration was correlated significantly with the depth of the ground water table. It also correlated significantly with electrical conductivity, total dissolved solids and nitrate concentration. 100% of surface water and 88.9% of ground water samples carried uranium concentration within the acceptable limit of WHO (30 µgL-1). The annual ingestion dose was found at 3.8 µSvy-1 (for males) and 2.8 µSvy-1 (for females) in surface water and 25.4 µSvy-1 (for males) and 18.5 µSvy-1 (for females) in ground water. In the sub-categories of the ground water sample, the annual ingestion dose followed the trend in males 35.8 µSvy-1 (borewell water) > 20.7 µSvy-1 (hand pump water) > 9.2 µSvy-1 (well water) and in females 26.1 µSvy-1 (borewell water) > 15.1 µSvy-1 (hand pump water) > 6.7 µSvy-1 (well water).

Treatment of Uranium-Contaminated Ground Water Using Adsorption Technology via Novel Mesoporous Silica Nanoparticles.

Contamination of underground water by uranium (U) and other heavy metals is a growing concern. Mesoporous silica nanoparticles (MSNs) have shown great potential as an adsorbent material for heavy metal removal. This study synthesized a novel MSN using surface-initiated atom transfer radical polymerization (SI-ATRP) and evaluated its effectiveness for removing uranium from aqueous solutions under different conditions. The particle size was reduced to 150-240 nm to enhance adsorption. Fourier transform infrared characterization and thermogravimetric analysis confirmed successful synthesis and modification. Results showed that the MSN adsorbent was highly effective in removing U, with a removal rate of 85.35% at 120 min. Temperature had a significant impact, with the highest removal rate of 96.7% achieved at 25 °C and a U concentration of 10 ppm. The highest removal rate of 91.89% was achieved at a pH of 6 and a U concentration of 50 ppm. The highest removal rate of 95.16% was achieved at 25 mg and a U concentration of 50 ppm at room temperature for 60 min. The MSNs also showed a 58.27% removal rate in a mixture solution at room temperature for 60 min. This study demonstrates the effectiveness of the MSN adsorbent for removing U under different conditions.

A comprehensive review of water quality indices (WQIs): history, models, attempts and perspectives.

Water quality index (WQI) is one of the most used tools to describe water quality. It is based on physical, chemical, and biological factors that are combined into a single value that ranges from 0 to 100 and involves 4 processes: (1) parameter selection, (2) transformation of the raw data into common scale, (3) providing weights and (4) aggregation of sub-index values. The background of WQI is presented in this review study. the stages of development, the progression of the field of study, the various WQIs, the benefits and drawbacks of each approach, and the most recent attempts at WQI studies. In order to grow and elaborate the index in several ways, WQIs should be linked to scientific breakthroughs (example: ecologically). Consequently, a sophisticated WQI that takes into account statistical methods, interactions between parameters, and scientific and technological improvement should be created in order to be used in future investigations.

[Direct determination of five xanthic acids in water by ultra performance liquid chromatography-tandem mass spectrometry].

Xanthates with different alkyl groups, such as ethyl, propyl, butyl, and amyl groups, are widely used in large quantities in the mining flotation of metallic minerals. Xanthates enter environmental waters through mineral processing wastewater discharge and are ionized or hydrolyzed into ions or molecules of xanthic acids (XAs) in water. XAs endanger aquatic plants and animals, as well as human health. To the best of our knowledge, XA analysis is mainly limited to butyl xanthate. Moreover, the isomers and congeners of XAs cannot be determined separately using the existing methods. Herein, a novel method based on ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established to separate and analyze five XAs, namely, ethyl-, isopropyl-, n-butyl-, isobutyl-, and amyl-XAs, in water. Water samples were filtered through a 0.22 µm hydrophilic polytetrafluoroethylene (PTFE) membrane and directly injected into the UPLC-MS/MS instrument. Separation was performed using a Waters Acquity UPLC BEH C18 column (100 mm×2.1 mm, 1.7 µm) with ammonia solution (pH 11)-acetonitrile (9∶1, v/v) as the mobile phase for isocratic elution. The five XAs were detected in the negative electrospray ionization (ESI-) and multiple reaction monitoring (MRM) modes. An internal standard method was used for quantification. The pretreatment and UPLC-MS/MS conditions were comprehensively optimized to achieve the separation and analysis of the five XAs via direct injection. The XAs showed negligible adsorption on hydrophobic PTFE, hydrophilic PTFE, hydrophilic polypropylene, and polypropylene membranes during filtration. However, the amyl-XA showed obvious adsorption on nylon and polyether sulfone membranes. The five XAs mainly formed [M-H]- parent ions in the ESI- mode and the main daughter ions obtained following collisional fragmentation depended on the alkyl groups of the XAs. Increasing the pH of the ammonia solution in the mobile phase to 11 led to the isomeric separation of n-butyl- and isobutyl-XAs. The optimized mobile phase inhibited the tailing of the chromatographic peak of amyl-XA and effectively improved all the chromatographic peak shapes of XAs. The BEH C18 column was selected as the chromatographic column owing to its better compatibility with high-pH solutions compared with the T3 C18 column. Preservation experiments conducted over 8 d showed that the concentration of all five XAs decreased over time at room temperature; among the XAs analyzed, the concentration of ethyl-XA revealed the most significant decrease. However, the recoveries of the five XAs at 4 and -20 ℃ remained high, ranging from 101% to 105% and from 100% to 106%, respectively, on the 8th day. The preservation observed with a high concentration of XAs was similar to that found with a low concentration. The preservation time was extended to 8 days at pH 11 and 4 ℃ away from the light. No significant matrix effects were observed for the five XA samples in surface water and groundwater, but industrial sewage exerted obvious matrix inhibitory effects on ethyl- and isopropyl-XAs. Owing to the short retention times of ethyl- and isopropyl-XAs, the co-fluxed interferents in the industrial sewage depressed the MS signals. The five XAs showed good linearity in the range of 0.25-100 µg/L, with correlation coefficients greater than 0.9996. The method detection limits were as low as 0.03-0.04 µg/L, and the intra- and inter-day precisions were 1.3%-2.1% and 3.3%-4.1%, respectively. The recoveries obtained under low, medium, and high spiked levels (1.00, 20.0, 80.0 µg/L) were 96.9%-133%, 100%-107%, and 104%-112%, respectively. The corresponding RSDs were 2.1%-3.0%, 0.4%-1.9%, and 0.4%-1.6%, respectively. The optimized method was successfully applied to the analysis of XAs in surface water, groundwater, and industrial sewage. The method could separate and detect various congeners and isomers of XAs without the need for cumbersome pretreatment processes, and its advantages include smaller sample requirements, simpler operation, higher sensitivity, and longer preservation time. The proposed technique presents excellent application potential in XA environmental monitoring and water evaluation, and mineral flotation studies.

An integrated simulation-optimization framework for assessing environmental flows in rivers.

The present study proposes an integrated simulation-optimization framework to assess environmental flow by mitigating environmental impacts on the surface and ground water resources. The model satisfies water demand using surface water resources (rivers) and ground water resources (wells). The outputs of the ecological simulation blocks of river ecosystem and the ground water level simulation were utilized in a multiobjective optimization model in which six objectives were considered in the optimization model including (1) minimizing losses of water supply (2) minimizing physical fish habitat losses simulated by fuzzy approach (3) minimizing spawning habitat losses (4) minimizing ground water level deterioration simulated by adaptive neuro fuzzy inference system(ANFIS) (5) maximizing macroinvertebrates population simulated by ANFIS (6) minimizing physical macrophytes habitat losses. Based on the results in the case study, ANFIS-based model is robust for simulating key factors such as water quality and macroinvertebrate's population. The results demonstrate the reliability and robustness of the proposed method to balance environmental requirements and water supply. The optimization model increased the percentage of environmental flow in the drought years considerably. It supplies 69% of water demand in normal years, while the environmental impacts on the river ecosystem are minimized. The proposed model balances the portion of using surface water and ground water in water supply considering environmental impacts on both sources. Using the proposed method is recommendable for optimal environmental management of surface water and ground water in river basin scale.

Depression, Anxiety and Stress Among Arsenic-Induced Cancer Patients in Indo-Gangetic Plains of Bihar: Role of Proactive Coping.

Arsenic induced cancer is a major public health issue in Indo-Gangetic plains of Bihar, India where 22 out of 38 districts report arsenic contamination of groundwater. Its psychological aspect is under studied in contrast to the physiological and social. This baseline correlational survey research explores the relationship and role of proactive coping on depression, anxiety and stress among this population. Depression, anxiety and stress were assessed in 77 consenting arsenic induced cancer patients with depression, anxiety and stress scales. Proactive Coping was assessed with proactive coping inventory. Results demonstrated negative association and influence of proactive coping on stress, anxiety and depression. Avoidance coping associated positively with depression and reflective coping predicted for depression and anxiety. The findings advocate for more research attention on psychological aspects of arsenic induced cancer. Timely psychological interventions to build proactive coping are warranted to alleviate depression, anxiety and stress among this population.

Heavy metal contamination in river water, sediment, groundwater and human blood, from Kanpur, Uttar Pradesh, India.

Exponential industrialization and anthropogenic activities have resulted in water contamination by various heavy metals in Kanpur city, India. Heavy metal pollution, an issue of great concern, is not only affecting river water, but contamination of groundwater is creating health issues and worries. In the present investigation, blood samples were collected from selected volunteers, water and sediment samples from four sites of river Ganga and drinking groundwater samples from 23 locations of Kanpur city. Heavy metals analysis in river water, sediment, and human blood, was done by inductively coupled plasma optical emission spectroscopy (ICP-OES) and atomic absorption spectroscopy (AAS) was used for groundwater samples. Human blood showed a high concentration of arsenic (As) (66.6 ± 0.00 and 76.9 ± 0.01 µg L-1 in males and female subjects, respectively) and thallium (Tl) (13.4 ± 0.004 and 16.6 ± 0.005 µg L-1 in males and female subjects, respectively) with higher concentrations in females than males. Other heavy metals (Nickle, Beryllium, Cadmium, Cobalt, Chromium, Lithium, Molybdenum, Lead) were not observed in any of the tested human blood samples. However, in groundwater sampling, iron (Fe), copper (Cu), and arsenic (As) were detected, one sample had the presence of chromium (Cr), and two samples showed lead (Pb) contamination. River water [Cu (32-125 µg L-1), Cr (19-725 µg L-1), Cd (1-59 µg L-1), Pb (37-163 µg L-1), As (32-153 µg L-1), Th (26.75 µg L-1)] showed a high level of the heavy metals, as compared to reference values of BIS, CPCB (2016a), WHO, EPA and USEPA. River sediment [Cu (4168-34,470 µg Kg-1), Cr (4040-145,650 µg Kg-1), Cd (326-5340 µg Kg-1), Pb (1840-19,350 µg Kg-1), As (103-188 µg Kg-1)] also showed high concentration when compared to reference values of USEPA and PASS. River site 4, with high Cr (725 µg L-1), also showed Cr levels (19.8 µg L-1) in the groundwater samples, indicating Cr contamination in groundwater while Pb was observed at groundwater samples close to two industrial sites. Drinking water might be the primary exposure pathway for As and Tl to enter the human body. The study recommends periodic monitoring of river water, sediment, groundwater, and human blood samples for contamination of heavy metals.

Encapsulation of zero valent iron nanoparticles in biodegradable amphiphilic janus particles for groundwater remediation.

Reactive Zero Valent Iron (ZVI) nanoparticles have been widely explored for in situ ground water remediation to degrade both non-aqueous phase liquid (NAPL) and water-soluble contaminants. However, they usually suffer from rapid oxidation and severe agglomerations restricting their delivery at NAPL/water interface. Aim of this study was to encapsulate the ZVI nanoparticles (50 nm) in amphiphilic bicompartmental Janus particles (711 ± 11 nm) fabricated by EHDC (electrohydrodynamic co-jetting). The dual compartments were composed of PLA (polylactic acid) and a blend of PLA, PE (poly (hexamethylene 2,3-O-isopropylidenetartarate) and PAG (photo acid generator). Upon UV irradiation, PAG releases acid to unmask hydroxyl groups present in PE to make only PE compartment hydrophilic. The entrapped ZVI nanoparticles (20 w/w%; ∼99 % encapsulation efficiency) were observed to degrade both hydrophilic (methyl orange dye) and hydrophobic (trichloro ethylene) contaminants. UV treated Janus particles provided stable dispersion (dispersed up to 3 weeks in water), prolonged reactivity (∼24 days in contaminated water), and recyclability (recyclable up to 9 times) as compared to non-treated ones. In addition, the amphiphilic Janus particles demonstrated high transportability (>95%) through porous media (sand column) with very low attachment efficiency (0.07), making them a promising candidate to target contaminants at NAPL/water interface prevailed in groundwater.

Temporal study of physicochemical parameters of leachates and assessment of solid waste and ground water quality of Pirana dumping site, Ahmedabad, India.

The characterisation of solid waste (SW), leachate, is essential for developing an appropriate management strategy or treatment method. However, due to a range of contributing factors, such as waste type and dumping site locations, forecasting leachate quality is often challenging. This research article discusses leachate quality indicators and the temporal variations of leachate quality collected throughout various seasons and after 1-2 years of storage. In addition to that, the article also provides the data of different physicochemical parameters of SW and ground water (GW) quality collected from of Pirana solid waste dumping area (Pirana SWD), Ahmedabad, India, and surrounding areas throughout various seasons. The parameters like pH, COD, TDS, sulphates, nitrates, ammonia nitrogen, hardness, and heavy metals were all monitored to see whether there any temporal variations. When leachates were obtained 'fresh,' all parameters evaluated showed significantly higher values. As time passed, the values of the parameters (COD, ammonia nitrogen) stabilised. Heavy metals such as Hg, As, Pb, and Cr were detected in both fresh and old samples. Similarly in SW, the presence of heavy metals Hg (0.39 ppb), Pb (1.12 ppb), and Cr (16.86 ppb) were also detected. In case of GW, some samples also show the high TDS but the presence of metals like Cr, Ni, and Zn is less than permissible limit.

Potential health risks assessment cognate with selected heavy metals contents in some vegetables grown with four different irrigation sources near Lahore, Pakistan.

Carcinogenic and health hazard causing heavy metals have been increasing in our dietary stuffs due to large amount of industrial effluents being dumped in water bodies that are ultimately used for irrigation purposes. The study was aimed to assess and compare the mean concentrations of heavy metals (Cd, As and Pb) in soil and vegetables irrigated with four different sources (Ground water, river water, domestic sewage water and industrial untreated effluents and domestic waste water receiving drains) for the estimation of carcinogenic and non-carcinogenic health risk associated with them. Prepared samples were analyzed by through ICP-OES. Statistical analysis revealed that domestic sewage water and drains water usage for irrigation purposes leads to high values of Estimated Daily Intake (EDI) of metals through vegetation. To assess the carcinogenic effects values daily intakes, Total hazard quotients (THQs) and Health indexes (HI), while for carcinogenic effects, Total cancer risks (TCR) were determined. The results of present study revealed that the daily intakes of these metals are far less than that of permissible levels but their bio-accumulating behavior produce high risks to human health. The HI values revealed that waste water usage is producing the vegetables of high health risks. In adults, the HI of Phaseolus vulgaris, Spinacia oleracea, Brassica compestris, Raphnus sativus, Daucus carota and Solanum tuberosum assessed as 0.81, 1.52, 1.26, 0.12, 0.22, and 0.15 (ground water irrigation), 0.046, 0.75, 0.51, 0.68, 0.90 0.064 (River Ravi water irrigation), 1.23, 3.34, 4.81, 4.23, 1.41 and 3.43 (domestic sewage irrigation) and 3.04, 5.50, 6.08, 2.50, 5.34 and 5.13 (Drain waste water irrigation), respectively. It was observed that cancer risks of As exceeded the threshold (1 × 10-4) in all i.e. ground river, domestic sewage and drain water grown vegetables, while, Cd and Pb were in permissible range.

Developmental Phenotypic and Transcriptomic Effects of Exposure to Nanomolar Levels of 4-Nonylphenol, Triclosan, and Triclocarban in Zebrafish (Danio rerio).

Triclosan, triclocarban and 4-nonylphenol are all chemicals of emerging concern found in a wide variety of consumer products that have exhibited a wide range of endocrine-disrupting effects and are present in increasing amounts in groundwater worldwide. Results of the present study indicate that exposure to these chemicals at critical developmental periods, whether long-term or short-term in duration, leads to significant mortality, morphologic, behavioral and transcriptomic effects in zebrafish (Danio rerio). These effects range from total mortality with either long- or short-term exposure at 100 and 1000 nM of triclosan, to abnormalities in uninflated swim bladder seen with long-term exposure to triclocarban and short-term exposure to 4-nonylphenol, and cardiac edema seen with short-term 4-nonylphenol exposure. Additionally, a significant number of genes involved in neurological and cardiovascular development were differentially expressed after the exposures, as well as lipid metabolism genes and metabolic pathways after exposure to each chemical. Such changes in behavior, gene expression, and pathway abnormalities caused by these three known endocrine disruptors have the potential to impact not only the local ecosystem, but human health as well.

Drinking water, fracking, and infant health.

This study assesses the health risks associated with drinking water contamination using variation in the timing and location of shale gas development (SGD). Our novel dataset, linking health and drinking water outcomes to shale gas activity through water sources, enables us to provide new estimates of the causal effects of water pollution on health and to isolate drinking water as a specific mechanism of exposure for SGD. We find consistent and robust evidence that drilling shale gas wells negatively impacts both drinking water quality and infant health. These results indicate large social costs of water pollution and provide impetus for re-visiting the regulation of public drinking water.

Spatial analysis and human health risk assessment of elements in ground water of District Hyderabad, Pakistan using ArcGIS and multivariate statistical analysis.

Availability of clean drinking water is a basic necessity of human population. Therefore, the current study was taken up for spatial analysis and human health risk assessment of elements in Ground water of District Hyderabad, Pakistan. Evaluation of 10 potential hazardous elements in one hundred eighteen samples of ground water from district Hyderabad, Pakistan was done to assess their natural and anthropogenic origin and possible effects on living organisms and human health. Based on statistical tools of Pearson Co-relation, Metal Clustering and Principal Component Analysis (PCA), three groups of elements were produced; First group included Mn, Fe, B and Cr, the second group contained Cu, Ni and As while third group included Pb, Cd and Zn. Higher Relative Standard Deviation (RSD) values of Cu, Ni, As, Pb, Cd and Zn showed their anthropogenic origin while Mn, Fe, B and Cr were found with lower concentration that indicated their natural origin. Histograms and box-plots of Mn, Fe, B and Cr were found to be normally distributed while these parameters were appeared abnormal for Cu, Ni, As, Pb, Cd and Zn. Risk assessment was quantified by hazard quotient (HQ) and cancer risk for both adult and child. Non-carcinogenic risks as depicted by HQs of all the 10 metal(loid)s were below the recommended HQ threshold of 1 for both child and adult. However, highest HQ was calculated for B (child 0.300 and adult 0.338) followed by the values for Mn and Ni. The potential risks of combined effect of all the 10 metal(loid)s through ingestion of groundwater was assessed using HI and calculated to be 0.694 for adult and 0.566 for child. This indicates the potential health risk of these metal(loid)s to human due to the consumption of the groundwater of district Hyderabad for drinking purpose. Considering the geometric mean for the studied area, carcinogenic risk of As through oral intake was calculated i.e. 1.50 × 10-4 and 2.62 × 10-5 for the adult and child However, this carcinogenic risk is 1.91 × 10-5 and 3.28 × 10-6 for Cd in adult and child and 1.94 × 10-3 and 3.32 × 10-4 for Cr in adult and child, respectively. Since the cancer risk 6exceeded the target risk of 1 × 10-4 for Cr i.e. 1.94 × 10-3 in adult, it can thus be considered as 'non-acceptable'. Spatial maps of elements produced by ArcGIS showed the hotspots of potential hazardous elements such as highest concentration of elements like Zn, Pb and Cd was found in urban areas while highest concentration of Cu, Ni and As was observed near Phulleli canal which passes from Hyderabad City and may contain contamination from waste material of residential area due to their anthropogenic activities.

High manganese and nickel concentrations in human hair and well water and low calcium concentration in blood serum in a pristine area with sulphide-rich bedrock.

We report the trace element status of residents living in areas with naturally sulphide-rich bedrock and soil in two municipalities in Finland, Sotkamo and Kaavi. Altogether, 225 people from these sparsely populated regions participated voluntarily by providing hair and blood samples. The concentrations of calcium, zinc and copper in serum as well as selenium and cadmium in whole blood did not show correlation with those concentrations in hair samples. Calcium concentration in serum was slightly lower in the sulphide-rich areas (median value 91.4 mg/l, n = 103) than in the areas with adjacent sulphur-poor bedrock (median value 93.6 mg/l, n = 82). The concentrations of Ni and Mn in hair correlated with those in drinking water. The highest Mn and Ni concentrations in the water samples from private wells were 1620 µg/l and 51 µg/l and the highest concentrations in human hair samples 36.44 mg/kg and 12.3 mg/kg, respectively. The challenge with elevated trace element concentrations in some well waters is well documented. In northern countries (Finland, Sweden, Norway and Canada), only 10% of the population depend on private well water, and 90% have access to monitored municipal water supplies. Compared with data available from sulphide mine sites globally, the nickel and manganese concentrations in human hair samples were high in our sulphide-rich study area at Sotkamo representing the trace element status of residents under natural conditions.

In-situ, Ex-situ, and nano-remediation strategies to treat polluted soil, water, and air - A review.

Nanotechnology, as an emerging science, has taken over all fields of life including industries, health and medicine, environmental issues, agriculture, biotechnology etc. The use of nanostructure molecules has revolutionized all sectors. Environmental pollution is a great concern now a days, in all industrial and developing as well as some developed countries. A number of remedies are in practice to overcome this problem. The application of nanotechnology in the bioremediation of environmental pollutants is a step towards revolution. The use of various types of nanoparticles (TiO2 based NPs, dendrimers, Fe based NPs, Silica and carbon nanomaterials, Graphene based NPs, nanotubes, polymers, micelles, nanomembranes etc.) is in practice to diminish environmental hazards. For this many In-situ (bioventing, bioslurping, biosparging, phytoremediation, permeable reactive barrier etc.) and Ex-situ (biopile, windrows, bioreactors, land farming etc.) methodologies are employed. Improved properties like nanoscale size, less time utilization, high adaptability for In-situ and Ex-situ use, undeniable degree of surface-region to-volume proportion for possible reactivity, and protection from ecological elements make nanoparticles ideal for natural applications. There are distinctive nanomaterials and nanotools accessible to treat the pollutants. Each of these methods and nanotools depends on the properties of foreign substances and the pollution site. The current designed review highlights the techniques used for bioremediation of environmental pollutants as well as use of various nanoparticles along with proposed In-situ and Ex-situ bioremediation techniques.

Temperature influence on the NAPL-water interfacial area between 10 °C and 60 °C for trichloroethylene.

Underground thermal energy storage (UTES) can contribute to renewable energy usability, especially in urban areas with the most demand and available infrastructure. But UTES may interact in those areas with non-aqueous phase liquids (NAPL) by increasing the temperature in storage formations. To determine temperature effects on NAPL dissolution rates into groundwater, the effective specific interfacial area (anw) between trichloroethylene (TCE) and water, as a function of temperature and TCE pore saturations, was calculated. The interfacial tension between the flushing solution and the NAPL, the adsorption coefficient and the retardation of a reactive tracer were determined by the drop weight method and interfacial tracer tests at 10 °C, 30 °C and 60 °C. From 10 to 60 °C anw increased by a factor of six to eight. Based on the results, a function to describe the anw between TCE and water was developed, which could improve numerical models on NAPL dissolution rates. The main mechanisms for the increase in anw are suggested to be NAPL blob migration on pore scale, and thermal-induced changes in wettability and in blob shape correlating with a temperature-induced decline in effective porosity of up to 32%. These results contribute to the understanding and predictability of UTES in contaminated aquifers, the general response of NAPL behavior on artificial increasing aquifer temperatures and the improvement of thermal and other groundwater remediation techniques.