Microplastics and associated polycyclic aromatic hydrocarbons in surface water and sediment of the Bay of Bengal coastal area, India: sources, pathway and ecological risk.

In the aquatic environment around the world, microplastic contamination has been a common and ongoing issue. Particularly, the ability of microplastics to absorb persistent organic pollutants (POPs) and then transmit these POPs to aquatic creatures has attracted a lot of interest. A stereomicroscope was used to detect the size, shape, and color of the microplastics (MPs), and Fourier Transform Infrared (FTIR) spectroscopy was used to identify the polymer composition of the MPs. To address MP transit, destiny, and mitigation, a study of MP pollution coastal areas is required. In the current study, MP pollution in the collected sample from upper layer of water and sediment of the Digha and Puri beaches along the coast of BOB was evaluated. The average concentration with SD of MPs observed in water was 5.3 ± 1.8 items/L whereas, in sediments, it was 173.4 ± 40.1 items/kg at Digha beach. The mean MPs abundance in the Puri beach was 6.4 ± 1.7 items/L in the water and 190.4 ± 28.0 items/kg in the sediments. The investigated total 16-PAHs concentrations were 164.7 ng/g, 121.9 ng/g, 73.6 ng/g, and 101.3 ng/g on the MPs surface of foam, fragment, fibers, and film respectively in the studied MPs sample. Smaller than 1000 µm size of MPs are distributed in the largest concentration. Fibers, films, fragments, and foam were the most common shapes of MPs. The molecular structure of MPs in water and sediment samples was analysed i.e., polyesters (PEs), polypropylene (PP), polyethylene (PE), polymethyl methacrylate (PMMA), polystyrene (PS), polyamide (PA), polycarbonates (PC), and polyurethane (PU). The obtained result offers an accurate assessment of the PLI, and the investigated polymer facilitates determining the polymer hazard levels, which emphasizes the risk associated with it.

Microplastic contamination in water and sediments of Mahanadi River, India: An assessment of ecological risk along rural-urban area.

Worldwide, environmental concerns about MPs pollution have increased. Microplastic contamination that pollutes the ocean is mostly caused by terrestrial transfer from close proximity locations. A study of MPs pollution near coastal locations becomes necessary to address the MPs transit, fate, and mitigation. In the current study MPs pollution in the surface water and sediment of the Mahanadi River estuary was assessed during Pre-MS and MS. The size, shape, and colour of the MPs were determined using a stereomicroscope, and the MPs polymer composition was identified by Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy. The mean concentration of MPs that were potentially discovered in water was 16.6 ± 5.2 and sediments 197.3 ± 5.4 during Pre-MS. In the MS observed mean abundance of MPs was 15.1 ± 5.4 in water and 164.6 ± 76.9 in sediments. The highest abundant size was smaller than 1 mm; the most prevalent shape were fibers followed by film and fragments; black and white was a prominent colour in water and sediments respectively. Polyesters (PEs), polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polyamide (PA), Polystyrene (PS), and Polycarbonates (PC) were found in the analysis of the chemical composition of MPs in water and sediments samples. The calculated PLI value shows pollution load at category I, with polymer hazard levels at categories III, IV, and V, indicating very high risk. The current research results show that river inflows and fishing-related actions are probably the main causes of MPs pollution.

The Health Risk and Source Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in the Soil of Industrial Cities in India.

Industrial areas play an important role in the urban ecosystem. Industrial site environmental quality is linked to human health. Soil samples from two different cities in India, Jamshedpur and Amravati, were collected and analyzed to assess the sources of polycyclic aromatic hydrocarbons (PAHs) in industrial areas and their potential health risks. The total concentration of 16 PAHs in JSR (Jamshedpur) varied from 1662.90 to 10,879.20 ng/g, whereas the concentration ranged from 1456.22 to 5403.45 ng/g in the soil of AMT (Amravati). The PAHs in the samples were dominated by four-ring PAHs, followed by five-ring PAHs, and a small percentage of two-ring PAHs. The ILCR (incremental lifetime cancer risk) of the soil of Amravati was lower compared to that of Jamshedpur. The risk due to PAH exposure for children and adults was reported to be in the order of ingestion > dermal contact > inhalation while for adolescents it was dermal contact > ingestion > inhalation in Jamshedpur. In contrast, in the soil of Amravati, the PAH exposure path risk for children and adolescents were the same and showed the following order: dermal contact > ingestion > inhalation while for the adulthood age group, the order was ingestion > dermal contact > inhalation. The diagnostic ratio approach was used to assess the sources of PAHs in various environmental media. The PAH sources were mainly dominated by coal and petroleum/oil combustion. As both the study areas belong to industrial sites, the significant sources were industrial emissions, followed by traffic emissions, coal combustion for domestic livelihood, as well as due to the geographical location of the sampling sites. The results of this investigation provide novel information for contamination evaluation and human health risk assessment in PAH-contaminated sites in India.

Distribution, risk assessment, and source apportionment of polycyclic aromatic hydrocarbons (PAHs) using positive matrix factorization (PMF) in urban soils of East India.

This study investigated 16 United States environmental protection agency priority PAHs profiles and their sources in 40 urban soils collected from two industrialised cities, Jamshedpur and Bokaro, in east India and assessed their health risk to humans. The results showed the predominance of high molecular weight (HMW) PAHs (4-5 rings). The total PAHs concentration in surface soils ranged from 2223 to 11,266 ng/g and 729 to 5359 ng/g (dw), respectively, for Jamshedpur and Bokaro. Higher concentrations of PAHs were recorded at the selected industrial areas and heavy traffic zones of both cities. In JSR city 4-ring PAHs contributed 43% of total PAHs trailed by 5-ring PAHs 27.2%. Similarly, in BKR city 4-ring PAHs contributed 34% of the total PAHs, followed by 3-ring PAHs 28.9% and 5-ring PAHs 22.9%. Total organic carbon in surface soils exhibited moderate correlation with the low molecular weight (ΣLMW) PAHs (R2 = 0.69) and a comparatively strong correlation with the ΣHMW PAHs (R2 = 0.89), suggesting strong adsorption of HMW PAHs to urban soils. The Diagnostic and PMF modelling analysis indicated that the major sources of PAHs contamination in soils were petroleum combustion, vehicular emissions, biomass, and coal combustion. The health risk assessment shows that the cumulative probability of carcinogenic risks was under the acceptable limits of 10-4 to 10-6. At some sampling areas in both cities, the maximum value of total exposure cancer risk slightly exceeded the acceptable limits indicating some carcinogenic risk for adults.

Accumulation of polycyclic aromatic hydrocarbons (PAHs) in surface sediment residues of Mahanadi River Estuary: Abundance, source, and risk assessment.

In this study, we examined the distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments from the Mahanadi River Estuary (MRE), identified sources, and evaluated the ecological toxicity. The PAHs distributions in MRE ranged from 13.1 to 685.4 ng g-1 (dry weight), with a mean value of 192.91 ± 177.56 ng g-1 (dry weight). Sediments at sites S11, S8, and S13 have the highest 3-rings, 4-rings, and 5-rings PAHs, respectively. In MRE, pyrene has a significantly higher concentration with a mean value of 30.51 ng g-1, followed by Fluoranthene (86.2 ng g-1), Chrysene (67.4 ng g-1), and Benzo(k)fluoranthene (54.2 ng g-1). Site S8 had a higher total PAH concentration than sites S11, S13, and S1. The diagnostic and principal component analysis suggests that PAHs originated from petroleum, oil, biomass, and coal combustion. Higher toxic and mutagenic equivalent quotients indicate potential aquatic toxicity and a need for continuous monitoring of MRE for PAHs pollution.

Bioremediation of metal(loid) cocktail, struvite biosynthesis and plant growth promotion by a versatile bacterial strain Serratia sp. KUJM3: Exploiting environmental co-benefits.

In this study the multiple metal(loid) (As, Cd, Cu and Ni) resistant bacterium Serratia sp. KUJM3 was able to grow in both single and multiple metal(loid) contaminated wastewater and removed them by 34.93-48.80% and 22.93-32%, respectively. It reduced As(v) to As(III) by 68.44-85.06% in a concentration dependent manner. The strain's IAA production potential increased significantly under both metal(loid)s regime. The lentil (Lens culinaris) seed germination and seed production were enhanced with the exogenous bacterial inoculation by 20.39 and 16.43%, respectively. Under both multi-metal(loid) regimes the bacterial inoculation promoted shoot length (22.65-51.34%), shoot dry weight (33.89-66.11%) and seed production (13.46-35%). Under bacterial manipulation the metal(loid)s immobilization increased with concomitant curtailment of translocation in lentil plant by 61.89-75.14% and 59.19-71.14% in shoot and seed, respectively. The strain biomineralized struvite (MgNH4 PO4 ·6H2O) from human urine @ 403 ± 6.24 mg L-1. The fertilizer potential of struvite was confirmed with the promotion of cowpea (Vigna unguiculata) growth traits e.g. leaf number (37.04%), pod number (234%), plant wet weight (65.47%) and seed number (134.52%). Thus Serratia sp. KUJM3 offers multiple benefits of metal(loid)s bioremediation, As(V) reduction, plant growth promotion, and struvite biomineralization garnering a suite of appealing environmental applications.

Deposition of trace metals associated with atmospheric particulate matter: Environmental fate and health risk assessment.

Anthropogenic and natural sources influence trace metals (TMs) bound to different sized particulate matter (PM) in dry and wet atmospheric deposition, which can create ecosystem and human health issues in the long run. Limited reviews are available summarizing worldwide concentrations in TMs in atmospheric PMs, their sources and pathways. Simultaneously, quantitative assessment of the potential human and ecosystem health risks imposed by the atmospheric particulate matter has not been adequately reviewed. Addressing this gap, here we review, the concentration of TMs in dry deposition mainly varies with the responsible sources, whereas, in wet deposition, it depends on the solubility of TMs. Other than deposition on impervious surfaces, the TMs incorporated PM can be deposited on biological agents. Health risk assessments show that ingestion and dermal contact pathways are more likely to cause health issues, however, the probability of occurring ingestion and dermal contact pathways is limited. Attention must be paid to the contribution from non-exhaust and exhaust vehicular emissions for TMs in atmospheric deposition, understanding their impact on stormwater management and urban agriculture. Behaviors of TMs in the atmosphere depends on many complex factors including origin, wind patterns, and weather conditions. Therefore, future research needs to be carried to model and predict the fate and transfer of TMs once they are generated through natural and anthropogenic sources. We believe that such research would allow establishing pollution control policies and measures in urban environments which will be critical to reduce the levels of TMs associated with atmospheric deposition in the environment.

Unregulated discharge of wastewater in the Mahanadi River Basin: Risk evaluation due to occurrence of polycyclic aromatic hydrocarbon in surface water and sediments.

Exposure to polycyclic aromatic hydrocarbons (PAHs) through contaminated water may adversely affect human health and ecology. Water and sediment samples collected from the Mahanadi River Basin (MRB) were analyzed for the presence of sixteen priority PAHs. Results showed that the concentrations of Σ16 PAHs in water and sediments ranged from 13.1 to 685.4 µg/L and 302.6 to 728.2 ng/g. In river water samples, the highest mean concentrations were recorded for Acenaphthylene (18.73 ± 11.61 µg/L) and Benzo(a)Anthracene (10.11 ± 8 µg/L). On the contrary, the maximum concentration was recorded for Phenanthrene (96.18 ± 50.66 ng/g) and Pyrene (76.69 ± 22.73 ng/g) in sediment samples. Human health risk assessment suggests low risk, with incremental lifetime cancer risk (ILCR) being 37.44 × 10-5 for children and 21.82 × 10-5 for adults. In contrast, ecological risk assessment showed a high toxic equivalent quotient of 40.68 ng/g and mutagenic equivalent quotient of 39.74 ng/g suggesting elevated adverse risk to aquatic species.

Characterization, Behavior, and Risk Assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in the Estuary Sediments.

Polycyclic aromatic hydrocarbons (PAHs) are persistent toxic substances that have ubiquitous presence in water, air, soil, and sediment environments. The growth of PAH toxicities and related ecotoxicology risk in estuary sediment has a serious concern. Present study examined the PAHs concentration, sources, and ecological risk from selected sites in Subarnarekha River estuary (SRE) sediment deposits. The sum of toxic 16 PAHs was ranged from 36.8 to 670.8 ng/g (mean = 223.46 ± 196.35 ng/g). The total PAH concentration varied significantly among the sampling sites (range 511.3 ng/g to 233.8 ng/g) based on allochthonous contaminant loads. Among the 16 compounds, Phen had the highest concentration (40.18 ng/g), followed by Pye (31.86 ng/g), Flur (29.36 ng/g), and NA (19.33 ng/g). Most of the sampling sites contained abundant 3-ring and 4-5-ring PAHs. Based on diagnostic ratios and PCA analysis petroleum combustion, biomass, and coal-burning have been identified as the major sources. The PAHs had high mutagenic equivalent factor and toxic equivalent factor values posing great ecological threats and health risks.

Per- and polyfluoroalkyl substances in water and wastewater: A critical review of their global occurrence and distribution.

Per- and polyfluoroalkyl substances (PFAS) are a family of fluorinated organic compounds of anthropogenic origin. Due to their unique chemical properties, widespread production, environmental distribution, long-term persistence, bioaccumulative potential, and associated risks for human health, PFAS have been classified as persistent organic pollutants of significant concern. Scientific evidence from the last several decades suggests that their widespread occurrence in the environment correlates with adverse effects on human health and ecology. The presence of PFAS in the aquatic environment demonstrates a close link between the anthroposphere and the hydrological cycle, and concentrations of PFAS in surface and groundwater range in value along the ng L-1-µg L-1 scale. Here, we critically reviewed the research published in the last decade on the global occurrence and distribution of PFAS in the aquatic environment. Ours is the first paper to critically evaluate the occurrence of PFAS at the continental scale and the evolving global regulatory responses to manage and mitigate the adverse human health risks posed by PFAS. The review reports that PFAS are widespread despite being phased out-they have been detected in different continents irrespective of the level of industrial development. Their occurrence far from the potential sources suggests that long-range atmospheric transport is an important pathway of PFAS distribution. Recently, several studies have investigated the health impacts of PFAS exposure-they have been detected in biota, drinking water, food, air, and human serum. In response to the emerging information about PFAS toxicity, several countries have provided administrative guidelines for PFAS in water, including Canada, the United Kingdom, Sweden, Norway, Germany, and Australia. In the US, additional regulatory measures are under consideration. Further, many PFAS have now been listed as persistent organic pollutants. This comprehensive review provides crucial baseline information on the global occurrence, distribution, and regulatory framework of PFAS.

Temporal variability of atmospheric particulate-bound polycyclic aromatic hydrocarbons (PAHs) over central east India: sources and carcinogenic risk assessment.

Atmospheric polycyclic aromatic hydrocarbons (PAHs) are of significant interest owing to their high potential health effects, including mutagenicity and carcinogenicity. We report 16 PAHs measured in ambient PM2.5 from June 2018 to May 2019 over three different sites located in central east India. The annual average PM2.5 mass concentrations of 97.3 ± 18.1 µg m-3, 101.9 ± 19.4 µg m-3, and 93.9 ± 20.3 µg m-3 were measured at RCI (Ranchi), GHY (Gamharia), and BKR (Bokaro), respectively. The mass concentrations at all sampling sites are relatively higher than the annual average concentration of the National Ambient Air Quality Standard. Total annual PAH concentrations (ng m-3) are found to be comparable at BKR (797.9 ± 39.1 ng m-3) and RCI (887.7 ± 38.8 ng m-3); however, a relatively higher average is observed over GHY (1015.1 ± 42.7 ng m-3). Using PAH diagnostic ratios and principal component analysis (PCA), their major sources were attributed to coal and wood combustion as well as vehicular emission of diesel and gasoline at all sampling sites. Significant seasonal variability is observed for PAH composition and mainly attributed to change in emission sources. Summer and winter compositions were found to be impacted by the transport from Indo-Gangetic Plains (IGP). However, ambient level PAHs during the post-monsoon season were impacted by mixed sources from Indo-Gangetic Plain and eastern India. These observations are supported by the analysis of back-trajectory and fire count data. The excess life time cancer risk (ELCR) values estimated for the study sites are within acceptable limits suggesting acceptable risk levels at BKR, GHY, and RCI. This study highlights the significance of ambient aerosol concentration for health risks in the pre-COVID-19 scenario.

Emission reduction of black carbon and polycyclic aromatic hydrocarbons during COVID-19 pandemic lockdown.

The global pandemic COVID-19 necessitated various responses throughout the world, including social distancing, use of mask, and complete lockdown. While these measures helped prevent the community spread of the virus, the resulting environmental benefits of lockdown remained mostly unnoticed. While many studies documented improvements in air quality index, very few have explored the reduction in black carbon (BC) aerosols and polycyclic aromatic hydrocarbons (PAHs) concentrations due to lockdown. In this study, we evaluated the changes in concentrations of BC, PAHs, and PM2.5 before and during the lockdown period. Our results show that lockdown resulted in a significant reduction in concentrations of these pollutants. The average mass concentration of BC, PAHs, and PM2.5 before the lockdown was 11.71 ± 3.33 µgm-3, 108.71 ± 27.77 ngm-3, and 147.65 ± 41.77 µgm-3, respectively. During the lockdown period, the concentration of BC, PAHs, and PM2.5 was 2.46 ± 0.95 µgm-3, 23.19 ± 11.21 ngm-3, and 50.31 ± 11.95 µgm-3, respectively. The diagnostic ratio analysis for source apportionment showed changes in the emission sources before and during the lockdown. The primary sources of PAHs emissions before the lockdown were biomass, coal combustion, and vehicular traffic, while during the lockdown, PAHs emissions were primarily from the combustion of biomass and coal. Similarly, before the lockdown, the BC mass concentrations came from fossil-fuel and wood-burning, while during the lockdown period, most of the BC mass concentration came from wood-burning. Human health risk assessment demonstrated a significant reduction in risk due to inhalation of PAHs and BC-contaminated air.

Characterization and health risk assessment of particulate bound polycyclic aromatic hydrocarbons (PAHs) in indoor and outdoor atmosphere of Central East India.

The selected 16 high-priority polycyclic aromatic hydrocarbons (PAHs) were characterized in PM2.5 in the indoor and outdoor air samples collected at the urban slum and rural sites in the Central East India. At the urban slum site, the indoor and outdoor concentrations of PAHs were 466.03± 11.94 ng/m3 and 321.71± 34.87 ng/m3, respectively. At the rural location, the indoor and outdoor concentrations were 294.85± 20.53 ng/m3 and 241.74± 29.04 ng/m3, respectively. Three-four and five-ring PAHs were found to be dominant in both urban slum and rural sites. Diagnostic ratio (DR) analysis and principal component analysis (PCA) conclude that diesel exhaust, gasoline, biomass, and coal combustion were the significant sources of 16 PAHs in indoor and outdoor environments, the urban slum and rural sites. Lifetime average daily dose (LADD) and incremental lifetime cancer risk (ILCR) values were calculated for health risk assessment for 6-year-old children and 24-year-old adults. The ELCR values in the urban slum site and the rural location were calculated 43.24 × 10-6 and 28.3 × 10-6. The ELCR values were observed between the acceptable limit 10-6-10-4 given by regulatory agency USEPA United States Environmental Protection Agency (1989).

COVID-19 lockdowns reduce the Black carbon and polycyclic aromatic hydrocarbons of the Asian atmosphere: source apportionment and health hazard evaluation.

ABSTRACT: The entire world is affected by Coronavirus disease (COVID-19), which is spreading worldwide in a short time. India is one of the countries which is affected most, therefore, the Government of India has implemented several lockdowns in the entire country from April 25, 2020. We studied air pollutants (i.e., PM2.5, Black Carbon (BC), and Polycyclic Aromatic Hydrocarbons (PAHs) level, and observed significantly sudden reduced. In India, most of the anthropogenic activities completely stopped. Therefore, we studied the levels of BC, PAHs and PM2.5 concentrations, their sources apportion, and health risk assessment during normal days, lockdown (from lockdown 1.0 to lockdown 4.0) and unlock down 1.0 situation at Sakchi, Jamshedpur city. It was observed that lockdowns and unlock down situations BC, PAHs and PM2.5 concentrations were significantly lower than regular days. We applied the advanced air mass back trajectory (AMBT) model to locate airborne particulate matter dispersal from different directions to strengthen the new result. The diagnostic ratio analyses of BC shows that wood burning contribution was too high during the lockdown situations. However, during normal days, the PAHs source profile was dedicated toward biomass, coal burning, and vehicle emission as primary sources of PAHs. During the lockdown period, emission from biomass and coal burning was a significant contributor to PAHs. The summaries of health risk assessment of BC quantified an equal number of passively smoked cigarettes (PSC) for an individual situation was studied. This study focuses on the overall climate impact of pandemic situations.

Health Risk Assessment, Composition, and Distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in Drinking Water of Southern Jharkhand, East India.

The studies on polycyclic aromatic hydrocarbons (PAHs) occurrence, distribution, health risk, and composition in drinking water are limited in India and worldwide. The main objective of this study was to find the contaminant sources, composition, health risk, and distribution of USEPA's 16 priority pollutant PAHs in the drinking water samples collected between July 2019 to September 2019 from six districts of Southern Jharkhand. The Σ16PAHs mean ± standard deviation [SD] concentration values were ordered as East Singhbhum (ES) (21.5 ± 14.8 ng L-1) > West Singhbhum (WS) (16.57 ± 13.21 ng L-1) > Saraikela Kharsawan (SK) (11.48 ± 9.92 ng L-1) > Khunti (KH) (10.32 ± 9.09 ng L-1) > Simdega (SM) (9.96 ± 7.85 ng L-1) > Gumla (GU) (9.41 ± 8.63 ng L-1). The results show that ES and WS districts' groundwater samples were more contaminated by the PAHs, which may be attributed to the presence of many small-, medium-, and large-scale industries and high vehicular density in these districts. The concentrations of lower molecular weight ring (3-rings) and middle molecular weight ring (4-rings) PAHs were dominant throughout all drinking samples. The concentration of the 3-ring PAH Anthracene and 4-ring PAH Fluoranthene were dominant in all districts. The molecular ratios suggested that the potential sources of PAHs are fuel combustion and coal, grass, and wood burning. Risk assessment shows that the incremental lifetime cancer risk and risk index (RI) were ranged from 0.02 × 10-10 to 4.93 × 10-10 for children and 0.01 × 10-10 to 2.98 × 10-10 for adults. The RI values for seven carcinogenic PAHs were 8.83 × 10-10 for children and 7.38 × 10-10 for adults. Although the carcinogenic risks were within the permissible values, chronic exposure to PAHs through the ingestion of drinking water could still be a human health concern.

An evolved fluorimetric determination of uranium in rock/mineral sample solutions containing hydrolysable elements such as Nb, Ta, Zr and Ti sequestered by bi-fluoride.

The aim of the present paper is to develop a novel method for fluorimetric determination of uranium in rock/mineral solutions containing hydrolysable elements such as Nb, Ta, Zr and Ti sequestered by bi-fluoride. These rocks/minerals are decomposed with ammonium bi-fluoride (NH4HF2) and sulfuric acid (H2SO4) mixture. Uranium in such mineral solutions is selectively extracted into ethyl acetate with 2,3-dihydroxynaphthalene at pH 10-12 in the presence of cetyltrimethylammonium bromide, prior to its pellet fluorimetric determination. Optimizations of certain parameters such as the effects of fluoride fluxes, mineral acids, masking agents and diverse ions are discussed in detail. This method is applied for the determination of uranium in synthetic mixtures and a set of in-house reference refractory minerals including certified reference material X1807 with a high degree of accuracy and precision. The results for the refractory minerals using the proposed method are in excellent agreement with results obtained by other standard methods. The novelty of the proposed method is that the decomposition mixture (NH4HF2/H2SO4) inhibits the hydrolysis of hydrolysable elements by formation of their soluble fluoro complexes, and the separation of uranium using the complexing agent 2,3-dihydroxynaphthalene is more eco-friendly compared to existing the conventional solvent extraction system using aluminum nitrate as the salting out agent.

Separation and Preconcentration of Trace Uranium(VI) by Solid Phase Extraction with 2,3-Dihydroxynaphthalene and Cetyltrimethylammonium Bromide on Molten Naphthalene and Its LED Fluorimetric Determination in Water Samples.

A simple and rapid solid phase extraction (SPE) procedure has been developed for the extraction and determination of uranium in water samples. The method is based upon the adsorption of uranium(VI)-2,3-dihydroxynaphthalene complex on microcrystalline naphthalene at the pH range 10 - 12 in the presence of a counter cation cetyltrimethylammonium ion. The solid mass consisting of uranium-2,3-dihydroxynaphthalene-CTA complex and naphthalene is ignited in the furnace at a temperature of 700°C for 1 h and then digested in dil. HNO3 solution. Uranium is then determined by LED fluorimetry using fluorescence enhancing pyrophosphate buffer. The effects of different variables like pH of the solution, reagent concentrations, counter cations, stirring time, interfering ions etc. have been investigated thoroughly for the quantitative recovery of uranium. The accuracy of the developed method has been ascertained by standard addition method as well as conventional pellet fluorimetry method involving co-precipitation of uranium using aluminum phosphate as a carrier.

Characteristics, toxicity, source identification and seasonal variation of atmospheric polycyclic aromatic hydrocarbons over East India.

Atmospheric PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) were analyzed over urban and rural sites during January to December 2018. Total annual average concentration of PM2.5 was 74.41 ± 24.96 µg/m3 over urban and 52.03 ± 13.11 µg/m3 over rural site during study time. The annual average concentration of PM2.5 over urban and rural atmospheres were found approximately twice in urban and found also higher over rural site, with respect to National Ambient Air Quality (NAAQ) standard of 40 µg/m3 for PM2.5 concentration. The annual concentration of PAHs was 750.80 ± 19.49 ng/m3 over urban, and, over rural, it was 559.59 ± 17.56 ng/m3. The seasonal variation of concentration of PAHs was in order of winter > post-monsoon > summer > monsoon. The most predominant PAHs were IcP (17.21%), B(ghi) P(15.22%), BkF (11.60%), DBahA (11.34%) and BbF (10.91%) to the total PAH concentration over urban site; over rural site, most predominant PAHs were IcP (16.02%), B(ghi)P, (15.63%), BkF (11.46%), DBahA (11.12%) and BbF (8.99%) of total PAHs. DBahA concentration was contributed approximately 46% carcinogenicity over both urban and rural sites, and BaP contributes 33.56% carcinogenicity over urban site and 34.62% carcinogenicity over rural site of total PAH samples. The Excess Life Time Cancer Risk (ELCR) values over urban were found at acceptable limit 10-6-10-4 given by the United States Environmental Protection Agency. Over rural site, the ELCR value was found near about acceptable limit. Diagnostic ratio analysis demonstrated that major sources of PAHs were pyrogenic sources and vehicular emission over study. Air parcel through trajectories over study site also contributed in PAH concentration.

Chemical characterization of carbonaceous carbon from industrial and semi urban site of eastern India.

Rigorous campaign was carried out from July 2013 to June 2014 at the remote and industrial site (Adityapur and Seraikela Kharsawan) in the eastern India aiming to identify and quantify the changes of aerosol chemical composition in the presence of industrial and biomass burning influence. The 24-h PM10 filter samples were analyzed by mass, carbonaceous species, organic ions. The results suggested that the average PM10 concentrations were 165 ± 43.93, 141 ± 30.86 µg/m(3) in industrial and remote site respectively. Secondary organic ions (SOC) were the dominant pollutants of PM10. Total carbon was a significant component explaining above 15 % of PM10. The annual average mass concentration of EC, OC, WSOC 26.39 ± 4.56, 5.11 ± 1.82, 18.56 ± 5.30 and 16.27 ± 5.75, 7.70 ± 2.1, 9.65 ± 1.92 µg/m(3), OC/EC, WSOC/OC 5.29 ± 1.08, 0.71 ± 0.17 and 2.34 ± 0.75, 0.67 ± 0.16) of industrial and remote site were respectively; and OC/EC particularly in industrial site it reached the highest 5.29 ± 1.08 which demonstrated that SOC should be a significant composition of PM10. The mass fraction of the highlighted species varies seasonally, resulting the air mass trajectories and corresponding cause severe strength. Based on exact mass concentration ratios of EC/OC, WSOC/OC, we predicted that industries and biofuel/biomass burning are a major source of atmospheric aerosols in the eastern part of India. This study provides the scientific baseline data of carbonaceous aerosols for eastern Jharkhand, India.