Seasonal variation in abundance and characteristics of microplastic in sewage sludge from major cities across the upper stretch of River Ganga, India.

Microplastic (MP) load in urban sewage sludge could vary annually in wastewater treatment plants (WWTPs) depending on seasonal precipitation and human activities. We investigated the seasonal dynamics in abundance and characterization of MP loading in WWTPs located in two cities across River Ganga, India's ecologically sensitive upper stretch. During a 12-month seasonal sampling (pre-monsoon, monsoon, and post-monsoon), sludge samples (n = 36) (primary sludge, PS; drying bed sludge, DBS) were collected and analyzed for load, polymer types, shape, colour, and size (20-1000 µm). Across the three seasons, MP concentrations (particles/kg) were found to be in the ranges of 93.4 ± 5.0 × 103-189.4 ± 11 × 103 in the PS and 39.6 ± 4.0 × 103-152.0 ± 7 × 103 in the DBS. The trend of MP loading was in the following order: monsoon > post-monsoon > pre-monsoon. The dominant MP size was 50-200 µm (36.22%) followed by 20-50 µm (27.65%), 200-500 µm (24.55%) and 500-1000 µm (11.58%). ATR-FTIR results revealed polypropylene, polyethylene terephthalate, polyvinyl chloride, and nylon dominating MP in sludge. This study highlights the importance of long-term monitoring of MP loading in sewage sludge to offer a more accurate estimate of MP contamination in sludge from WWTPs and develop a possible mechanism for its elimination to safeguard the environment.

Phycoremediation of milk processing wastewater and lipid-rich biomass production using Chlorella vulgaris under continuous batch system.

This study compiles the results of phycoremediation of milk processing wastewater (MPWW) and production of lipid-rich Chlorella vulgaris biomass using a continuous batch system operated for 12-wks. After a 4-wks interval, a new MPWW was loaded photobioreactor to provide appropriate nutrient supply to algae. Results indicated that MPWW supported the algal growth efficiently and the maximum algal growth was recorded in the ranges of 400.36 to 421.58 mg L-1 during 4-wk's of the cultivation cycle. Average reduction in total nitrogen, TN (45.82-69.18%); nitrate, NO3 (93.32-94.54%); total ammonium nitrogen, TAN (92.94-94.54%); sulphate, SO4-2 (85.13-87.34%); total phosphorus (75.09-78.78%); and biochemical oxygen demands, BOD (89.53-92.40%) was recorded during 12-wks phycoremediation of MPWW. Harvested algal biomass (dry weight basis, DW) exhibited a significant content of total sugar (45.5%) and total lipid (39.7%). The lipid profiling results indicated the presence of palmitic acid (39.9%), oleic acid (21.08%), linoleic acid (13.13%), and other C18 compounds in algal biomass, suggesting the suitability of MPWW for Chlorella vulgaris cultivations. Algal biomass exhibited a high heating value (MJ/Kg of DW) in the range of 17.3 to 25.1, comparable to other lignocellulose biomass to be used for bioenergy purposes. Results of this study indicate that MPWW could be utilized as a valuable medium for Chlorella vulgaris cultivation under a circular economy approach: wastewater treatment and bioenergy feedstock production. The effect of controlled environmental conditions on algal growth behavior and lipid composition in biomass, while using MPWW as a medium, could be investigated in future studies.

Spectre of SARS-CoV-2 RNA in the ambient urban waters of Ahmedabad and Guwahati: A tale of two Indian cities.

COVID-19 positive patients can egest live SARS-CoV-2 virus and viral genome fragments through faecal matter and urine, raising concerns about viral transmission through the faecal-oral route and/or contaminated aerosolized water. These concerns are amplified in many low- and middle-income countries, where raw sewage is often discharged into surface waterways and open defecation is common. Nonetheless, there has been no evidence of COVID-19 transmission via ambient urban water, and the virus viability in such aquatic matrices is believed to be minimal and not a matter of concern. In this manuscript, we attempt to discern the presence of SARS-CoV-2 genetic material (ORF-1ab, N and S genes) in the urban water (lakes, rivers, and drains) of the two Indian cities viz., Ahmedabad (AMD), in western India with 9 wastewater treatment plants (WWTPs) and Guwahati (GHY), in the north-east of the country with no such treatment facilities. The present study was carried out to establish the applicability of environmental water surveillance (E-wat-Surveillance) of COVID-19 as a potential tool for public health monitoring at the community level. 25.8% and 20% of the urban water samples had detectable SARS-CoV-2 RNA load in AMD and GHY, respectively. N-gene > S-gene > ORF-1ab-gene were readily detected in the urban surface water of AMD, whereas no such observable trend was noticed in the case of GHY. The high concentrations of SARS-CoV-2 genes (e.g., ORF-1ab; 800 copies/L for Sabarmati River, AMD and S-gene; 565 copies/L for Bharalu urban river, GHY) found in urban waters suggest that WWTPs do not always completely remove the virus genetic material and that E-wat-Surveillance of COVID-19 in cities/rural areas with poor sanitation is possible.

Fate of pharmaceutical active compounds (PhACs) from River Yamuna, India: An ecotoxicological risk assessment approach.

The river Yamuna is a major tributary of river Ganges and is a major source of freshwater in the National Capital Territory (NCT) catering 16.8 million people. This is the first report on occurrence, fate and ecotoxicological risk assessment of various pharmaceuticals active compounds (PhACs) in the Yamuna river. In this study, spatial and temporal distribution of nine PhACs "aspirin, ibuprofen, paracetamol, caffeine, ranitidine, diclofenac, carbamazepine, codeine, and diazepam", belonging to different therapeutic groups have been reported. Nine PhACs were analyzed in all the samples collected from the NCT stretch of river Yamuna. No specific trend in the distribution of the pharmaceutical residues was observed, however, the results revealed comparably higher PhACs contamination at YMN-2 (downstream Wazirabad, at this point, Najafgarh drain joins river Yamuna). Ecotoxicological risk assessment was carried out using Hazard quotients (HQ) for normal and worst case scenarios. The HQ showed that the levels of PhACs present in the samples were insufficient to cause acute toxicity to the flora and fauna of the river Yamuna. However, such residues could possibly cause chronic toxicity to the aquatic life and human beings as a huge amount of water of the river Yamuna is used for the drinking purposes in the NCT Delhi, the state capital of India.

Risk assessment of antibiotic residues in different water matrices in India: key issues and challenges.

Global detection of antibiotic substances in water matrices has considerably increased in the recent past. However, in India research on this issue is limited or generalised in the literature. Risks associated with the presence of antibiotics in the environment can be quantified using a hazard quotient (HQ) approach. Here, HQs were developed using the measured environmental concentration (MEC) approach for antibiotic residues in Indian water matrices previously reported in the literature. In the present study, environmental risk assessment, using the HQ index [HQ = measured environmental concentration (MEC)/predicted no effect concentration (PNEC)] for different antibiotics, was performed according to the guidelines of European Medicine Evaluation Agency (EMEA). MEC and PNEC levels were obtained from the literature. PNEC values were also calculated from EC50 using a safety factor when no PNECs were reported in the literature. HQs were obtained for industrial effluents (HQ = 10(4)) that were greater than any previously reported values. Ciprofloxacin, a fluoroquinolone antibiotic, seemed to present the greatest risk in India. The HQ indices for Indian water matrices were in the following order: industrial effluents > lake water > river water > hospital effluents > treated sewage ≃ groundwater. A very high HQ represents a potential environmental concern for aquatic environments in India and demands that immediate attention be devoted to regulating these compounds, especially in pharmaceutical industrial wastewater.

Occurrences and fate of selected human antibiotics in influents and effluents of sewage treatment plant and effluent-receiving river Yamuna in Delhi (India).

Antibiotics consumption has increased worldwide, and their residues are frequently reported in aquatic environments. It is believed that antibiotics reach aquatic water bodies through sewage. Medicine consumed for healthcare practices are often released into sewage, and after sewage treatment plant, it reaches the receiving water bodies of lakes or rivers. In the present study, we determined the fate of some commonly used antibiotics in a sewage treatment plant (STP) located in Delhi and the environmental concentration of these antibiotics in the Yamuna River, which receives the sewage and industrial effluent of Delhi. There are many reports on antibiotics occurrences in STP and river water worldwide, but monitoring data from the Indian subcontinent is sparse. Samples were taken from a STP and from six sampling sites on the Yamuna River. Several antibiotics were tested for using offline solid-phase extraction followed by high-performance liquid chromatography equipped with photodiode array analysis. Recoveries varied from 25.5-108.8 %. Ampicillin had the maximum concentration in wastewater influents (104.2 ± 98.11 µg l(-1)) and effluents (12.68 ± 8.38 µg l(-1)). The fluoroquinolones and cephalosporins had the lower concentrations. Treatment efficiencies varied between 55 and 99 %. Significant amounts of antibiotics were discharged in effluents and were detected in the receiving water body. The concentration of antibiotics in the Yamuna River varied from not detected to 13.75 µg l(-1) (ampicillin) for the compounds investigated.

Vermicomposting of milk processing industry sludge spiked with plant wastes.

This work illustrates the vermistabilization of wastewater sludge from a milk processing industry (MPIS) unit spiked with cow dung (CD), sugarcane trash (ST) and wheat straw (WS) employing earthworms Eisenia fetida. A total of nine experimental vermibeds were established and changes in chemical parameters of waste material have been observed for 90 days. Vermistabilization caused significant reduction in pH, organic carbon and C:N ratio and substantial increase in total N, available P and exchangeable K. The waste mixture containing MPIS (60%)+CD (10%)+ST (30%) and MPIS (60%)+CD (10%)+WS (30%) had better waste mineralization rate among waste mixtures studied. The earthworm showed better biomass and cocoon numbers in all vermibeds during vermicomposting operation. Results, thus suggest the suitability of E. fetida for conversion of noxious industrial waste into value-added product for land restoration programme.

Nitrate contamination in groundwater of some rural areas of Rajasthan, India.

Efforts were made to evaluate the level of nitrate in some agro-economy based rural habitations of northern Rajasthan, India. A total of 64 groundwater samples from 21 different villages/sub-villages of district Sri Ganganagar, India were collected and analyzed for nitrate (as NO(3)(-)), sulphate (as SO(4)(2-)) and few other parameters. NO(3)(-) level in groundwater was 7.10-82.0 mg l(-1) for individual samples. But average NO(3)(-) for total samples was 60.6+/-33.6 (SD) mg l(-1), which indicates the non-suitability of groundwater for drinking purposes, if BIS permissible limit (22.6 mg l(-1)) is considered as reference level. SO(4)(2-) ranged form 28.6 to 660.3 mg l(-1) in this area. The regression analysis indicates the difference sources for NO(3)(-) and SO(4)(2-) contamination in different regions rather than a common source. The point and non-point sources of NO(3)(-) and SO(4)(2-) in groundwater of this region may be N-fertilizer, sewerage, animal waste, organic manure, geology of sub-surface soil layers, pit latrines, etc. Results thus indicated that groundwater of this part of the State is severely polluted due to anthropogenic activities. The continuous consumption of such water may pose serious health hazardous in local residents.