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Sewage treatment plant (STP) acts as a potential source of microplastic contamination in the environment. The presence of microplastics in the sewage treatment plant is reported over the globe in varying concentrations. Hence, the current study is intended to evaluate the presence and abundance of microplastics occurring in sewage treatment plants in India. The samples were processed through digestion and density separation, followed by microscopic and polymer identification through Fourier transform infrared spectroscopy. Also, different wastewater parameters were studied to analyze their influence. High microplastic concentrations were detected in the influent (1860 ± 265 MPs/L), which reduced by > 90%, to around 148 ± 51 MPs/L in the effluent. The concentration of microplastics in sewage sludge was 830 MPs/kg. The prominent plastic types identified include low-density polyethylene, polypropylene, polyurethane, polyvinyl chloride, and rayon. The smaller particles prevail in the effluent, releasing around 30 billion particles per day to the environment. This suggests that the current STP is efficient in removing the majority of the particles, but considerations are needed to avoid the ecological risks associated. [ABSTRACT FROM AUTHOR]

There has been a ton of debate on developing goals and the conflicts regarding environmental preservation. In the wastewater treatment industry, biochar seems to appear as a low-cost and environmentally friendly alternative because of its high porosity and adsorbent capacity. This study used the Scopus database to map articles on the topic through a systematic methodology and screening. The results demonstrate the approach researchers are giving to biochar adsorbing characteristics. It was observed that research about biochar applied to wastewater is recent and shortage. China and India were the countries that most published about it. Sewage sludge was the most common biomass used for biochar production, and pyrolysis temperature remained mainly at 300° C to 700 °C. Also, the removal of heavy metals was the greater purpose of the studies. Finally, this mapping described biochar formation and its use as an adsorbent for wastewater treatment purposes, providing important data for directing future studies. [ABSTRACT FROM AUTHOR]

The use of sewage sludge in agriculture is known to be environmentally friendly as it is a practical way of recycling municipal waste. A short-term experiment was carried out to study the changes in soil chemical and microbiological properties influenced through the addition of sewage sludge along with saline irrigation under a pearl millet-wheat crop rotation. There were three irrigation (canal water (0.35 dS m-1), 8 and 10 dS m-1 electrical conductivity saline water) and five fertilizer treatments (control-F1, sewage sludge (5 t ha-1)-F2, sewage sludge (5 t ha-1) +50% recommended dose of fertilizer (RDF)-F3, sewage sludge (5 t ha-1)+75% RDF-F4 and RDF-F5). The results showed that soil organic carbon, and available nitrogen, and phosphorus were reduced significantly under saline conditions but there was an increase in available potassium with the increasing salinity levels of the irrigation water. A significant reduction in soil microbial biomass carbon and enzyme activities was caused by 8 and 10 dS m-1 as compared to 0.35 dS m-1 at different growth stages of crops. Treatment F4 attained the highest soil microbial activity at each crop growth stage by a significant margin among all of the fertilizer treatments, which is associated with a substantial build-up of organic carbon and available NPK in the soil. Soil microbial activities followed a particular trend: at 35 and 75 days after sowing>harvest>sowing in pearl millet and wheat, respectively. Sewage sludge dumping is a major problem in India, and the present study suggests that by applying sewage sludge, soil biological health is improved; therefore its use in agriculture is recommended to farmers. [ABSTRACT FROM AUTHOR]

Sewage treatment plants (STPs) as a carrier of microplastics (MPs) have received considerable attention worldwide recently. In India, the majority of studies on MPs have been conducted in sediments, riverine, and marine systems, while knowledge on MPs occurrence in STPs is scarce. Henceforth, this work evaluated the presence of MPs in sewage and sludge in a hybrid growth, secondary treatment-based STP system. Optical microscopy, scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy methods were used to examine the abundance of MPs in raw sewage, effluent from different treatment units of the STP, and sludge samples. A total number of MPs of 201 ± 19 (2021) and 197 ± 22 (2022) were detected in the studied STP system. Results showed that MPs ranged between 64.3 ± 4.89–47.66 ± 4.71 n/L (sewage) and 1.14 ± 0.30–1.38 ± 0.65 n/g (sludge) with the overall removal efficacy of the studied STP estimated to be around 80%. Fragments and fibers were predominant among all shapes and particles mostly belonged to sizes <50 μm and <50 μm–250 μm in sewage and sludge, respectively. In total, seven polymers were identified of which low-density polyethylene (LDPE) constituted the highest proportion in sewage (26%–31%) and polyvinyl chloride (PVC) contributed the highest in the sludge (22%–27%). Moreover, MPs control measures have been discussed based on the findings of this study to restrict MPs re-entry into the environment via treated effluent and sludge. [Display omitted] • First study on MPs occurrence and removal in a hybrid growth MBBR-based STP. • Around 80% MPs were removed via the primary and secondary treatment stages in the STP. • LDPE (in sewage) and PVC (in sludge) were the most prevalent polymers. • Small-sized MPs (<250 μm) like fragments and fibers were predominant shapes. • Advanced treatment options for MPs removal from secondary-treated effluent discussed. [ABSTRACT FROM AUTHOR]

Distillery sludge is a major source of aquatic pollution, but little is known about their microbial community and their association with the organic and metal pollutants. Sugarcane molasses-based distillery is an important industry in India, although the waste is usually treated prior to disposal, the treatment is often inadequate. The adverse effects of the organic and metal pollutants in sugarcane molasses-based distillery sludge on the microbial biodiversity and abundance in the disposal site have not been elucidated. This study aims to address this gap of knowledge. Samples were collected from the discharge point, 1 and 2 km downstream (D1, D2, and D3, respectively) of a sugarcane distillery in Uttar Pradesh, India, and their physico-chemical properties characterised. Using QIIME, taxonomic assignment for the V3 and V4 hypervariable regions of 16 S rRNA was performed. The phyla Proteobacteria (28–39%), Firmicutes (20–28%), Bacteriodetes (9–10%), Actinobacteria (5–10%), Tenericutes (1–9%) and Patescibacteria (2%) were the predominant bacteria in all three sites. Euryechaeota, were detected in sites D1 and D2 (1–2%) but absent in D3. Spirochaetes (5%), Sinergistetes (2%) and Cloacimonetes (1%) were only detected in samples from site D1. Shannon, Simpson, Chao1, and Observed-species indices indicated that site D1 (10.18, 0.0013, 36706.55 and 45653.84, respectively) has higher bacterial diversity and richness than D2 (6.66, 0.0001, 25987.71 and 49655.89, respectively) and D3 (8.31, 0.002, 30345.53 and 30654.88, respectively), suggesting the organic and metal pollutants provided the stressors to favour the survival of microbial community that can biodegrade and detoxify them in the distillery sludge. This study confirmed that the treatment of the distillery waste was not sufficiently effective and provided new metagenomic information on its impact on the surrounding microbial community. It also offered new insights into potential bioremediation candidates. [Display omitted] • First report of bacterial community and profile in sugarcane distillery sludge. • Proteobacteria (28–39%), Firmicutes (20–28%) & Actinobacteria (5–10%) detected. • Organic and metal pollutants exerted selective pressure on microbial community. • Highest diversity (H' >10) and richness (Chao1>36706) in the most polluted site. • Bacterial community could provide candidates for sustainable remediation. [ABSTRACT FROM AUTHOR]

Urbanization and industrialization has increased the strength and qualities of municipal sewage in Bangalore, India. The disposal of sewage into natural water bodies became a serious issue. Byramangala reservoir is one such habitat enormously polluted in South India. The water samples were collected from four hotspots of Byramangala tank in 3 months. The biochemical oxygen demand (BOD) and bacterial counts were determined. The fecal coliforms were identified by morphological, physiological, and biochemical studies. The antibiotics sensitivity profiling of isolated bacteria were further carried out. We have noticed that a high content of BOD in the tank in all the 3 months. The total and fecal counts were found to be varied from 1.6 × 10 to 8.2 × 10 colony forming unit/ml and >5,500/100 ml, respectively. The variations in BOD and total count were found to be statistically significant at p > 0.05. Many pathogenic bacteria were characterized and most of them were found to be multidrug resistant. Salmonella showed resistance to cefoperazone, cefotaxime, cefixime, moxifloxacin, piperacillin/tazobactam, co-trimoxazole, levofloxacin, trimethoprim, and ceftazidime. Escherichia coli showed resistance to chloramphenicol, trimethoprim, co-trimoxazole, rifampicin, and nitrofurantoin while Enterobacter showed resistant to ampicillin, cefepime, ceftazidime, cefoperazone, and cefotaxime. Klebsiella and Shigella exhibited multiple drug resistance to conventional antibiotics. Staphylococcus showed resistance to vancomycin, methicillin, oxacillin, and tetracycline. Furthermore, Salmonella and Klebsiella are on the verge of acquiring resistance to even the strongest carbapenems-imipenem and entrapenem. Present study revealed that Byramanagala tank has become a cesspool of multidrug-resistant 'superbugs' and will be major health concern in South Bangalore, India. [ABSTRACT FROM AUTHOR]

An investigation was conducted from 2001 to 2005 for determining the residual concentration of five pesticides, viz., total-HCH, total-DDT, total-Endosulfan, Dimethoate and Malathion in fish samples collected from various points of the river Ganga. Fish samples were analyzed for pesticide residues using standard laboratory procedures by GC method. It was found that total-HCH concentration remains above the MRL values for maximum number of times in comparison to four other pesticides. The pesticide contamination to fish may be due to indiscriminate discharge of polluted and untreated sewage-sludge to the river. The pesticide contents in some places are alarming. Thus proper care, maintenance, treatment and disposal of sewage water and sludge are most vital and should be the prime thrust for the nation. [ABSTRACT FROM AUTHOR]

Abstract: Use of sewage sludge, a biological residue produced from sewage treatment processes in agriculture is an alternative disposal technique of waste. To study the usefulness of sewage sludge amendment for palak (Beta vulgaris var. Allgreen H-1), a leafy vegetable and consequent heavy metal contamination, a pot experiment was conducted by mixing sewage sludge at 20% and 40% (w/w) amendment ratios to the agricultural soil. Soil pH decreased whereas electrical conductance, organic carbon, total N, available P and exchangeable Na, K and Ca increased in soil amended with sewage sludge in comparison to unamended soil. Sewage sludge amendment led to significant increase in Pb, Cr, Cd, Cu, Zn and Ni concentrations of soil. Cd concentration in soil was found above the Indian permissible limit in soil at both the amendment ratios. The increased concentration of heavy metals in soil due to sewage sludge amendment led to increases in heavy metal uptake and shoot and root concentrations of Ni, Cd, Cu, Cr, Pb and Zn in plants as compared to those grown on unamended soil. Accumulation was more in roots than shoots for most of the heavy metals. Concentrations of Cd, Ni and Zn were more than the permissible limits of Indian standard in the edible portion of palak grown on different sewage sludge amendments ratios. Sewage sludge amendment in soil decreased root length, leaf area and root biomass of palak at both the amendment ratios, whereas shoot biomass and yield decreased significantly at 40% sludge amendment. Rate of photosynthesis, stomatal conductance and chlorophyll content decreased whereas lipid peroxidation, peroxidase activity and protein and proline contents, increased in plants grown in sewage sludge-amended soil as compared to those grown in unamended soil. The study clearly shows that increase in heavy metal concentration in foliage of plants grown in sewage sludge-amended soil caused unfavorable changes in physiological and biochemical characteristics of plants leading to reductions in morphological characteristics, biomass accumulation and yield. The study concludes that sewage sludge amendment in soil for growing palak may not be a good option due to risk of contamination of Cd, Ni and Zn and also due to lowering of yield at higher mixing ratio. [Copyright &y& Elsevier]

Sewage sludge, generated post wastewater treatment, constitutes only a small percentage of the total amount of sewage treated, however, its sustainable management is inevitable. In this study, the energy recovery potential of sewage sludge by incineration and anaerobic digestion is investigated for India. The dewatered sludge has total solid content of 25–45% whereas, the primary characteristics of sewage sludge showed significant organic content of about ∼23–40% (dry basis). The calorific value was found to be 8–21 MJ/kg for sludge dry matter. The energy recovery potential of sewage sludge was 555–1068 kWh/tonne on sludge dry matter basis for incineration and 315–608 kWh/tonne for anaerobic digestion. Additionally, the energy recovery potential of current sewage treatment in India was found to be ∼15.3 × 105 or 8.6 × 105 MWh, annually for incineration and anaerobic digestion, respectively. The study had provided in depth view of sludge to be considered as energetic material and its energy recovery potential countrywide, which would not only help for give a proper direction for recovering energy but also helpful to deal with the issue of sludge management in India. Image 1 • Sludge generated from sewage treatment plants was explored for energy alternatives. • The sewage sludge contains high heating value, organic matter and volatile matter etc. • Energy recovery potential of sewage sludge produced in India was estimated. • The energy recovery from sewage sludge could reduce energy demands and reduce land requirement for its disposal as well. [ABSTRACT FROM AUTHOR]

Sewage sludge (SS) management has been regarded as a serious environmental and health issue around the globe, especially in developing countries like India, mainly due to the lack of proper regulatory criteria, and appropriate engineering infrastructures. The present research work demonstrates the utilization of Fly Ash (FA) in varying percentages (with an interval of 10%) with SS as brick for sustainable building material with special emphasis on dimensional Effect. The impact of dimensional effect is measured using compressive strength behaviour for a stress rate of 14 MPa/min of two different sizes of brick i.e. D1 and D2 of sizes 7 × 7x7 cm3 and 2 × 2x2 cm3, respectively. Owing to the sintering effect, the maximum strengths of 4.02 MPa and 7.6 MPa are noticed for a composition of 60% SS+40% FA for D1 and 40% SS + 60% FA for D2, respectively. According to the Indian Standards (IS) 13757: 1993, an exhibited strength of more than 3.5 MPa by any brick composition enables it to be used as a common building brick. In general, due to the formation of triangular wedges, the D2 bricks exhibited better strength for any mixing ratio of FA and SS. The added benefit in our study was lower thermal conductivity (0.48 Wm−1K−1) of the prepared fired brick implying its better insulation property. Our study uniquely highlights the possible utilization of FA for stabilizing SS for sustainable substitution of natural clay fired brick. Future study may further investigate the compositional effect of FA on the thermal and thermodynamic attributes of the bricks. Image 1 • Pioneer study on bricks that visualizes dimensional effect along with mechanical properties. • 40–60% fly ash with sewage sludge satisfies Indian codal provisions as construction material. • Thermal conductivity of synthesized brick is lower than conventional fired clay bricks. • Dimensional effect significantly influences the compressive strength behaviour. [ABSTRACT FROM AUTHOR]

Occurrence of 15 different pharmaceuticals and personal care products (PPCPs) (ibuprofen, diclofenac, ketoprofen, acetaminophen, ciprofloxacin, erythromycin, amoxicillin, ofloxacin, tetracycline, metoprolol, triclosan, salicylic acid, N, N diethyl-meta-toluamide, caffeine and β-Estradiol) belongs to eight different classes in an urban stretch of River Ganges were detected for three seasons in two holy cities Rishikesh and Haridwar (India). The overall concentration of PPCPs in the River Ganges ranged between Below Detectable Limit (BDL) to 1104.84 ng/L, with higher concentrations at anthropogenically influenced lower reaches of the River Ganges at Haridwar. Acetaminophen, triclosan, N, N diethyl-meta-toluamide (DEET), tetracycline, and caffeine showed the highest detection frequency (>90-100%) in the river. PPCPs concentration, especially for NSAIDs (Ibuprofen, ketoprofen and acetaminophen), antibiotics (ciprofloxacin, tetracycline and ofloxacin) and metabolite (salicylic acid) was found to be higher in winter compared to summer in the Ganges, possibly due to the lower biodegradation efficiency related to lesser temperatures and inadequate sunlight. While metoprolol (beta-blockers), triclosan (antibacterial), DEET (insect repellent) and caffeine (human indicator) showed a higher load in summer, possibly due to their intense uses during this period. Results of risk quiescent (RQ) revealed higher ecological risk for algae while the moderate risk for river fish biota., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Chemical speciation of cadmium (Cd) in four contrasting Indian soil types, namely, an ultisol, an alfisol, an entisol and a vertisol withand without sewage sludge amendment was studied for a period of 16 weeks, utilising sequential extraction methods involving different chemical extractants, namely, 0.5 M KNO 3, deionised water, 0.5 M NaOH, 0.05 M Na 2 EDTA and 4 M HNO 3, representing the exchangeable, adsorbed, organic-bound, carbonate and sulfide/residual forms of Cd, respectively. Results indicated that the extractability of Cd in the four soil types varied according to the pHand CEC of soils. At acidic pH and low CEC, high amounts of plant-available forms of Cd (exchangeable + adsorbed + organic-bound fractions) could be extracted, whereas, alkaline pH and high CEC favoured thepresence of fixed or bound forms of Cd (carbonate + sulfide/residualfractions). Further, irrespective of the soil types, the sewage sludge and Cd-enriched sewage sludge treatments resulted in the predominant extraction of the carbonate fraction at different periods of incubation. [ABSTRACT FROM AUTHOR]