In Mirzapur (U.P.), a power-starved district, the UASB (Upflow Anaerobic Sludge Blanket) technique was adopted. Almost all of the available technologies do not treat heavy metals, so, is the case with the UASB also. The present study is to assess how much heavy metal can get accumulated in plant tissues in different species. The result of the present study was that the concentration of Pb(1106.31)>Zn(221.45)>Cd(49.26)>Hg(23.37) mg/Kg in the sludge while the concentration of Zn(93.35)>Pb(52.00)>Hg(16.93)>Cd(1.53) mg/Kg in the soil. When the sludge was mixed with the soil the trend got changed and the trend was Pb(596.36)>Zn(219.86)>Cd(24.70)>Hg(22.63) mg/Kg. Three different species that were chosen for the study were Basella Alba (Spinach), Solanum Lycopersicum (Tomato) & Brassica Juncea (Mustard). The trend of accumulation of studied heavy metals in the Brassica Juncea (Mustard) was Zn(85.33)>Pb(25.88)>Hg(11.23)>Cd(0.99) mg/Kg. In Solanum lycopersicum (Tomato) the trend was Pb(231.11)>Zn(108.72)>Hg(12.43)>Cd(9.41) mg/Kg  and in Basella alba (Spinach) was Zn(103.81)>Pb(83.90)>Hg(10.78)>Cd(4.18) mg/Kg. Overall the study reveals that the accumulation of heavy metals takes place in plants grown in soil mixed with sewage sludge. The reduction in the concentration of Pb, Cd, Hg and Zn in sludge mixed with soil after the harvesting of plant in case of Solanum lycopersicum were 39.38%, 47.93%, 6.18% and 49.89% respectively; while in case of Basella alba these were 25.23%, 57.53%, 71.58% and 49.16% respectively; and in case of Brassica Juncea these reduction were 25.86%, 60.80%, 70.96% and 49.04% respectively.

Sludge/TiO2 composite was synthesized from drinking water treatment sludge, as a waste material and TiO2 , by a sol- gel method. Various sludge adsorbent / TiO2 ratios (1:1, 1:2 and 2:1 w/w) were prepared, and characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray Fluorescence (XRF), and BET. The prepared composites were applied successfully for photodegradation of methylene blue (MB) dye from a solution. The photocatalytic degradation of MB dye was investigated using UV irradiation, or UV/H2O2. Initial dye concentration, solution pH, composite dosage, and UV irradiation time were applied to study the optimum conditions for MB degradation. The results revealed the highest MB dye degradation with composite (2:1). It was found that the maximum MB degradation efficiency was at pH=7, 4 h irradiation time, 0.125 g composite dose, and 50 ppm initial dye concentration. MB removal efficiency was 95.7% using UV irradiation, and 99.8% of that using UV/ H2O2. The rate of MB dye degradation followed the first order kinetics. Results from this study offer the best conditions for recycling drinking water treatment sludge, and use it for wastewater treatment.

In recent decades, one of the environmental concerns is contamination with emerging pollutants of microplastics. Microplastics enter the environment through wastewater treatment plants and can absorb harmful pollutants. This study investigated microplastic pollution in the sludge of Zahedan wastewater treatment plants. To investigate microplastic pollution in the sludge of Zahedan wastewater treatment plants, 5 kg samples of sludge were passed through stainless-steel sieves and digested using H2O2 solution. NaCl was used based on density to separate microplastics. FESEM and FTIR analyses were used to investigate the surface morphology and polymer type of microplastics. The abundance of microplastic particles in the sludge ranged from 71-95 N/Kgdry.sludge, and their size varied from 25-500 micrometers. The most common color observed was transparent, and the fiber shape was the most prevalent. The study highlights the importance of addressing microplastic pollution in wastewater treatment plants to prevent harmful effects on the environment. Also, the data obtained from this study can be used to improve the treatment process and understand the removal of microplastics in urban wastewater treatment plants.

International audience | The Telesphore project aims to identify and to quantify the transfers of pharmaceuticals residues and biocides and their related processes from biosolids and manure spread on grassland as fertilizers. Real land-spreading conditions were reproduced on six in-situ lysimeters and the pathway of pharmaceuticals and biocides was tracked by sampling infiltrated water and soil over one year. The study has focused on 32 pharmaceuticals, biocides and their transformation products, selected from their previous detection in several organic fertilizers. Six months after biosolids and manure spreading, the soil concentrations were in the range of nanograms per gram of soil and only few compounds were detected in infiltrated water. Ketoprofen was found to be the most mobile and persistent pharmaceutical compound after biosolids application whereas thiabendazole was the most frequently detected substance in infiltrated water after manure amendment.

Chicken poultry industry produces a vast amount of feather waste and is often disposed into landfills, creating environmental pollution. Therefore, we explored the valorization of chicken feather waste into lipids and keratinous sludge biomass. This study demonstrates the successful utilization of keratinous sludge biomass as a unique precursor for the facile preparation of novel keratinous sludge biomass-derived carbon-based molybdenum oxide (KSC@MoO₃) nanocomposite material using two-step (hydrothermal and co-pyrolysis) processes. The surface morphology and electrochemical properties of as-prepared nanocomposite material were analyzed using HR-SEM, XRD, XPS, and cyclic voltammetric techniques. KSC@MoO₃ nanocomposite exhibited prominent electrocatalytic behavior to simultaneously determine hydroquinone (HQ) and catechol (CC) in environmental waters. The as-prepared electrochemical sensor showed excellent performance towards the detection of HQ and CC with broad concentration ranges between 0.5–176.5 μM (HQ and CC), and the detection limits achieved were 0.063 μM (HQ) and 0.059 μM (CC). Furthermore, the developed modified electrode has exhibited excellent stability and reproducibility and was also applied to analyze HQ and CC in environmental water samples. Results revealed that chicken feather waste valorization could result in sustainable biomass conversion into a high-value nanomaterial to develop a cost-effective electrochemical environmental monitoring sensor and lipids for biofuel.

Percolation of water through oily sludge during storage and handling of the sludge can cause soil and groundwater contamination. In this study, oily sludge from a refinery was equilibrated with water to obtain the water-soluble fraction (WSF) of oily sludge. The WSF had dissolved organic carbon (DOC) of 166 mg/L. Human cell line-based toxicity assay revealed IC₅₀ of 41 mg/L indicating its toxic nature. The predominant compounds in WSF of oily sludge included isomers of methyl, dimethyl and trimethyl quinolines and naphthalenes along with phenol derivatives and other polynuclear aromatic hydrocarbons (PAHs). Biodegradation of WSF of oily sludge was studied using a consortium of Rhodococcus ruber, Bacillus sp. and Bacillus cereus isolated from the refinery sludge. The consortium of the three strains resulted in 70% degradation over 15 days with a first-order degradation rate of 0.161 day⁻¹. Further analysis of the WSF was performed using the stir-bar sorptive extraction (SBSE) followed by GCxGC-TOF MS employing a PDMS Twister. The GCxGC analysis showed that Bacillus cereus was capable of degrading the quinoline, phenol and naphthalene derivatives in WSF of oily sludge at a faster rate compared to pyridine and benzoquinoline derivatives. Quinoline, phenol, biphenyl, naphthalene, pyridine and benzoquinolines derivatives in the WSF of oily sludge were reduced by 87%, 92%, 88%, 77%, 40% and 62%, respectively with respect to the controls. The WSF of oily sludge contained, n-alkanes, ranging from n-C12 to n-C18 which were removed within 2 days of biodegradation.

This study aims to investigate the effects of long-term nicosulfuron residue on an herbicide factory ecosystem. High-throughput sequencing was used to investigate the environmental microbial community structure and interactions. The results showed that the main contributor to the differences in the microbial community structure was the sample type, followed by oxygen content, pH and nicosulfuron residue concentration. Regardless of the presence or absence of nicosulfuron, soil, sludge, and sewage were dominated by groups of Bacteroidetes, Actinobacteria, and Proteobacteria. Long-term exposure to nicosulfuron increased alpha diversity of bacteria and archaea but significantly decreased the abundance of Bacteroidetes and Acidobateria compared to soils without nicosulfuron residue. A total of 81 possible nicosulfuron-degrading bacterial genera, e.g., Rhodococcus, Chryseobacterium, Thermomonas, Stenotrophomonas, and Bacillus, were isolated from the nicosulfuron factory environmental samples through culturomics. The co-occurrence network analysis indicated that the keystone taxa were Rhodococcus, Stenotrophomonas, Nitrospira, Terrimonas, and Nitrosomonadaceae_MND1. The strong ecological relationship between microorganisms with the same network module was related to anaerobic respiration, the carbon and nitrogen cycle, and the degradation of environmental contaminants. Synthetic community (SynCom), which provides an effective top-down approach for the critical degradation strains obtained, enhanced the degradation efficiency of nicosulfuron. The results indicated that Rhodococcus sp. was the key genus in the environment of long-term nicosulfuron exposure.

Serious pollution is caused by heavy metals (HMs) emission during sludge combustion treatment, but the addition of minerals has the ability to alleviate the migration of HMs to the gaseous state. In this study, HMs (As, Cr, Zn and Cu) behavior, speciation, and environmental risk during sludge combustion with CaO and montmorillonite (MMT) additive was investigated in the lab-scale tube furnace. The results showed that the sludge combustion was mainly determined by volatile matter. In general, CaO inhibited the volatilization of Cr, Zn, and Cu, but promoted As volatilization. MMT inhibited the volatilization of HMs, but the effect was not obvious at high temperatures. Besides, the improvement of retention effect was not found for Cr and Cu with the increase of CaO at 1000 °C, there might exist threshold value for CaO on HMs retention process. Meanwhile, CaO increased acid-soluble fraction of As significantly at high temperatures, decreased residual fraction of Cr by oxidation, converted Zn and Cu to residual fraction. MMT increased the acid-soluble fraction of As and residual fraction of Cr. In view of the HMs environmental risk in ash, the combustion temperature of sludge was necessary to control under 1000 °C and minerals additive amount was needed to manage above 1000 °C.

Although concerns have been raised about co-selection for antibiotic resistance and various antibiotics and non-antibiotic agents, the data on their association in urban sludge is still limited. In addition, antibiotic contamination can result in not only the toxicity but also the antibiotic resistance. In this study, the first large-scale identification of antibiotics and non-antibiotic agents concern for co-selection of resistance against antibiotics was conducted in urban sludge. Co-occurrence analysis showed that antibiotic resistance genes (ARGs) had no significant correlation with the corresponding antibiotics. Therefore, the results of co-occurrence analysis based on antibiotic concentration and ARG abundance were always ambiguous and difficult to interpret. However, antibiotic resistance was positively correlated with highly toxic compounds such as diclofenac, enrofloxacin and nicotine, suggesting that environmental contaminants might influence antibiotic resistance while exerting toxicity through mechanisms such as changes in microbial community and enzyme activity. The close correlation between class 1 integrase gene (intI1) and diclofenac/enrofloxacin indicated that the co-selection scenario between environmental contaminants and ARGs was likely mediated via intI1. In total, the derived co-occurrence patterns improve our understanding of the co-selection between ARGs, antibiotics and non-antibiotic agents, and also reaffirm the importance of potential role of non-antibiotic agents in the global spread of antibiotic resistance.

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.