Polluted waters are an important reservoir for antibiotic resistance genes and multidrug-resistant bacteria. This report describes the microbial community, antibiotic resistance genes, and the genetic profile of extended spectrum β-lactamase strains isolated from rivers at, Pune, India. ESBL-producing bacteria isolated from diverse river water catchments running through Pune City were characterized for their antibiotic resistance. The microbial community and types of genes which confer antibiotic resistance were identified followed by the isolation of antibiotic-resistant bacteria on selective media and their genome analysis. Four representative isolates were sequenced using next generation sequencing for genomic analysis. They were identified as Pseudomonas aeruginosa, Escherichia coli, and two isolates were Enterobacter cloacae. The genes associated with the multidrug efflux pumps, such as tolC, macA, macB, adeL, and rosB, were detected in the isolates. As MacAB-TolC is an ABC type efflux pump responsible for conferring resistance in bacteria to several antibiotics, potential efflux pump inhibitors were identified by molecular docking. The homology model of their MacB protein with that from Escherichia coli K12 demonstrated structural changes in different motifs of MacB. Molecular docking of reported efflux pump inhibitors revealed the highest binding affinity of compound MC207-110 against MacB. It also details the potential efflux pump inhibitors that can serve as possible drug targets in drug development and discovery.

It is necessary to determine an environmentally friendly method of reusing the vast amount of coal waste that is generated during coal preparation. This study evaluates the applicability of using weathered coal waste in a permeable reactive barrier to prevent groundwater contamination. Coal waste, with different weathering degrees, was obtained from two coal mining sites in South Jeolla Province, Korea. The reactivities of the coal waste with inorganic contaminants, such as copper, cadmium, and arsenic, were examined in batch and column experiments. The batch experiment results indicate that the coal waste removal efficiencies of copper (99.8%) and cadmium (95.4%) were higher than those of arsenic (71.0%). The maximum adsorption capacities of coal waste for copper, cadmium, and arsenic calculated from the Langmuir isotherm model were 4.440 mg/g, 3.660 mg/g, and 0.718 mg/g, respectively. The equilibrium of adsorption was attained within 8 h. The column experiment results reveal that the coal waste effectively removed inorganic contaminants under flow-through conditions. Faster breakthrough times were observed in single solute system (As(V) = 19.3 PV, Cu(II) = 47.6 PV) compared with binary solute system (As(V) = 27.8 PV, Cu(II) = 65.4 PV). To confirm the applicability of using coal waste in a groundwater environment, its decontamination ability was analyzed at low concentrations and under various pH conditions. To examine the potential ecological risks in the subsurface environment, a test to determine acute toxicity to Daphnia magna and a toxic characteristic leaching procedure (TCLP) test were conducted. The coal waste was found to satisfy appropriate standards. The acute toxicity test also confirmed the ecological safety of using coal waste in a groundwater environment. The acceptably high capacity and fast kinetics of inorganic contaminant sorption by the coal waste indicate it could potentially be employed as a reactive material. The recycling and application of this abundant waste material will contribute to solving both coal waste disposal and water pollution problems.

Although environment protection efforts worldwide, the chemistry and biological contamination of waters represents an important challenge to be overcome, especially regarding its contamination by domestic wastewater effluents. In this context, this research presented an analysis by using an innovative wastewater treatment system for domestic effluents based on the electro-oxycoagulation approach implanted in wastewater treatment station located at Palma Sola, Santa Catarina, Brazil. We evaluated samples from domestic effluent (before and after treatment), fountain water, and river water collected from the municipality water system, as well as investigated the residual compound yielded by wastewater treatment. In these samples, we performed physicochemical analysis, investigation of viable helminth eggs, and toxicity and microbiological measurements before and after the treatment. Further, the levels of contaminant metals by X-ray fluorescence-based technique were analyzed. Results show an improvement in the quality of treated water, as demonstrated by microbiological, physicochemical, toxicity, and metal analysis of effluent after treatment. After treatment, river water and fountain water levels of metals in accordance with the maximum limits allowed by Brazilian regulatory agencies. Analysis of residual compound indicated that the workers that handle the residue were not contaminated with the identified metals. Thus, the electro-oxycoagulation-based method demonstrated high efficiency for the treatment of domestic effluents and further prevents contamination of the rivers by the released effluent without treatment.

A series of Ho-modified Mn/Ti catalysts with various content of Ho were prepared by impregnation method, and the low-temperature catalytic performance was tested. Techniques of BET, SEM, XRD, H₂-TPR, and XPS were carried out to research the effects of Ho modification on the physicochemical properties of Mn/Ti catalysts. Results showed that appropriate Ho addition could reduce the starting temperature of Mn/TiO₂ catalyst to 100 °C. 0.2HoMn/Ti exhibiting a wider temperature range of 140~220 °C with nearing 100% NOₓ conversion. It was found that the 0.2HoMn/TiO₂ catalyst possessed a better dispersion of active component, enhanced redox capacity, a higher concentration of Mn⁴⁺ species, and a larger amount of Oᵦ content on the catalyst surface, which are all likely predominant factors related to the excellent SCR activity. Additionally, Ho improved the Lewis acid sites and enhanced the adsorption and activation ability of NH₃, as well as the NO to NO₂ oxidation ability. The selective catalytic reduction with ammonia (NH₃-SCR) deNOₓ mechanism over HoMn/Ti catalysts obeyed both the Eley–Rideal (E-R) and Langmuir–Hinshelwood (L-H) mechanisms under low-temperature reaction conditions.

The bio-resource utilization of sewage sludge is presented by preparation of novel waste sludge–doped graphite carbon nitride (g-C₃N₄) photocatalyst. The sludge flocs which constitute bacteria and organic substances served as a pore-forming framework in the catalyst, while the inorganic fractions including those transition metals and crustal metals can function as dopants for sludge-based g-C₃N₄ composite. The physicochemical properties of as-prepared catalyst were well analyzed by multiple characterizations. The composite catalyst showed higher surface area (50 m²/g) and more mesoporous structures (8.9 × 10⁻² cm³/g) as compared with pristine g-C₃N₄ (8.4 m²/g and 6.6 × 10⁻² cm³/g, respectively). The photoelectrochemical results showed that introduced sewage sludge impurities lowered down the photocarriers recombination efficiency and enhanced more efficient electron-hole separation by about 100 times. The photocatalytic activity was tested by degradation of typical dye Eriochrome Black T (EBT). The optimal sample improved removal of EBT by 56% in 90 min under ultraviolet irradiation (λ = 254 nm). According to the results of main metal ion leaching concentration and reuse tests, the composite catalyst exhibited excellent stability and repeatability.

The present study demonstrates the development of polyphenol oxidase (PPO) biosensor for the detection of catechol using strontium copper oxide (SrCuO₂) and polypyrrole nanotubes (PPyNT) matrix. The SrCuO₂ micro-seeds, a perovskite compound, are synthesized by co-precipitation under pH 8.0. The as-synthesized micro-seeds are characterized by scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction spectroscopy (XRD). The proposed sensor is fabricated on pencil graphite (P-Gr) by successive deposition of PPyNT, SrCuO₂, and PPO enzyme. The developed PPO/SrCuO₂/PPyNT/P-Gr sensor is characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) techniques. The PPO/SrCuO₂/PPyNT/P-Gr displayed excellent electrocatalytic activity towards the oxidation and detection of catechol. The as-developed sensor showed sensitive response ascribing to limit of detection (LOD) of 0.15 μM and sensitivity of 15.60 μA μM⁻¹ cm⁻². The fabricated sensor exhibited excellent repeatability and longer shelf life. The proposed biosensor finds its application within the broad linear range of 1–50 μM. Real sample analysis of mineral water, tap water, and domestic wastewater using developed sensor showed acceptable recovery. Hence, the biosensor endeavors its application in environmental monitoring and protection.

The occurrence, seasonal variation, and environmental impact of five widely used parabens, methyl-(MeP), ethyl-(EtP), n-propyl-(n-PrP), n-butyl-(n-BuP), and benzyl-(BzP) parabens, were investigated in a municipal wastewater treatment plant (WWTP) located in Guangzhou, China, for 1 year. The concentrations of ∑₅parabens in the influent and the effluent were 94.2–957 and 0.89–14.7 ng L⁻¹, respectively. The influent paraben concentrations in autumn were significantly lower than in winter, spring, and summer, and the concentrations were generally higher in spring. The removal efficiencies of ∑₅parabens in the dissolved phase were over 96%, with high efficiencies in MeP, EtP, and n-PrP. Risk assessment indicated that parabens in the effluent were not likely to pose an environmental risk to aquatic ecosystems. The present study indicates that the treatment processes employed in full-scale WWTPs are effective at removing parabens and highlights the possibility of utilizing WWTPs for restoring water quality in riverine and coastal regions heavily impacted by paraben contamination.

Bisphenol A (BPA) is considered as xenoestrogen, a crucial component utilized for the manufacturing of plastic products. It has a potential to disrupt the endocrine system and induces endocrine-related metabolic disorders. We aimed to investigate the exposure of BPA in Pakistani population and its association with sociodemographic features, dietary habits, and risk factors of diabetes mellitus (DM). This cross-sectional study was conducted on 400 participants among which 61.75% participants were diabetic and 38.25% were non-diabetic. We developed a structured questionnaire, gathered sociodemographic data, and collected their urine and blood samples for the estimation of BPA and various biomarkers as risk factors of DM, respectively. Pearson correlation coefficient was determined for urinary BPA levels and DM risk factors. Urinary BPA values were adjusted for confounders. Sociodemographic data shown that urinary BPA level was significantly higher (p < 0.05) in obese people (BMI > 27) living in semi-urban and industrial areas. BPA was detectable in 75% of study participants. Urinary BPA level was found to be higher in diabetic participants compared with that of non-diabetics. A significant correlation is observed between BPA exposure and DM risk factors. We found that urinary BPA level was correlated with elevated levels of HbA1c (r = 0.6028), HOMA-IR (r = 0.5356), CRP (r = 0.6946), BUN (r = 0.6077), AST (r = 0.5151), FFA (r = 0.5759), TGs (r = 0.5608), and MDA (r = 0.6908). Hence, our study adds to the growing body of evidence supporting the role of BPA exposure as a risk factor for DM and may be associated with higher glycemic index, increased pro-inflammatory and oxidative stress biomarkers, dyslipidemia, and impaired functioning of the liver and kidney. Heating food in plastic containers and consumption of packed food items are the main sources of BPA exposure which are positively associated with DM.

The escalating generation of biosolids and increasing regulations regarding their safe handling and disposal have created a great environmental challenge. Recently, biosolids have been incorporated into the hydrolysis step of a two-step thermal lipid conversion process to act as water replacement in the production of renewable chemicals and fuels. Here, the hexane extract recovered from hydrolysis of biosolids, lipids from brown grease hydrolyzed using either water (control) or biosolids as a water replacement, was pyrolyzed at 410–450 °C for 2 h. The product distribution and composition were not significantly different when biosolids were used to hydrolyze brown grease instead of water. The liquid product consisted mainly of alkanes, alkenes, aromatics, and cyclic compounds similar to those in petroleum-derived liquid fuels. However, the use of biosolids as a water substitute resulted in a significant increase in sulphur content of the pyrolysate, which will necessitate processes to reduce the sulphur content before or after pyrolysis. Nevertheless, the pathways proposed in this paper are considered as potentially economically viable approaches to not only resolve the issues associated with disposal of biosolids but also to produce renewable hydrocarbons for fuel and chemical applications. Graphical abstract

Low-cost bioadsorbent such as shrimp shell chitin was used for the removal of polyphenols and COD from olive mill wastewater (OMW). In order to achieve a high polyphenols and chemical oxygen demand (COD) removal efficiency and to reduce the number of experiments, two levels of fractional 2⁴ factorial design experiments were carried out. The influence of different experimental parameters such as solution pH, adsorbent concentration, contact time, stirring speed, and their interactions during polyphenols and COD removal were investigated. Optimized values of pH, adsorbent concentration, contact time, and stirring speed were found equal to 12, 10 g/L, 24 h, and 420 rpm/min, respectively. The maximum polyphenol uptake under these experimental conditions reached 69.47%. Whereas the maximum removal of COD achieve 43% in 10 g/L, 12, 24 h, and 80 rpm/min for adsorbent concentration, pH, contact time, and stirring speed as optimal conditions, respectively. The experimental equilibrium data were tested using the Freundlich and Langmuir isotherm models. It was found that adsorption of polyphenols on shrimp shell chitin is well fitted both models. Kinetics of the adsorption process was studied by investigating the pseudo-first-order, pseudo-second-order kinetics, and intraparticle diffusion mechanism and showed that the pseudo-second-order kinetic model provided a better correlation for the experimental data studied in comparison to the pseudo-first-order model and intraparticle diffusion. These results revealed that shrimp shell chitin can be used as an effective and low-cost adsorbent to remove polyphenols and COD from OMW.