In this paper, Pd-Sn modified Ru-Ir electrode was prepared by thermal oxidation method, and the effects of doping amount of Pd-Sn and synthesis conditions on Pd-Sn modified Ru-Ir electrode performance were studied. Linear sweep voltammetry(LSV), cyclic voltammetry(CV), and the Tafel curve were used to study the electrochemical performance of the Pd-Sn modified Ru-Ir electrode materials. The effects of the doping amount of Pd-Sn on the microstructure and valence states of Pd-Sn modified Ru-Ir electrode materials were investigated by SEM, TEM, XRD, and XPS. When the mass of Pd-Sn accounted for 1.5% of the total mass of the elements, the molar ratio of Ru-Ir was 2:1, and the molar ratio of Pd-Sn was 3:1; the LSV, CV, and the Tafel curves indicated that Pd-Sn modified Ru-Ir electrode had the lowest chlorine evolution potential (1.0640 V vs. SCE), the best CV curve coincidence, and the smallest corrosion current density (6.5 × 10⁻⁴ A/cm²), showing the best chlorine evolution performance, the best durability, and corrosion resistance; the characterization of SEM, TEM, XRD, and XPS showed that Pd-Sn was successfully doped into Ru-Ir electrode materials; the crystallinity of Pd-Sn modified Ru-Ir electrode was the highest, and the binding energy was the lowest, but the crystal form of Ru-Ir solid solution did not have changed. The optimal synthesis conditions of Pd-Sn modified Ru-Ir electrode material were as follows: Pd-Sn molar ratio was 3:1, calcination temperature was 500 ℃, calcination time was 4 h, and water was used as solvent. Pd-Sn modified Ru-Ir electrode can efficiently treat high chlorine ammonia–nitrogen wastewater, when the reaction volume was 200 mL, the initial concentration of NH₃-N was 100 mg/L, the concentration of chloride ion was 5000 mg/L, the current was 0.75 A, and the reaction time was 40 min; the removal rate of ammonia nitrogen can reach 100%.Responsible editor: Weiming Zhang.

Dissolved oxygen (DO) is one of the most critical factors to measure the water quality in ponds, which greatly impacts on healthy growth of aquatic organisms. To improve the prediction accuracy of DO and grasp its changing trends, a novel hybrid DO prediction model based on the long short-term memory network (LSTM) optimized by an improved sparrow search algorithm (ISSA) is proposed. Firstly, to discard redundant information and improve the calculation speed of the model, the key factors that have a greater correlation with DO are selected as the input parameters by extreme gradient boosting (XGBoost). Secondly, towards expanding the searching range of sparrows and balancing the global and local search, we introduce an adaptive factor exponential declining strategy for producers, and an arcsine decreasing strategy for scouters, which nonlinearly decreases with the increase of iterations. Besides, we also improve the position updating of scouters, making the sparrows gradually move to the best position. Finally, LSTM is optimized by ISSA to get the best initial weights and thresholds to construct an XGBoost-ISSA-LSTM DO prediction model. Specifically, we first analyze the method for water quality prediction, which can make short-term prediction (including about 1 h, 2 h) and long-term prediction (including about 12 h, 24 h) of DO. In 1-h prediction, the root mean square error (RMSE) of the model is 0.5571, the mean absolute error (MAE) is 0.2572, and the R² is 0.9276. In 24 h prediction, RMSE of the model is 0.6310, MAE is 0.4562, and R² is 0.9082. The experimental results show that the proposed model has better generalization performance and higher prediction accuracy compared with other common models. Therefore, the presented model based on XGBoost-ISSA-LSTM is more effective and could meet the actual demand of accurate prediction of DO.

The proposed research work presents the performance analysis of the vertically mounted bifacial module (VBFM) with and without tracking during the summer and winter seasons. Also, various parameters like energy efficiency, electrical efficiency, electrical exergy, thermal exergy, exergy efficiency, environmental analysis, economic analysis, exergoeconomic analysis, enviroeconomic analysis, and exergoenviroeconomic analysis of the VBFM were studied and presented. The comparative analysis was carried out between two bifacial solar modules installed in two different orientations (east–west and south-north). The experiments were conducted in the real climatic condition of Minjur, Tamil Nadu, India. Under the summer and winter climatic conditions, when the lifetime period of 10, 15, and 20 years are considered higher energy production factor and higher life cycle conversion efficiency was obtained from the vertically mounted bifacial module—east–west (VBFM-EW) with tracking during summer and vertically mounted bifacial module—north–south (VBFM-SN) module without tracking during the winter season. Exergetic cost was calculated by considering 15, 20, 25, and 30 years of the system with 2%, 5%, and 10% interest rates. The maximum exergetic cost was obtained from 30 years of the system under a 2% interest rate. The enviroeconomic and exergoenviroeconomic analysis provides the carbon credits earned from the E-W module was a maximum of Rs 11,036.18 during the summer season and Rs 12,413.48 from the VBFM-SN module during the winter season, considering the life of the system as 15 years.

Sulfate radical (•SO₄⁻)–based advanced oxidation processes have attracted a great deal of attention for use in water disinfection because of their strong oxidation ability toward electron-rich moieties on microorganism molecules. However, a few studies have focused on the effects of •SO₄⁻ on pathogenic microorganism inactivation in marine aquaculture water containing various inorganic anions. We employed the gram-negative bacteria E. coli and gram-positive bacteria S. agalactiae as representatives to evaluate the application of UV/persulfate (S₂O₈²⁻, PDS), to the disinfection of marine aquaculture water in a comprehensive manner. Total inactivation of 4.13ˍlog of E. coli cells and 4.74ˍlog of S. agalactiae cells was reached within 120 s in the UV/PDS system. The inactivation of pathogenic bacteria in marine aquaculture water increased with the increasing PDS concentration and UV intensity. An acidic pH was beneficial for UV/PDS inactivation. Halogen-free radicals showed a strong influence on the inactivation. Anions in seawater, including Cl⁻, Br⁻, and HCO₃⁻ inhibited the disinfection. The inactivation rates of pathogenic bacteria followed the order seawater < marine aquaculture water < freshwater. Pathogenic bacteria could also be effectively inactivated in actual marine aquaculture water and reservoir water. The analysis of the inactivation mechanisms showed that S₂O₈²⁻ was activated by UV to produce •SO₄⁻, which damaged the cell membranes. In addition, antioxidant enzymes, including SOD and CAT, were induced. The genomic DNA was also damaged. Inorganic disinfection byproducts such as chlorate and bromate were not formed during the disinfection of marine aquaculture water, which indicated that UV/PDS was a safe and efficient disinfection method.

The advantages of using constructed wetlands (CWs) for the decentralized treatment of wastewater include the operational simplicity, low cost, high-purification potential, and generation of plant biomass. Different plant configurations and species have been evaluated in CWs to increase the efficiency and the commercial and landscaping interest of plants grown in these units. Owing to its characteristics such as tolerance to different water levels, ease of acquisition, and associated economic value, crimson fountain grass (Cenchrus setaceus) is a potential plant to grow in CWs. The objective of this study was to evaluate the production of crimson fountain grass flower stems grown in horizontal-subsurface-flow (HSSF) CWs with different baffle arrangements. The three 1.0-m² HSSF CWs cultivated with 10 crimson fountain grass seedlings differed in the presence of partitions inside the units, as follows: no internal partitions; horizontal baffles; vertical baffles. The cultivated grass was analyzed for clump fresh weight (g), flower stem length (cm), panicle length (cm), panicle diameter (mm), and panicle dry weight (g). The experimental design was completely randomized with a split-plot in time, with three treatments, 10 replicates, and nine collection periods. The results obtained in the CWs during 9 months of monitoring indicated that the grass grown in the CWs with vertical baffles had higher clump fresh weight, longer stem length, and greater panicle size and dry weight. Given the high water and nutrient availability, the cultivation of ornamental plants in CWs can be considered a profitable option that allows high production of plant structures in a small physical space.

The worldwide resurgence of natural dyes in all fields is due to the carcinogenic effects of effluent loads shed by synthetic industries. Coconut coir (Cocos nucifera) containing tannin as a source of natural colorants has been selected for coloration of bio-mordanted silk under the influence of ultrasonic radiations at various dyeing conditions. For extraction of tannin dye from cocos powder, different media were employed, and dyeing variables such as dyeing time, dye bath pH, dyeing bath temperature, and the effect of salts on dyeing were optimized. For achieving new shades with excellent color characteristics, bio-mordants in comparison with chemical mordants were employed. It has been found that acid-solubilized extract after ultrasonic treatment for 45 min has yielded high color strength, when coconut coir extract of 4 pH from 6g of cocos powder, containing 5g/100mL salt solution as exhaust agent, was used to dye silk at 75°C for 65 min. Among bio-mordants turmeric (K/S=13.828) and among chemical mordants iron has shown excellent results (K/S=2.0856). Physiochemical analysis of fabric before and after US treatment shows that there is no change in the chemical structure of the fabric. It is found that ultrasonic waves have excellent potential to isolate the colorant followed by dyeing and environmental friendly mordanting at optimal conditions, but also the usage of herbal-based plant anchors, i.e., bio-mordants, has made the natural dyeing process more sustainable and clean.

Tobacco smoking is endocrine-disrupting and may interfere with vitamin D endocrine systems (VDES), but supporting evidence is limited and inconsistent. Also, there is a lack of evidence on whether the association between tobacco smoke exposure and VD levels exhibit temporal variation. Data from the National Health and Nutrition Examination Survey was used to evaluate the association between tobacco smoke exposure and VD levels among US general participants from 2001 to 2014. We examined the linear association between serum cotinine and 25(OH)D concentrations, as well as relationship between tobacco smoke exposure categories (active, passive, non-smoking) with VD status (deficiency, inadequacy, sufficiency, intoxication), and assessed whether specific gender, age (3–11, 12–19, 20–59, ≥ 60 years), ethnicity/race, or body mass index (BMI) groups were disproportionately impacted. During 2001–2004, a decrease in both serum cotinine and passive smoking prevalence was observed, with a stabilized active smoking rate. The estimates for the association between tobacco smoke exposure and suboptimal VD levels increased over the study period. Overall results indicated that serum cotinine was negatively associated with 25(OH)D in all participants. Tobacco smoke exposure, including both active and passive smoking exposure, was associated with increased risk of VD deficiency. Moreover, active smoking was additionally related to enhanced risk of VD inadequacy. These associations showed some age and gender differences, with consistent and stronger associations observed in female adults. In contrast, effects of tobacco smoke exposure on VD levels were mostly negative or non-significant among children and adolescents aged 3–19 years. The percentage of US general population with active smoking exposure stabilized over the 14-year period and was still high. Tobacco smoke exposure may disrupt vitamin D levels with an increasing temporal trend in the risk. Our results also provided initial evidence of smoking exposure on VD intoxication, which needs to be further verified. Convincing studies have linked tobacco use exposure, to dysfunctional VDES accompanied with declined serum levels of VD metabolites. However, evidence on the association between tobacco smoke exposure and VD status was rather limited and inconsistent, and there were no researches to date that estimated the temporal variation of the association as well as the effects of smoke exposure on VD intoxication. This study analyzed national survey data, to evaluate the temporal trends in effects of tobacco smoke exposure on VD levels over a decade, and to comprehensively assess the impacts of tobacco smoke exposure on VD levels across specific subgroups. The evidence suggests that the prevalence of active smoking exposure stabilized over the 14-year period and was still high. Moreover, tobacco smoke exposure may disrupt vitamin D levels among general population, with an increasing temporal trend and age-, gender-differences in risk.

Noise has become an important environmental risk factor. Some studies have shown that exposure to noise can cause coronary artery disease, high blood pressure, and stroke. At present, the relationship between noise exposure and the risk of atrial fibrillation (AF) is inconsistent. Based on previous studies, we proposed the hypothesis that noise exposure is associated with a higher risk of AF. Eight databases, such as PubMed, Embase, Cochrane Library, and Web of Science, were searched from inception until January 5, 2022. The pooled relative risk (RR) with its 95% confidence interval (CI) was used to estimate the association between AF and highest noise level and per 10 dB (A) increment of noise. According to the size of heterogeneity, the random or fixed effects model was adopted as the pooling method. A total of 5 articles comprising 3,866,986 participants were identified, providing 7 estimates of highest noise level and 6 estimates of per 10 dB (A) increment of noise exposure. For the highest noise level, there was a statistically significant association between noise exposure and the risk of AF (RR = 1.05; 95% CI: 1.02–1.09; I² = 44.1%). In addition, we found the risk of AF for per 10 dB (A) increment of noise exposure was 1.01 (95% CI: 1.00–1.02; I² = 81.3%). In summary, our study found that noise exposure was associated with a higher risk of AF. More high-quality studies are needed in the future to confirm these conclusions given the limitations of study.

Dissimilatory nitrate reduction to ammonium (DNRA) is an essential intermediate step in the nitrogen cycle, and different sediment physicochemical properties can affect the DNRA process. But the detailed research on the environmental nitrogen cycling in urban river networks based on DNRA communities and the functional gene nrfA is lacking. In this study, the flow line of the Huangpu River in Shanghai was analyzed using isotope tracer, quantitative real-time PCR, and high-throughput sequencing techniques to evaluate the role of DNRA on the stability of the river network and marine. The significant positive correlation between the rate of DNRA and sediment organic carbon was identified. At the genus level, Anaeromyxobacter is the most dominant. Notably, both heterotrophic and autotrophic DNRA species were discovered. This study added diversity to the scope of urban freshwater river network ecosystem studies by investigating the distribution of DNRA bacteria along the Huangpu River. It provided new insights into the biological nitrogen cycle of typical urban inland rivers in eastern China.

Sodium silicate is always used as an activator for the synthesis of geopolymer. However, the effect of sodium silicate concentration on the geopolymer used as adsorbent was still unclear. Therefore, the immobilization of Sr²⁺ in geopolymers activated by different concentrations of sodium silicate was studied through kinetic and isotherm modeling and solid characterizations including XRD, FTIR, TG, SEM–EDS, and N₂ adsorption–desorption isotherm. The adsorption amount of Sr²⁺ decreased with the sequence of S1, S2, and S3. According to the kinetic and isotherm modeling results, these sorption processes fitted better with pseudo-second-order, mainly governed by film diffusion. However, the diffusion mode was gradually closed to particle diffusion as for the sequence of S3, S2, and S1. Besides, the Langmuir model can be more befitting to sorption data than the Freundlich model, and the free energies decreased with the order of S1, S2, and S3. In addition, the specific surface areas did not change regularly with S1, S2, and S3. Thus, the distribution of Al tetrahedrons has a decisive role in the sorption process of Sr²⁺, even though the specific surface area is also a critical factor. More Al tetrahedrons can be formed under the activation of sodium silicate with higher concentration, leading to the low Si/Al molar ratio of the as-synthesized geopolymer.