Super-enrichment of sediment As (42-133 mg kg-1, n = 7) at shallower depth is due to redox trapping during past groundwater discharge. Active As and Fe reduction is supported by the contrast between the As(III)-dominated groundwater and the As(V)-dominated sediment, and by the decreasing sediment As(V) and Fe(III) (hydr)oxides concentrations with depth.In this paper, a bifunctional tri-site fluorescent probe was designed for the first time not only for visualization and quantitative analysis of sensing H2S in wastewater by coupling paper strip and smartphone (Color recognizer, Xiyi Technology) but also for sensitively monitoring GSH in living cells, which relied on different emission channels and the pH of solutions. The recognition properties of GH towards H2S/GSH were satisfactorily demonstrated through fluorescence, UV-vis, 1H NMR and DFT calculations. More importantly, integrated with the paper strip, portable smartphone-sensing platform with a color recognizer app would accomplish cost-effective and rapid assays for colorimetric water quality testing, which displayed huge application potential in fields of environmental monitoring.Biosynthetic crystals (BC) were prepared through microbially induced calcium carbonate precipitation (MICP) for fluoride (F-) removal from the groundwater. Batch experiments were conducted to evaluate the fluoride adsorption capacity and the impacts of critical factors (organic matter, pH, initial fluoride concentration and BC dosage) on defluorination efficiency of BC. The maximum adsorption amount and defluorination efficiency were recorded as 5.10 mg g-1 and 98.24%, respectively. The adsorption kinetics and isotherms studies showed that pseudo-second-order kinetic model and Freundlich isotherm model were best fitting to the reaction.  https://www.selleckchem.com/products/Nolvadex.html  Adsorption thermodynamic parameters indicated a spontaneous, endothermic and thermodynamically favorable adsorption process. Moreover, the mechanism of F- removal by BC was further analyzed by SEM, XPS, XRD and FTIR. The method can cope with the problem of applying the external organic substances in MICP, and avoid the microbial safety risk in the effluent. As an economically and environmentally friendly adsorbent, BC can be used for F- removal from groundwater.People typically spend most of their time indoors. It is of importance to establish prediction models to estimate PM2.5 concentration in indoor environments (e.g., residential households) to allow accurate assessments of exposure in epidemiological studies. This study aimed to develop models to predict PM2.5 concentration in residential households. PM2.5 concentration and related parameters (e.g., basic information about the households and ventilation settings) were collected in 116 households during the winter and summer seasons in Hong Kong. Outdoor PM2.5 concentration at households was estimated using a land-use regression model. The random forest machine learning algorithm was then applied to develop indoor PM2.5 prediction models. The results show that the random forest model achieved a promising predictive accuracy, with R2 and cross-validation R2 values of 0.93 and 0.65, respectively. Outdoor PM2.5 concentration was the most important predictor variable, followed in descending order by the household marked number, outdoor temperature, outdoor relative humidity, average household area and air conditioning. The external validation result using an independent dataset confirmed the potential application of the random forest model, with an R2 value of 0.47. Overall, this study shows the value of a combined land-use regression and machine learning approach in establishing indoor PM2.5 prediction models that provide a relatively accurate assessment of exposure for use in epidemiological studies.Behavior of veterinary antibiotics, the corresponding resistant genes in soil layer of constructed wetlands (red soil), and their response to different hydraulic loading rates (HLR) (2, 5, and 10 cm/d) were investigated. Results indicated that the soil layer had perfect performance for oxytetracycline and ciprofloxacin, yet sulfamethazine removal was unsatisfactory. Detection rates of oxytetracycline, ciprofloxacin and sulfamethazine in the effluent of simulation systems of soil layer were 8.33-36.36%, 8.33-47.83% and 100%, respectively. The model analysis of adsorption and hydrolysis indicated that physical adsorption, which was controlled by exchange reaction process based on diffusion, was the primary adsorption mechanism of target antibiotics in red soil, and the hydrolysis half-life values of antibiotics in the water of soil layer were shorter than them in wastewater. The removal response of oxytetracycline and ciprofloxacin to change of HLR was insignificant, yet the respective effluent concentrations of sulfamethazine at HLR of 2-10 cm/d were 41.90, 61.35 and 73.54 μg/L during treating synthetic livestock wastewater, which revealed significant positive correlation (P less then 0.05). The relative abundances of each target resistance genes in soil showed significant increase after treating wastewater (10-5-10-6 to 10-4-10-1), and the total level of those at different HLRs (2, 5, and 10 cm/d) were 3.02 × 10-2, 7.54 × 10-2 and 8.65 × 10-1, respectively. In summary, HLR could affect the removal efficiency of partial antibiotic in soil layer of constructed wetlands, and the expression of antibiotic resistance in the soil gradually increased with increase in the HLR.A novel lysine and EDA double cross-linked graphene aerogel (LEGA) was constructed. The prepared LEGA was utilized as a methylene blue (MB) adsorbent in the wastewater treatment. It exhibits a three-dimensional interconnected porous structure benefiting dye adsorption. Its compression property is highly enhanced with the addition of lysine. Adsorption isotherm and kinetics of MB onto LEGA were discussed. Their results show that MB adsorption onto LEGA was fitted to follow Langmuir adsorption isotherm model and the pseudo-second-order kinetic model. LEGA has an excellent adsorption capacity towards MB as high as 332.23 mg/g and its MB adsorption process is proved to be an exothermic process. The mechanism for MB adsorption onto LEGA was proposed as the ion exchange, electrostatic interaction, π-π stacking interaction and hydrogen bonding. Thus, LEGA is confirmed to be a sustainable and green MB adsorbent with highly removal efficiency in the treatment of wastewater.