Water quality models are important tools used in the management of water resources. The models are usually developed for specific regions, with particular climates and physical characteristics. Thus, applying these models in regions other than those they were designed for can generate large simulation errors. With consideration to these discrepancies, the goal of this study is to identify the models employed in different countries and assist researchers in the selection of the most appropriate models for management purposes. Published studies from the last 21 years (1997–2017) that discuss the application of water quality models were selected from three engineering databases: SpringerLink, Web of Science, and Scopus. Seven models for water quality simulations have been widely applied around the world: AQUATOX, CE-QUAL-W2, EFDC, QUALs, SWAT, SPARROW, and WASP. The countries most frequently applying water quality models are the USA, followed by China, and South Korea. SWAT was the most used model, followed by the QUAL group and CE-QUAL-W2. This study provides the opportunity for researchers, who wish to study countries with fewer cases of applied water quality models, to easily identify the work from that region. Furthermore, this work collated central themes of interest and the most simulated parameters for the seven countries that most frequently employed the water quality models.

With the rapid development of construction industry, consumption of concrete block has increased rapidly in China. As a kind of green building material and resource comprehensive utilization product, autoclaved aerated fly ash and concrete block have better performance in terms of heat preservation, sound insulation, and fire resistance. However, some typical issues are associated with autoclaved aerated fly ash and concrete block production process such as energy and material consumption as well as pollutant emissions. To examine the environmental and economic impacts of its production process is imperative. Choosing 1 m³ of autoclaved aerated fly ash and concrete block product as functional unit and “cradle to gate” as system boundary, a life cycle inventory is developed. The key processes and key materials with significant environmental impact are identified. Results show that the top four environmental impact categories are marine ecotoxicity, freshwater ecotoxicity, freshwater eutrophication, and human toxicity. Key processes are fly ash slurry production, lime grinding, and steam curing processes. These processes account for 46.58%, 26.00%, and 19.62% of the total environmental load respectively. The key materials are cement, lime, and natural gas, which account for 44.91%, 22.79%, and 20.61% respectively of overall environmental impact. Sensitivity analysis shows that the fly ash slurry production should be optimized preferentially, followed by lime grinding and steam curing processes. These findings are helpful to facilitate the sustainable production of autoclaved aerated fly ash and concrete block.

To study the effects of vermicomposting on the chemical properties and bioavailability of Cd/Zn in sludge, earthworms (Eisenia foetida) at different densities were inoculated into pure sludge, and sludge and earthworms were collected regularly to determine the earthworm biomass, the main chemical indexes, the structure of the functional groups, and the Cd/Zn content in the sludge. The results showed that the growth curve of earthworms in pure sludge could be well fitted by the logistic model. Earthworm activity eventually reduced the total organic carbon (TOC), fulvic acid (FA), and C/N ratio and increased the electrical conductivity (EC), total nitrogen (TN), humic acid (HA), and HA/FA ratio in the sludge. TOC, TN, and pH inhibited the bioavailability of Cd/Zn, while HA and EC promoted the bioavailability of Cd/Zn. Earthworm activity ultimately increased the content of Cd/Zn in the sludge. The bioavailability of Cd/Zn was reduced during the rapid growth period of the earthworms but increased during the stable growth period of the earthworms. A suitable vermicomposting time should be determined to ensure the activation or passivation of Cd/Zn.

Particulate-bound poly-aromatic hydrocarbons (PAHs) are of great concern due to their mutagenicity and carcinogenicity effect on human health. In this context, identification, quantification and inhalation cancer risk (ICR) assessment due to PM₁₀- and PM₂.₅-bound PAHs has been carried out at six monitoring stations in a critically polluted Jharia coalfield/Dhanbad City. Identification of pollution sources at study area has been performed by using PCA statistical methods. Air quality index (AQI) and air quality health index (AQHI) were calculated based on the concentration levels of PM₁₀. Location-wise direct comparison between AQI, AQHI and ICR was performed to analyse the risk levels. Consequently, maximum concentration levels of particulate (PM₂.₅ and PM₁₀)-bound total PAHs (400 and 482 ng/m³) were recorded at the monitoring station Lodna Thana, followed by Bank More and Sijua Stadium, respectively. It was also observed that mine fire-affected station Lodna Thana was exaggerated with presence of PAHs due to wood and open coal burning activities. Moreover, about 1000 and 889 cases of inhalation cancer risk were estimated due to direct exposure of PM₁₀- and PM₂.₅-bound PAHs in the study area, respectively. Active mine fire-affected station Lodna Thana was recorded with maximum probability of lung tumour due to inhalation cancer risk. This study has reported higher AQHI at station Dugdha Basti, Lodna Thana and Bank More, which results increased number of tumours due to ICR. This result concludes that Jharia coalfield/Dhanbad City are not only critically polluted area but it is also an inhalation cancer prone area due to direct exposure of active mine fire.

2-Mercaptothiazoline (MTZ) is broadly present in daily use as an antifungal reagent, a brightening agent, and a corrosion inhibitor. MTZ is potentially harmful for human health. Although the toxic effects of MTZ on experimental animals have been reported, the effects of MTZ on the proteins in the circulatory system at the molecular level have not been identified previously. Here, we explored the interaction of MTZ with bovine hemoglobin (BHb) in vitro using multiple spectroscopic techniques and molecular docking. In this study, the binding capacity, acting force, binding sites, molecular docking simulation, and conformational changes were investigated. MTZ quenched the intrinsic emission of BHb via the static quenching process and could spontaneously bind with BHb mainly through van der Waals forces and hydrogen bond. The computational docking visualized that MTZ bound to the β2 subunit of BHb, which further led to some changes of the skeleton and secondary structure of BHb. This research provides valuable information about the molecular mechanisms on BHb induced by MTZ and is beneficial for clarifying the toxicological actions of MTZ in blood.

The extensive use of antibiotics has resulted in the development of antibiotic-resistant bacteria (ARB), which may not be completely removed by traditional wastewater treatment processes. More effective approaches to disinfection are needed to prevent the release of ARB into the surface water. The metal-free photocatalyst graphitic carbon nitride (g-C₃N₄) has aroused great interest as a possible agent for water and wastewater treatment, due to its low cytotoxicity and photoactivity with visible light. In this study, the efficacy of g-C₃N₄ was assessed as a possible means to enhance ARB inactivation by irradiation. ARB were isolated and purified from secondary effluents in 4 municipal wastewater treatment plants. Of these, 4 typical multi-drug ARB isolates, belonging to Enterobacteriaceae, were selected for irradiation experiments. Inactivation was seen to increase with irradiation time. At 60 min, the inactivation of the 4 ARB isolates by light at > 300 nm and > 400 nm was in the range of 0.25–0.39 log and 0.16–0.19 log, respectively. The use of g-C₃N₄-mediated photocatalysis at the same wavelengths significantly enhanced that to 0.64–1.26 log and 0.31–0.41 log, respectively. The antibiotic susceptibility of the ARB isolates remained unchanged either prior to or after irradiation and was independent of photon fluence, reaction time, and the presence of g-C₃N₄. This study establishes a baseline for understanding the effectiveness of g-C₃N₄ photocatalysis on inactivation of ARB in wastewaters and lays the foundation for further improvement in the use of photocatalysis for wastewater treatment.

Voles (Cricetidae) cause extensive damage to a variety of crops throughout much of the Northern Hemisphere. The removal of vegetation from crop fields at the end of the growing season, combined with a subsequent burrow fumigant application of aluminum phosphide, has the potential to substantially curtail vole activity but has not been thoroughly examined. We set up a study to test the impact of these management tools in perennial globe artichoke (Cynara cardunculus var. scolymus) fields in Monterey County, CA, during 2010 and 2011, to determine their potential utility as part of an integrated pest management (IPM) program for managing California voles (Microtus californicus). We used both chewing indices and mortality estimates derived via radiotelemetry to assess the efficacy of aboveground vegetation removal and aluminum phosphide applications on vole abundance. We determined the impact of plowing artichoke fields on vole activity as well. Both removal of vegetation and applications of aluminum phosphide substantially reduced vole presence within treated fields. Plowing also reduced vole abundance to the point of little residual activity following treatment. These management practices appear to be effective at eliminating voles from crop fields. Combining these tools with management practices designed to slow down reinvasion by neighboring vole populations (e.g., barriers, repellents, traps) has the potential to substantially reduce farmer reliance on rodenticides for vole management, although rodenticides will still be needed to curtail populations that reestablish within crop fields. Such an IPM approach should substantially benefit both farmers and agro-ecosystems.

To estimate the impact of mercury discharged from artisanal and small-scale gold mining (ASGM) activity, variations in the concentrations of elemental mercury (Hg0), mercury ion (Hg2+), particulate mercury (P-Hg), and total mercury in filtered river water (FT-Hg) were investigated from sampling locations extending from 10 km upstream to 30 km downstream of ASGM operations in West Java, Indonesia. The average of the annual concentrations at the ASGM site from 2013 to 2017 were 0.14–0.85 μg L⁻¹, 0.27–12.9 μg L⁻¹, 4.3–49.5 μg L⁻¹, and 1.2–12.5 μg L⁻¹ for Hg0, Hg²⁺, P-Hg, and FT-Hg, respectively. The concentration of mercury species decreased as the distance from the ASGM site increased, while the ratio of P-Hg increased towards the lower reaches of the river system, with the percentage of P-Hg estimated at 90% of Hg at the sample location furthest downstream. A high mercury concentration of 600 mg kg⁻¹ was observed for suspended particulate matter (SPM) at the ASGM site. The SPM maintained a high concentration of mercury, even in the downstream area. In the annual variations of the mercury species from 2013 to 2017, FT-Hg and P-Hg concentrations tended to decrease from 2016, which suggested a decline of ASGM activity in this area. However, SPM and river sediment showed no apparent changes in their mercury concentrations over this period, indicating that the contamination in the river system is persistent and does not recover quickly.

Neutral polyfluoroalkyl and perfluoroalkyl substances (nPFASs) were detected in the surface water and sediment from the Haihe River (HR) and Dagu Drainage Canal (DDC), Tianjin, China. N-methyl perfluorooctane sulfonamide ethanol (MeFOSE) and N-ethyl perfluorooctane sulfonamide ethanol (EtFOSE) were the predominant nPFASs in surface water and sediment, which was different from the composition in air. The concentrations of ΣnPFASs in water from the HR (1.88–8.21 ng/L) were lower than those from the DDC (3.72–11.32 ng/L). Concentrations of ΣnPFASs were higher in the middle of the HR in the Dongli District due to industrial activity, whereas at lower reaches of the DDC, high ΣnPFAS concentrations might be due to effluent from wastewater treatment plants (WWTPs). The detection frequency in sediment (13.5%) was less than that in water (83%). The concentrations in sediment from the DDC (below limit of qualification (LOQ) to 5.58 ng/g) were higher than those from the HR (below LOQ to 2.46 ng/g). The distribution coefficient (log KD) between water and sediment was calculated, and they were highly related to the compound structures. The contribution of nPFASs to nPFASs+PFAAs was up to 52% in sediment in the DDC, suggesting the importance of nPFASs in aquatic systems.

A total of 26 samples of surface sediments collected in the Neva River (including the St. Petersburg city area) and in the Russian part of the Gulf of Finland were analyzed for 17 polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs), 12 dioxin-like polychlorinated biphenyls (dl-PCBs), and 10 polybrominated diphenyl ethers (PBDEs). The concentrations of total PCDD/Fs and dl-PCBs in sediments ranged from < 0.05 to 219 pg g⁻¹ d.w. and from 44 to 246,600 pg g⁻¹ d.w. respectively. The total World Health Organization toxic equivalent (WHO-TEQPCDD/F ₊ PCB) values varied between 0.01 and 59.0 pg g⁻¹. In the majority of cases, the PCDD/F and dl-PCB concentrations do not exceed the threshold effect level (TEL) recommended by Helsinki Commission (HELCOM) as quantitative target for the sum of PCDD/Fs and dl-PCBs. The congener profile indicates that combustion is the primary source of PCDD/Fs in most of the studied samples. For the PCBs, the historical use of technical PCB products was identified as the major source. ΣPBDE₁₀ concentrations ranged from 0.004 to 1.8 ng g⁻¹ d.w. The congener profile results show that BDE-47 (tetra-BDE) is the dominant congener in sediment samples. According to the sediment and water quality guidelines established in the EU (PNEC) and in Canada (FEQG), all the samples studied can be classified as lowly contaminated by PBDEs. The sediment concentrations of PCDD/Fs, dl-PCBs, and PBDEs measured in this study were comparable to or lower than those reported for other areas of the Baltic Sea.