In order to improve the heavy metal wastewater treatment by avoiding formation of amorphous sludge phase, we develop a faster formation of high crystalline layered double hydroxide (LDH) sludge to remove Cu and Zn from wastewater by controlled double-jet precipitation (CDJP) without hydrothermal or heat aging post-treatment. A series of experimental procedures are conducted to determine the optimal parameters. Results show that the optimal adding rate, pH value, and stirring rate is 0.5 mL min⁻¹, 9.0, and 500 rpm, respectively. The CuZnAl-LDH phase sludge is formed in a well-crystallized hexagonal platelet, which assembled into a flower-like architecture. Comparative studies show that the formation of amorphous LDH sludge in conventional precipitation (CP) could be divided roughly into two stages—from the mixed copper hydroxide, zinc hydroxide, and scarbroite to the mixed low crystallinity CuAl-LDH and ZnAl-LDH. However, in CDJP method, the high crystalline LDH sludge evolved from a new four-step evolution process that is the formation of an amorphous (quasi-)multinary metastable ternary CuZnAl-LDH phase, followed by the indiffusion of cations and substitution of anions to fabricate crystalline LDH, the integrated LDH hexagonal platelets assembled into a flower-like architecture by the screw dislocation growth mechanism, the coarsening growth of each ternary LDH platelet, respectively. Thereinto, the formation of (quasi-)multinary metastable LDH phase instead of metal hydroxide in initial stage would be an obvious advantage of the CDJP method compared to CP method due to the former skipping the sequential precipitation.

In this paper, the adsorption behavior of zinc onto magnetic zeolite/cellulose nanofibers (MZNF) was studied. The prepared adsorbent was characterized by SEM, FTIR, and VSM analyses. The mass ratio of adsorbent in composite, pH, contact time, adsorbent dosage, initial Zn⁺² concentration, temperature, and agitation speed were investigated in batch experiments. The results showed that zeolite played an important role in the prepared nanocomposite due to its great surface area. pH 7 exhibited the highest Zn⁺² removal efficiency. Rapid adsorption at the first 30 min of the reaction is one of the advantages of the prepared adsorbents. Moreover, increase at temperature led to higher efficiency and maximum efficiency was attained at 30 °C. Under optimum conditions, MZNF showed removal efficiency of 96% and maximum adsorption capacity of 9.45 mg/g. The presence of the competing ions did not reduce the efficiency of the process and adsorption efficiency was higher than 93%. The calculated RSD of 1.42% exhibits the suitability of the process. Equilibrium data were examined by various isotherms and kinetics equations. It was concluded that Pseudo second-order model and Langmuir models described the adsorption process well. Based on these results, MZNF obtained in this work can be served as a promising candidate for Zn⁺² removal in wastewater.

Grafting polyacrylamide (PAM) chains onto microparticles may combine the advantages of the flocculation property of the former and the fast sedimentation of the later to realize better flocculation performance. In this work, inexpensive microcrystalline cellulose (MCC) microparticles, and monomer of acrylamide (AM) were mixed, and then irradiated under microwave. The obtained material was characterized by Fourier transform infrared spectroscopy and X-ray diffraction, and the results demonstrated successful modification of MCC with AM on the particle surface. The modification procedure has been carefully investigated to obtain an optimum preparation condition. Kaolin suspension was selected as a model to evaluate the flocculation properties of the obtained AM-MCC. Our results indicate that the AM-MCC with the highest grafting ratio of 95.5% exhibits the best flocculation performance, which is even better than that of PAM, and the turbidity can be decreased to 1.4% of the naked kaolin suspension within 2.5 min. Therefore, this work provides a low cost strategy to prepare biodegradable AM-MCC, which may have promising potential application in the water treatment and other fields.

The shortage of drinking water is a major problem in the rural areas of the Mekong Delta, especially, when surface water, a main local direct drinking water source is being threatened by pesticide pollution and salinity intrusion. A hybrid process coupling electrodialysis (ED) and nanofiltration (NF) is proposed as an effective process easy to setup in a small plant to treat complex matrix with high salinity and pesticide concentration as is the Mekong Delta surface water. Performance of the ED–NF integration was evaluated with synthetic solutions based on the comparison with a single NF step generally used for pesticide removal. Both energy consumption and water product quality were considered to assess process efficiency. The ED stage was designed to ensure a 50% removal of salinity before applying NF. As expected, the NF rejection is better in the hybrid process than in a case of a single NF step, especially for pesticide rejection. The integration of a NF stage operated with NF270 membrane consumes less energy than that with NF90 membrane but its efficiency was observed not high enough to respect the Vietnamese guidelines. Using NF90, the optimal recovery rate of the NF stage varies from 30 to 50% depending on the salt content in the feed.

Bisphenol A (BPA) is a key endocrine-disrupting chemical (EDC) in the manufacturing industry. It is found in the structure of compounds such as polycarbonate and epoxy in combination with other chemicals. Our objective was to investigate the effect of BPA on rat ovaries. A total of 32 female rats were divided into four equal groups: In group 1 (control), vehicle was administered; in group 2, BPA 50 μg/day was administered intraperitoneally; in group 3, BPA 100 mg/kg/day was administered intraperitoneally; and in group 4, BPA 100 mg/kg/day and vitamin C (50 mg/kg) were administered intraperitoneally, while vitamin E (50 mg/kg) was administered intramuscularly. Thirty days after the treatment, the effects of BPA on the ovaries were evaluated by terminal deoxynucleotidyltransferase [TdT]-mediated dUTP-biotin nick end labeling (TUNEL) assay. There was no difference in the number of apoptotic cells between group 2 and group 4. In addition, there was no significant difference between control group and group 2, 4. However, the number of apoptotic cells per unit area was significantly increased in group 3 compared with all groups (p < 0.01, p < 0.05). In conclusion, this study showed that high doses of BPA (100 mg/kg/day) have a toxic effect on the ovaries. The fact that the number of apoptotic cells in the group administered with high dose of BPA + 50 mg/kg/day vitamin C + 50 mg/kg/day vitamin E was lower than that of the high-dose BPA-administered group shows that these vitamins may have a protective effect.

This study investigated a previously developed thermophilic microbial community with the ability to effectively degrade azo dyes. To identify the key microbes of this microbial community, a dilution-to-extinction approach was combined with polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and Illumina high-throughput sequencing technology (HTST). Strains belonging to Tepidiphilus sp. almost disappeared from the degradation solution at dilution ratios above 10⁻⁷; furthermore, at this ratio, the diluted microbial community almost lost their decolorization ability, indicating this ratio as the critical point for effective azo dye decolorization. Strains belonging to Tepidiphilus sp. were indicated as possible key functional microbes of this microbial community for effective azo dye decolorization. Moreover, the synergistic action of other microbes, such as Anoxybacillus sp., Clostridium sp., and Bacillus sp., was suggested to further promote the decolorization process by secreting azoreductase and laccase. Caloramator spp. were found have the ability to degrade proteins and amino acids, which might promote the degradation process with further degradation microbes. The loss of these bacteria might diminish the synergistic relationships among different strains, which further results in the failure of efficient azo dye decolorization and degradation by this microbial community.

The PM₂.₅ as one of the main pollutants in Tehran city has a devastating effect on human health. Knowing the key parameters associated with PM₂.₅ concentration is essential to take effective actions to reduce the concentration of these particles. This study assesses the relationship between meteorological (humidity, pressure, temperature, precipitation, and wind speed) and environmental parameters (normalize difference vegetation index and land surface temperature of MODIS satellite data) on PM₂.₅ concentration in Tehran city. The Geographically Weighted Regression (GWR) was employed to assess the impact of key parameters on PM₂.₅ concentrations in winter and summer. For this purpose, first the seasonal average of meteorological data were extracted and synchronized to satellite data. Then, using the ordinary least square model, the important parameters related to PM₂.₅ concentration were determined and evaluated. Finally, using the GWR model, the relationships between parameters related to PM₂.₅ concentration were analyzed. The results of this study indicate that meteorological and environmental parameters in winter season (71%) have a much higher ability to explain PM₂.₅ concentration than summer season (40%). In winter, PM₂.₅ concentration has a negative correlation with vegetation at most parts of the study area, a negative correlation with LST in the western and a positive correlation in the eastern part of the study area, a positive correlation with temperature, and a negative correlation with wind speed in the northeastern part of the study area. Precipitation has a positive correlation with PM₂.₅ concentration in most parts of the study area in both seasons. But, it was investigated in case of higher precipitation (more than 2 mm), PM₂.₅ concentration decreases. But, there is no negative relationship in any of the dependent parameters with PM₂.₅ concentration in summer. In this season, the air temperature parameter showed a high correlation with PM₂.₅ concentration. Also, spatial variations of the local coefficients for all parameters are higher in winter than in summer.

The hazel bolete Leccinellum pseudoscabrum (Kallenb.) Mikšík 2017 specimens and beneath soil layer (0–10 cm) have been examined on the occasion of ²¹⁰Po and ²¹⁰Pb activity concentrations, the nuclide bioaccumulation potential by species and distribution in fruit bodies. Mushrooms and forest soils came from six geographically distant locations in the northern and central parts of Poland. The threat to humans from ²¹⁰Po and ²¹⁰Pb contained in mushrooms has been also assessed. The absolute values of the ²¹⁰Po radioactivity, respectively, in caps and stems of fruit bodies were in the range 0.74 ± 0.06–8.59 ± 0.36 Bq kg⁻¹ dry biomass and from 0.81 ± 0.06–8.23 ± 0.37 Bq kg⁻¹ dry biomass, while the values of the ²¹⁰Pb radioactivity in caps and stems were in the range 0.61 ± 0.04–6.33 ± 0.22 Bq kg⁻¹ dry biomass and 0.83 ± 0.04–4.59 ± 0.24 Bq kg⁻¹ dry biomass, respectively. A potential related effective dose assessment showed that mushrooms L. pseudoscabrum can contribute at 0.89–10.3 μSv kg⁻¹ db from ²¹⁰Po decay and 0.42–4.37 μSv kg⁻¹ db from ²¹⁰Pb decay.

Integrated hydrodynamic modelling is an efficient approach for making semi-quantitative scenarios reliable enough for groundwater management, provided that the numerical simulations are from a validated model. The model set-up, however, involves many inputs due to the complexity of both the hydrological system and the land use. The case study of a Mediterranean alluvial unconfined aquifer in the lower Var valley (Southern France) is useful to test a method to estimate lacking data on water abstraction by small farms in urban context. With this estimation of the undocumented pumping volumes, and after calibration of the exchange parameters of the stream-aquifer system with the help of a river model, the groundwater flow model shows a high goodness of fit with the measured potentiometric levels. The consistency between simulated results and real behaviour of the system, with regard to the observed effects of lowering weirs and previously published hydrochemistry data, confirms reliability of the groundwater flow model. On the other hand, accuracy of the transport model output may be influenced by many parameters, many of which are not derived from field measurements. In this case study, for which river-aquifer feeding is the main control, the partition coefficient between direct recharge and runoff does not show a significant effect on the transport model output, and therefore, uncertainty of the hydrological terms such as evapotranspiration and runoff is not a first-rank issue to the pollution propagation. The simulation of pollution scenarios with the model returns expected pessimistic outputs, with regard to hazard management. The model is now ready to be used in a decision support system by the local water supply managers.

One of the cheapest and proper methods for the ultimate disposal of Municipal Solid Waste (MSW) is landfilling. However, determining the location of landfill sites is a difficult and complex task due to depending on social, environmental, technical, economic, and legal factors. To solve the aforementioned challenges related to the landfill site suitability analysis, the combinations of Geographic Information System (GIS) and Multi-Criteria Decision-Making (MCDM) have been studied by academia and applied by experts over the years. This notice is apparent by the large number of academic papers which have been announced in the near future. To provide a framework of the existing literature, and to guide colleagues, a state-of-the-art of recent papers is crucial. The goal of this study is to review all scientific papers in GIS-based MCDM modeling for landfill site suitability analysis in academic journals. A total of 106 studies published between 2005 and 2019 are recorded and surveyed. The studies are then investigated and classified by a generated taxonomy including following categories: GIS software, application area, uncertainty, MCDM techniques, cell sizes in GIS, and criteria. Based on the review conducted, it is observed that while Analytical Hierarchy Process (AHP) and Weighted Linear Combination (WLC) are the most widely used MCDM methods for weighting the criteria and ranking the alternatives, respectively. On the other hand, while environmental dimension is the most commonly preferred main criteria, surface water comes first in the sub-criteria pool. Criteria analysis shows that surface and ground water, geology, land use, distance to fault zone, distance to urban areas, and distance to road and slope are the most commonly used criteria groups among others. These classifications and observations are helpful for identifying research gaps in the current literature and provide insights for future modeling and research efforts in the field.