Nowadays, the current synthesis techniques used in industrial production of nanoparticles have been generally regarded as nonenvironmentally friendly. Consequently, the biosynthesis approach has been proposed as an alternative to reduce the usage of hazardous chemical compounds and harsh reaction conditions in the production of nanoparticles. In this work, pure, iron (Fe)-doped and silver (Ag)-doped zinc oxide (ZnO) nanoparticles were successfully synthesized through the green route using Clitoria ternatea Linn. The optical, chemical, and physical properties of the biosynthesized ZnO nanoparticles were then analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), UV–Vis diffuse reflectance spectroscopy (DRS), zeta potential measurement, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and surface analysis. The biosynthesized ZnO nanoparticles were crystallized with a hexagonal wurtzite structure and possessed smaller particle sizes than those of commercially or chemically produced samples. The existence of biomolecules to act as reducing and stabilizing agents from C. ternatea Linn aqueous extract was confirmed using FTIR analysis. The biosynthesized ZnO nanoparticles mainly comprised of negatively charged groups and responsible for moderately stable dispersion of the nanoparticles. All these properties were favorable for the sonocatalytic degradation of Congo red. Sonocatalytic activity of ZnO nanoparticles was studied through the degradation of 10 mg/L Congo red using ultrasonic irradiation at 45 kHz and 80 W. The results showed that the sonocatalytic degradation efficiency of Congo red in the presence of biosynthesized ZnO nanoparticles prepared at 50 °C for 1 h could achieve 88.76% after 1 h. The sonocatalytic degradation efficiency of Congo red in the presence of Ag-doped ZnO was accelerated to 94.42% after 10 min which might be related to the smallest band gap energy (3.02 eV) and the highest specific surface area (10.31 m²/g) as well as pore volume (0.0781 cm³/g). Lastly, the biosynthesized ZnO nanoparticles especially Ag-doped ZnO offered significant antibacterial potential against Escherichia coli which indicated its ability to inhibit the normal growth and replication of bacterial cells. These results affirmed that the biosynthesized ZnO nanoparticles could be used as an alternative to the current chemical compounds and showed a superior sonocatalytic activity toward degradation of Congo red.

We aimed to quantify the relationship between the outpatient visits of hand, foot, and mouth disease (HFMD) and diurnal temperature range (DTR). The data of daily HFMD outpatient visits and meteorological parameters were obtained. A distributed lag nonlinear model combined with generalized linear model was used to estimate simultaneously nonlinear and delayed effects between DTR and daily HFMD outpatient visits after controlling confounding factors. A total of 15,275 HFMD visits were enrolled. DTR was significantly associated with HFMD outpatient visits in children. High DTR (P₇₅: 11.4 °C) and extreme DTR (P₉₅: 15.3 °C) were compared with 8.5 °C, and HFMD visits increased by a maximum of 3.93% (95% CI: 1.82 to 6.07%) and 4.47% (95% CI: 0.45 to 8.65%) in single-day lag effect, respectively. Furthermore, the extreme DTR effect decreased with the lag time and lasted for 10 days. Cumulative lag effects with markedly increasing percent of visits are over 64.88%. Furthermore, the effects were most pronounced among female children and children aged 0–2 years. Our study suggested that DTR changes were associated with HFMD outpatient visits, and populations of female and aged 0–2 years were more sensitive.

Concerns on health effects from uranium (U) mining still represent a major issue of debate. Any typology of active job in U mines is associated with exposure to U and its decay products, such as radon (Rn), thorium (Th), and radium (Ra) and its decay products with alpha-emission and gamma radiation. Health effects in U miners have been investigated in several cohort studies in the USA, Canada, Germany, the Czech Republic, and France. While public opinion is particularly addressed to pay attention to the safety of nuclear facilities, health hazard associated with mining is poorly debated. According to the many findings from cohort studies, the most significant positive dose-response relationship was found between occupational U exposure and lung cancer. Other types of tumors associated with occupational U exposure are leukemia and lymphoid cancers. Furthermore, it was found increased but not statistically significant death risk in U miners due to cancers in the liver, stomach, and kidneys. So far, there has not been found a significant association between U exposure and increased cardiovascular mortality in U miners. This review tries to address the current state of the art of these studies.

Fenton process was successfully applied to degrade three reactive dyes, blue 19 (RB19), red 195 (RR195), and yellow 145 (RY145), a mixture of dyes and a real textile effluent. A 2³ full factorial design coupled with a response surface methodology (RSM) was conducted to evaluate the effects of H₂O₂, Fe²⁺, and dye concentration on the Fenton reaction measured by absorbance reduction (AR) as response. Considering the analysis of variance (ANOVA), the statistical models could be used to describe experimental results and to predict the process behavior. The results obtained by RSM indicated that the optimum conditions for Fenton were [H₂O₂] = 50 mg L⁻¹, [Fe²⁺] = 0.5 mmol L⁻¹, and dye concentration = 0.075 g L⁻¹, obtaining up to 90% of AR. From kinetic study, the absorbance reduction for RY145 followed a second-order model, while RB19 and RR195 followed a first-order model. The mixture of dyes and the real textile effluent obtained lower AR, 56% and 22%, respectively. The phytotoxicity tests indicate that the Fenton reactions were very effective to reduce the toxicity of almost all contaminated solutions; however, for more complex solution (mixture of dyes and real effluents), a longer reactional time is necessary. Therefore, the results pointed that the Fenton reaction is very efficient in solution discoloration.

The use of roadway deicers, typically made of sand or salt, is essential for achieving safe roadway conditions by reducing ice and snow. Unfortunately, deicers can have detrimental effects on the surrounding infrastructure and environment. Traditional inorganic deicers, such as abrasives and chloride salts, have the most widespread usage, but recent concerns of the negative effects of chlorides on the environment have led to emerging alternative organic deicers. This paper provides a comprehensive review of the effectiveness and impacts of organic deicers including agro-based products, acetates, formates, glycols, and succinates. The benefits and negative impacts on the road, environment, and infrastructure are reviewed, as well as the performance of each deicer for snow and ice control on roadways. The environmental concerns of the organic deicers are discussed, including the largest environmental concern: the increase in biological oxygen demand (BOD) to receiving water bodies. The impact of deicers on metals and infrastructure is presented as it varies considerably for each alternative deicer. Finally, opportunities and challenges to implementing alternative deicers in the field is discussed.

Cleansing of crude oil-contaminated sand is anticipated to rely heavily on the ability of cleaning solution to access the contamination sites and the bonding strength between crude oil and sand. In this research, the actual produced sand sample from an oilfield and reference sand sample taken from a beach were subjected to porosity, permeability, and wettability tests. Results revealed that the particle size of the sands dominated the porosity and permeability outcomes. While the porosity of the reference sand at 46.64% was barely higher than the produced sand, the permeability (in Darcy) of the former exceeded the latter by 10 folds. In wettability and interfacial study, the highest adhesion strengths at the oil-sand interface were calculated according to Young-Dupre equation. The computed values were 58.42 mN/m for the reference sand and 65.88 mN/m for the produced sand, assuming 3-species geometric-mean model from Owen/Wendt theory. The types of intermolecular bonding at the interface were dispersive (London dispersion force from Van der Waals bonding), dipole-induced dipole attraction and mechanical adhesions, justifiable through elementary analysis. All the findings including corroboration from thermogravimetric analysis suggest that relatively higher energy was required to remediate the produced sand from oil reservoir as compared to the reference sand retrieved from shoreline.

Sorption is an effective process for the remediation of mine water with low metal concentrations. To identify promising low-cost organic sorbents for nickel (Ni), adsorption and retention properties of peat, compost, brown algae, sawdust, and wood ash were compared. Batch adsorption and desorption experiments were conducted at pH 7 in 0.05 M NaNO₃ solutions to simulate the ionic strength and pH of a contaminated neutral drainage. Results of adsorption kinetic experiments were best represented by the Elovich model and the fastest rates were obtained with peat (796,075 mg g⁻¹ min⁻¹) and compost (791 mg g⁻¹ min⁻¹). Results of equilibration adsorption experiments were fitted to Langmuir and Freundlich isotherms and the highest adsorption capacities were observed for peat (around 22 mg g⁻¹) and compost (around 9 mg g⁻¹). Desorption experiments revealed that peat and compost adsorbed more Ni and also released a lower percentage of the adsorbed metal upon exposure to Ni-free solutions.

The aim of this study is to evaluate the effects of biochar on the plant’s growth. A pot experiment was carried out in our study. Rice straw-derived biochar were charred at two heating temperatures (400 °C/800 °C) and two oxygen-limited atmospheres (CO₂/N₂), respectively. The FESEM/EDS technique (field emission scanning electron microscopy with X-ray energy-dispersive spectroscopy) was used to study soils, biochar and plant samples. FESEM images indicated that the structure of the biochar was highly heterogeneous with larger macropores, which can enhance soil porosity. Fine soil mineral particles blocked the biochar inner pores and channels after returning biochar to soil. EDS analysis indicated that the Al and Fe contents increased on the surface of biochar after their returning, which reduced the toxicity of Al and Fe in the soil. The returning straw directly inhibited the growth of leaf-used lettuce. Four returning biochar all significantly improved leaf-used lettuce growth, and the effects of biochar prepared under 400 °C and a CO₂ atmosphere were better than those prepared under 800 °C and a N₂ atmosphere. Changes of nitrogen content in the biochar before and after their returning were consistent with the improvement of soil available nitrogen, and plant growth was positively correlated with the nitrogen content of biochar. This study explored the impact of biochar on soil nutrients and revealed the mechanism of biochar returning to the field to promote plant growth. It is of great significance in studying and improving the characteristics of soil nutrients.

The indoor air pollution (IAP) is one of the leading risk factors of childhood pneumonia in developing countries. This study makes the first attempt to examine the prevalence trend of pneumonia among under-five children in Pakistan in association with IAP-related factors, using bivariate and multivariate statistical methods. Three waves of Pakistan Demographic Health Survey for 2006–2007, 2012–2013, and 2017–2018 were used. Our study findings showed a steady decline in the prevalence of pneumonia synchronized with the decreased use of polluting fuel during the last decade (2006–2017). In bivariate regression, odd ratios of childhood pneumonia were 1.27 and 1.21 times higher in overcrowded houses in 2006–2007 and 2012–2013, respectively, and 1.25 times higher in families relying on biomass for cooking in 2017–2018. In the multivariate model, polluting fuel and overcrowded homes had higher adjusted odd ratios of pneumonia in all survey years, and children age 37–48 months, older mothers, and large birth sized children had lower AOR of pneumonia in 2006–2007 and 2012–2013. Countrywide promotion of IAP mitigation measures such as sponsoring cleaner fuels, separate place for cooking, and lessening home overcrowding may play a vital role in alleviating the prevalence of childhood pneumonia.

Fouling behavior of the novel anaerobic ammonium oxidation (anammox) self-forming dynamic membrane bioreactor (SFDMBR) was elucidated, which is using nylon mesh as the filter with controlled fouling and successful anammox process. Properties of anammox sludge and foulants in the anammox SFDMBR and MBR (using PVDF microfiltration membrane) were compared to analyze the alleviated fouling in the SFDMBR, of which transmembrane pressure could be kept below 10 kPa for 50 days in one filtration cycle of 82 days with flux of 12 L m⁻² h⁻¹. Colorimetrical determination and excitation emission matrices-parallel factor (EEM-PARAFAC) analysis of the foulants showed that humic acid content in foulants on nylon mesh was obviously lower than that on PVDF membrane. Considering that the small-sized and flexible humic acids prefer to plug into membrane pores, the alleviated irreversible fouling in the SFDMBR could be attributed to the less microbial humic acid content of foulants (8.8 ± 1.0%) compared with the MBR (20.7 ± 2.9%). The adequate efflux of humic-like substances in the operation with nylon mesh was speculated to be the main mechanism of fouling control in the SFDMBR. These findings highlighted the potential of anammox SFDMBR in practical applications, because of the high humic acid contents in real ammonium-laden wastewater. Our study highlights the important role of humic acids in fouling behavior of the novel anammox SFDMBR to provide guidance for fouling control strategies. Graphical abstract