In recent years, ionic liquids as green solvents have been received great attention owing to their remarkable properties. In this context, in the present study, the separation of glutaric acid from water was examined using green solvents instead of conventional organic solvents. As green solvents, four different types of imidazolium-based ionic liquids were utilized. Tributyl phosphate (TBP) was used as an extractant in ionic liquids. The effects of various factors like initial acid concentration (0.156–0.749 mol. L⁻¹), TBP concentration in ionic liquids (0–3 mol. L⁻¹), and type of ionic liquid were investigated. To evaluate the separation efficiency of glutaric acid from water, various parameters like extraction efficiencies (E), distribution coefficients (D), and loading factors (Z) were calculated. The values of these parameters changed in range of D (0.03–3.54), E (0.51–77.98%), and Z (0.040–0.177). The maximum D value of 3.54 and E value of 77.98% was obtained for reactive extraction of glutaric acid by using 3 mol. L⁻¹ TBP in [BMIM][Tf₂N] and 0.156 mol. L⁻¹ initial glutaric acid concentration. Consequently, it was found that 77.98% of glutaric acid was separated from water at optimal conditions. This result indicated that imidazolium-based ionic liquids can be used for the reactive separation of glutaric acid from the water.

Laboratory studies were conducted to evaluate effect of soil water content, organic soil amendment, and mineral nutrient application on decomposition of three types of biodegradable containers: recycled paper, wood pulp fiber, and coconut coir over 182 days. Soil respiration was assessed through alkaline trap and titration method to determine decomposition of biodegradable containers. Percentage of carbon content remaining in the container material after 182 days was also quantified. Relative to soil water content, recycled paper containers under 40% water holding capacity (WHC) had higher carbon dioxide released than 60%WHC. Carbon analysis indicated that less carbon remained for all container types under 60% than 40%WHC. For recycled paper and coconut coir pots, treatments receiving container and soil amendment had significantly increased soil respiration. Post-experiment carbon analysis revealed less carbon remained in the recycled paper, wood pulp fiber, and coconut coir containers in the absence of organic soil amendment. For coconut coir, the interaction of container × mineral nutrients appeared to increase soil respiration with higher carbon dioxide released under biodegradable container × low mineral nutrient. This study suggests that cultural practices (i.e., irrigation and organic matter amendment) could facilitate degradation for certain biodegradable container types; however, to provide extensive cultural practice recommendations regarding biodegradable containers, more research is needed.

The risks of the health-associated problems of pesticide-exposed non-target organisms are ubiquitous, therefore an emerging concern to strike the balance between benefit and risk factors. In the present study, by elucidating multiple biomarkers, the effects of Phenthoate 50 EC on the acute toxicity tests and different pathophysiological changes of common carp (Cyprinus carpio) fingerlings were studied in time- and concentration-dependent manners. The LC₅₀ of Phenthoate 50 EC for the fish was 7.39 (6.716–8.076) ppm at 96 h. As an indicator of neurotoxicity, compared to the control group, significant (P < 0.01) reduction in brain acetylcholinesterase (AChE) activity was observed, whereas plasma glutamate-oxalacetate transaminase (PGOT) and plasma glutamate pyruvate transaminase (PGPT) activities were increased significantly (P < 0.01) at the doses of 2.22 and 3.69 ppm of Phenthoate 50 EC, respectively. Histopathological changes in the insecticide-treated fish liver suggested the hepatic tissue damages, while alteration of the blood, gills and kidney morphology; progressive decrease (P < 0.05) in the serum calcium levels; and significantly (P < 0.01) decreased blood glucose level at 2.22 and 3.69 or 5.17 ppm of Phenthoate 50 EC demonstrated the oxidative stress and requirement of the up-surging energy demands due to the exposure of this organophosphate chemical. These results advice the modulation caused by this widely used agrochemical on the physiology of aquatic fauna by changing the enzymatic and biochemical indices at cellular level.

Arsenic (As), a toxic metalloid, is finding its route to human through intake of As-contaminated water and consumption of food grown on contaminated soil. Rice is the most As-affected crop. Present study is aimed to assess the impact of stabilized orthosilicic acid (a proprietary formulation for plant-available silicon (Si) and earlier used as fertilizer for rice to enhance growth and yield) in reducing the accumulation of As in rice grains. Application of arsenic in the form of arsenate (Asⱽ) and arsenite (Asᴵᴵᴵ) significantly affected plant growth in a dose-dependent manner. Higher doses of Asⱽ and Asᴵᴵᴵ (50 and 25 mg L⁻¹ respectively) significantly decreased the yield attributes leading to lower yield. A significant accumulation of As in grain was observed in both Asⱽ- and Asᴵᴵᴵ-exposed plants in a dose-dependent manner. Arsenic exposure also increased the level of Si in rice grains. Application of Si, either in soil or on leaves (foliar), greatly reduced grain As accumulation (up to 67% in Asⱽ and 78% in Asᴵᴵᴵ) and enhanced the growth and yield of plants under As stress. The level of thiols and activities of antioxidant enzymes were also enhanced under Si application. Foliar Si application was more effective in increasing grain Si level and reducing grain As than soil Si. The level of other trace elements was also significantly enhanced by Si application irrespective of the presence or absence of As in comparison with control. Arsenic exposure constrained some of the trace elements, such as Zn and Co, which were restored by Si application. Results of the present study showed that the application of currently used Si formulation may effectively reduce grain As level even in highly As-contaminated soil and improve grain quality of rice.

The equipment manufacturing industry is the industrial base of China, which makes it imperative to coordinate the relationship between industrial development and environmental protection. Using panel data of the seven sub-industries in China’s equipment manufacturing industry from 2011 to 2015, this paper evaluates the static and dynamic aspects of green economic development efficiency by combining the super-efficiency slack-based measure model of unexpected output and the data envelopment analysis-Malmquist index model. The results show investments in research and development, and environmental regulations have yielded some positive results, but that regulations have also yielded some undesired output in terms of diminished economic benefits. Pure technical efficiency and scale efficiency have both declined, indicating that the scale and industrial structure need to be further optimized. The results of this study present an objective and comprehensive assessment of green economic development of China’s equipment manufacturing industry and provide valuable insights for improving green economic development efficiency.

This study established the correlation between respiratory syncytial virus (RSV) bronchiolitis and climate factors in the area of Sousse, Tunisia, during 13 years (2003–2015), from neonates and children <= 5 years old and hospitalized in Farhat Hached University-Hospital of Sousse. The meteorological data of Sousse including temperature, rainfall, and humidity were obtained. RSV detection was carried out with the direct immunofluorescence assay. The impact of climate factors on viral circulation was statistically analyzed. From 2003 to 2015, the total rate of RSV bronchiolitis accounted for 34.5% and peaked in 2007 and 2013. RSV infection was higher in male cases and pediatric environment (p<0.001) and was detected in 47.3% of hospitalizations in intensive care units. The epidemic of this pathogen started in October and peaked in January (41.6%). When the infectivity of RSV was at its maximum, the monthly average rainfall was high (31 mm) and the monthly average temperature and the monthly average humidity were at their minimum (11 °C and 66%, respectively). RSV activity was negatively correlated with temperature (r = − 0.78, p = 0.003) and humidity (r = − 0.62, p = 0.03). Regression analysis showed that the monthly average temperature fits into a linear model (R² = 61%, p < 0.01). No correlation between RSV activity and rainfall was observed (p = 0.48). The meteorological predictions of RSV outbreaks with specific Tunisian climate parameters will help in determining the optimal timing of appropriate preventive strategies. In the area of Sousse, preventive measures should be enhanced since October especially, when the temperature is around 11 °C and humidity is above 60%.

The ecotoxicity of nickel depends on water quality characteristics such as pH and dissolved organic carbon. Bioavailability models to predict nickel toxicity have been developed for and validated in European natural waters. In this study, we examined the acute toxicity of nickel to the strain of Daphnia magna that is used for toxicity tests in Japan, using water samples from five Japanese rivers. Based on the results of these toxicity tests, we examined the predictive capacity of the bioavailability model for acute nickel toxicity to D. magna and validated the model. The 50% effect and lethal concentrations (EC₅₀ and LC₅₀) of dissolved nickel for D. magna ranged from 0.52 to 4.0 mg/L and from 0.62 to 5.3 mg/L, respectively. Our results indicate that acute nickel toxicity varied as a result of the different water quality conditions in Japanese rivers. The bioavailability model predicted EC₅₀ and LC₅₀ values in water samples from Japanese rivers by errors more than a factor of 2, while the bioavailability models validated with the results of our toxicity tests were able to accurately predict these values with errors less than a factor of 2. Therefore, our results indicate that the bioavailability model validated using the results of the toxicity tests conducted using Japanese water samples could accurately predict acute nickel toxicity to the strain of D. magna.

The effects of CuO NPs and bulk Cu at 0–1000 mg L⁻¹ on the growth, photosynthesis and biochemical parameters were investigated in 30-day-old rice plants grown hydroponically. ICP-OES measurements showed that CuO NPs released ≤ 1 mg L⁻¹ of Cu²⁺ ions compared with ≤ 81 mg L⁻¹ by bulk Cu at their highest concentration. Both treatments showed that growth, photo-phosphorylation and carbon dioxide assimilation declined considerably. Bulk particles caused oxidative stress whereas NP showed no such effect. Electromicrographs showed that CuO NPs accumulated in chloroplasts resulting in destacking and distortions of thylakoid membranes while bulk Cu showed no such behaviour. Results suggest that NP affected the growth by accumulation in non-ionic form in chloroplasts causing damage to thylakoid membrane without oxidative damage, whereas the bulk Cu affected the growth by causing oxidative damage as a result of release of Cu²⁺ ions without affecting the ultrastructure of the chloroplasts.

The MeHg content in the reed wetland soil of Liaohe was studied by the indoor-simulated constant temperature culture method. Under different aerobic and anaerobic conditions, the flooding salinity (CK, 0.5%, 1.0%, 1.5%, 2.0%) changes relationship whether SRB plays a leading role in the formation of MeHg. The results showed that under aerobic conditions, the content of MeHg in the surface layer and the bottom layer showed a trend of decreasing first and then increasing with the increase of culture time. Both of them have a lower MeHg content when the flooding salinity is 2.0%. The number of SRB bacteria showed a trend of “upgrading-depleting” with the increase of flooding salinity. Under anaerobic conditions, the MeHg content of surface and bottom soil changed slowly in the early stage of culture (the first 10 days), and the MeHg content increased rapidly after 15 days of culture, and decreased significantly on the 25th day. The number of SRB bacteria showed a trend of “depleting-upgrading” as the flooding salinity increased. Linear fitting showed that there was no obvious linear relationship between the change of MeHg content in soil and the number of SRB bacteria, and other microorganisms may play a role in methylation of mercury. Under anaerobic conditions, MeHg content in surface soil was significantly positively correlated with organic matter (p < 0.01), but negatively correlated with total mercury (p < 0.05). The mercury methylation process is affected by many environmental factors, and the mechanism of mercury methylation in different environments is different.

Microplastic pollution is a significant and growing environmental issue. Recent studies have evaluated the atmosphere as an important pathway of microplastic contamination. Airborne microplastics can be transported long distances and accumulate in various terrestrial and aquatic environmental matrices, where they represent a threat to the biosphere. This review systematically summarizes the existing knowledge on airborne microplastics, including the different sampling and analytical techniques, occurrence and sources. We investigate the different sample collection techniques from street dust to indoor and outdoor air and examined sample preparation, pre-treatment and characterization techniques. We further explored the key factors with respect to their occurrence in the environment such as concentration levels, polymer composition, size distribution, shape and colour characteristics. The sources of airborne microplastics were also summarized. The results show that microplastics are ubiquitous in all atmospheric compartments including street dust and indoor and outdoor air at various concentrations, which is influenced by the community’s lifestyle choices, anthropogenic activities and meteorological conditions. Various forms of microplastics including spherules, film, fragments, fibres and granules were identified with fibrous microplastics being the most dominant. Additionally, microplastics of 20 different polymers and varying colour characteristic have been reported in studies focusing on airborne microplastic contamination. The size distribution of microplastics varied among the studied air compartments; however, they were mostly distributed towards the smaller size ranges, less than 1 mm. Our review highlights a need to consider atmospheric pathways in addition to soil and water migration dispersion processes for any holistic assessments of microplastic threats to the biosphere. Moreover, standardization of airborne microplastic sampling methods is needed to optimize the effectiveness of future work in this area. Graphical Abstract Microplastics in atmospheric environments