Enhanced debromination of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) by zero-valent zinc with ascorbic acid

• Highly efficient debromination of BDE-47 was achieved in the ZVZ/AA system. • BDE-47 debromination by the ZVZ/AA can be applied to a wide range of pH. • AA inhibits the formation of (hydr)oxide and accelerates the corrosion of ZVZ. • Reduction mechanism of BDE-47 debromination by the ZVZ/AA system was proposed. A new technique of zero-valent zinc coupled with ascorbic acid (ZVZ/AA) was developed and applied to debrominate the 2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47), which achieved high conversion and rapid debromination of BDE-47 to less- or non-toxic forms. The reaction conditions were optimized by the addition of 100 mg/L ZVZ particles and 3 mmol/L AA at original solution pH= 4.00 using the solvent of methanol/H₂O (v:v= 4:6), which could convert approximately 94% of 5 mg/L BDE-47 into lower-brominated diphenyl ethers within a 90 min at the ZVZ/AA system. The high debromination of BDE-47 was mainly attributed to the effect of AA that inhibits the formation of Zn(II)(hydr)oxide passivation layers and promotes the corrosion of ZVZ, which leads to increase the reactivity of ZVZ. Additionally, ion chromatography and gas chromatography mass spectrometry analyses revealed that bromine ion and lower-debromination diphenyl ethers formed during the reduction of BDE-47. Furthermore, based on the generation of the intermediates products, and its concentration changes over time, it was proposed that the dominant pathway for conversion of BDE-47 was sequential debromination and the final products were diphenyl ethers. These results suggested that the ZVZ/AA system has the potential for highly efficient debromination of BDE-47 from wastewater.     

Photosynthesis and related metabolic mechanism of promoted rice (Oryza sativa L.) growth by TiO2 nanoparticles

• The rice growth was promoted by nano-TiO₂ of 0.1–100 mg/L. • Nano-TiO₂ enhanced the energy storage in photosynthesis. • Nano-TiO₂ reduced energy consumption in carbohydrate metabolism and TCA cycle. Titanium dioxide nanoparticle (nano-TiO₂), as an excellent UV absorbent and photo-catalyst, has been widely applied in modern industry, thus inevitably discharged into environment. We proposed that nano-TiO₂ in soil can promote crop yield through photosynthetic and metabolic disturbance, therefore, we investigated the effects of nano-TiO₂ exposure on related physiologic-biochemical properties of rice (Oryza sativa L.). Results showed that rice biomass was increased >30% at every applied dosage (0.1–100 mg/L) of nano-TiO₂. The actual photosynthetic rate (Y(II)) significantly increased by 10.0% and 17.2% in the treatments of 10 and 100 mg/L respectively, indicating an increased energy production from photosynthesis. Besides, non-photochemical quenching (Y(NPQ)) significantly decreased by 19.8%–26.0% of the control in all treatments respectively, representing a decline in heat dissipation. Detailed metabolism fingerprinting further revealed that a fortified transformation of monosaccharides (D-fructose, D-galactose, and D-talose) to disaccharides (D-cellobiose, and D-lactose) was accompanied with a weakened citric acid cycle, confirming the decrease of energy consumption in metabolism. All these results elucidated that nano-TiO₂ promoted rice growth through the upregulation of energy storage in photosynthesis and the downregulation of energy consumption in metabolism. This study provides a mechanistic understanding of the stress-response hormesis of rice after exposure to nano-TiO₂, and provides worthy information on the potential application and risk of nanomaterials in agricultural production.     

Understanding interactions between urban development policies and GHG emissions: A case study in Stockholm Region

Human-induced urban growth and sprawl have implications for greenhouse gas (GHG) emissions that may not be included in conventional GHG accounting methods. Improved understanding of this issue requires use of interactive, spatial-explicit social–ecological systems modeling. This paper develops a comprehensive approach to modeling GHG emissions from urban developments, considering Stockholm County, Sweden as a case study. GHG projections to 2040 with a social–ecological system model yield overall greater emissions than simple extrapolations in official climate action planning. The most pronounced difference in emissions (39% higher) from energy use single-residence buildings resulting from urban sprawl. And this difference is not accounted for in the simple extrapolations. Scenario results indicate that a zoning policy, restricting urban development in certain areas, can mitigate 72% of the total emission effects of the model-projected urban sprawl. The study outcomes include a decision support interface for communicating results and policy implications with policymakers.

     

Combined toxicity of imidacloprid,acetochlor, and tebuconazole to zebrafish ( Danio rerio ): acute toxicity and hepatotoxicity assessment

Compound pollution refers to two or more kinds of pollutants with different properties, a pollutant from different sources, or the simultaneous existence of two or more different types of pollutants in the same environment. In this study, we aimed to investigate the individual and combined toxicity of the insecticide imidacloprid (IMI), the herbicide acetochlor (ACT), and the fungicide tebuconazole (TBZ) to zebrafish. The acute toxicity test results showed that the 96-h LC50 values of IMI, ACT, and TBZ were 276.84 (259.62–294.35) mg active ingredient (a.i.) L−1, 1.52 (1.34–1.74) mg a.i. L−1, and 8.16 (7.7–8.6) mg a.i. L−1, respectively. The combinations of IMI, ACT, and TBZ with toxicity ratios of 1:2:2, 1:4:4, 2:4:1, and 4:1:4 displayed synergistic toxic effects on zebrafish, while the toxicity ratios of 1:1:1, 1:1:2, 2:1:2, 2:2:1, and 4:2:1 of IMI, ACT, and TBZ, respectively, exhibited antagonistic toxic effects on zebrafish. The following experiments were performed with a toxicity ratio of 1:4:4 (IMI:ACT:TBZ). The activities of four enzyme biomarkers related to oxidative stress in the liver, catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), and malondialdehyde (MDA) content were evaluated in each exposure group on days 7, 14, 21, and 28. Compared with those of the control group, the activities of CAT, SOD, and GST and the MDA content were significantly altered at different time points in the individual and combined exposure groups. Additionally, the activities of CAT, SOD, and GST and the MDA content were significantly altered in the combined group compared with those of the individual group after 14 days or 21 days of exposure. Therefore, it was confirmed that combined toxicity studies are indispensable in risk assessment.     

In situ hydrothermal fabrication of visible light-driven g-C3N4/SrTiO3 composite for photocatalytic degradation of TC

Environmental Science and Pollution Research - A series of g-C3N4/SrTiO3 (CN/SrTiO3) composites with the different mass ratio of g-C3N4 were prepared by facile in situ hydrothermal growth method,...     

Monitoring land cover change detection with NOAA-AVHRR and MODIS remotely sensed data in the North and West of Africa from 1982 to 2015

Environmental Science and Pollution Research - Mapping land cover changes (LCC) cover three decades over North and West Africa regions provides critical insights for the climate research that...     

High heterogeneity of bacterioplankton community shaped by spatially structured environmental factors in West Lake,a typical urban lake in eastern China

Environmental Science and Pollution Research - Elucidating the bacterioplankton spatial distribution patterns and its determinants is a central topic in ecological research. However, research on...     

The influence on carbon,nitrogen recycling,and greenhouse gas emissions under different C/N ratios by black soldier fly

Environmental Science and Pollution Research - Currently, sustainable utilization, including recycling and valorization, is becoming increasingly popular in waste management. Black soldier fly...     

Effects of rainfall on surface environment and morphological characteristics in the Loess Plateau

Environmental Science and Pollution Research - Slope failure is a one of major process that causes severe landform variation and environment variation, and slope failure has become a major hidden...     

Compression behaviors of mechanically biologically treated wastes of Tianziling landfill in Hangzhou,China

Environmental Science and Pollution Research - This study aimed to investigate the compression behaviors of mechanically biologically treated (MBT) wastes. For this purpose, the short-term...