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Regional unified environmental efficiency of China: a non-separable hybrid measure under natural and managerial disposability
2020
Wang, Xu | Wang, Yingming
Attributing to the booming industry, China has made huge economic achievements during recent decades/years. However, the issue of energy and environment has challenged the sustainable development of the industry a lot in China. Investigating the non-separable relationship among energy, capital, and CO₂ emission under natural and managerial disposability, this paper proposes two hybrid measure approaches to measure unified environmental efficiency of industry in China during 2011–2016. Besides, production efficiency, emission efficiency, damage to scale, and return to scale of 30 regions in China are calculated and recognized. The results show that (1) unified environmental efficiency of Chinese industry under natural disposability is higher than that under managerial disposability in early few years, but they are close to each other finally. (2) Unified environmental efficiency gaps among regions under natural disposability are wider than those under managerial disposability. Increasing capital investment and improving technology can help reduce efficiency gaps among regions. (3) It is available to increase production efficiency and reduce CO₂ emission by cutting down energy consumption for most regions; insufficient capital investment and poor production technology cause the decreasing return to scale and production efficiency.
Afficher plus [+] Moins [-]Pollution characteristics and underlying ecological risks of primary semi-volatile organic compounds (SVOCs) in urban watersheds of Shanghai, China
2020
Shao, Hai-yang | Zhang, Zhou-chong | Chai, Jian-fei | Xu, Gang | Tang, Liang | Wu, Ming-hong
We investigated the pollution characteristics of ninety semi-volatile organic compounds (SVOCs) in the rivers and lakes of Shanghai. Total concentrations of Σ₉₀SVOCs in water and sediment samples from 30 sites ranged from 1.47 to 19.5 μg/L and 2.38 to 9.48 mg/kg, respectively. PAEs and PAHs were the major contaminant compounds found in all samples. OCPs accounted for less than 3% of the total concentrations of Σ₉₀SVOCs and other SVOCs were either not detected or only detected in trace amounts. Our results indicated that domestic swage, industrial wastewater, petroleum products, and other human activities were the pollutant sources to the water and sediment. It is noteworthy that products that contain the banned chemicals HCH and DDT are still under use within the studied areas. Ecological and health risk assessment results showed that dieldrin and BBP have the potential to cause adverse effects on the environment, while B(a)p and DBP have high carcinogenic risks to humans.
Afficher plus [+] Moins [-]Enantioselective fate of mandipropamid in grape and during processing of grape wine
2020
Xu, Guofeng | Jia, Xiaohui | Zhang, Haiping | Zhang, Jianyi | Nie, Jiyun
Enantioselective monitoring of chiral fungicide mandipropamid enantiomers were carried out in grapes and wine-making process. The enantiomers of mandipropamid were separated on a Lux Cellulose-2 column and determined by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC–MS/MS). The processing procedure included washing, fermentation, and clarification. Significant enantioselectivity was observed in grape under field conditions and during wine-making processing. The half-lives of R-mandipropamid and S-mandipropamid were 5.63 days and 7.79 days under field conditions 43.3 h and 69.3 h during wine-making processing, respectively. The EF values ranged from 0.498 to 0.283 in grape under field conditions, and the EF values were from 0.458 (0 h) to 0.362 (312 h) during the whole fermentation process. The results indicated that R-mandipropamid degraded faster than S-mandipropamid in grape under field conditions and during the fermentation process. The processing factors (PFs) were less than 1 for each procedure, and the PF ranged from 0.005 to 0.025 in the overall process, which indicated that the wine-making process can reduce mandipropamid residue in grape wine. The results of this study could help facilitate more accurate risk assessments of mandipropamid in table grapes and during wine-making process.
Afficher plus [+] Moins [-]Photocatalytic degradation of methyl orange from wastewater using a newly developed Fe-Cu-Zn-ZSM-5 catalyst
2020
Ahmad, Mushtaq | Aziz, Abdul Raman Abdul | Mazari, Shaukat Ali | Baloch, Abdul Ghaffar | Nizamuddin, Sabzoi
Photo-Fenton oxidation is one of the most promising processes to remove recalcitrant contaminants from industrial wastewater. In this study, we developed a novel heterogeneous catalyst to enhance photo-Fenton oxidation. Multi-composition (Fe-Cu-Zn) on aluminosilicate zeolite (ZSM-5) was prepared using a chemical process. Subsequently, the synthesized catalyst was characterized by using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (spectroscopy) (EDX), and Brunauer–Emmett–Teller (BET). Activity of the synthesized catalyst is analysed to degrade an azo dye, methyl orange. Taguchi method is used to optimize color removal and total carbon content (TOC) removal. The dye completely degraded, and 76% of TOC removal was obtained at optimized process conditions. The amount of catalyst required for the desired degradation of dye significantly reduced up to 92% and 30% compared to conventional homogenous and heterogeneous Fenton oxidation processes, respectively.
Afficher plus [+] Moins [-]Titanium dioxide nanoparticles induced the apoptosis of RAW264.7 macrophages through miR-29b-3p/NFAT5 pathway
2020
Xu, Siyi | Sui, Jing | Fu, Yanyun | Wu, Wenjuan | Liu, Tong | Yang, Sheng | Liang, Geyu
Titanium dioxide nanoparticles (TiO₂ NPs) are widely found in consumer and industrial products, contributing to their prevalent presence in our surroundings. In this study, several miRNAs in the immuno-related pathways were found to be dysregulated in RAW264.7 cells after 24-h exposure to TiO₂ NPs, including miR-29b-3p, which had not been previously found to be associated with the dysregulation of immunity after exposure to TiO₂ NPs. The KEGG pathway and GO enrichment analysis suggested that miR-29b-3p functioned both in the T and B cell receptor signaling pathways. The NFAT5 gene was predicted to regulate miR-29b-3p using the MiRDB online database. The expression of miR-29b-3p and NFAT5 was found to be inversely correlated using qRT-PCR and western blotting analysis. Dual-luciferase reporter gene assays demonstrated the precise regulatory relationship between miR-29b-3p and NFAT5. The upregulation of miR-29b-3p was found to reinforce the apoptosis of cells, while no changes were found in terms of the cell cycle or cell proliferation, using MTT, cell apoptosis, and cycle detection experiments. Our results demonstrate that miR-29b-3p is involved in the response of RAW264.7 cells to exposure to TiO₂, proving evidence for the further study of the toxicity and mechanisms of nano-TiO₂ exposure.
Afficher plus [+] Moins [-]Effects of sediment oxidation on phosphorus transformation in three large shallow eutrophic lakes in China
2020
Li, Qingman | Shi, Wenqing
Oxidation of surface sediments is an important means for altering phosphorus (P) exchanges across sediment–water interface (SWI) in shallow lakes. In this study, the potential and composition of regenerated oxidation capacity (OC) of surface sediments were evaluated in three large shallow lakes (Tai Lake, Chao Lake, and Dianchi Lake) in China; the transformation of sedimentary P was quantified through P fractionation scheme. The composition of the regenerated OC differed among these three lakes, with Fe(III) and SO₄²⁻ dominant in Dianchi Lake, Mn(IV) and Fe(III) in Chao Lake and Tai Lake. Oxidation of sediments enhanced the transformation of sedimentary P and altered P exchanges across the SWI. In Chao Lake, the HCl-P was transformed to BD-P; in Tai Lake, the NaOH-P was involved too, and transformed to BD-P; whereas in Dianchi Lake, an increase in NH₄Cl-P was also observed except for the transformation from HCl-P to BD-P. The sediment-to-water flux of P was enhanced with 0.17 mg/g DW in Dianchi Lake and 0.08 mg/g DW in Chao Lake, while a contrary water-to-sediment flux of P was observed in Tai Lake, reaching 0.01 mg/g DW. This study advances our knowledge on the impacts of sediment oxidation on P cycles in lakes, which will be beneficial to eutrophication control.
Afficher plus [+] Moins [-]Efficient Removal of Paracetamol by Manganese Oxide Octahedral Molecular Sieves (OMS-2) and Persulfate
2020
Tepe, Ozlem | Tunç, Zeynep | Yıldız, Burçin | Şahin, Mehmet
Pharmaceutically active compounds are gradually increasing in different environments such as surface waters, groundwater, and soil. Paracetamol is a pharmaceutical used as a pain reliever and antipyretic. In this study, paracetamol removal was investigated using manganese oxide octahedral molecular sieves (OMS-2) and persulfate. In the first stage of the study, OMS-2 was produced in a laboratory, and then paracetamol removal was investigated in OMS-2 only, persulfate only, and a combination of OMS-2/PS. When using 5 mM persulfate and 0.1 g/L OMS-2, the paracetamol removal efficiency increased to 99.5%. The use of OMS-2 with persulfate resulted in faster and more effective removal of paracetamol compared with OMS-2 only and persulfate only. In another stage of the study, the effects of reaction temperature and pH were investigated. For this purpose, the pH was changed in the range of 2–8, while the temperature was examined at 20, 30, and 40 °C. A high rate of paracetamol removal occurred at all pH and temperature values tested. Paracetamol removal was investigated at different OMS-2 and persulfate concentrations, optimum OMS-2 amount was determined as 0.1 g/L, and optimum persulfate dosage was 20 mM. The reusability of the OMS-2 catalyst was investigated, showing a decrease in removal efficiency with each cycle. In the later stages of the study, free radical quenching studies, the effect of humic acid and inorganic anions and the characterization of the synthesized OMS-2 were performed.
Afficher plus [+] Moins [-]Impact of Soil Biochar Incorporation on the Uptake of Heavy Metals Present in Wastewater by Spinach Plants
2020
Nzediegwu, Christopher | Prasher, Shiv | Elsayed, Eman | Dhiman, Jaskaran | Mawof, Ali | Patel, Ramanbhai
The effect of plantain peel biochar on the uptake of six heavy metals (Cd, Cr, Cu, Fe, Pb and Zn) in spinach (Spinacia oleracea L.) irrigated with untreated wastewater was investigated in nine outdoor lysimeters (0.45 m diameter × 1.0 m height) arranged in a completely randomised design with three replicates. The lysimeters were packed with sandy soil (bulk density 1.35 Mg m⁻³) and brought to field capacity 1 day before starting the experiment. Biochar (1% w/w) was mixed in the top 0.10 m of soil under biochar amendment. Spinach were planted in each lysimeter, irrigated (every 10 days for 4 times in total), harvested (harvest 1 and harvest 2) and analysed for the heavy metals. Spinach leaves accumulated more heavy metals than the roots and stems. Biochar amendment did not affect the translocation of heavy metals (Cd, Cu, Cr, Fe and Pb) to spinach leaves, possibly due to competition with other compounds in the soil solution. However, the biochar amendment improved CEC and increased the pH of soils which resulted in a 42% reduction of translocation of Zn in spinach leaves. Assuming daily spinach consumption of 200 g per person, Zn in spinach grown in soil amended with biochar would be below the provisional maximum tolerable daily intake limit for adults (20 mg) as prescribed by WHO/FAO/IAEA. Consumption of spinach grown with wastewater in soil without biochar amendment may not be safe because of Zn toxicity. Likewise, the concentration of Cd, above CODEX permissible levels in the spinach leaves and eleven times higher in wastewater than freshwater irrigation, raises a concern for consumers in developing countries where untreated wastewater is often used for irrigation.
Afficher plus [+] Moins [-]Bioaugmentation of Soil Contaminated with Zinc
2020
Strachel, Rafał | Wyszkowska, Jadwiga | Baćmaga, Małgorzata
An experiment described in this work aimed to establish the role of bioaugmentation in minimizing adverse outcomes of loamy sand contamination with zinc. The bioaugmentation was conducted with the use of microbial strains being most resistant to the action of zinc, which were isolated from the soil contaminated with 1250 mg Zn²⁺ kg⁻¹ dry matter (DM) of soil after 12-month incubation. The soil was inoculated with 4 strains of bacteria (Bacillus licheniformis KT986159.1, Bacillus sp. KF956639.1, Gordonia amicalis KM113029.1, Leifsonia sp. KJ191763.1) and 4 strains of fungi (Penicillium raperi KC797647.1, Penicillium janthinellum AY373921.1, Penicillium glabrum LT558918.1, Trichoderma harzianum LN714612.1). In the case of the non-contaminated soil, a metal dose of 250 mg Zn²⁺ kg⁻¹ DM of soil contributed to enhanced proliferation and microorganisms and enzymatic activity. In turn, zinc in its highest dose (1250 mg Zn²⁺ kg⁻¹ DM of soil) evoked adverse effects, which were manifested in reduced numbers and diversity of microorganisms and suppressed activity of soil enzymes. This contamination rate stimulated only the proliferation of fungi, but their ecophysiological diversity was reduced either. The bioaugmentation treatment minimized adverse effects of zinc. Unfortunately, the use of autochthonous microorganisms failed to reduce zinc bioavailability in the soil.
Afficher plus [+] Moins [-]Response Surface Methodology as an Optimization Tool for Anaerobic Digestion of Food Waste
2020
Parra-Orobio, Brayan Alexis | Torres-López, Wilmar Alexander | Torres-Lozada, Patricia
Biowastes are the main fraction of municipal solid waste (MSW), and of this, food waste (FW) is the predominant component. Given that FW is predominantly biodegradable organic matter, approach strategies such as anaerobic digestion (AD) are suitable to apply on these substrates because these process also produces methane gas as a renewable energy source, particularly important given the depletion of nonrenewable energy sources. This study evaluated the influence of two parameters on AD: substrate-inoculum ratio (S/I: 0.5 to 2.0 gVSₛᵤbₛₜᵣₐₜₑ gVSᵢₙₒcᵤₗᵤₘ⁻¹) and pH (7.0 to 8.0 units) on biochemical methane potential (BMP) using the response surface methodology (RSM), a valuable tool which can be used to establish strategies that allow for the control and optimization of the AD of FW. Of the conditions evaluated, it was found that the optimal S/I ratio and pH conditions to guarantee the highest BMP (297.05 ± 14.38 mL CH₄ gVS⁻¹) were S/I ratio = 0.19 gVSₛᵤbₛₜᵣₐₜₑ gVSᵢₙₒcᵤₗᵤₘ⁻¹ and pH = 7.5. Although the hydrolysis constant (kₕ) was low, in all conditions, it was in the range reported for substrates with a high carbohydrate content, such as FW (0.002–0.25 day⁻¹). In this study, pH was found to be the factor that had the most significant effect on kₕ and BMP.
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