Zobrazení zdroje stránky Matzenreese6035

In this study, a novel Al°-CNTs-Cu2O composite, capable of activating O2 to generate H2O2 and further to reactive oxygen species (ROSs) at a wide pH range, was synthetized, characterized and applied for the degradation of sulfamerazine. In the activation of O2 by Al°-CNTs-Cu2O composite, H2O2 was generated from the reaction of O2 with Al°-CNTs, which could be catalytically decomposed into O2- and OH by Cu2O, the formed Cu(II) could be rapidly reduced to Cu2O by Al°-CNTs in composite, which made Al°-CNTs-Cu2O composite reusable and decreased the leaching of copper ions into solution. The removal efficiency of SMR and TOC was 73.91 % and 56.80 %, respectively at initial pH = 5.8, T = 20 °C, O2 flow rate = 100 mL/min, Al°-CNTs-Cu2O dosage = 2 g/L, SMR = 50 mg/L, and reaction time = 60 min. The removal efficiency of SMR kept almost unchanged and the concentration of copper ions in solution was below 0.5 mg/L. The Al°-CNTs-Cu2O/O2 process could be used as a novel catalyst for the degradation of refractory organic contaminants in water and wastewater by Fenton-like process at a wide pH range through the in situ generation of H2O2. Coal fly ash (CFA) is a valuable industrial solid waste, but conventional methods used for its disposal can lead to serious and long-lasting environmental issues. The study of technologies for CFA recycling has been of major concern, while the harm caused by CFA is only partially understood, limiting its reuse. In this review, the basic physico-chemical properties of CFA are introduced, followed by a systematic summary and discussion of the leachability of CFA via different leaching methods and the chemical speciation of some typical metal elements in CFA, which is related to its harmful effects. The specific harm that CFA causes to humans, wild animals, and plants and the study status of magnetic property of CFA are presented. Because of the pervasive concerns of many people, the utilisation of CFA in the USA and Europe and an economic and environmental analysis of its disposal is provided and discussed. Finally, some possible directions for future research involving CFA are proposed. China has applied the ultra-low emission technology in coal-fired power plants to control traditional air pollutants and to reduce Hg emissions synergically. In this study, we applied field experiment, model calculation, and literature review to evaluate the Hg control effect of ultra-low emission technology and the potential cross-media effect comprehensively. The dominant ultra-low emission technology significantly improves the atmospheric Hg removal efficiency from 75% to 87%. Such improvement mainly comes from the effect of dust removal devices. Based on the calculated distribution characteristic of Hg content of wastes, we find out that the improvement of Hg control effect of air pollution control devices significantly increase the Hg content of fly ash, which rises from 0.16 mg/kg to 0.33 mg/kg. However, the Hg content of gypsum decreases from 0.75 mg/kg to 0.51 mg/kg. [https://www.selleckchem.com/products/ABT-263.html this website] Whether or not to carry out ultra-low emission retrofits, Hg contents of wastes from coal-fired power plants are overall lower than the limit of 25 mg/kg which is intended to be set as the limit for Hg-containing wastes. However, the embodied more than two hundreds of tons Hg in these wastes still require policies to guide the disposal of these wastes. V.Nanoscale zerovalent iron (nZVI) and sulfidated nanoscale zerovalent iron (S-nZVI) have been increasingly studied for heavy metal removal in the subsurface. However, a comprehensive comparison of the effectiveness of the technologies and the stability of derived metal-adsorbed composites is lacking. In this study, we evaluated the colloidal stability and transport of nZVI, S-nZVI and S-nZVI modified with nanosized silica (FeSSi). Furthermore, we monitored the metal immobilization performance of the three nanoparticles (NPs) under anoxic conditions in synthetic groundwater for 30 days. The NP-metal composites were thereafter discharged into a river water and metal remobilization was monitored for 20 days. Sulfidation improved the colloidal stability of nZVI in both simple media and in natural waters, although a lower initial agglomeration rate constant (ka) was observed in unmodified nZVI at acidic pH. The transport of nZVI in saturated soil column was enhanced with sulfidation due to decreased electrostatic attraction between the NPs and sand. The three NPs sequestered more than 80 % of Cu2+, Zn2+, Cd2+ and Cr2O72- from groundwater. Among the three NPs tested, S-nZVI had a slightly higher removal capacity for metals than nZVI in synthetic groundwater and the chemical stability of metal-S-nZVI composites upon discharge into river water was the highest. Prothioconazole (PTA) is a novel, broad-spectrum, chiral triazole fungicide that is mainly used to prevent and control the disease of cereal crops. However, the adverse effects of PTA and its major metabolite on nontarget organisms have aroused wide concern. In the present work, the acute toxic of the metabolite prothioconazole-desthio (PTA-desthio), with an LC50 of 1.31 mg L-1, was 3.5-fold more toxic than the parent compound, indicating that the metabolism of PTA in zebrafish was toxic. The stereoselective uptake and metabolism of PTA and PTA-desthio in zebrafish was firstly investigated using LC-MS/MS. Remarkable enantioselectivity was observed S-PTA and S-PTA-desthio were preferentially uptake with the uptake rate constants of 8.22 and 8.15 d-1 at exposure concentration of 0.5 mg L-1, respectively, and the R-PTA-desthio were preferentially metabolized. PTA-desthio was rapidly formed during the uptake processes. The antioxidant enzyme activities in the zebrafish changed significantly, and these effects were reversible. A metabolic pathway including 13 phase I metabolites and 2 phase II metabolites was firstly proposed. A glucuronic acid conjugate and sulfate conjugate were observed in zebrafish. The results of this work provide information that highlights and can help mitigate the potential toxicity of PTA to the ecological environment and humans health.