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Electrochemical oxidation of polyethylene glycol (PEG) in an acidic(pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the printing wiring board industry. A paraffin composite copper hexacyanoferrate modified(PCCHM) electrode was used as the anode and a bare graphite electrode was used as the cathode. The changes in PEG and total organic carbon (TOC) concentrations during the course of the reaction were monitored. The efficiency of the PCCHM anode was compared with bare graphite anode and it was found that the former showed significant electrocatalytic property for PEG and TOC removal. Chlorides present in the solution were found to contribute significantly in the overall organic removal process. Short chain organic compounds like acetic acid, oxalic acid, formic acid and ethylene glycol formed during electrolysis were identified by HPLC method. Anode surface area and applied current density were found to influence the electro-oxidation process, in which the former was found to be dominating. Investigations of the kinetics for the present electrochemical reaction suggested that the two stage first-order kinetic model provides a much better representation of the overall mechanism of the process if compared to the generalized kinetic model. 相似文献
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Verónica Bastos José M.P. Ferreira-de-Oliveir Joana Carrol Ana L. Daniel-da-Silv Iola F. Duarte Conceição Santos Helena Oliveira 《环境科学学报(英文版)》2017,29(1):191-201
The antibacterial potential of silver nanoparticles(AgNPs) resulted in their increasing incorporation into consumer,industrial and biomedical products.Therefore,human and environmental exposure to AgNPs(either as an engineered product or a contaminant)supports the emergent research on the features conferring them different toxicity profiles.In this study,30 ran AgNPs coated with citrate or poly(ethylene glycol)(PEG) were used to assess the influence of coating on the effects produced on a human hepatoma cell line(HepG2),namely in terms of viability,apoptosis,apoptotic related genes,cell cycle and cyclins gene expression.Both types of coated AgNPs decreased cell proliferation and viability with a similar toxicity profile.At the concentrations used(11 and 5 μg/mL corresponding to IC50 and-IC10 levels,respectively) the amount of cells undergoing apoptosis was not significant and the apoptotic related genes BCL2(anti-apoptotic gene)and BAX(pro-apoptotic gene) were both downregulated.Moreover,both AgNPs affected HepG2 cell cycle progression at the higher concentration(11 μg/mL) by increasing the percentage of cells in S(synthesis phase) and G2(Gap 2 phase) phases.Considering the cell-cycle related genes,the expression of cyclin B1 and cyclin E1 genes were decreased.Thus,this work has shown that citrate- and PEG-coated AgNPs impact on HepG2 apoptotic gene expression,cell cycle dynamics and cyclin regulation in a similar way.More research is needed to determine the properties that confer AgNPs at lower toxicity,since their use has proved helpful in several industrial and biomedical contexts. 相似文献
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通过高钙离子浓度、高pH值方法结合PEG处理诱导红豆草羟脯氨酸抗性系和苜蓿根癌农杆菌转化系原生质体融合,融合机制表现为两种形式,第一种为相连膜在中间部位形成一个大的小泡,第二种为随相连膜的解体产生很多较少的泡状结构,融合过程中形成的小泡直接来自凝集膜,而不是亚显微小泡相互融包的产物,温度明显影响原生质体融合的频率和速度,甘油和二甲基亚砜可以防止膜破裂,从而促进原生质体融合,培养20d以后,在选择培养基得到含10-20个细胞的细胞团。 相似文献
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Millions of tons of polyethylene glycols (PEGs) are manufactured worldwide and most of them will reach conventional sewage disposal systems after industrial utilization. This raises environmental concerns, but not much is known about the environmental fate of these polymers. The main goals of this research were to evaluate sorption and mobility of PEG in sandier soils of Brazil. PEG 4000 was applied to the soils either freely in solution or as a simulated bioassay residue. The bioassay was prepared to simulate PEG as it is present in the animal feces. It allowed us to compare PEG mobility for both forms of environment disposal. PEG showed very low sorption (<22% of the applied PEG) and high mobility potential (>43% of the applied amount in the free-PEG and >24% of the applied amount in the bioassay-PEG experiment) in the studied soils. When PEG was applied, simulating its supply to animal diets, about 30% of its applied amount was retained into the bioassay residues and its leaching potential was reduced, whereas the remaining amount (about 70%) was readily available in solution and could be directly released into the environment. 相似文献
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首次使用PEG作为TiO2改性的主要物质,用溶胶凝胶法制备TiO2-WO3颗粒,TiO2-PEG颗粒、TiO2-PEG-WO3颗粒和TiO2颗粒。通过对甲基橙光催化的研究表明:在同样条件下,TiO2-PEG400颗粒的甲基橙光降解效果明显优于其他颗粒,甲基橙光降解率最高达到97.5%。 相似文献