Electroreductive dechlorination of chlorophenols with Pd catalyst supported on solidelectrode was studied. As solid electrodes, carbon cloth (CC), carbon felt (CF) and titanium mesh were used, and palladium was plated on solid electrodes by either electrolytic or electroless method. On each electrode with Pd, chlorophenols were qualitatively dechlorinated to phenol, while they were entirely intact on electrodes without Pd. Moreover, neither base electrode nor plating method significantly affected the activity of Pd as far as it was sufficiently loaded on the electrode. Based on the results in the experiments using one electrode repeatedly, Pd catalyst proved to possess a satisfactory duarability under the present condition. It was suggested that the reactive species responsinble for the dechlorination of chlorophenols could be formed during preliminary electrolysis. Thus, (Pd)x-H resulting from the adsorption of electrogenerated hydrogen on metallic Pd might be assumed most probable. 相似文献
• The sustainable approaches related to Fenton sludge reuse systems are summarized.• Degradation mechanism of Fenton sludge heterogeneous catalyst is deeply discussed.• The efficient utilization directions of Fenton sludge are proposed. The classical Fenton oxidation process (CFOP) is a versatile and effective application that is generally applied for recalcitrant pollutant removal. However, excess iron sludge production largely restricts its widespread application. Fenton sludge is a hazardous solid waste, which is a complex heterogeneous mixture with Fe(OH)3, organic matter, heavy metals, microorganisms, sediment impurities, and moisture. Although studies have aimed to utilize specific Fenton sludge resources based on their iron-rich characteristics, few reports have fully reviewed the utilization of Fenton sludge. As such, this review details current sustainable Fenton sludge reuse systems that are applied during wastewater treatment. Specifically, coagulant preparation, the reuse of Fenton sludge as an iron source in the Fenton process and as a synthetic heterogeneous catalyst/adsorbent, as well as the application of the Fenton sludge reuse system as a heterogeneous catalyst for resource utilization. This is the first review article to comprehensively summarize the utilization of Fenton sludge. In addition, this review suggests future research ideas to enhance the cost-effectiveness, environmental sustainability, and large-scale feasibility of Fenton sludge applications. 相似文献
Catalytic wet air oxidation (CWAO) coupled desalination technology provides a possibility for the effective and economic degradation of high salinity and high organic wastewater. Chloride widely occurs in natural and wastewaters, and its high content jeopardizes the efficacy of Advanced oxidation process (AOPs). Thus, a novel chlorine ion resistant catalyst B-site Ru doped LaFe1-xRuxO3-δ in CWAO treatment of chlorine ion wastewater was examined. Especially, LaFe0.85Ru0.15O3-δ was 45.5% better than that of the 6%RuO2@TiO2 (commercial carrier) on total organic carbon (TOC) removal. Also, doped catalysts LaFe1-xRuxO3-δ showed better activity than supported catalysts RuO2@LaFeO3 and RuO2@TiO2 with the same Ru content. Moreover, LaFe0.85Ru0.15O3-δ has novel chlorine ion resistance no matter the concentration of Cl− and no Ru dissolves after the reaction. X-ray diffraction (XRD) refinement, X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and X-ray absorption fine structure (XAFS) measurements verified the structure of LaFe0.85Ru0.15O3-δ. Kinetic data and density functional theory (DFT) proved that Fe is the site of acetic acid oxidation and adsorption of chloride ions. The existence of Fe in LaFe0.85Ru0.15O3-δ could adsorb chlorine ion (catalytic activity inhibitor), which can protect the Ru site and other active oxygen species to exert catalytic activity. This work is essential for the development of chloride-resistant catalyst in CWAO.
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