Catalytic oxidative degradation of 4‐chlorophenol: Effect of operating parameters and prediction of intermediates/by‐products

Abstract

The presence of chlorophenols (CP) in industrial wastewater is a major concern due to their microbial toxicity. The present study was performed to investigate the efficacy of advanced oxidation process (i.e., conventional and modified Fenton's process) for the degradation of 4‐chlorophenol (4‐CP) in an aqueous solution (concentration = 200 mg L−1) under varying reaction conditions. The decomposition of 4‐CP was confirmed by chemical oxygen demand (COD) reduction, total organic carbon (TOC) reduction, detection of low molecular weight carboxylic acids (such as oxalic, acetic, formic and malonic) and Cl‐ concentration in the treated 4‐CP aqueous solution. The maximum COD and TOC reductions were 74% and 42% after 30 min of Fenton reaction at an initial pH, Fe2+ concentration, and H2O2 to Fe2+ molar ratio of 3.0, 1.26 mM and 20, respectively which were found to increase to 79 and 55%, respectively when Cu2+ was also added with Fe2+ during modified Fenton process. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1734–1742, 2017

Vis‐NIR Light‐Responsive Photocatalytic Activity of C3N4−Ag−Ag2O Heterojunction‐Decorated Carbon‐fiber Cloth as Efficient Filter‐Membrane‐Shaped Photocatalyst

“…Subsequently, the intermediate products of 4‐CP were measured after 0.5 h under Xe light irradiation by GC‐MS, and the typical products are listed in Table S2. Based on these intermediate products and previous literature, the possible photocatalytic degradation pathway of 4‐CP was proposed as follow (Figure b). The main active species ( .…”

“…Subsequently, the intermediate products of 4-CP were measured after 0.5 h under Xe light irradiation by GC-MS, and the typical products are listed in Table S2. Based on these intermediate products and previous literature, [52][53][54][55][56] the possible photocatalytic degradation pathway of 4-CP was proposed as follow ( Figure 10b). The main active species ( * O 2 À and h + ) during CF/C 3 N 4 /Ag/Ag 2 O cloth-mediated photocatalytic reaction have strong oxidation ability, and they can attack 4-CP to produce hydroquinone and benzoquinone (hydroquinone can be found with retention times of 19.026 min by GC-MS, while benzoquinone was not detected due to its unstable structures).…”

Catalytic Effect of Hydrogen Peroxide in the Electrochemical Treatment of Phenolic Pollutants using a BDD Anode

“…In this context, the mineralization of phenols is a priority for environmental protection, because they can be found in surface and groundwater sources considering their half‐life time; for example, chlorophenols in the water are stable at least 3.5 months ,,. Thereupon, several investigations have been carried out in order to eliminate 4‐chlorophenol (4‐CP) applying different electrochemical methods as Electro‐Fenton, Photoelectro‐Fenton and Peroxi‐Coagulation process, in addition to coupled treatments such as Electrochemical reduction‐oxidation, Fenton Oxidation, Catalytic Oxidation, Nanoparticles . In these studies, the oxidation of chlorophenols achieves the mineralization of organic compounds obtaining a percentage removal in the range of 60–85 %.…”