Pentachlorophenol removal from aqueous solutions by microwave/persulfate and microwave/H2O2: a comparative kinetic study

Abstract

Pentachlorophenol (PCP) is one of the most fungicides and pesticides used in wood protection. Poisoning from PCP may be happened in dermal absorption, and respiration or ingestion. With regard to health and environmental effects of PCP, many methods were studied for its removal. Microwave assisted other methods are environmental friendly, safety, and economical method, therefore, in this study; a modified domestic microwave assisted hydrogen peroxide (MW/H2O2) and sodium persulfate (MW/SPS) was used for PCP removal from aqueous solutions. PCP removal rate was measured under different factors such as pH, energy intensity, SPS, H2O2 concentration, Tert- butyl alcohol (TBA) and chemical oxygen demand (COD). The concentration changes of PCP were determined using spectrophotometer and HPLC spectra, respectively. The best removal PCP rate obtained in condition of pH of 11, 0.02 mol L−1 of SPS, 0.2 mol L−1 of H2O2 and energy intensity of 600 W. Moreover, COD removals in MW/H2O2 and MW/SPS process were 83% and 94%, respectively, also TBA test decreased 15% and 3% of PCP removal in MW/SPS and MW/H2O2 processes respectively. Experimental results indicated that sulfate radical was stronger than hydroxyl radical and examinations order reaction was in first order. In this study, was cleared that MW/SPS process was more effective than MW/H2O2 process in PCP removal.

Bisphenol A removal from aqueous solutions using novel UV/persulfate/H2O2/Cu system: optimization and modelling with central composite design and response surface methodology

“…In addition, using the increased level of PS can lead to more radicals, and synchronization of this phenomenon along with increased the initial level of BPA, can cause to more faster degradation of BPA [73, 74]. The obtained results of this work are confirmed with similar study’s results by application of the PS and other AOPs processes for BPA removal from various fields of environment [57, 61, 71, 75, 76]. …”

Determination of parabens in wastewater and sludge in a municipal wastewater treatment plant using microwaveassisted dispersive liquid-liquid microextraction coupled with gas chromatography-mass spectrometry

“…This phenomenon leads to more penetration of solvent into the matrix and better extraction of the solute. Microwave power should not increase the unwanted temperature and pressure (37). In the present study, it was observed that a decrease in the parabens extraction, when microwave power increased, could be due to the possible degradation of parabens (23), therefore, 450 W microwave power and 30 s reaction time were selected for the next experiments.…”

“…At pH above 8, the parabens alkaline hydrolysis process begins, leading to the production of alcohol and hydroxybenzoic acid (45). It is revealed that pH value together with the organic compounds type are highly contributed in increasing the chemical reaction efficiency using microwave oven (37,46). Florisil is usually applied to decrease the matrix interference effects on the microwave absorption through solvent and analyte (23).…”

Degradation of 4-Chlorophenol by Microwave-Enhanced Advanced Oxidation Processes: Kinetics and Influential Process Parameters

“…The obtained reaction rate constants are in the range of what was reported in a previous publication, when the difference in process conditions is taken into account. Asgari et al [22] investigated the kinetics of the degradation of 4-CP by MW-H 2 O 2 at different process conditions (initial 4-CP concentration 100 mg/L, hydrogen peroxide concentration 6.8 g/L, temperature of 105 • C, and pH = 11). Here they found an observed reaction rate constant of 0.055 min −1 .…”