Catalytic decomposition of 2-chlorophenol using an ultrasonic-assisted Fe3O4–TiO2@MWCNT system: Influence factors, pathway and mechanism study

Abstract

As a reusable sonocatalyst, magnetically separable FeO-TiO@MWCNT (FMT) was synthesized by an ultrasound-assisted wet impregnation method and was evaluated in the removal of 2-chlorophenol (2CP). Physical and chemical properties of the catalyst composite materials were investigated by all catalysts were systematically characterized using Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-ray Analysis (EDX), Dynamic light scattering (DLS), and N-physisorption. The efficiency and kinetics of 2CP removal by FMT-assisted sonocatalysis (FMT-US) was systematically investigated under various operational parameters i.e. pH, FMT and 2CP concentration, temperature and ultrasonic power. The results indicated that 0.4gL FMT dosage, pH 5, temperature of 35°C as well as 50 w ultrasound power are the most favorable conditions for the degradation of the 2CP. Furthermore, both of the superoxide and hydroxyl radicals were produced in the reaction, however, superoxide radicals were assumed to be the dominating reactive species for the 2CP degradation, according to the scavenging tests and electron paramagnetic resonance tests. Moreover, the FMT catalyst exhibited a high reusability and stability in the US/FMT system during the five repetitive experiments. The intermediate products were identified by GC-MS, thereby a possible degradation pathway is proposed. The chemical oxygen demand (COD) and corresponding total organic carbon (TOC) removal efficiencies were 64.9% and 56.7%, respectively. Finally, toxicity tests showed that the toxicity of the solution increased during the first 5min and then decreased significantly with the progress of the oxidation. The mechanisms of ultrasound irritation enhanced FMT activation were also proposed.

Facile and efficient 3-chlorophenol sensor development based on photolumenescent core-shell CdSe/ZnS quantum dots

“…Besides this, the chlorophenol is used as disinfectant in municipality's water, agro-fungicides and chlorinated pesticides. All the results are responsible for contamination of ground and surface water [41][42][43] . Therefore, a sensitive and comfort system is necessary to analyze the environmental (both ground and surface) and portable water.…”

Removal of sodium salicylate from aqueous solution using spruce wood sawdust as an eco-friendly adsorbent

“…The adsorption experiments were conducted in 150 mL Erlenmeyer flasks containing 50 mL of adsorbate solution with a constant agitation speed of 150 rpm. The adsorption tests of sodium salicylate on the wood sawdust were performed at different experimental conditions such as initial pH (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12), solid/liquid contact time (0-300 min), adsorbent dosage (0.1-1.5 g/L), temperature (25-50°C) and initial concentration (10-200 mg/L). The initial solution pH was adjusted to the desired values by the addition of HCl (0.1 M) or NaOH (0.1 M) solutions.…”

“…Various wastewater decontamination technologies such as photocatalytic degradation [5][6][7][8] , reduction 9 , electrocoagulation 10 , and adsorption [11][12][13][14] . Among these techniques, the adsorption was considered as one of the most promising methods for the removal of pollutants from aqueous solutions because of its flexibility, low-cost, high efficiency and operational simplicity [15][16][17] .…”

Evaluation of Low Cost-Activated Carbon Produced from Waste Tyres Pyrolysis for Removal of 2-Chlorophenol

“…Various process, such as: adsorption [4] catalytic wet oxidation [5], biodegradation [6], ozonation, and electrochemical degradation [7], have been studied regarding treatment of waste water containing chlorophenol. Among all the studied process, adsorption technology for treatment of chlorophenol was well-agreed as the most significant technique.…”