An activated carbon fiber cathode for the degradation of glyphosate in aqueous solutions by the Electro-Fenton mode: Optimal operational conditions and the deposition of iron on cathode on electrode reusability

Abstract

a b s t r a c tAn activated carbon fiber (ACF) cathode was fabricated and used to treat glyphosate containing wastewater by the Electro-Fenton (EF) process. The results showed that glyphosate was rapidly and efficiently degraded and the BOD 5 /COD ratio was increased to >0.3 implying the feasibility of subsequent treatment of the treated wastewater by biological methods. The results of ion chromatography and HPLC measurements indicated that glyphosate was completely decomposed. Effective OH generation and rapid recycling/recovery of the Fe 2þ ions at the cathode were responsible primarily for the high performance of the ACF-EF process. Factors such as inlet oxygen gas flow rate, Fe 2þ dosage, initial glyphosate concentration, applied current intensity, and solution pH that may affect the efficiency of the ACF-EF process were further studied and the optimum operation condition was established. Results of SEM/EDX, BET and XPS analysis showed the deposition of highly dispersed fine Fe 2 O 3 particles on the ACF surface during the EF reaction. The possibility of using the Fe 2 O 3 -ACF as iron source in the EF process was assessed. Results showed that the Fe 2 O 3 -ACF electrode was effective in degrading glyphosate in the EF process. The deposition of Fe 2 O 3 particles on the ACF electrode had no adverse effect on the reusability of the ACF cathode.

Technologies Employed in the Treatment of Water Contaminated with Glyphosate: A Review

“…Under this process, AMPA was the principal degradation intermediary [67]. Another application of Electro-Fenton was reported by Lan et al [68] where activated carbon fiber (ACF) was used as a cathode; under optimum operation conditions (t = 360 min; pH = 3; current intensity = 0.36 A; 1 mM of Fe 2+ ; pure O 2 flow rate = 100 mL•min −1 ), it achieved a 50.4% of total organic carbon (TOC) remotion and a 72% of chemical organic demand (COD) remotion. The most recent application of Fenton-process using carbon felt cathode showed that the maximal removal percentage of glyphosate was 91.91% with an applied current density of 10 mA•cm −2 , pH 3, 0.1 mM Fe 2+ , 0.05 M Na 2 SO 4 , and 0.1 mM as glyphosate concentration under 40 min of treatment.…”

Facile Preparation of Granular Copper Films as Cathode for Enhanced Electrochemical Degradation of Methyl Orange

“…There are many ways to deal with organic pollutants [ 1 ], for instance, coagulation [ 2 ], membrane treatment [ 3 ], advanced oxidation process [ 4 ], biological treatment [ 5 ] and adsorption [ 6 ]. Among them, advanced oxidation has become a hot spot in the field of water treatment due to such advantages as high efficiency, fast reaction rate and thorough degradation in the treatment of organic pollutants [ 7 ]. As one of the advanced oxidation techniques, electrochemical degradation can be achieved by heterogeneous reaction between the electrode and the organic matter, or by electrolyzing H 2 O to generate strong oxidizing substances, such as hydroxyl radical (•OH), to degrade organic pollutants in water.…”

Effective removal of aqueous glyphosate using CuFe2O4@biochar derived from phragmites

“…However, the glyphosate residue in soil may enter the aquatic environment through rain washing, resulting in a great environmental issue due to the biosafety concerns . Various methods including precipitation, membrane separation, oxidation, biodegradation, and adsorption have been developed for the removal of glyphosate from aqueous effluents. Among these methods, adsorption technology is particularly attractive, owing to its high efficiency, easy operation and low‐cost features.…”