Comparison of advanced oxidation processes for degrading Ponceau S dye. Application of photo-Fenton process.

Abstract

The major part of this work is devoted to the examination of the degradation of Ponceau S (PS) in aqueous medium by using the photo-Fenton process. The influence of pH of the medium, oxidant dose (H2O2), ferrous ion dose and the presence of inorganic ions such as bicarbonate, sulphate and nitrate on degradation kinetics was also analyzed. Before that, the efficiency of this process was compared to three other advanced oxidation processes (AOPs) such as H2O2/UV, Fenton (Fe2+/H2O2), and solar photo-Fenton. It was found that all dye degradation kinetics obeyed a pseudo-first order, and their apparent rate constants were represented by the ratios: kapp (H2O2/UV/Fe2+) =0.295 kapp (sunlight/Fe2+/H2O2) =0.141 kapp (Fe2+/H2O2) = 0.111 kapp (H2O2/UV) =0.031.Under reference conditions (0.06 mM of PS in ultrapure water), photo-Fenton oxidation using 0.06 mM of Fe2+, 1mM of H2O2 and the pH optimal value of 3 yielded more than 94.3% in only10 min of dye degradation with an apparent rate constant of 0.2951 min-1. Elsewhere, the addition of the salts in aqueous medium has, in general, an inhibition effect on the decolorization kinetics due to controlled ionic interactions of metals with inorganic ions. The most adverse effect on PS disappearance rate was observed when bicarbonate ions were present in the treated medium.

Exploring a Substitute for Hydrogen Peroxide in Fenton Process – A Case Study on the COD Removal of Acid Orange 8

“…( 13)). The maximum efficiency at pH 3.0 is attributed to the high oxidation potential (2.8 V vs. NHE) of HO • radicals 13,33,34 and the lower efficiency at pH > 3.0 is due to the formation of Fe(OH) 3 , which leads to a decrease in the generation of HO • due to the unavailability of Fe 2+ ions. 35 Additionally at higher pH, the formation of HO • also retards due to the decomposition of HP to O 2 gas.…”

Adsorption of crystal violet on activated bamboo fiber powder from water: preparation, characterization, kinetics and isotherms

“…3,4 Synthetic dyes from water can be eliminated using the membrane separation method, filtration, advanced oxidation method, 5 coagulation and flocculation, and photocatalytic degradation. 6 Laftani et al 7 used the sun-Fenton oxidation process to degrade Lichun red dye in water. The experimental results show that under the degradation conditions of Fe 2+ concentration of 0.06 mM, H 2 O 2 of 1 mM, and initial solution pH of 3, the sun-Fenton oxidation process takes only 10 minutes to degrade dye.…”

“…The adsorbent used to adsorb pollutants in water usually refers to its large surface area; porous adsorbent or material, activated carbon, bentonite, natural zeolite, silica gel and resin can be used as typical adsorbents to treat dyes in water. 11,12 Maliheh et al 13 used the response surface optimization method to optimize the adsorption conditions of natural zeolite, and under the optimal adsorption conditions, the adsorption capacity of natural zeolite on crystal violet dye reached 177.75 mg g −1 . Yu et al 14 prepared biochar by KOH activation and anaerobic pyrolysis with corn cob xylost residue as raw material, showing excellent adsorption performance for Congo red and methyl orange dye, and good recyclability when treating methylene blue solution, with 68.7% adsorption capacity still maintained after 6 cycles.…”

Theoretical study of Ponceau S oxidation using the electro-Fenton process under optimal operational conditions

“… 1 Their effluents can be very coloured and resistant to biodegradation. 2,3 Consequently, they can cause a wide variety of environmental and health problems. Regarding synthetic dyes released in effluents from textile industries, azo dyes represent almost 50% of about 700 000 tons of dyes produced in the world.…”