Degradation of organic contaminants in effluents—synthetic and from the textile industry—by Fenton, photocatalysis, and H2O2 photolysis

Abstract

In this study, the oxidation of the dye rhodamine B (RhB), present in a synthetic effluent, and the degradation of organic matter present in a textile effluent, were assessed by photolysis (HO, UV), homogeneous Fenton (Fe, HO), and photocatalysis (TiO, UV). The results showed that photolysis and Fenton had an efficiency of 100 % and photocatalysis, 96 %, to discoloration 10 mg L RhB, present in the synthetic effluent. The best experimental conditions determined for these reactions showed that the one performed with 51 mg L HO and UV light had the best results, where 100 % of RhB was discolored in only 6 min of reaction. The optimum conditions determined in the first part of this study for the RhB oxidation did not show satisfactory results for the degradation of organic matter present in the textile effluent sample, and it was necessary to increase the amount of reagents in the three processes. After resizing the concentration of the reagents for the reactions with the textile effluent, the following reductions of color, total organic carbon (TOC), and total soluble solids (SS) were obtained: photocatalysis 29, 25, and 32 %; photolysis 85, 69, and 35 %; Fenton 98, 90, and 23 %; and biological (followed by physicochemical) treatment carried out by the textile industry 96, 48, and 9 %. It is observed that the Fenton reaction showed the best result, followed by photolysis reaction, a treatment carried out by industry and, at last, photocatalysis.

Optimization and toxicity assessment of a combined electrocoagulation, H2O2/Fe2+/UV and activated carbon adsorption for textile wastewater treatment

“…They are recognized as valuable methods to increase the biodegradability of textile wastewater due to its high oxidative efficiency. A variety of AOPs have been reported in the literature, among them UV/H 2 O 2 , UV/O 3 (Boczkaj and Fernandes, 2017), TiO 2 -assisted photocatalysis, Fenton process (Fe 2+ /H 2 O 2 ) (De Lima et al, 2017;Rosa et al, 2015), electrochemical AOPs (Chatzisymeon et al, 2006) and ultrasonication (Darvishi et al, 2016). The Fenton oxidation is an attractive method to mineralize dyes remaining in textile wastewater.…”

Effects of Technical Textiles and Synthetic Nanofibers on Environmental Pollution

“…Geo-Tech membrane fabrics have been used on the coasts of water streams to prevent the widespread release of pollutants from different sources, such as industrial wastes and oil spills. This can be accomplished by applying ditch lining, landfill lining and stabilization membrane fabrics onto vegetation banks to prevent losing precious topsoil and stop the motion of soil containing pesticides or other dangerous substances into water resources [ 108 , 130 , 131 ].…”

Treatment of real non-biodegradable wastewater: Feasibility analysis of a zero-valent iron/H2O2 process

“…At high concentrations of H2O2, the self-decomposition of the hydrogen peroxide in H2O and O2 may ocurr [38].…”