Application of a novel rGO-CuFeS2 composite catalyst conjugated to microwave irradiation for ultra-fast real textile wastewater treatment

VIEIRA, YASMIN; CERETTA, MARÍA BELÉN; FOLETTO, EDSON LUIZ; WOLSKI, ERIKA ALEJANDRA; SILVESTRI, SIARA

Journal of Water Process Engineering

Elsevier Ltd.

Año: 2020 vol. 36

2214-7144

The disposal of wastewater containing large amounts of dyes is a public health and environmental problem, dueto its toxicity into the aquatic biota, the reduction in sunlight penetration, which consequently interference inphotosynthetic activity. In the present study a new composite, based on the heterojunction of reduced grapheneoxide (rGO) and chalcopyrite (CuFeS2), was developed to treat a real textile wastewater (RW). The efficiency ofthe composite assisted by microwave irradiation was evaluated to catalyze the decolorization and degradation ofRW containing a high concentration of the azo Direct Black 22 (DB22). A small amount (0.5 w/w%) of rGO onCuFeS2was enough to uplift the efficiency of decolorization to 74 % of DB22 and 97 % TOC in the RW, only inthefirst min of treatment, and 97 % and 99 %, respectively, at 6 min. The improvement in catalytic activity canbe attributed to the dipolar polarization effect, hot spots and the generation of hydroxyl radicals. Additionally, asynergistic effect between the composite and microwave irradiation, assisted by hydrogen peroxide, reduced theRW phytotoxicity, improving the radicle length ofLactuca sativathree times (from 0.87 cm to 2.65 cm with theapplication of a single minute of treatment). The reduction in phytotoxicity led to an increase in the germinationpercentage from 36 % to 53 %. Finally, the use of MW irradiation coupled to a novel rGO-CuFeS2composite, inpresence of H2O2under acid medium, provides a feasible and highly rapid method to treat RW, reducing itsphytotoxicity. Capsule: A novel rGO-CuFeS2catalyst was developed and applied together with microwave irradiation for anultra-fast degradation treatment (6 min) in real textile wastewater.