Comparison of real wastewater oxidation with Fenton/Fenton-like and persulfate activated by NaOH and Fe(II). (1st February 2020)

• Record Type: Journal Article
• Authors: Rodríguez, Sergio; Lorenzo, David; Santos, Aurora; Romero, Arturo
• Is Part Of: Journal of environmental management. Volume 255(2020)
• Publication Date: 2020-02-01
• Subjects: Industrial wastewater -- Fenton -- Fenton-like -- Persulfate -- NaOH activation; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2019.109926
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Treatment of polluted wastewaters from industrial activities has become a source of major concern for the environment. In this work, real wastewater from a physico-chemical (WWFQ) treatment was tested through different oxidation technologies: Fenton and Fenton-like reagent and persulfate activated by NaOH and Fe(II). Oxidation reactions with Fenton's reagent were carried out in a 0.25 L batch reactor at 25 °C by adding either Fe(II) or Fe(III) and H2 O2 to an aqueous solution of wastewater, whose pH was previously adjusted to 2 or 3. Iron concentration ranging from 25 to 100 mg/L and peroxide concentration from 2500 to 10000 mg/L were used. The total organic carbon slightly decreased when WWFQ was treated. Moreover, better results were obtained when Fe(II) was used than Fe(III). Both iron concentration and oxidant dosage had a positive influence on the chemical oxygen demand (COD) removal, until an asymptotic value of 30% was obtained. Oxidation of pollutants contained in WWFQ was studied with persulfate (18.4–294 mM) activated with NaOH and Fe(II) (36.8–588 mM). Again, a positive influence of both persulfate and NaOH was observed, although a similar asymptotic COD value was observed. This parallelism between both technologies confirms recalcitrant compounds were obtained. Graphical abstract: Image 1 Highlights: Real wastewater was treated with Fenton and Fenton-like reagent. Persulfate activated by NaOH and Fe(II) was used to remediate a real wastewater. Color of the samples was effectively removed by the treatments studied. Asymptotic COD of 30% was obtained regardless the oxidation technology applied. Oxidation routes were proposed from characterization of reaction intermediates.