Removal of diclofenac in wastewaters using different advanced oxidation techniques (AOPs).

Resumen

The aqueous effluents that come to the sewagetreatment plants of used urban waters show acomplex composition associated to the currenthuman and industrial development. So, the presenceof certain pollutants, in many cases, may interferethe proper operation of the biological wastewatertreatment systems. Between these pollutants,emerging contaminants are considered [1].Emerging contaminant is considered anysynthetic or naturally occurring chemical or anymicroorganism that is not commonly monitored inthe environment but has the potential to enter theenvironment and cause known or suspected adverseecological and/ health effects. It is important toknow its incidence in the environment to be includedin future legal regulations. So, several advancedoxidation treatments are proposed combined withphotooxidation processes to get a fully satisfactoryoutcome as regards their degradation [2,3].Emerging contaminants present high rates oftransformation/removal, which may compensatetheir continual introduction in the environment. Forthis reason, it is necessary to raise awareness abouttheir origin, transformation and the effects that canhave this new generation pollutants to proposemodifications or improvements in the mechanismsof water treatment, in order to ensure good qualityand without detrimental effects on human health.Within emerging contaminants occupy animportant place pharmaceutical compounds andmore specifically the diclofenac. In this study,different combinations of advanced oxidationtreatments have been studied to remove diclofenacin urban wastewater. In all cases, the analyticaldetermination of diclofenac, was done by highperformance liquid chromatography (HPLC).The output produced on site electrolysis ofsodium chloride (Biodyozon) in situ at differentconcentrations was used in treatments, differentdoses of ultraviolet radiation (using a low-pressureUVC lamp of 8 Watts), various concentrations ofhydrogen peroxide, and various combinations ofthe above technologies.Initially, a synthetic wastewater was preparedwith an initial concentration of diclofenac of 38mg/L. With a dose of Biodyozon of 2 ppm of freechlorine and 72 hours of contact, all diclofenac wasremoved. With used doses of ultraviolet radiationwas achieved to remove 88.5 % of initial diclofenac.The combination of UV radiation and Biodyozon,as well as combining ultraviolet radiation andhydrogen peroxide, allowed to eliminate 100% ofinitial diclofenac