USO DE TÉCNICAS COMBINADAS PARA O TRATAMENTO DE EFLUENTES TÊXTEIS: SEPARAÇÃO FÍSICO-QUIMICA E FOTODEGRADAÇÃO UV- H2O2

Abstract

This study aimed to assess the combined technique (chemical and physico-oxidation), which is based on application of coagulant, followed by the use of UV in combination with hydrogen peroxide (H2O2), in order to degrade the organic matter present in a textile effluent. The experiments were divided into two stages, the first step was sought to a reference to the coagulation process, in terms of operational variables to direct characterization of the pH to said to be ideal and to thereafter, effecting a scan to determine the dosage of coagulant reagent, JERONIMO, v(8), no 8, p. 1626-1638, SET-DEZ, 2012. Rev. Elet. em Gestao, Educacao e Tecnologia Ambiental (e-ISSN: 2236-1170) http://cascavel.ufsm.br/revistas/ojs-2.2.2/index.php/reget 1627 necessary to obtain satisfactory levels of efficiency (removal of turbidity greater than 80%). The testing of jar was carried out with pH adjustment (3.0 to 12.0 with change 2.0) and the insertion of the coagulating agent (10 to 300 mg / L). The results indicate the optimal conditions at pH 3,0, with the addition of 100mg / L of the coagulant, aluminum sulfate Al2SO4. All experiments were done at room temperature. The second process step is the treatment of the supernatant resulting from the first step, using the oxidation process, performed in a photochemical reactor with proper temperature control, emission of radiation (via a mercury vapor lamp middle pressure free bulb). During the experiments the temperature was kept constant at 37.5 ° C (derived from the heat generated by the lamp), by passing the cooling water system. We used a relation of 1 L to 0.1 L effluent of hydrogen peroxide (102 g/L), then the mixtures were subjected to agitation, followed by continuous exposure to UV for 120 minutes. The reactions were monitored by chemical oxygen demand (COD) and turbidity. The results for the removal of Chemical Oxygen Demand (COD) were approximately 80% and reduced turbidity to values of about 1.8 NTU.