variavel0=<b>CLÁUDIA T. BENATTI</b> - claudiatb@deq.uem.br UEM
<b>CÉLIA R. G. TAVARES</b> - celia@deq.uem.br UEM
<b>TEREZINHA A. GUEDES</b> - taguedes@uem.br UEM
<b>MATEUS P. GASPARr</b> -  UEM
<b>Rafael Gustavo Schreiner</b> -  UEM
<b>Abstract.</b> Characterizing and establishing a treatment process for practical and  economic disposal of laboratory wastewaters has become an urgent environmental concern of the Department of Chemical Engineering of the State University of Maringá &#8211; Brazil. The studies initiated at the Control Pollution Laboratory, whose wastes has been packaged and later on characterized. These wastes showed to have seasonal characteristics according to laboratory works. During the period of June-July of the current year, the main characteristics of these wastes were pH<1, 621 mg/L of total phenol, 4363 mg/L of chemical oxygen demand (COD) and 0.2 mg/L of cyanide and those during the period of August-September were pH<1, 28 mg/L of total phenol, 2847 mg/L of COD and 0.4 mg/L of cyanide. Fenton and related reactions are potentially useful oxidation processes for destroying toxic organics compounds in water. In these reactions, hydrogen peroxide (H2O2) is combined with ferrous or ferric iron (Fe2+ or Fe3+) in the presence or absence of light to generate hydroxyl radicals (OH·). This study will investigate the feasibility of Fenton system in the dark (Fe2+/H2O2) at room temperature to treat laboratory wastewaters. The ratio of [phenols]:[ Fe2+], [Fe2+]:[H2O2] and pH were set as variables. Percent phenols removal will be investigated as a response. A response surface model will be generated with the aim to determine an optimal ratio of [substract]:[ Fe2+]:[H2O2].
<b>Keywords.</b> Fenton`s reagent, laboratory wastewater, characterizatio n, oxidation.