Investigation of the geometry of an electrochemical reactor in order to minimize the operational energy cost in the treatment of cosmetic effluents

Abstract

Low biodegradability and high toxicity are common characteristics of cosmetic effluent. They have stimulated the application, development, and improvement of advanced technologies, such as electrocoagulation (EC). In this sense, this study aimed to optimize the treatment conditions of operational parameters considering the theoretical energetic operational cost of the treatment of cosmetic effluents through a new design of a cylindrical electrochemical reactor in continuous upward flow (CER-CUF). The effects of hydraulic retention time (HRT), electrical current density (j), and electrical conductivity on COD removal, turbidity, and residual Al concentration were investigated using a Central Composite Rotational Design (CCRD). The COD and turbidity removal efficiencies were 61.96 % and 44.71 %, respectively, with a total operating cost of 0.258 US$ m−3 to treat the effluent cosmetic under optimized conditions (HRT:5 min/j: 5 mA cm−2 and EC:2000.00 μS cm−1) in CER-CUF. These results contribute to advancing of knowledge about electrocoagulation technology and the possibility of full-scale application, in addition to encouraging the use of CER-CUF for treating effluents from the cosmetic industry.