Optimal Evaluation of Coag-Flocculation Factors for Alum-Brewery Effluent System by Response Surface Methodology

M.C. Menkiti, M.C. Aneke, E.B. Ogbuene, O.D. Onukwuli, E.O. Ekumankama

Centre for Environmental Management and Control, University of Nigeria, Enugu Campus, Nigeria..
Department of Chemical Engineering, Nnamdi Azikiwe University, Awka, Nigeria.
Department of Food Science and Technology, Ebonyi State University, Abakaliki, Nigeria.
School of Built and Natural Environment, Northumbria University, Ellison Building, New Castel Upon Tyne, United Kingdom.

DOI: 10.4236/jmmce.2012.115039                

Abstract

This work investigates coag-flocculation optimization treatment of alum-brewery effluent system via response surface methodology (RSM). To minimize suspended and dissolved particles (SDP), experiments were carried out using nephelometric jar test and 2³-factorial design with three star-points, six-center-points and two replications. A central composite design, which is the standard design of RSM, was used to evaluate the effects and interactions of three major factors (coagulation pH, coagulant dosage, settling time) on the treatment efficiency. Multivariable quadratic model developed for the response studied indicates the optimum conditions to be 9, 500mg/l and 20minutes for coagulation pH, coagulant dosage and settling time, respectively. At optimum, the SDP was reduced from 10831.490mg/l to 801.451mg/l, representing 92.601% removal efficiency. RSM has demonstrated to be appropriate approach for the optimization of the coag-flocculation process by statistical evaluation.

Keywords

Coag-flocculation, Brewery effluent, Alum, Response surface methodology, Central composite design

Conflicts of Interest

The authors declare no conflicts of interest.

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