Title: Effect of ferric chloride coagulation, lime precipitation, electrocoagulation and the Fenton's reagent on the particle size distribution of olive mill wastewater

Authors: B. Hande Gursoy-Haksevenler; Serdar Dogruel; Idil Arslan-Alaton

Addresses: The Scientific and Technological Research Council of Turkey, Marmara Research Center, Institute of Environment, P.O. Box 21, 41470 Gebze-Kocaeli, Turkey ' Istanbul Technical University, Faculty of Civil Engineering, Department of Environmental Engineering, 34469 Maslak, Istanbul, Turkey ' Department of Environmental Engineering, Faculty of Civil Engineering, Istanbul Technical University, 34469 Maslak, Istanbul, Turkey

Abstract: Size fractionation of olive mill wastewater (COD:155000 mg/L; TOC:40000 mg/L; BOD5:37700 mg/L; total phenols:4100 mg/L; absorbance at 395 nm:145 cm⁻¹) before and after FeCl₃ coagulation, Ca(OH)₂ precipitation, electrocoagulation and the Fenton process was investigated. Particulate organic compounds were the major components of COD (54%), TOC (43%), BOD5 (43%), absorbance (57%), followed by an appreciable soluble size fraction. For the total phenols parameter, a dominant fraction (54%) appeared in the colloidal (5-8 nm) size range besides significant particulate (22%) and soluble (24%) size fractions. FeCl₃ coagulation and Ca(OH)₂ precipitation appeared to be most efficient in organic matter removal, whereas electrocoagulation was superior in phenolics removal. No shift in the size distribution pattern was observed after chemical treatment since phase-transfer was the dominant removal mechanism of the selected processes. The highest inhibition of the Vibrio fischeri photobacteria was observed in the particulate size range and decreased in the solube size range due to the elimination of the phenolic content.

Keywords: acute toxicity; ferric chloride coagulation; electrocoagulation; Fenton's reagent; lime precipitation; olive mill wastewater; OMW; particle size distribution; removal mechanisms; wastewater treatment; organic matter removal; phenolics removal.

DOI: 10.1504/IJGW.2014.061010

International Journal of Global Warming, 2014 Vol.6 No.2/3, pp.194 - 211

Received: 10 Oct 2012
Accepted: 12 Mar 2013
Published online: 02 Jul 2014 *

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