Organic Pollutants Removal from Olive Mill Wastewater Using Electrocoagulation Process via Central Composite Design (CCD)

Abeer El Shahawy,Khalda M A Elamin,Mahmoud Nasr,Saedah R Al-Mhyawi,Inas A Ahmed,Ahmed H Ragab

doi:10.3390/w13243522

Abstract

Electrocoagulation (EC) was studied in this study as a potential alternative approach for treating Olive Mill Wastewater (OMW). Aluminum plates were utilized as anode and cathode to evaluate the removal of Chemical Oxygen Demand (COD) from OMW and the aluminum electrode’s weight loss. Central Composite Experimental Design (CCD) and Response Surface Methodology were used to optimize its performance. Anodes were weighed before and after each electrocoagulation experiment, to compare the experimental and the theoretical dissolved aluminum weights calculated using Faraday’s law. We discovered the following EC conditions for CCD: current density = 15 mA/cm2, pH = 4, and electrolysis time of 30 min. Under these conditions, the maximum COD removal ratio was 41%, equating to an Al weight loss of 288.89 g/m3 at an estimated operating cost of 1.60 USD/m3. According to the response optimizer, the most economical operating settings for COD removal efficiency of 58.888% are pH 4, a current density of 18.41 mA/cm2, electrolysis time of 36.82 min, and Al weight loss of 337.33 g/m3, with a projected running cost of 2.00 USD/m3.

Highlights

Introduction published maps and institutional affilOlive Mill Wastewater (OMW) is released with different quantities and composition, depending on the region, age of growth, harvesting season, yearly changes, and olive type
The objectives of this study are threefold (1) examine OMW treatment by the EC process to reduce the organic load (chemical oxygen demand (COD)) and achieve improved OMW management, (2) study the impact of current density, pH and exposure time on the EC process, anode consumption, and electrode weight loss, and (3) represent an economic evaluation of the EC batch-scale approach for OMW treatment based on Response Surface Methodology (RSM) methodology model simulation
The results Central Composite Experimental Design (CCD) indicated that the quadratic model fit the three responses based on the response surface regression analysis

Summary

Introduction

Olive Mill Wastewater (OMW) is released with different quantities and composition, depending on the region, age of growth, harvesting season, yearly changes, and olive type. OMW comprises 83–96% water, 3.5–15% organics, and 0.5–2% mineral salts. The organic component is made up of sugars (1–8%), N-compounds (0.5–2.4%), organic acids (0.5–1.5%), lipids (0.02–1%), and phenols and pectins (1–1.5%). OMW could include high concentrations of dyes that float on the surface of water bodies, and further reduce light penetration and the plants’ photosynthetic activities. Suspended particles can suffocate aquatic species and reduce their oxygen utilization ability. The presence of phytotoxic phenolics means that untreated OMW is not allowed to be utilized for irrigation in agriculture because of the potential health risks.

Objectives

Methods

Results

Conclusion