Treatment of Poultry Slaughterhouse Wastewater (PSW) Using a Pretreatment Stage, an Expanded Granular Sludge Bed Reactor (EGSB), and a Membrane Bioreactor (MBR).

Honeil Basile Meyo,Ephraim Kaskote,Mahomet Njoya,Moses Basitere,Seteno Karabo Obed Ntwampe

doi:10.3390/membranes11050345

Abstract

This study presents the biological treatment of poultry slaughterhouse wastewater (PSW) using a combination of a biological pretreatment stage, an expanded granular sludge bed reactor (EGSB), and a membrane bioreactor (MBR) to treat PSW. This PSW treatment was geared toward reducing the concentration of contaminants present in the PSW to meet the City of Cape Town (CoCT) discharge standards and evaluate an alternative means of treating medium- to high-strength wastewater at low cost. The EGSB used in this study was operated under mesophilic conditions and at an organic loading rate (OLR) of 69 to 456 mg COD/L·h. The pretreatment stage of this laboratory-scale (lab-scale) plant played an important role in the pretreatment of the PSW, with removal percentages varying between 20% and 50% for total suspended solids (TSS), 20% and 70% for chemical oxygen demand (COD), and 50% and 83% for fats, oil, and grease (FOG). The EGSB further reduced the concentration of these contaminants to between 25% and 90% for TSS, 20% and 80% for COD, and 20% and >95% for FOG. The last stage of this process, i.e., the membrane bioreactor (MBR), contributed to a further decrease in the concentration of these contaminants with a peak removal performance of >95% for TSS and COD and 80% for the FOG. Overall, the system (pretreatment–EGSB–MBR) exceeded 97% for TSS and COD removal and 97.5% for FOG removal. These results culminated in a product (treated wastewater) meeting the discharge standards.

Highlights

The contamination of clean water sources contributes to the global water crisis
It was observed that the quality of the poultry slaughterhouse wastewater (PSW) feed and product fluctuated considerably, with a noticeably high concentration of the chemical oxygen demand (COD), total suspended solids (TSS), and FOG on the 70th day of operation
This was attributed to various factors, including a significant change in the quality of the PSW fed to the pretreatment stage

Summary

Introduction

The contamination of clean water sources contributes to the global water crisis. the treatment and reuse of wastewater is indispensable. Adequate management of water sources is critical in semiarid and dry regions of countries such as South Africa (SA) [1,2]. To protect both amphibian and earthbound living animals, the wastewater needs to be treated effectively before discharging it into freshwater sources [3,4]. Biological treatment is deemed the most suitable for wastewater laden with high organic matter, suspended solids, fats, oil, and grease (FOG), macronutrients, and pathogens [6,7]. It is important to treat such wastewater before it is discharged into the environment [3,10]

Objectives

Methods

Results

Conclusion