Bioflocculants producing microorganisms from poultry slaughterhouse wastewater for application in a biological dissolved air flotation system

Abstract

The South African poultry industry has developed rapidly over the years due to increased poultry product demand by consumers. High demand of poultry products results into the generation of a high volume of poultry slaughterhouse wastewater (PSW) (Basitere et al., 2017). This wastewater contains a high concentration of organic constituents and inorganic matter and as such the wastewater cannot be discharged into fresh water receiving bodies without pre-treatment. This wastewater provides a suitable environment for microbial proliferation due to its temperature, pH and the availability of growth promoting organic constituents which harness microbial growth. The microorganisms that are produced in such growth conditions produces intra- and extra-cellular polymeric substances some of which are bioflocculants which used in flocculation process required for the pre-treated of the PSW to minimise total suspended solids (TSS) and other pollutants. Flocculation is a process whereby flocculants are added into the wastewater such that micro-flocs can coalesce resulting into the formation of larger flocs, which in turn results in removal, agglomerated suspended solids and FOG globules (Li et al., 2014; Sharma et al., 2006). This application is desirable when using a Dissolved Air Flotation system (DAF). The aim of this study was to isolate bacterial strains and subsequently identify them prior to characterising and identifying the functional groups and flocculation mechanisms of bioflocculants produced from these isolates.