Performances of SBR, chemical–DAF and UV disinfection for poultry slaughterhouse wastewater reclamation

Abstract

Since the poultry slaughter industry is highly water-consuming and wastewater generator, it is essential to take a step towards achieving the sustainability of wastewater reclamation and reuse schemes. This paper evaluates the performance of a lab-scale advanced wastewater treatment system that consists of sequencing batch reactor (SBR), chemical–dissolved-air flotation (DAF) system and ultraviolet (UV) disinfection, used for the reclamation from anaerobically pre-treated poultry slaughterhouse wastewater. Twelve-hour cycles in a fill-aerobic-anoxic-settle-discharge sequence and ethanol addition as carbon source for denitrification at 1.41±0.19C/N ratio were the SBR operating conditions for nitrogen removal. Ferric chloride and cationic polymer as flocculant aid were the chemicals used for phosphorus removal. 4.5–5.5 coagulation pH, 1.32±0.19 Fe/P molar ratio associated with 1.0mgL−1 cationic polymer, 20% recycle rate and 10cmmin−1 flotation velocity were the best chemical–DAF system operating conditions from which resulted >99% phosphorus and 65±25% suspended solids removals. UV radiation dosages ranging from 23 to 32mWscm−2 have effectively inactivated the coliform organisms and Salmonella. Under such operating conditions, organic matter, nutrients, suspended solids and indicator organisms in the final effluent met the quality standards of the legislation for both potable water and effluent discharge to the receiving waters. Zero discharge potentials for the sustainability of the poultry slaughter industry were also explored. The use of all the reclaimed water in closed circuit is expected to reduce the well water input by 60% with no treated effluent discharge to the river during this stage. The use of reclaimed water in semiclosed circuit is expected to reduce the well water input by 46% and the treated effluent discharge to the river by 76%.