Treatment Of Poultry Slaughterhouse Wastewater With Membrane Technologies
Abstract
To address some challenges of food security and sustainability of the poultry processing industry, a sequential membrane process (UF-FO-RO) is proposed to treat semi-processed slaughterhouse wastewater and recover the water. The pretreatment of PSWW with UF removed 36.7% of chemical oxygen demand (COD), 38.9% of total phosphorous (TP), 24.7% of total solids (TS), 14.5% of total volatile solids (TVS), 27.3% of total fixed solids (TFS) and 12.1% of total nitrogen (TN). The flux of the UF membrane was successfully restored to 94% after 1st wash and 87% after 2nd wash by cleaning the UF membrane with 0.1% sodium hydroxide solution and 0.2% phosphoric acid. Then, the PSWW was treated with FO membrane in FO mode, pressure retarded osmosis (PRO) mode, and L-DOPA coated membrane in the PRO mode. All these modes achieved complete removal of COD and TP. However, the FO mode showed the highest pollutant removal efficiency; 90.5% of TS, 85.3% of TVS, 92.1% of TFS, and 37.2% of TN. The FO mode also achieved the highest average flux 10.4±0.2 L/m2-h. The performance of the FO membrane was entirely restored by flushing the membrane with 0.1% sodium dodecyl sulfate solution, proving that the membrane fouling presented in the FO process was reversible. Since the FO mode showed the highest removal efficiency of pollutants and highest average flux, the FO mode was optimal for treating PSWW. The FO mode permeate was further treated by RO membrane to separate the filtrate from the draw solution and purify the PSWW for reusing it in the poultry industry. The RO significantly removed the COD, TS, TVS, TFS, and TP. However, the TN was reduced by only 62% because of the high ammonia concentration present in the draw solution. Overall, the sequential membrane process (UF-FO-RO) showed excellent performance by providing high rejection efficiency for pollutant removal and water recovery. The process removed most of the pollutants from PSWW and produced water that could be reused for industrial poultry processing purposes.