Effect of Sodium Chloride Concentration on Removal of Chemical Oxygen Demand and Ammonia from Turkey Processing Wastewater in Sand Bioreactors

Highlights Sand bioreactors can effectively treat organic matter at salt levels at least up to 13 g L-1 NaCl. Acclimation of the systems for ammonia removal can take >4 weeks. Clogging and reduction in treatment efficacy can be alleviated through resting of sand bioreactors. Abstract. The treatment of high salt (>1%) wastewater is an issue in several food industries, including meat curing, vegetable pickling, and fish processing. Novel solutions involving biological treatment of saline wastewaters are increasingly important as companies strive to minimize waste production. Sand bioreactors are a secondary treatment option that do not produce secondary sludge. The purpose of this study was to assess the feasibility of treating high salt content poultry processing wastewater with sand bioreactors. Twelve laboratory-scale sand bioreactors consisted of 14.5-cm diameter columns with three layers composed of 15 cm of gravel, 15 cm of coarse sand, and 46 cm of fine sand. The columns were dose fed at 4 cm day-1 turkey processing wastewater with 0, 6, and 13 g L-1 NaCl. Removal of chemical oxygen demand (COD) and ammonia were monitored for over an 11-month period. Each bioreactor successfully removed >90% COD and ammonia during steady state after 4 to 5 week of acclimatization. Clogging caused a decrease in treatment in three sand bioreactors after 6 to 7 months, but was alleviated with rest periods.