Simultanous removal of high concentration nitrogen and phosphorus from abattoir wastewater by using a sequencing batch reactor

A sequencing batch reactor(SBR)was used to remove high concentration nitrogen,phosphorus and COD in the abattoir wastewater.The results showed that step-feed could avoid high-level build-up of nitrate and nitrite during the nitrification and create anaerobic conditions for biological phosphorus removal.Two types of abattoir wastewater were used as raw wastewater,one was the effluent from abattoir wastewater and the other was the pre-fermentor wastewater.After a 3-month start-up,removal efficiencies of total phosphorus,total nitrogen and COD were higher than 96%,95% and 95.5%,respectively,when total phosphate,total nitrogen and COD in the influent were 36.5 mg/L,226 mg/L and 2615 mg/L,respectively,under the condition of a sludge age of 14 days at 35 ℃.The concentrations of total phosphate,total nitrogen and COD in the effluent were lower than 1.4 mg/L,10.8 mg/L and 95 mg/L,respectively.