Using porous ceramic media in the upflow packed-bed reactor (UPBR) system for nitrogen removal via autotrophic nitrification and denitrification

Abstract

In this study, the feasibility of an innovative upflow packed-bed reactor (UPBR) system using porous sulfur and lime ceramic media (CERAMED-L and CERAMED-SL) to remove nitrogen for wastewater treatment was evaluated. The specific lime dissolution rates for CERAMEDs in the UPBRs show an inverse proportion to pH and resulted in 2.32 g as CaCO3 kg(-1) CERAMED-L d(-1) and 1.64 g as CaCO3 kg(-1) CERAMED-SL d(-1) at a pH 6.7. The calculated specific nitrification rate resulted 1.73-2.29 kg NH4+-N m(-3) CERAMED-L d(-1), with a F/M ratio in the range 0.08-0.31 g NH4+-N g(-1) VS d(-1). The alkalinity shortage in the feed solution seemed to be overcome by supplying specific alkalinity of 3.88 kg as CaCO3 m(-3) CERAMED-L d(-1) through the dissolution of lime from CERAMED-L. Autotrophic denitrification efficiencies were in the range of 83-96% during the test period, and the average specific denitrification rates of 0.97-1.92 kg NO3-N m(-3) CERAMED-SL d(-1) and 0.19-0.36 g NO3--N g(-1) VS d(-1) were obtained.