EVALUATION OF THE AMMONIUM REMOVAL CAPABILITIES OF ANAMMOX SLUDGE IN A FIXED BED REACTOR USING FELIBENDY CUBES AS BIOMASS CARRIER

Abstract

Nitrogen removal from ammonium-rich wastewater has been attracting increasing attention due to the serious water pollution consequences such as eutrophication of water bodies. The most widely used ammonium removal technology around the world was the conventional nitrification-denitrification process. However, the application of the conventional process was limited by high operational cost and addition of the external organic matters for the denitrification step [1]. Anaerobic ammonium oxidation (Anammox) is a biological reaction in which the anaerobic ammonium oxidation bacteria (AnAOB) combine nitrite and ammonium to form nitrogen gas using nitrite as electron acceptor under anoxic condition [1], [2]. The ANAMMOX process has some advantages compared to conventional nitrification–denitrification processes: it does not require the addition of external carbon, less sludge production and low energy consumption [3]. In the fixed-bed reactor using FELIBENDY cubes as biomass carrier, NH₄⁺-N and NO₂^--N removal efficiencies were improved over the operational time from 40.87% and 31.56% to 86.35% and 82.96%, respectively. During operation period of 191 days, T-N removal efficiencies increased stepwisely from 22.8% to 71.47% while influent T-N concentrations gradually increased stepwise from 35 to 235 mg N/L. This showed the effectiveness of FELIBENDYcubes biomass carrier as the support material for extremely slow growing Anammox bacteria.

Keywords: Anammox; rich Ammonium; waste water; NH₄⁺-N; NO₂^-N; FELIBENDY cubes; biomass carrier; F-AX.

Received: September 8^th, 2016, revised: September 22^th, 2016, accepted: October 13^th, 2016