Abstract
The objective of this study is to evaluate applicability of DHS reactor to nitrification process receiving a high strength ammonium influent. The most prominent advantage of DHS reactor is no need for external aeration because sponge carriers are exposed to air. DHS reactor in this study was operated with an artificial wastewater composed of ammonium-nitrogen solely (completely organic free) at ambient temperature. The total experimental period of 350·days was divided into 4 phases according to ammonium-nitrogen loading rate. The maximum nitrification rate of 1.78 kg-N·m-3·d-1 was observed at a HRT of 6 h and at an ammonium-nitrogen loading rate of 2.00 kg-N·m-3·d-1. The maximum oxygen uptake rate was estimated from nitrogen elimination rate to be 66 g-O2·g-VSS-1·d-1. Nitrification potential of DHS reactor was verified to be comparable to other types of nitrification processes equipped with external aeration. There is a need of further investigation to enhance the nitrification performance by overcoming the restriction of partial oxygen permeation into carrier-sponge inward depth.
