Organic Oxidation, Nitrification and Denitrification Using RBC and Bio-carrier

本研究は，排水中の有機物を主に回転円板法で低減させた後，担体を用いて硝化を行った実験と原排水を水素供与体として用いた回分式脱窒の実験を行った．また，回転円板法の温度特性も明らかにし，立体格子状とセラミック板を用いた場合の処理効率の比較実験も行った．その結果，①回転円板法により処理された排水中の有機物（BOD）濃度が20mg/l以下になると，担体による硝化速度が速くなり，BOD濃度が20mg/l以上では，硝化速度が急激に低減した．②担体を用いて回分式脱窒において水素供与体として原排水を用いても十分に脱窒が生じた．③回転円板体にセラミック板を用いても有機物処理効率はさほど低減しない．In this study, the organic matter in the wastewater was at first reduced by a Rotating Biological Contactor (RBC) with cubic latticed substratum. Then, nitrification was carried out in the treated wastewater by using the bio-carrier. Furthermore, batch experiments of denitrification were performed using the raw wastewater as a hydrogen donor. From the experiments, the temperature characteristics of RBC were clarified. In order to examine the removal efficiency, the comparative experiments between the RBC with cubic latticed substratum and ceramic board were carried out. It was found that (1) rate of nitrification by the bio-carrier increases when the BOD concentration of the wastewater treated by RBC is less than 20 mg/l. On the other hand, when the BOD concentration exceeds 20 mg/l, rate of nitrification suddenly decreases; (2) denitrification by the bio-carrier occurs efficiently even the raw water is used as the hydrogen donor in the batch experiment; (3) there is no significant difference between the efficiency of organic oxidation by the RBC with cubic latticed substratum and ceramic board