HR: 16:45h
AN: B44A-04    [Abstracts]
TI: Oxygen Limited Bioreactors System For Nitrogen Removal Using Immobilized Mix Culture
AU: * Pathak, B K
EM: bipinpathak@yahoo.com
AF: Bipin K. Pathak, University of Yamanashi, Kazama lab 4-3-11 Takeda, Kofu, Yam 400-8511 Japan
AU: Sumino, T
EM: t-sumino@hitachiplant.co.jp
AF: Tatuso Sumino, Hitachi Plant Engineering and construction Co; Ltd Kamihongo 537, Matusdo, Chiba, Chi 271 Japan
AU: Saiki, Y
EM: yuko.saiki@asahibeer.co.jp
AF: Yuko Saiki, Asahi breweries Ltd., Moriya-shi, Ibaraki, 302-0106 Japan
AU: Kazama, F
EM: kfutaba@yamanashi.ac.jp
AF: Bipin K. Pathak, University of Yamanashi, Kazama lab 4-3-11 Takeda, Kofu, Yam 400-8511 Japan
AB: Recently nutrients concentrations especially nitrogen in natural water is alarming in the world wide. Most of the effort is being done on the removal of high concentration of nitrogen especially from the wastewater treatment plants. The removal efficiency is targeted in all considering the effluent discharge standard set by the national environment agency. In many cases, it does not meet the required standard and receiving water is being polluted. Eutrophication in natural water bodies has been reported even if the nitrogen concentration is low and self purification of natural systems itself is not sufficient to remove the nitrogen due to complex phenomenon. In order to recover the pristine water environment, it is very essential to explore bioreactor systems for natural water systems using immobilized mix culture. Microorganism were entrapped in Polyethylene glycol (PEG) prepolymer gel and cut into 3mm cubic immobilized pellets. Four laboratory scale micro bio-reactors having 0.1 L volumes were packed with immobilized pellets with 50% compact ratio. RUN1, RUN2, RUN3 and RUN4 were packed with immobilized pellets from reservoirs sediments, activated sludge (AS), mixed of AS, AG and biodegradable plastic and anaerobic granules (AG) respectively. Water from Shiokawa Reservoirs was feed to all reactors with supplemental ammonia and nitrite nitrogen as specified in the results and discussions. The reactors were operated dark incubated room in continuous flow mode with hydraulic retention time of 12 hours under oxygen limiting condition. Ammonium, nitrate nitrite nitrogen and total organic carbon (TOC) concentrations were measured as described in APWA and AWWA (1998). Laboratory scale four bioreactors containing different combination of immobilized cell were monitored for 218 days. Influent NH4+-N and NO2--N concentration were 2.27±0.43 and 2.05±0.41 mg/l respectively. Average dissolved oxygen concentration and pH in the reactors were 0.40-2.5 mg/l and pH 6.5-7.4 respectively. The molar ratio of NO2-N and NH4+-N was varied from 0.85 to 4.1 and RUN3 has closed to Stoichiometric ratio of anaerobic ammonia oxidation process. Total nitrogen removal in all reactors was ranged from 11-79% and RUN3 showed best removal performance (Table 1). Table 1 Characteristic of N removal process Parameters RUN1 RUN2 RUN3 RUN4 Effluent TOC (mg/l) 1.22 2.08 2.33 1.97 NO2- -N/ NH4+-N converted 1.18 0.85 1.32 4.15 Average NH4+-N removal % 86 95 74 32 Average NO2- -N removal % 97 81 98 92 Average TN removal % 11 36 79 59 Four different kinds of laboratory scale nitrogen removal bio-rectors were monitored for 218 days. Comparing reactors based on observed data, the bioreactor containing mix culture (RUN3) removed the 79% of incoming total nitrogen and suggests best for nitrogen removal in the natural water systems. It is recommended that further study is required in pilot scale to understand scaling effects and other natural phenomenon.
DE: 0469 Nitrogen cycling
DE: 0470 Nutrients and nutrient cycling (4845, 4850)
DE: 0485 Science policy (6620)
DE: 0496 Water quality
SC: Biogeosciences [B]
MN: Fall Meeting 2005