주대영 Dae Young Ju

DOI: Vol.22(No.3) 383-385, 2006

양기현 Kee Hyoun Yang , 김덕중 Deok Joong Kim , 조은채 Eun Chae Jo

DOI: Vol.22(No.3) 386-396, 2006

윤주환 Zu Whan Yun

DOI: Vol.22(No.3) 397-405, 2006

Since the first sewage treatment plant had been in operation in 1976, the Korean water industry was in the logarithmic growing stage corresponded with the country`s rapid economic expansion up to late 1990`s. Unfortunately, however, the current industry status seems to require not only new paradigm for water environment but the development of new growth engine, since there are various warning signals for stalling growth from the field engineers to policy makers. Because of sharing of the awareness, the Korean government recently launched an ambitious development policy for water industry. This paper describes the new paradigm-shift in water environment in view point of the water as renewable resources. Based on the new paradigm, it has been suggested the prerequisite conditions to meet for the development of a new Korean water industry.

Paradigm, Water environment, Water industry

김일중 Il Choong Kim

DOI: Vol.22(No.3) 406-409, 2006

조용완 Yong Wan Cho

DOI: Vol.22(No.3) 410-416, 2006

김동우 Dong Woo Kim

DOI: Vol.22(No.3) 417-424, 2006

김건하 Geon Ha Kim

DOI: Vol.22(No.3) 427-430, 2006

Uncertainty is one of the key issues of the water quality management. Uncertainty occurs in the course of all water quality management stages including monitoring, modeling, and regulation enforcement. To reduce uncertainties of water quality monitoring, manualized monitoring methodology should be developed and implemented. In addition, long-term monitoring is essential for acquiring reliable water quality data which enables best water quality management. For the water quality management in the watershed scale, fate of pollutant including its generation, transport and impact should be considered while regarding each stage of water quality management as an unit process. Uncertainties of each stage of water quality management should be treated properly to prevent error propagation transferred to the next stage of management for successful achievement of water quality conservation.

Management, Modeling, Monitoring, Uncertainty, Water quality

박수정 Su Jung Park , 김문경 Moon Kyung Kim , 기영선 Young Sun Ki , 오소린 So Rin Oh , 신미연 Mi Yeon Shin , 오지윤 Ji Yoon Oh , 변재철 Jae Cheol Byeon , 이성민 Seong Min Lee , 정은희 Eun Hee Jung , 김은미 Eun Mi Kim , 조경덕 Kyung Duk Zoh , 최경

DOI: Vol.22(No.3) 431-436, 2006

This study was conducted in the summer of 2005 in Shindong-myeon, Chuncheon-si, Gangwon-do to assess the quality of drinking water and to evaluate their potential pollutants. Ninety four water samples were collected from three classes of water supplies such as simple piped water, supplied own water and others (Supplied local water). Most residents used simple piped water (72.63%). 31.25% residents thought the water quality was bad and landfill was the main source of pollution that affected water quality. To correspond this perception, water quality was measured according to Drinking Water Quality Standard. The general bacteria, coliforms, and NO3-N exceeded the standard but the water qualities in these four areas were suitable for Drinking Water Quality Standard. The simple piped water showed low mean concentration of excess rate compared to supplied own piped water except general bacteria. Hardness, pH, and NO3-N showed significantly higher effects on drinking water quality. To evaluate the effect of effluent from landfill, water quality was measured according to distance and altitude. However, there was no effect of landfill effluent. To find out the effect of rainfall, we compared water quality of the year 2003 with that of 2005. The result showed significant differences in hardness and NO3-N concentration. This study confirmed that NO3-N, coliforms, and general bacteria are main pollutant of water supply in rural community. Therefore, it is necessary to regularly maintain simple piped water supply, supplement sewer facilities, and educate residents about public health risk associated with drinking water in rural area.

Landfill, Rainfall, Supplied water, Supplied own water, Water quality

문경석 Gyeong Seok Mun , 장희수 Heui Su Jang

DOI: Vol.22(No.3) 437-443, 2006

The Water usage is relationship which is close with the administrative cost from industrial facility. It is not easy to reduce a water usage. This research is the optimization of the waste water quantity which process waste water integration of the standard thermal power plant in system operate time. The turbine rotates by force of the steam and it produces an electricity. Demineralization Water is manufacture purity manufacturing equipment and it is supplied in power plant channel. We knew a possibility of reducing from pure control process. When it is reduced the Back Washing time, Rinsing time of the gravity filter and the activated carbon filter. Also, It is possible even from regeneration phase in Condensate Polishing Demineralization System. In addition, There is also the water which the drain of the sampling water for watching the condition of power plant process will be able to use. Integrates these processes it will be able to reduce an annual 30,000 ton degree. The research is want to use the fundamental data for the water curtailment of the power plant.

Power plant water re-use, Waste water re-application, Water curtailment

박영식 Young Seek Park , 김동석 Dong Seog Kim

DOI: Vol.22(No.3) 444-450, 2006

This study was carried out to compare the performance of two types of sequencing batch biofilm reactors (SBBRs), anoxic-oxic-anoxic-oxic (AO)2 SBBR and anoxic-oxic-anoxic A2O SBBR, on the biological nutrient removal. The TOC removal efficiency in A2O SBBR was higher than that in (AO)2 SBBR. At the 1st non-aeration period, the release of PO4(3-)-P in A2O SBBR was higher than that in (AO)2 SBBR because of the high TOC removal. At the 1st aeration-period, the nitrification was not completed in (AO)2 SBBR, however, it was completed in A2O SBBR and the nitrification rate in A2O SBBR was higher than that in (AO)2 SBBR. The release and uptake of PO4(3-)-P in A2O SBBR was much higher than in (AO)2 SBBR. Also, the profiles of DO and pH in reactors were used to monitor the biological nutrient removal in two SBBRs. The break point in DO and pH curves at the aeration period coincided with the end of nitrification.

(AO)2 sequencing batch biofilm reactor, A2O sequencing batch biofilm reactor, Biological nutrient removal, DO, pH

신정섭 Jung Sub Shin , 고광백 Kwang Baik Ko , 이지영 Ji Young Lee , 임세호 Se Ho Lim , 강승현 Seung Hyun Kang , 박재한 Jae Han Park

DOI: Vol.22(No.3) 451-455, 2006

Heterotrophic biomass yield coefficients, Y(H), for aerobic, anoxic and anaerobic reactors were successfully estimated for the two wastewater treatment plants, where one plant was operating in the A2/O process and the other was operating in the 4-stage BNR process. The estimation of Y(H) was undertaken by plotting the biomass COD concentrations versus the soluble COD concentrations in order to calculate the △biomass COD/△soluble COD in each batch reactor. The batch reactors employed in this study were fed by filtered influent and mixed liquors in the ratio of 10:1, and operated in the aerobic, anoxic and anaerobic conditions, which represented the actual operating conditions for the A2/O and 4-stage BNR process. The average Y(H) values of the aerobic, anoxic and anaerobic reactor for the A2/O process were 0.52, 0.41 and 0.18㎎ COD/㎎ COD, respectively, and those for the 4-stage BNR process were 0.58, 0.40 and 0.20㎎ COD/㎎ COD, respectively. The average ratio of the Y(H) for aerobic reactors to those for the anoxic reactors were about 1:0.79 for the A2/O process, and about 1:0.69 for the 4-stage BNR process. The experimental method for anoxic and anaerobic Y(H) estimation shown in this study has turned out to be simple and efficient in its practical application.

A2/O process, Heterotrophic biomass yield coefficients, 4-stage BNR process

정용준 Yong Jun Jung , 임기성 Ki Sung Lim

DOI: Vol.22(No.3) 456-461, 2006

The facility of constructed wet land combined with filter media was examined in order to improve the water quality of a polluted stream, which has been performed as a part of national projects. Throughout 2 years of operation for a stream, it can provide the design and operating parameters for the purpose of future construction. The influent flow rate was about 50% against the design capacity. The removal efficiencies of BOD, COD(Mn), SS, T-N and T-P were 62.9%, 47.1%, 74.8%, 22.4% and 33.5%, respectively. In order to keep this facility stable, the removal of surface filter media and supplement should be periodically conducted. In addition, the proper selection of sites is recommended not to be flooded.

Constructed wet Land, Filter media, Polluted stream, Water quality

권구호 Koo Ho Kwon , 김시원 Si Won Lee , 이민재 Min Jae Lee , 민경석 Kyung Sok Min , Kyung Sok Min

DOI: Vol.22(No.3) 462-467, 2006

An improvement of nitrogen and phosphorus removal in SBR using the elutriated acids from the food waste as an external carbon source was investigated in this study. The food waste was elutriated at 35℃ and pH 9 to produce the external carbon source. The elutriate of food waste were continuously collected. The elutriated liquid contained VFAs of 39,180 ㎎/L representing soluble COD of 44,700 ㎎/L. The SBR showed poor denitrification and EBPR (enhanced biological phosphorus removal) without elutriated VFAs addition. An average denitrification rate was 0.4 ㎎ NOx-N/g MLVSS/day. In turn, EBPR was also inhibited by this poor denitrification because the remaining nitrate in anaerobic phase resulting a poor denitrification. On the other hand, the denitrification in anoxic phase significantly improved with an elutriated VFAs addition. Nitrate removal was 82% while the denitrification rate was 2.9 ㎎ NOx-N/g MLVSS/day with 18.4 mL/cycle of elutriated VFAs. With the enhanced denitrification, nitrate concentration in anaerobic phase could effectively be controlled to a very low level. The elimination of nitrate inhibition in anaerobic phase resulted enhancement of EBPR. The specific phosphate release rate was 1.9㎎ PO4(3-)-P/g MLVSS/day with less than 0.5 ㎎/L of PO4(3-)-P concentration.

External carbon source, Food waste, SBR, EVFAs

김영철 Young Chul Kim , 이진우 Jin Woo Lee , 강민기 Min Gi Kang

DOI: Vol.22(No.3) 468-474, 2006

In the secondary settling tanks, three different types of settling phenomena occurs; i.e., zone settling for sludge thickening in the bottom part of settling tank, and discrete and flocculent settling for clarification in the upper part. In this paper, morphological parameters of the floc in sludge blanket layers along the length of a long rectangular tank were investigated. The plant used for this study had a serious bulking problem caused by Microthrix parvicella. Floc size decreased as the surface area of settling tank increases, which indicates that in the secondary settling tank where zone settling believed to be predominant, free or flocculent type of settling contributes to floc size distributions. Large floc particles deposit in the front zone of settling tank, but small and loose flocs mostly in the zone near its outlet. On the other hand, filament length contained in one gram of sludge blanket solid increases along the flow direction. Large flocs with less filaments settle faster, but small flocs having more filaments result in poor settling. These results support function of microorganism selection occurring in secondary settling tank. In addition, designing a long rectangluar settling tank with double hoppers might be one of the ways of bulking control, but this idea has to be verified with a further study.

Bulking, Filament, Floc, Microthrix parvicella, Secondary settling tank

김영택 Young Taek Kim , 배윤선 Yoon Sun Bae , 노은경 Eun Kyung Roh , 박철휘 Chul Hwi Park

DOI: Vol.22(No.3) 475-481, 2006

The major problem in closing water like lakes and ponds in Korea is that because they are exposed to surrounding, so easily polluted. The pollution in closing water can be caused by not only artificial factor like sewage but also natural factor like elution from sediment. For insurance of safe and satisfied water source, lots of studies and projects are now going on. In this study, we examined the behavior and effect of microbubble (3~10 ㎛ produced by device called O.S.D (Oxygen Solubillization Device) in small size pond. The value of oxygen transfer coefficient (K(La)) was 0.68/min independently of airflow rate, 6.5 times higher than commercial aeration stone and the variation of nitrogen concentration was 0.008 NO3/O2, DO concentration was potentially saturated for 24 hr. From the results of pilot plant, SOD of experiment (O.S.D) and control were12.18 gO2 · m(-2) · d(-1) and 47.95 gO2 · m(-2) d(-1) respectively. In conclusion, because O.S.D has extraordinary physico-chemical characteristics, it can contribute to improvement of both the waterbody and the sediment environment.

Oxygen solubilization device, Oxygen transfer coefficient (K(La)), Sediment Oxygen Demand, SOD

정병철 Byung Cheol Jeong , 박권삼 Kwon Sam Park , 정병곤 Byung Gon Jeong

DOI: Vol.22(No.3) 492-497, 2006

Feasibility of simultaneous removal of organic materials and nitrogen in the wastewater from fisheries processing plant was evaluated using entrapped mixed microbial cell (EMMC) process. The experiment was performed using activated sludge from municipal sewage treatment plant which was immobilized with gel matrix by cellulose triacetate. It was found the stable operation at the treatment system which is composed of anoxic and oxic tank, was possible when the organic and nitrogen loading rates were increased stepwise. The organic and nitrogen loading rates were conducted from 0.65 to 1.72 ㎏COD/m3/d and from 0.119 to 0.317 ㎏ T-N/m3/d with four steps, respectively. The maximum nitrogen loading rate which could satisfy the regulated effluent standard of nitrogen concentration, was 0.3 ㎏ T-N/m3/d. The removal efficiency of total nitrogen was decreased apparently as increasing nitrogen loading rates, whereas the removal efficiency of ammonium nitrogen was effective at the all tested nitrogen loading rates. Therefore, it was concluded that nitrification was efficient at the system. Nitrate was removed efficiently at the anoxic tank. whereas the nitrification efficiency at the oxic tank ranged 94.0% to 96.9% at the tested loading rates. The removal efficiencies of chemical oxygen demand (COD) and those of total nitrogen at the entire system ranged from 94.2% to 96.6% and 73.4% to 83.4%, respectively.

COD, Entrapped Mixed Microbial Cell(EMMC) process, Fish processing wastewater, T-N

백미화 Mi Hwa Baek , 김동수 Dong Su Kim

DOI: Vol.22(No.3) 498-503, 2006

Adsorption features of Cd(2+) on waste tire particles have been investigated for the purpose of enhanced wastes recycling along with the development of an economic process for wastewater treatment. The isoelectric point of waste tire particles was found to be ca. pH 7 and the adsorbed amount of Cd(2+) was increased with pH under experimental conditions. The variation of the adsorption behavior of Cd(2+) with pH was well explained by the change of the electrokinetic potential of waste tire particles according to the pH. Adsorption of Cd(2+) was observed to reach its equilibrium within 45 minutes after the adsorption started under experimental conditions and followed the Freundlich model well. Kinetic analysis showed that the adsorption reaction of Cd(2+) was second order and thermodynamic estimation substantiated the endothermic behavior of Cd(2+) adsorption. As the amount of adsorbent increased, more adsorption of Cd(2+) was accomplished and the adsorption capacity of adsorbent was found to be enhanced by its pre-treatment with NaOH. Also, the adsorption of adsorbate was promoted as the ionic strength of wastewater was increased.

Adsorption, Cadmium ion, Waste tire, Wastewater treatment

김건하 Geon Ha Kim

DOI: Vol.22(No.3) 504-512, 2006

In order to estimate microbial contaminant discharge from diffuse sources, rainfall runoff was monitored at forestry, agriculture and urban watersheds. Total coliform and E. coli were monitored at the study watersheds as they are regulated by the environmental laws. Concentration and EMC (Event Mean Concentration) of coliform of rainfall runoff at the urban watershed were the highest followed by those from agricultural and forestry watersheds. By monitoring coliform concentrations of overlying water and sediment at five monitoring points in the downstream of the Geum River, average concentration from spring to summer was higher than those values from fall to spring. Coliform concentrations in the pore water were higher compared to those of overlying water and closely related with flow rate of the river.

Coliform, Diffuse sources, Event Mean Concentration, EMC, Microbial contaminant, Sediment, Water quality

박혜경 Hae Kyung Park , 서용찬 Yong Chan Seo , 조일형 Il Hyung Cho , 박병황 Byung Hwang Park

DOI: Vol.22(No.3) 513-520, 2006

The effect of chlorination on disinfection byproducts (DBPs) production from bloom-forming freshwater algae including 7 strains of cyanobacteria and 6 strains of diatoms was investigated. The release and degradation of hepatotoxin (microcystins) by the chlorination on Microcystis under differential condition of the chlorination time and dose were also investigated. The disinfection byproducts formation potentials (DBPFP) of cyanobacterial species and diatoms were ranged from 0.017 to 0.070 μmol DBPs/㎎ C and from 0.129 to 0.708 μmol DBPs/㎎ C respectively. Among three major groups of DBPs, haloacetonitrils (HANs) was major product in most test strains except Aphanizomenon sp. and Oscillatoria sp. Haloacetic acids (HAAs) was less than 5 % of total DBPs. Chloroform and dichloroacetonitril (DCAN) were dominant compounds in trihalomethanes (THMs) and HANs respectively. After 4 hours chlorination of toxic Microcystis aeruginosa under the dose range of 0.5 to 10 ㎎ Cl2/L, the concentration of intracellular microcystins decreased, but dissolved dissolved microcystins concentration increased with the treatment of more than 3 ㎎ Cl2/L. However the total amount of microcystins was almost constant even at 10 ㎎ Cl2/L of chlorination. To conclude, our results indicate that the chlorination causes algal cell lysis and release of intracellular microcystins in the intact form to surrounding waters.

Bloom-forming algae, Disinfection byproducts, Haloacetonitriles, Microcystins

박재충 Jae Chung Park , 박재범 Jae Bum Park , 송성일 Sung Il Song , 김현숙 Hyun Suk Kim , 박정원 Jung Won Park

DOI: Vol.22(No.3) 521-526, 2006

We have studied the possibility of removing Anabaena macrospora by injecting copper sulfate (CuSO4 · 5H2O) into the raw water of a drinking water purification plant. Anabaena macrospora caused the unpleasant geosmin odor of drinking water in August 2001. The cell break-point of A. macrospora was 0.3 ㎎/L of CuSO4. We were able to reduce the standing crops of A. macrospora effectively because CuSO4 could break A. macrospora selectively. Because 0.3 ㎎/L of CuSO4 could break both cells and akinetes, it reduced the possibility of a recurrent problem for them to meet a favorable condition. When CuSO4 was injected in the early growth phase of algae and the mixing intensity was high, A. macrospora could be removed most effectively. The odor caused by A. macrospora was sustained for a while without any sudden change of environmental condition. Therefore, we hope that it could shorten the period of obstacle by injecting the optimal amount of 0.3 ㎎/L of CuSO4. The water quality, alkalinity, conductivity, hardness and pH didn`t changed by the injection of CuSO4.

Anabaena macrospora, CuSO4, Drinking water, Geosmin, Water purification plant

김성표 Sung Pyo Kim

DOI: Vol.22(No.3) 527-533, 2006

Tetracycline is one of the mostly used antibiotics around the world. The purpose of this study was to evaluate the fate of two different types of tetracycline resistant bacteria in biological wastewater treatment plants. Tetracycline resistant enterics and heterotrophic bacteria were monitored under two different lab-scale experimental conditions. Tetracycline resistant enteric bacteria showed the lower percentages of total enteric bacteria and net specific growth rate in the monitored activated sludge system as compared to tetracycline resistant heterotrophic bacteria. Therefore, total enterics, potentially E.coli, might not be the best indicator microorganism for evaluating the antibiotic resistant bacteria in biological wastewater treatment plant.

Tetracycline, Tetracycline resistant bacteria

박보화 Bo Hwa Park , 고광백 Kwang Baik Ko , 박재한 Jae Han Park , 임세호 Se Ho Lim , 신동록 Dong Rok Shin , 윤혜정 Hye Jung Yun , 이지영 Ji Young Lee , 문태호 Tae Hoon Moon

DOI: Vol.22(No.3) 534-539, 2006

The supply of oxygen for aeration is the largest energy consumer at activated sludge wastewater treatment plants. Replacement of less efficient aeration systems with fine pore aeration devices can save up to 50 percent of aeration energy costs. The purpose of this study was the diagnosis and evaluation of a domestic wastewater aeration system by the off-gas method which had been studied by US EPA and ASCE. For this study, an off-gas analyzer and its hood were made to collect off-gas. Also, a vacuum pump was connected to the analyzer to make suction of off-gas. Experiments were conducted at a domestic activated sludge wastewater treatment plant which had a single spiral roll aeration system installed with P.E tube diffuser. Data on OTE(f), SOTE(pw), OUR, and air flow rate were obtained from these experiments. In case of replacing an aeration system, it is recommended that it should be replaced with perforated membrane disc or ceramic disc fine bubble diffusers installed in a full floor coverage or grid pattern.

Aeration system, Off-gas analyzer, OTE, OUR, SOTE

길경익 Kyung Ik Gil

DOI: Vol.22(No.3) 540-545, 2006

The anaerobic digester supernatant (ADS) with high NH4-N concentration often results in a NH4-N overloading to the mainstream process of municipal wastewater treatment plant (MWTP). The nitrogen removal from the ADS is therefore important in order to achieve a stable mainstream process performance as well as to prevent NH4-N overloading due to ADS. Recently because of several advantages compared to the full nitrification, many works have shown interests in controlling the build-up of NO2-N in nitritation processes. The application of nitritation could save the aeration power compared to the full nitrification processes. In addition, the denitrification of NO2-N could reduce organic carbon requirements compared to the NO3-N denitrification. The purpose of this research was to find out the characteristics of the ADS nitritation and NO2-N accumulating factors from the laboratory reactor study. As a result based on the long-term laboratory experiment, it can be concluded that the degree of nitritation was closely related with the availability of alkalinity, free ammonia (FA), solid retention time (SRT) and solid concentration in the nitritation reactor.

Anaerobic digester supernatant, Free ammonia, Nitritation, Recycle water, Solid retention time

김승준 Seung Jun Kim , 최용수 Yong Su Choi , 배우근 Woo Keun Bae

DOI: Vol.22(No.3) 546-556, 2006

The purpose of this study is to improve the polluted stream water quality by pilot-scale five different constructed wetlands (CWs). Cell 1 to 3 are newly designed 2SFCW (Surface-subsurface flow CW) with 1 to 3 flow shifters (FS) in the middle of the wetland system. Cell 4 and 5 are control CW (CCW), but Cell 5 is the same type as Cell 3. The FS, which converts the route of surface and subsurface flow between two wetlands connected in series, was able to enhance the treatability of TN via nitrification and denitrification and of SS due to filtration and sedimentation. The void fraction and dispersion number of Cell 1, 2 and 3 obtained from the RTD analysis were found to be 0.73 and 0.17, respectively. COD and TP removal efficiencies of Cell 1 to 3 were similar to that of Cell 4 and 5. SS removal efficiencies of Cell 1 to 3 and 5 with FS were 5-10% higher than that of Cell 4 without FS. TN removal efficiencies of Cell 1 to 3 were 3-14% higher than that of Cell 4 and 5. The average R2 values of COD, SS, TN and TP obtained from nonlinear regression analysis were similar to the results of other researchers.

Flow shifter, Hydraulic Loading rate, Residence time distribution, Stream, Surface-subsurface constructed wetland

김영철 Young Chul Kim , 박무종 Moo Jong Park , 신동진 Dong Jin Sheen

DOI: Vol.22(No.3) 557-565, 2006

Proper operation of clarifier partly depends on outlet conditions. Effluent has to be uniformly withdrawn to prevent scouring of settled sludge and carry over of settling sludge from the clarifier. In this paper, 3-D numerical model was employed to analyze the flow and settling performance of the rectangular clarifier. There were two simulation conditions of which in the same clarifier, the first one was assumed to have a 11.5 meter weir length and the second has 8.5 meters. Shape, location and placement of the weir structure were different, but both of those outlets meet weir loading design criteria. Simulation results indicate that clarifier with longer weir generally gave strong and unstable currents at the mid-stream where the weir starts while in the clarifier with short and relatively simple weir, uniform and stable flow was observed in most parts of the settling zone, and especially at the weir region. These flow conditions affected settling performance. Effulent SS concentration from clarifier equipped with the long and complicated placement of weir was 24.5 ㎎/L, but 7.0 ㎎/L from the clarfieir having short weir length. From this study, it can be concluded that as reported from other studies, weir loading does not guarantee settling performance and 3-D numerical model can be a useful tool for determining and validating outlet structure.

Clarifier, Outlet, Settling, Sludge, Weir

한혜정 Hye Jeong Han , 윤주환 Zu Whan Yun

DOI: Vol.22(No.3) 566-571, 2006

A sequencing batch biofilm reactor (SBBR) operated with a cycle of anaerobic - aerobic - anoxic - aerobic has been evaluated for the nutrient removal characteristics. The sponge-like moving media was filled to about 10% of reactor volume. The sewage was the major substrate while external synthetic carbon substrate was added to the anoxic stage to enhance the nitrogen removal. The operational results indicated that maximum T-N and T-P removal efficiencies were 97% and 94%, respectively were achieved, while COD removal of 92%. The observations of significant nitrogen removal in the first aerobic stage indicated that nitrogen removal behaviour in this SBBR was different to conventional SBR. Although the reasons for aerobic nitrogen removal has speculated to either simultaneous nitrification and denitrification or anoxic denitrification inside of the media, further researches are required to confirm the observation. The specific oxygen uptake rate (SOUR) test with biofilm and suspended growth sludge indicated that biofilm in SBBR played a major role to remove substrates.

Biofilm, Enhanced biological phosphorus removal, EBPR, Nitrogen removal, Sequencing batch reactor, SBR, Specific oxygen uptake rate, SOUR