신정훈 Sin Jeong Hun , 정진영 Jeong Jin Yeong , 정윤철 Jeong Yun Cheol , 손대희 Son Dae Hui

DOI: Vol.19(No.5) 463-471, 2003

The objective of this study was to investigate the performances of the activated sludge and fixed-film biological reactor in treating industry wastewater containing dimethyl sulfoxide [DMSO, (CH₃)₂SO]. When the influent DMSO concentration increased from 400 ㎎/L to 800 ㎎/L at hydraulic retention times from 48 to 24 hours, the soluble TOC removal efficiencies of the activated sludge and fixed-film reactors were in the range of 95.3-97.5% and 96.5-97.6% respectively. Meanwhile, the TCOD removal efficiency of the activated sludge was in the range of 80.5-98.0%. while that of the fixed-film reactor was 94.9-98.5%. The reason for the high fluctuation of TCOD removal in the activated sludge process was the increase in the SS concentration in the effluent. The sludge washout was caused by the destruction of sludge floc due to the DMSO concentration in the suspended culture. However, the fixed-film reactor showed a stable effluent quality compared to that of the activated sludge reactor during whole operating period.

Industry wastewater, DMSO, dimethyi sulfoxide, Activated sludge, Fixed-film biological reactor

신응배 Sin Eung Bae , 김미경 Kim Mi Gyeong , 김재헌 Kim Jae Heon

DOI: Vol.19(No.5) 473-483, 2003

In this study, five representative substrates (glucose, acetate, starch, humic acid, and glycogen) having different characteristics of biodegradability and microbial acclimation were chosen for evaluating biosorption capacity using activated sludge and autoclaved sludge as sorbents, and also effects of contact time, substrate concentration and anaerobic/aerobic conditions were investigated. Results showed that the anaerobic biosorption finished within 10 minutes after contact with substrates and the removal of glucose was two times greater than that of acetate. Considering that the microbes used in this study have been acclimated to glucose, this implies that the microbial acclimation is an important factor for biosorption. In cases of glucose, acetate, and starch, the substrate was removed by biological mechanism rather than by physicochemical mechanisms. The sorption experiments using the autoclaved sludge showed the constant substrate removal of 10-20 ㎎ COD/g SS. Results also showed that the biosorption of the activated sludge fitted the Langmuir isotherm and was largely affected by substrate affinity, biodegradability and microbial acclimation.

Anaerobic-Intermittently Aerated Process, Biosorption, Acclimation, Isotherm, 혐기-간헐포기 공정, 순응, 등온흡착식

김충곤 Kim Chung Gon , 임제현 Im Je Hyeon , 강선홍 Kang Seon Hong

DOI: Vol.19(No.5) 485-492, 2003

This study was performed to examine Package Type Reactor whether it could be applied to field regardless of the temperature change. For this purpose the temperature of two packages [Run Ⅰ (ASBR-Struvite Tank-SBR), Ⅱ (Struvite Tank-ASBR-SBR) 1 was changed to 35℃→30℃→25℃ continuously to compare the removal efficiency of each Run. The removal efficiency of the organic materials of both Runs was proved to be stable regardless of the temperature change. T-N and T-P showed very high removal efficiency. T-N removal efficiency in Run I was 71.3%, 80.1%, and 71.2% in 35℃. 30℃, and 25℃ respectively, and in Run Ⅱ 74.246, 78.896, and 70.9%. T-P removal efficiency in Run Ⅰ was 79.5%, 83.1% and 84.1% in 35℃, 30℃, and 25℃ respectively, and in Run Ⅱ 85.5%, 85.8%, and 85.5%. The removal efficiency of COD in Struvite tank was very low regardless temperature change, but the removal efficiency of NH₄-N was higher. As a result of this study, each Run of Package Type Reactor was proved to have great removal efficiency in swine wastewater treatment, and to be a very good biological process in temperature change.

Struvite, ASBR, SBR, swine wastewater, temperature

황규대 Hwang Gyu Dae , 강재순 Kang Jae Sun , 장준기 Jang Jun Gi

DOI: Vol.19(No.5) 493-501, 2003

In the sonochemical reaction, the solid of sludge can be disintegrated and solubilized by hydromechanical shear force, pyrolysis, and free radical attack during the cavitation. This study was performed to evaluate the feasibility of ultrasonically treated raw sludge as carbon source for biological denitrification and phosphate release. A 530W ultrasonic processor with a frequency of 40kHz was used to sonicated the raw sludge from wastewater plant. To find the optimal SCODcr buildup condition. we examined the effects of solid concentration of sludge, ultrasonic density, irradiation time, aeration, and pH on TSS and SCODcr concentration during the ultrasonic irradiation on raw sludge. Ultrasonic irradiation was applied to raw sludges with different solid contents (1, 3, and 5%.) and different ultrasonic density (0.04, 0.06, and 0.12W/rnl). Ultrasonic irradiation showed a rapid and significant decrease in TSS concentration in raw sludge. The kinetic of the degradation rates of TSS by ultrasonic irradiation was satisfactorily described by a pseudo-first order reaction. The degradation efficiency of solid in raw sludges were over 60%, and ranged from 3.0 to 7.2 ㎎TSS/W . hr. Also the SCODcr yields of 2.1 -3.2 ㎎SCODcr/W·hr in this study were observed and depended strongly on ultrasonic density. With aeration. the sonication on raw sludge further increased SCODcr concentration. However, it is less effective to irradiate ultrasonically the pH-adiusted raw sludge. The optimal operating condition to increase soluble organics was to sonicate the sludge with 5% TSS under the ultrasonic density of 0.12W/ml and showed the yield of 3.2 ㎎SCODcr/W . hr. Also the sonicated sludges with different sonication time(ranging between 0-9hrs) under 0.I2W/ml were fed into the batch reactors as carbon source. Those ones had a strong influence on the denitrification rate and the P-release concentration. The specific denitrification rates of batch reactors varied within a range from 0.46 to 1.97 mgNO₃-N/gVSS·hr, and 1.33-1.85 gSCODCr consumed/gNO₃-N removed was observed. The concentration of phosphate which was released by poly P microbes were in the range of 0-4.75㎎/L. and 0.55-1.22gPO₄-P released /gSCODcr consumed was showed. The economically most competitive sludge as carbon source was one under 3hr sonication time to accomplish the high denitrification rate and the P-release concentration. Therefore, the ultrasonically treated sludge can be another carbon source for BNR process.

Raw Sludge, Ultrasonic Irradiation, Cavitation, Carbon Source, BNR Process, Denitrificaton, P-release

차기철 Cha Gi Cheol , 유영욱 Yu Yeong Ug , 이명규 Lee Myeong Gyu , 김동진 Kim Dong Jin , 유익근 Yu Ig Geun , 엄태규 Eom Tae Gyu

DOI: Vol.19(No.5) 503-511, 2003

The relationship between SMP (soluble microbial products) and membrane fouling in the MBR (submerged hollow-fiber membrane bio-reactor) was investigated. The phenol was used as a substrate. The MBR was performed under condition that SMP concentration is changed from 20㎎/L to 60 ㎎/L. The membrane fouling increased with increasing of SMP concentration. The effect of resistance values on the membrane fouling was the order of R_(c)>R_(g)>R_(f)>R_(m). The increase of viscosity and non-biodegradable matters in the MBR was closely connected with the SMP concentration. The concentration of SMP should be kept less than 40 ㎎/L for stable operating of MBR. The T_(max) (time for maximum) decreased with increasing of SMP concentration. The removal rate of organic matters and total nitrogen in the MBR showed over 98% and 90%, respectively.

Soluble microbial products, Hollow-fiber membrane, Phenol, Membrane fouling, Resistance value, 생물대사산물, 중공사막, 페놀, 막오염, 저항값

김재훈 Kim Jae Hun

DOI: Vol.19(No.5) 513-519, 2003

The purpose of this study is to understand the removal characteristics of dissolved organic matter by URC(Ultra Rapidly Coagulation) process and the conventional coagulation process. The components ratio of dissolved organic matter in the raw sample was as follows : The hydrophilic matter was 64.2% and the hydrophobic matter was 35.8%. After URC, these component ratio were changed to 50.7% and 49.3%. And after conventional coagulation process, these were changed to 59.4% and 40.6%. The hydrophilic matter was removed more 9.2% by URC than the conventional coagulation process. And the hydrophilic matter was removed two times by contrast with the hydrophobic matter by URC more than conventional coagulation process. We obtained the result that URC is the more effective treatment process than conventional coagulation process to remove the hydrophilic matter of dissolved organic matter.

DOM, Coagulation process, Removal characteristics, Hydrophilic, Hydrophobic

최상일 Choe Sang Il , 공준 Gong Jun , 조장환 Jo Jang Hwan

DOI: Vol.19(No.5) 521-531, 2003

Monovalent sodium, divalent calcium and trivalent aluminum cations were used to recycle 0.0694M sodium dodecyl sulfate based on stoichiometric level. The calcium and aluminum dodecyl sulfate precipitate has a very low solubility in water and can not be directly recycled to the surfactant based separation. It must be transformed to the monovalent salt before it can be redissolved in water for recycle. Therefore, sodium carbonate solution was added to a slurry of the precipitated calcium and aluminum dodecyl sulfate for optimizing applied sodium carbonate. The washing test was performed to compare recycled anionic surfactants to the original amount. As diesels desorted from diesel containing soil have a sensitive effect on the precipitation of surfactant by hydrophobic affinity, the experiment was also conducted to determine the application range of diesel and minimize recycle loss of anionic surfactant.

Soil Washing, Washing Effluent, Anionic Surfactant, Sodium Dodecyl Sulfate, Surfactant Recovery

윤춘경 Yun Chun Gyeong , 황하선 Hwang Ha Seon , 정광욱 Jeong Gwang Ug , 함종화 Ham Jong Hwa

DOI: Vol.19(No.5) 533-542, 2003

A pilot study was performed to examine the repair of indicator microorganisms after UV irradiation for agricultural reuse of reclaimed water. The effluent of biofilter for 16-unit apartment was used as input to the UV disinfection system, and average SS and BOD concentration were 3.4 and 5.9 mg/L, respectively. and the mean level of total coliform was in the range of 1.0×10₄MPN/100mL. Two UV doses of 6 and 16 mW·s/㎠ were applied and microorganism repair was monitored under the dark, photoreactivating light, and sun light. Microorganism repair was observed in the UV dose of 6 mW·s/㎠ , and numbers increased up to 5% at the photoreactivating light and 1 % at the dark. However, microorganisms were inactivated rather than reactivated at the sun light and numbers decreased to non-detectible level in 4 hours. In the case of 16 mW·s/㎠ , microorganism repair was not observed indicating that UV dose might affect the repair process. Therefore, concerns associated with microorganism repair could be controlled by sufficient UV dose application. Agricultural reuse of reclaimed water might be even less concerned due to exposure to the sun light which could further inactivate microorganisms. The pilot study result is encouraging, however, sanitary concern in water reuse is so critical that more comprehensive investigation is recommended.

Photoreactivation, Dark repair, UV disinfection, UV dose, Total coliform, Fecal coliform, Escherichia coli

김영철 Kim Yeong Cheol , 강민기 Kang Min Gi , 이진우 Lee Jin U

DOI: Vol.19(No.5) 543-554, 2003

In order to Polish nutrients in the effluent from small Sewage treatment plant mostly designed for targeting organic matters, aquatic treatment system coupled the non-mixed high-rate algal ponds(HRAPs) with constructed wetland(CW) were developed. The treatment studies show that its performance based on median concentration of the final elfluent was TN 2.0㎎/L. TP 0.3㎎/L, and COD 22㎎/L. respectively, and also, it was fairly stable. However, overall performance for nitrogen was highly affected by water temperature and plant density of the CW. At the operational period of lower temperature. as the performance of HRAPs was lowered inherently due to less sunlight. then CW`s contribution started to increase, so that this system functioned in a cooperative manner. At the CW most of the nitrogen was removed by nitrification-denitrification occurred in locally Aerobic/Anoxic Zone between cattails. Phosphorus balance indicates that at Ihe HRAPs most of the P was thought to be reduced through chemical precipitation at the high PH while at the CW₁ the P reduction was due to the plant uptake. The amount of plant biomass production(wet basis) was 1.4㎏ per one square meters of CW from one cubic meters of secondary effluent.

High-rate algal ponds, Constructed wetland, Nutrients, Secondary effluent, 고속산화지, 인공습지, 영양소, 2차 처리수

이호식 Lee Ho Sig , 민유미 Min Yu Mi , 박장현 Park Jang Hyeon , 박영환 Park Yeong Hwan , 전태성 Jeon Tae Seong , 이경미 Lee Gyeong Mi

DOI: Vol.19(No.5) 555-565, 2003

The purpose of this study is to develop automatic control operation system which is possible operation and maintenance efficiently includes of nutrient removal in small wastewater treatment plants. The SBR (Sequencing Batch Reactor) system that anoxic. anaerobic and oxic reaction occurs consecutively in single reactor was used in this study. The two SBR systems that Experimental SBR by automatic control program and Control SBR by fixed cycle were used in this experiment. The Control SBR was operated 1cycle by 6 hours which is anoxic 2.5hr. oxic 2 hr, settle 1hr, decant 0.33hr and idle 0.17hr. respectively. The cycle of Experimental SBR was controlled anoxic oxic, settle and decant by real time according to ORP result unlike the Control SBR. According to result that Experimental SBR system of automatic control program, complete nitrilication was made under Oxic condition and denitrification occurs as NO₃^(-)N concentration decreases by 0.5 ㎎/L in anoxic condition and excellent nitrogen removal efficiency was seen generally. The Experimental SBR system was occurred "phosphate release and uptake" elfectively and was displaying Dhowhate removal efficiency more than 80% as the concentration of effluent is kept by 0.4 ㎎/L low thereby.

Automatic control operation system, Nutrient removal, Small wastewater treatment plants, SBR

김경숙 Kim Gyeong Sug , 오병수 O Byeong Su , 주설 Ju Seol , 정봉철 Jeong Bong Cheol , 안규홍 An Gyu Hong , 강준원 Kang Jun Won

DOI: Vol.19(No.5) 567-574, 2003

This study illustrates the analytical results of micropollutants in Kyung-an of Pal-dang reservoir. Sampling was performed 7 times form Aug. 2000 to Oct. 2002. The analytical method used in this study enables us to detect about 300 kinds of chemicals commonly found in surface water at ppt level by GC/MS. This investigation was focused on pesticides and phthalates of micropollutants present in Kyug-an stream. Regarding analytical results, 2∼9 kinds of pesticides and 6∼7 kinds of phthalates were detected and their total concentrations were 0.2∼3.6㎍/L and 3.1∼9.1㎍/L, respectively. Pesticides (isoprothiolane, molinate and flutolanil) and phthalates(dimethyl phthalate, diisobutyl phthalate, dibuthyl phthalate and buthyl benzyl phthalate) were selected for target compounds to evaluate the removal efficiency of three treatment processes (ozone, UV, and ozone/UV process). Of applied processes, Ozone/UV process showed the highest removal efficiency for all target compounds. UV process was also reasonable for eliminating pesticides and phthalates beside dimethyl phthalate. Ozone process was effective for pesticides oxidation but not for phthalates.

Pesticides, Phthalates, Ozone, UV, Ozone/UV

이대인 Lee Dae In , 박청길 Park Cheong Gil

DOI: Vol.19(No.5) 575-583, 2003

The objective of this paper is to estimate the reduction rate of pollutant loads from pollution sources using the three dimensional eco-hydrodynamic model for effective water quality management of Masan Bay that was designated as a special management area. COD distribution of the bay was mostly over 3㎎/L. this value exceeded the seawater quality criteria Ⅲ. Total loads of COD, DIN and DIP from point sources were 15.532.5, 11,107.6 and 440.9㎏/day. respectively. A pattern of simulated residual current was dominated by southward flow at surface level. The calculated results by ecological modeling were in fairly good agreement with the observed values. It was evaluated that reduction of total polutant loads from point sources by over 60% is required in order to keep the level below 3 ㎎/L in COD which is the aiming seawater quality criteria of Masan Bay.

Masan Bay, Water Quality Management, Eco-Hydrodynamic Model, COD, Polutant Loads

학회자료

DOI: Vol.19(No.5) 585-586, 2003