최의소 Eui So Choi

DOI: Vol.18(No.4) 337-339, 2002

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황갑수 Gab Soo Hwang , 신형선 Hyung Seon Shin , 김강주 Kang Joo Kim , 여성구 Sung Koo Yeo , 박성민 Seong Min Park , 임규재 Kyu Jae Lim

DOI: Vol.18(No.4) 341-354, 2002

Heavy metal concentration/distribution in sediments and bivalves from the tidal flats in Saemankeum coastal area, western Korea, were investigated, Among 6 sampling sites, S2, S5 and S6 showed the higher levels of Zn, Cr, Ni, Cu and Cd contamination and S1 did the higher level of Pb contamination than other sites, while S-4 showed the lowest levels of these metal contamination. Overally, the levels of Zn, Cu and Pb concentrations in Sinonovacula constricta were estimated to be relatively high. The shell lengths of the collected mussels were linearly related to their dry weights of the whole soft parts, but the mussels collected from S3 were in a poor nutrition, resulting in the distinctively high levels of metal concentrations in the body. It was shown that in S. constricta, Cr, Ni, Cu and Zn are distributed equally into the whole soft parts or a little more into the flesh, after absorption, while Fe, Cd, Pb and Mn are transferred more into the non-flesh parts than into the flesh parts, In S. constricta, the heavy metal concentrations in the flesh increase with those in the whole soft parts. The bioaccumulation factors(heavy metal concentration in S. constricta/heavy metal concentration in sediment) showed that, of the examined metals, Cd is the most cumulative in the body of S. constricta, followed by Zn and Cu, while Mn. Cr Ni and Pb are not cumulative.

김충환 Chung Hwan Kim , 정상기 Sang Gi Jung , 김학성 Hag Seong Kim

DOI: Vol.18(No.4) 355-363, 2002

A demonstration plant was carried out to investigate the removal efficiency of NH_3-N and KMnO_4 consumption depending on the existence of pre-chlorination for the ozonation and activated carbon process in the S water treatment plant which is located at the middle of Keum River. The averge removal efficiency of KMnO_4 consumption for O_3/GAC processes with pre-chlorination and O_3/BAC processes without pre-chlorination were 48.6% and 50% respectively. It is similar to removal effect of KMnO_4 consumption for GAC and BAC process depending on the existence of pre-chlorination. Otherwise, the removal of THMFP for GAC and BAC process was 58% and 68% respectively. NH_3-N was not almost removed by sand filter and ozonation, but the average removal efficiency in the BAC process was about 31%. Especially, NH_3-N was not almost removed by O_3/BAC processes at the low temperature (below 10℃) in the winter season, O_3/BAC processes have the advantage of removal of organic substance when it is compared to pre -chlorination followed by O_3/GAC processes. Pre-chlorination followed by O_3/GAC processes were required to remove NH_3-N in the winter season because the removal of NH_3-N was almost ineffective by O_3/BAC process.

박종훈 Jong Hoon Park , 강선홍 Seon Hong Kang

DOI: Vol.18(No.4) 365-370, 2002

This study aims to study the effect of HRT and influent concentration on swine wastewater treatment using UASB(Upflow Anaerobic Sludge Blanket). Sample was separately collected from the piggery farm; urine(liquid part) and solid part to compare their treatment characteristics. Reactors were used two UASB(3.2 L) in this research under constant temperature (35℃). Their operating conditions were as follows; Run 1(UASB ; HRT 6-days, 1 cycle/d), Run 2(UASB ; HRT 3-days, 1 cycle/d). Biogas was collected and analyzed using GC(HP-6890). By comparing the results of Run 1 and Run 2, the effect of HRT was investigated, The treatment efficiency of Run 1 which had longer HRT was higher than that of Run 2 in both solid and liquid parts of piggery sample. Methane content in collected biogas is more than 80%.

이병헌 Byung Hun Lee , 강성재 Seong Jae Kang , 임성일 Sung Il Lim , 유평종 Pyung Jong Yoo

DOI: Vol.18(No.4) 371-377, 2002

The purpose of this study is to develop effective operating process in order to achieve more suitable conditions of Anoxic-Oxic-Anoxic-Stripper(AOAS) SBR through real-time control. To improve the removal efficiency, glucose, methanol and synthetic food waste acid fermentant were added as an external carbon source, In the case of glucose and synthetic food waste acid fermentant, TN, TP were removed to average 86.9%, 73.0% respectively. Methanol was removed to average 64.6%, 55.4% respectively. The synthetic food waste acid fermentant proved to be the most efficient and allowed for the substitution of an external carbon source. The removal rate of COD_Cr, was approximately 90% at all cases. The results of the study that a correlation between ORP (Oxidation- Reduction Potential), pH and DO and nitrification or denitrification when an external carbon source is added and when it isn`t was showed that ΔORP is suitable parameter. ORP reacted properly to denitrification (ΔORP < -10) and nitrification (ΔORP <0). The use of real-time control saved anywhere between 61 and 67 minutes at the anoxic(1) stage and 26 to 52 minutes at the oxic(1) stage. When the time saved from the anoxic(1) and oxic(1) was added to the anoxic(2) stage for the removal efficiency of TN and TP increased from 0.7 to 13.9% and 12 to 35 % respectively.

전석준 Seok Jun Jeon

DOI: Vol.18(No.4) 379-386, 2002

In this study, estimation model for iron compound originated from upflow, anaerobic fixed bed reactor, which treats sewage domestic wastewater, was developed. The estimation model was formulated by a mathematical expression which was based on the mass balance. Below the HRT of 60 minute, sulfide concentration combining with iron FeS_2 is the highest because the maximum sulfate consumption rate V_maxs and half-saturation constant of sulfate K_ms exert an important effect on the estimation model as temperature was increased. But increment of FeS_2 concentration is weakened above the HRT of 60 minutes and represent the lowest value at the HRT of 108 minutes, It implies that liquid phase distribution ratio of sulfide αr becomes lower as temperature was increased, While phosphorus concentration combining with iron Fe_3(PO_4)_3 is increased as HRT and temperature are increased, which is affected by phosphorus removal rate constant k_p. As the result of estimating the iron concentrations of corrosion by the model, the concentration of iron corrosion is higher than any other at the HRT of 108 minute and 20℃. The predicted values were compared with measured ones at different HRT(13.5, 27, 54, 108 min) and temperature(20, 25, 30℃). The experimental data could be fitted with the simulated curves. Therefore, the mathematical expression could be applicable to design full-scale wastewater treatment plants.

이광현 Kwang Hyun Lee , 한성범 Sung Bum Han , 최대웅 Dae Woong Choi

DOI: Vol.18(No.4) 387-394, 2002

The efficiency variation of UF(tubular)/RO(spiral wound) process using acrylic wastewater treated by photo-catalyst pretreatment and coagulant-filter-neutralization pretreatment processes were discussed wit the variation of appled pressure and temperature. Ultrafiltration tubular module using acrylic wastewater treated by photo-catalyst pretreatment and coagulant-filter-neutralization pretreatment processes was shown that COD and T-N were not highly affected with the variation of appled pressure and temperature. It was shown that removal efficiency of COD and T-N was low. Removal efficiency of TDS and turbidity with ultrafiltration tubular module was better with the acrylic wastewater by photo-catalyst pretreatment than acrylic wastewater by coagulant-filter-neutralization pretreatment. T-N and TDS were shown high removal efficiency in reverse osmosis membrane process

정명규 Myung Kiu Chung , 김학희 Hak Hee Kim

DOI: Vol.18(No.4) 395-400, 2002

Lead is one of the most toxic metal and is detectable in practically all phases of environment and in all biological system. Transport, industrial and domestic waste products are the main sources of this pollutant, Ingested lead is rapidly absorbed and widely distributed throughout the body, causing extensive tissue damage. In this study, we chose the freshwater decapods Maceobrachium nipponnese as a sensitive indicator organism for environmental pollution. In order to investigate the possibility in use of Na^+/L^+ ATPase activity as a biomarker of lead pollution. we tested the acute toxicity of lead to Maceobrachium nipponnese. The LC_50(96hr) value for lead in Maceobrachium nipponnese was found to be 446㎍/L with the 95% confidence limits. The lead exposure group at LC_50 showed a significant Na^+/K^+ATPase inhibition, depending on the exposure time. Comparision of several concentrations of lead revealed that the Na^+/K^+ATPase activity in Maceobrachium nipponnese was significantly decreased in a concentration dependent manner. These results suggest that Na^+/K^+ATPase activity in Maceobrachium nipponnese may possibly be used as a biomarker of lead pollution in aquatic ecosystem.

고광백 Kwang Baik Ko , 서준석 Jun Suk Suh

DOI: Vol.18(No.4) 401-409, 2002

In this study, to evaluate the applicability of ORP and pH as process control parameters for an intermittent aeration process, a 200L/d bench-scale plant was installed and operated for 90 days. It was fed with synthetic wastewater which contained COD_Cr : 400mg/L, TN : 40mg/L and TP : 7mg/L. ORP & pH were measured on-line and compared with the variation of nutrient concentrations. As the results, both of the ORP and pH were able to monitor successfully nitrification and denitrification. Bending-points on the ORP curve and peak points on the pH curve corresponded to the termination of nitrification and denitrification, For P uptake and release, pH was the best indicator for performance evaluation. The aerobic pH apex was appeared when P uptake was accomplished and there was a relationship between the P release and pH variation. But the pH curve needed filtering because there were many noises on it. In this study, the shape of the ORP & pH curves were varied as the operating conditions such as aeration rates and organic loads were changed. It allowed the operating states of biological systems to be effectively evaluated. It it is properly managed to show the bending points and peak points clearly, the on-line monitoring of ORP & pH will be a reliable and effective technique for process control of intermittent aeration processes.

손종렬 Jong Ryueul Sohn , 모세영 Se Young Mo

DOI: Vol.18(No.4) 411-419, 2002

In this study, the series of ultrasonic irradiation for removal of refractory aromatic compounds has been selected as a model reaction in the batch reactor system in order to obtain the reaction kinetics. The products obtained from the ultrasonic irradiation were analysed by GC and GC/MSD. The decomposition of benzene produced toluene, phenol, and C1-C4 compounds, while the intermediates during the ultrasonic irradiation of 2,4-Dichorophenol(DCP) were phenol, HCl, catechol, hydroquinone, and benzoquinone. It was found that more than 80% of benzene, and 2,4-DCP solutions were removed within 2 hours in all reaction conditions. The reaction order in the degradation of these three compounds was verified as pseudo-zero or first order. From the fore-mentioned results, it can be concluded that the refractory organic compounds could be removed by the ultrasonic irradiation with radicals, such as H and OH radical causing the high increase of pressure and temperature. Finally, it appeared that the technology using ultrasonic irradiation can be applied to the treatment of refractory compounds which are difficult to be decomposed by the conventional methods.

장미라 Mi Ra Jang , 정효준 Hyo June Jeong , 이홍근 Hong Keun Lee

DOI: Vol.18(No.4) 421-433, 2002

This study was conducted to develope a simple, rapid and solvent-free solid-phase microextraction(SPME) procedure for extracting three organochlorine, one triazine and nine organophosphorus pesticides from water. The optimal conditions of SPME for analyses of organochlorine pesticides were obtained at 250℃ of desorption temperature, 45 minutes of equilibrium time, pH 6 and NaCl 0% addition using 100㎛ polydimethylsiloxane fiber and those of triazine and organophosphorus pesticides were obtained at 270℃ of desorption temperature, 60 minutes of equilibrium time, pH 6 and NaCl 0% addition using 100㎛ polydimethylsiloxane fiber. This method showed good lineality for organochlorine pesticides between 0.0001 and 10㎍/L with regression coefficients ranging 0.9986∼0.9992 and for triazine and organophosphorus pesticides between 0.01 and 100㎍/L with regression coefficients ranging 0.9867∼0.9998.

전병희 Byong Hee Jun , 부경민 Kyung Min Poo , 김양훈 Yang Hoon Kim , 임정훈 Jeong Hoon Im , 김창원 Chang Won Kim

DOI: Vol.18(No.4) 435-440, 2002

A pilot scale SBR (effective volume, 20㎥) for the treatment of piggery wastewater treatment was performed with three different kinds of wastewater; fermenter effluent, scraper type and slurry type, The react phase in SBR was performed by sub-cycle operation consisting of repeated short cycle of anoxic-aerobic step. The fermenter effluent was characterized by the rapid nitrification and NO_X-N accumulation due to depletion of organic matter in wastewater. The scraper type wastewater showed appropriate nitrogen removal efficiency, however, a poor response capacity for high loading rate often resulted in increased nitrogen concentration in effluent. Moreover, severe P release was the most serious problem in scraper type wastewater. SBR treated slurry type wastewater with high nitrogen removal efficiency to satisfy effluent quality requirement. It was thought that high concentration of organic matter in slurry made it possible to uptake P during SBR operation, where P concentration of 140mgP/l was decreased to 8mgP/l. As results, SBR was suitable to treat slurry type wastewater which has been discharged to the ocean till now.

학회자료

DOI: Vol.18(No.4) 441-442, 2002

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