박선구 Park Seon Gu , 임연택 Im Yeon Taeg

DOI: Vol.19(No.6) 585-597, 2003

김지훈 Kim Ji Hun , 김형수 Kim Hyeong Su , 염익태 Yeom Ig Tae , 한기봉 Han Gi Bong

DOI: Vol.19(No.6) 599-606, 2003

The permeability of membrane filtration system depends on characteristics of the raw water and operating conditions. The purpose of this study was to determine the optimum operation parameters for water treatment using plate type MF membrane(pore size 0.22㎛). The pilot microfiltraion(MF) membrane separation system had been operated in a dead-end filtration mode and applied to actual Pal-dang raw water. The experimental results are shown as follows; (1)permeate flux 30LMH was determined the optimum operation condition, (2)the chemical cleaning efficiency was only found to be 100% using "H₂SO₄+NaOCl", (3)the removal efficiencies of SS and turbidity were found to be almost 100%. However, The removal efficiencies of UV_(260) and DOC were 30% and 13%, respectively. Also, in order to improve the permeate flux and the removal efficiency of dissolved organic matter, granular activated carbon system should be added to the MF membrane System.

Plate type membrane, Microfiltraion, Dead-end filtration, Permeate flux

안익성 An Ig Seong , 정팔진 Jeong Pal Jin , 원찬희 Won Chan Hui , 조선영 Jo Seon Yeong

DOI: Vol.19(No.6) 607-613, 2003

This research is carried out in full scale sewage plant in order to induce the most suitable condition of biological treatment which fits operation system of low concentration influent municipal sewage. However the research on extreme operating condition over the standard of discharged water(BOD:20㎎/ℓ) could not be done.(because this research was carried on real running plant) The experimental result of proper dewatered sludge will stabilize circular system of sewage plant(cake product:about 3.0ton/day) and it will contribute to the stabilization of aeration tank, the main treating process. The treatment plant have shown the tendency in lower concentration of influent about 55㎎/L(as BOD) with comparison to the originally designed Influent(150㎎/L as BOD). When the plant was run with MLSS as 1,000-3,500㎎/L for 5 months, F/M ratio over 0.1 was available for more effective management with all of SVI, SDI. and effluent BOD considered for the plant. The result of BOD-SS equivalent regression of effluence indicated that suitable operation of F/M ratio improve removal about 50% soluble effluent BOD.

optimizing procedure, SVI, F/M ratio, dewatered sludge, BOD SS equivalent regression

정팔진 Jeong Pal Jin , 조선영 Jo Seon Yeong , 정진필 Jeong Jin Pil , 이은주 Lee Eun Ju

DOI: Vol.19(No.6) 615-622, 2003

A wide variety of research concerning the functions about biological reactor has been performed in many practical area. Besides these functions, a particular interest is the selection of activated sludge which comes into the final clarifiers. It has been found that microorganisms which prevent the setting and it can be controlled with this method. As a result, the influence a bulking can be reduced. On the other hand, bulking controls by microorganisms of selective setting character have been rarely studied at the activated sludges aeration basin. Our present study, is focus to, see how much effective the series operation(S-1) is compared to the parallel(P-1) one by studying the management of the final clarifiers functioning in the two different ways : parallel and series. There were mainly three stage for the operating period. First stage(Run-1 ; was the bulking which is induce, in particular period and the settleability in each reactor was compared at second stage(Run-2) when the sludge bulking was produced. Finally, P-1 and S-1 which is experimented in Run-2 were switched at third stage(Run-3). When microorganisms, which is cause the bulking, grew massively, sludge settleability of S-1 is superior to that P-1. This outcome stemmed from the fact that only by microorganisms, which have a good settleability were returned to the clarifiers of S-1 reactor at the first stage. In addition, although microorganisms grew massively, as well as a good sludge settleability was kept at the second stage because microorganisms, which are the cause of bulking were wasted.

Activated sludge, Bulking, Clarifiers, SVI, Settleability

정승현 Jeong Seung Hyeon , 신현무 Sin Hyeon Mu , 정병곤 Jeong Byeong Gon

DOI: Vol.19(No.6) 623-633, 2003

In order to investigate optimum process of leachate treatment depending on the landfill site age, anaerobic decomposition rate of organic matter and the change of ratio of humic and fulvic substances, distribution of organic matter after and before anaerobic degradation were studied. As the age of landfill site increases, it was observed that biodegradable organics were getting lower and the removal rate of dissolved organic carbon (DOC) under the anaerobic condition was decreased. It was found that over 50 % of the raw leachate was composed of high molecular weight organics (above M W. 10 K NMWL) and most of those were consisted of fulvic and humic acids. The older the landfill site is, the higher molecular weight of organic composition is. In the raw leachate. the fraction of fulvic was twice as much as that of humic acid. The removal efficiencies of fulvic and humic acids by anaerobic treatment were approximately 80 % and 20 %, respectively and which indicated that if humic acid were removed effectively, the leachate treatment efficiency could be improved.

Leachate, Landfill, Dissolved Organic Carbon, Humic Acids, Fulvic Acids

성기준 Seong Gi Jun , 장윤영 Jang Yun Yeong

DOI: Vol.19(No.6) 635-641, 2003

The fate and transport of trinitrotoluene (TNT) and its metabolites, amino-dinitrotoluene (ADNT) that can be produced by sequential reactions in phytoremediation were investigated using a two-region phytoremediation model. The data acquired from the experiments conducted for 50 days at Indian mallow planted soil whose top 20 ㎝ of 1 m PVC column was packed with TNT contaminated soil at concentration of 126 ㎎/㎏, were used for model applications. Although the results showed that increase of microbial activity in the planted soil could enhanced degradation of TNT and ADNT, the decrease of mass transfer rate between soil water and solid phases was also observed. Therefore, bioavailability in soil was believed to be an important factor affecting the overall fate of TNT and its metabolites. The enhanced degradation due to increased microbial activity, decreased mass transfer rate due to the root exudates, and contaminant retardation due to root water uptake suggested that phytoremediation could play an important role for reducing TNT and its metabolites leaching to the ground water and/or nearby water system.

Phytoremediation, Trinitrotoluene, Model Application, Sequential Degradation, Fate and Transport, 식물상 복원공법, 모형 적용, 연속적 분해반응, 거동 특성

차기철 Cha Gi Cheol , 정태영 Jeong Tae Yeong , 정형근 Jeong Hyeong Geun

DOI: Vol.19(No.6) 643-654, 2003

Characteristics for hydrogen and VFA production (volatile fatty acid) from waste activated sludge was investigated using two stage reactor (acid formation reactor; first stage, photosynthetic reactor; second stage). The acid reactor used Submerged and external separation membrane. The photosynthetic reactor connected with the acid reactor. The COD removal rate in acid formation reactor with submerged and external separation membrane showed about 55% and 75%, respectively. The total VFA produced more in acid reactor with external separation membrane than in acid reactor with submerged separation membrane. The influent COD removal rate per total VFA production rate showed about 11% and 18%, respectively. Hydrogen gas production was not showed in acid reactor but showed in photosynthetic reactor. The hydrogen production per T-VFA in photosynthetic reactor connected with submerged and external separation membrane acid reactor showed about 50.1 ㎖ H₂/g T-VFA and 160.5 ㎖ H₂/g T-VFA, respectively. The Y value in steady state condition of photosynthetic reactor connected with submerged and external separation membrane acid reactor showed about 0.0028 ㎎-biomass ㎎-substrate- and 0.0004㎎-biomass . ㎎-substrate-` , respectively.

Hydrogen Production, Waste Activated Sludge, Acid Formation Reactor, Photosynthetic Reactor, Membrane Separation, 수소생성, 하수슬러지, 산생성과 광합성 반응조, 분리막

김동건 Kim Dong Geon , 박대원 Park Dae Won , 장원석 Jang Won Seog

DOI: Vol.19(No.6) 655-661, 2003

A novel coagulation technology using the atomized molten slag with ferrous sulfate has been developed to treat a turbid and colored water or wastewater. The atomized molten slag is produced by atomizing the molten slag from steel making process. The atomized molten slag has magnetic iron oxide in its constituent molecules so that it is magnetized. In this study, this new coagulation technology was compared with metal hydroxide flocs such as FeCl₃ and PAC in treating textile wastewater. The settling velocity of sludge formed with the atomized molten slag is almost 10 times greater than that of sludge formed with FeCl₃ or PAC. The coagulation using the atomized molten slag showed higher removal rate of color, suspended solid, TOC. COD, TKN and T-P. Weighted Coagulation Additives(WCA) such as molten slag, Ca(OH)₂, and bentonite were added to the coagulation basin, while the process of coagulation and flocculation were monitored by PDA (Photometric Dispersion Analyzer). The zeta potential of sludge and specific resistance were measured. In the result, molten slug was proved to be the promising material for efficient coagulation, because it led to bigger floc and faster sedimentation than other WCA.

Wastewater, Atomized Molten Slag, PDA, Photometric Dispersion Analyzer, Coagulation, Flocculation, Zeta Potential, WCA, Weighted coagulation Additives, 폐수, 분사된 제강슬래그, 응집, 응결, 표면전위, 가중응집제

이현동 Lee Hyeon Dong , 배철호 Bae Cheol Ho , 홍성호 Hong Seong Ho , 한영근 Han Yeong Geun , 권택중 Kwon Taeg Jung

DOI: Vol.19(No.6) 663-671, 2003

Lining materials of ceramic mortar lining technique, CMP-1800 and DR-7800, were assessed on physical and chemical properties in the study. Compared with conventional cement mortar lining materials, the physical and chemical properties of ceramic mortar lining was increased. The improvement of the physical and chemical properties on ceramic mortar lining was thought to be the effect of the binding and compaction of its configuration by SBR(Styrene-butadiene rubber) included DR-1800 and ceramic mortar powder(CMP-1800) as presented in SEM pictures. Especially, compression strength of ceramic mortar lining was 1.4 times higher than cement mortar lining. And after curing time of 16 hours, compression strength(l8.5 N/㎟) of ceramic mortar lining was reached to the same compression strength(l7.4 N/㎟) after 28 day curing of cement mortar lining. Therefore it was thought that drinking water service of ceramic mortar lining was possible after 16 hours curing. In addition to, Calcium loss of ceramic mortar lining was lower than conventional ductile cast iron pipe(DCIP). This results showed the resistance of ceramic mortar lining pipe was stronger than DClP for the degradation and deterioration on aggressive water quality. And heavy metals such as Pb and Cr was not detected in all tested pipes including ceramic mortar lining pipe.

Rehabilitation, Ceramic mortar lining, SBR, Styrene-butadiene rubber, Ceramic mortar powder, CMP

박혜경 Park Hye Gyeong , 정원화 Jeong Won Hwa

DOI: Vol.19(No.6) 673-684, 2003

Long-term variations of algal growth at dam site of lake Paldang from 1996 to 2002 have been studied. Yearly mean value and standard deviation of chlorophyll a concentration have increased except 2002 representing the increase of algal growth potential in lake Paldang. Relative abundance of algal groups and seasonal succession pattern did not show same pattern every year and have fluctuated year by year. Diatoms have occurred throughout the year but showed large amount of biomass in winter and early spring. Cyanobacteria have dominated in summer. Relative abundance of other algal group increased in 2001 and 2002, causing higher chlorophyll a concentration during these years. Comparing with monthly mean value of cyanobacterial biomass and efflux from Paldang dam in summer season, the amount and time of mass efflux from Paldang dam, that is, the period of heavy rain appeared to determine the amount of cyanobacterial biomass of the year in artificial dam lake, lake Paldang. Based on the correlation analysis between chlorophyll a concentration and environmental factors, significantly high positive relationships were found in COD and BOD, and no significant relationships were found in nutrients, suggesting that primary productivity of phytoplankton occupies an important position within total organic matter loads in lake Paldang.

Lake Paldang, Phytoplankton, Long-term variation

김영철 Kim Yeong Cheol , 박재홍 Park Jae Hong , 이동률 Lee Dong Lyul

DOI: Vol.19(No.6) 685-697, 2003

The results of investigation for the long-term changes in water quality of the small streams in agricultural reservoir indicate that nitrogen is determined mainly by the agricultural activities while phosphorus and suspended solids are affected by the soil particles moved by irrigation return flow or/and rainfall discharge. However, nitrogen is related with factors of the flow more than suspended solids concentration but rather tends to decrease with the abundant stream flows caused by rainfalls. As the use of land for rice paddy in the watershed increases, more nitrogen loss was also observed. It was found that about 50% of the total phosphorus and nitrogen exists in dissolved form. There is a possibility to develop tools which can be used to predict dissolved forms of the nutrient by TDS values easily and reliably measured by electrical conductivity. Coefficient of determination(R²) between TDS and phosphorus concentration was higher than the nitrogen concentration. Especially, the more rice paddy area, the higher correlation coefficient. In addition, TDS was inversely correlated with flow(or depth) due to the dilution effect of rainfall water, so that multiple rating curves from flow depth to approximate TDS and then nutrients could be useful. Most of the water quality parameters were found to have a log-normal probability distribution.

Small agricultural streams, Nutrients, Irrigation, Return flow, Rainfall

이희자 Lee Hui Ja , 김광수 Kim Gwang Su

DOI: Vol.19(No.6) 699-706, 2003

In this study, organic material removal and the settleability of granular sludge on operating conditions were investigated. The removal rate of SS and COD reached to 95% and 87% respectively at recycle rate of 100, HRT of 2.1hr and organic loading rate of 0.9 ㎏/㎥·day. The COD removal rate of granular sludge linearly increased with the increase of the influent COD concentration. As compared to activated sludge flocs, aerobic granulation significantly improves the settleability of sludge. so the SVI decreased from initial 220㎎/L to 59㎎/L. Low pH and high DO concentration lead to the formation of stable aerobic granules in aerobic upflow reactor. During the early stages of granule formation, a high exopolymer production was observed, which would promote the initial cell flocs. It was concluded that the advantages of aerobic granules can be seen as good settling ability, high retainable biomass concentration and ability to withstand high organic loading rate.

Granular Sludge, Settleability, Aerobic Granules, Upflow Reactor

유순주 Yu Sun Ju , 하성룡 Ha Seong Lyong , 황종연 Hwang Jong Yeon , 김창수 Kim Chang Su

DOI: Vol.19(No.6) 707-713, 2003

This study aims to identify the relationship between characteristics of aqueous organic matter and chlorination by-products formation potential according to spatial and temporal effect in Daecheong reservoir as well as Guem river. To evaluate distribution and characteristics of dissolved organics as precursor of disinfection by-products, specific ultraviolet absorbance (SUVA) and apparent molecular weight cutoff were investigated at raw water and treated unit water in water treatment facilities. Disinfection by-products formation potentials, trihalomethanes (THMs) and haloacetic acid (dichloroacetic acid, trichloroacetic acid), were measured at 7days incubation time. The findings are as follows. SUVA, which represents the portion of humic substance was found to be ranged with 1.41-5.55(average 2.60) and 1.52-4.77(average 2.45) in reservoir and river, respectively. The molecular weight less than 1,000 which includes the molecular weight of hydrophilic organic matter was occupied with 66.4% and 64.1% in river and reservoir, respectively. While the molecular weight of 100,000-1,000 including humic substances was ranged with 14.7% and 17.6% in reservoir and river, respectively. Trihalomethane formation potential (THMFP) showed good correlation with ultraviolet absorbance (UV245) and SUVA in reservoir. In river, however, it showed good relationship between DOC and UV254. It was understood that THMFP was strongly related to the contents of hydrophobic organic matter among natural organic matter (NOM). On the other hand, haloacetic acid formation potential(HAAFP) showed quite good consistency with organic matter of 1,000Mw as well as low molecular weight among humic substances.

NOM, SUVA, Apparent molecular weight cutoff, DBPs, THMFP, HAAFP

정용준 Jeong Yong Jun , 목증상추 Mog Jeung Sang Chu , 민경석 Min Gyeong Seog

DOI: Vol.19(No.6) 715-721, 2003

5 kinds of pesticides removal with 4 flat sheet NF membranes was examined in a stirred type batch cell experiment and rejection properties were reviewed in the point of solute characteristics. Rejection of Aldicarb, Diazinon, MEP, NAC and Malathion, which are mainly included in the drinking water quality standard, with NTR-729HF having nominal NaCl rejection of 92% was revealed over 91.5%. Molecular weight and width regarded as solute characteristics were applied to explain the rejection property and showed the relevant trend in NTR-729HF and NTR-7250 having relatively higher nominal NaCl rejection. log P as hydrophobicity also played a role on the factor of pesticide rejection. Concerning to pesticide rejection with NF membranes, these three factors should be reviewed together, not independently. In considering the efficiency of pesticides rejection efficiency with different NF membrane, the appropriate NF membrane should be selected for real system.

Pesticide, rejection property, batch cell, molecular width, hydrophobicity

이대인 Lee Dae In , 조현서 Jo Hyeon Seo , 이문옥 Lee Mun Og

DOI: Vol.19(No.6) 723-730, 2003

A study on the pollution level and spatial characteristics of water quality and sediment environment of the western Chinhae Bay in summer that is famous for shellfish culture grounds was carried out August 1999. Dissolved oxygen was hypersaturated at surface layer resulting from photosynthesis by phytoplankton, but oxygen deficiency or anoxic water mass by bulk decomposion of organic matters appeared at bottom layer. Chemical oxygen demand exceeded seawater quality criteria Ⅱ, and dissolved form was dominated in organic carbon, Inorganic nitrogen and phosphorus in surface layer were relatively low compared to the bottom layer due to uptake of phytoplankton. By Redfield ratio, the limiting factor for algal growth was nitrogen. The range of Chl. a was 4.83-24.94㎎/㎡. The Chl. a in inner bay and the west part of Kajodo represented very high valures that exceeded possibility concentration of red tide outbreak. H₂S and COD values in sediment were very hi9호. This means that sediment was severely poluted by organic matters. In summary, the organic matters caused by aquatic organisms in water column exist in abundance, which increase nutrients by remineralization of sinking organics. Dissolved oxygen is rapidly consumed, and ultimately sediment environment is getting worse. This situation is more serious in the west part of Kajodo. For water quality management, effective countermeasures such as appropriate aquaculture density by estimation of carrying capacity and reduction of pollutants from polluted sediment are necessary.

Water Quality, Sediment, The Western Chinhae Bay, Organic Matter, Water Quality Management

최용욱 Choe Yong Ug

DOI: Vol.19(No.6) 731-740, 2003

The flow injection analysis(FIA) of a ammonia has been studied by fluorogenic derivatization with naphthalene-2,3-dicarboxaldehyde(NDA) in the presence of sulfite ion. The mixing and reaction coil length, sulfite concentration, reaction pH and temperature were optimized for NDA/sulfite derivatization of ammonia by using flow injection analysis. The excitation and emission wavelengths for fluorometric detection were 350 and 497㎚, respectively. The detection limit was 20㎍/L, which was obtained by twice of peak-to-peak noise level, and the repeatability was better than 1% at the 10-300ng level. Application of the use of the method was given for the analysis of ammonia nitrogen in Jeonju stream passing through Jeonju city.

flow injection analysis, FIA, ammonia nitrogen, naphthalene-2,3-dicarboxaldehyde, NDA

서정범 Seo Jeong Beom , 황창민 Hwang Chang Min

DOI: Vol.19(No.6) 741-749, 2003

This study was aimed at finding out the influence of salinity on the treatability and settleability in activated sludge process. For this, according to salinity, the distinctive feature of organic concentration such as TOC and BOD, sludge volume index(SVI) and observed yield coefficient were examined. The result of batch reactor test showed that the influence of salinity at the high concentration of MLSS was low on the removal efficiency of TOC. On the other hand, the result of continuous flow stirred tank reactor(CSTR) test showed that the TBOD removal efficient was higher the F/M ratio 0.4㎏BOD/㎏MLSS·day than the F/M ratio 0.2㎏BOD/㎏MLSS·day. The influence of salinity on the SVI was found higher the F/M ratio 0.4㎏BOD/㎏MLSS ·day than the F/M ratio 0.2㎏BOD/㎏MLSS·day to 10,000㎎/L of salinity. The test also showed that filamentous microorganism rapidly increased when salinity was l5,000㎎/L. SVI was stabilized in the reactor with F/M ratio 0.4㎏BOD/㎏MLSS·day causing activated sludge more viscous. On the other hand, when the F/M ratio kept at about 0.2㎏BOD/㎏MLSS·day, SVI increased rapidly due to a sludge bulking.

Activated Sludge, Salt concentration, Biodegradability, Settleability

학회자료

DOI: Vol.19(No.6) 751-751, 2003