• 상하수도학회지
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• 제31권6호
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• pp.539-549
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• 2017

In water treatment process using microfiltration membranes, manganese is a substance that causes inorganic membrane fouling. As a result of analysis on the operation data taken from I WTP(Water Treatment Plant), it was confirmed that the increase of TMP was very severe during the period of manganese inflow. The membrane fouling fastened the increase of TMP and shortened the service time of filtration or the cleaning cycle. The TMP of the membrane increased to the maximum of $2.13kgf/cm^2$, but it was recovered to the initial level ($0.17kgf/cm^2$) by the 1st acid cleaning step. It was obvious that the main membrane fouling contaminants are due to inorganic substances. As a result of the analysis on the chemical waste, the concentrations of aluminum(146-164 mg/L) and manganese(110-126 mg/L) were very high. It is considered that aluminum was due to the residual unreacted during coagulation step as a pretreatment process. And manganese is thought to be due to the adsorption on the membrane surface as an adsorbate in feed water component during filtration step. For the efficient maintenance of the membrane filtration facilities, optimization of chemical concentration and CIP conditions is very important when finding the abnormal level of influent including foulants such as manganese.

• 상하수도학회지
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• 제26권5호
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• pp.659-668
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• 2012

In Korea, almost every water treatment plant suffers from seasonal problem of algae and turbidity which result from eutrophication and heavy rainfall. To relieve this problem, experimental investigation was performed to study the applicability of a floating-media and sand filter to preliminary water treatment in terms of algae and turbidity removal. Experimental results using pure-cultured algae influent showed that the shape of algae species as well as filtration velocity affects the removal efficiency. From the experiments using natural river water, it was concluded that algae removal is more sensitive to floating-media depth but turbidity more sensitive to sand depth. As the filtration velocity increased, the removal of turbidity decreased but that of algae was not affected. The floating-media and sand filter removed more than 30 % of TP, TN, turbidity, Chl-a and CODcr, and less than 20 % of DOC and $UV_{254}$.

• 한국물환경학회지
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• 제26권3호
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• pp.399-405
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• 2010

In order to quantify removal efficiency of Cryptosporidium in water treatment process and evaluate factors influencing removal efficiency of Cryptosporidium in each step of water treatment process, large pilot plant system ($100m^3/day$) and Cryptracer, surrogate of Cryptosporidium, were used. The removal efficiency of Cryptracer was around 0.8~1 log in coagulation process and 3.3~4.8 log in sand filtration process under ordinary environmental conditions. Factors influenced removal efficiency of Cryptracer were high fluctuate turbidity and water temperature. High fluctuate turbidity made difficult to adjust optimum PAC concentration, caused to drop removal efficiency of coagulation process (0.5 log). Inadequate coagulation process influenced to sand filtration process (2.1 log), caused to decline of removal efficiency in the whole process (2.6 log). Low temperature below $2^{\circ}C$ also influenced coagulation process (0.6 log). Therefore, It is shown that careful attention in the control of Cryptosporidium is needed in flood period, when high fluctuate turbidity would be, and winter period of low temperature.

• 한국환경보건학회지
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• 제27권4호
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• pp.15-24
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• 2001

The objective of this study it to evaluate the microbial safety in rapid sand filters adapted in most drinking water treatment plants. The potential pathogens to cause water quality problems Are presumed to be Giardia and Gryptosporidium. They look like particles in view of their size. It has been reported that if the number of particles (larger than 2 ${\mu}{\textrm}{m}$ in water) is less than 100 per mL and its turbidity is below 0.1 NTU, it is considered as a safe water in terms of pathogens. In order to achieve such a good water quality. filter-aids (chemicals) were added to the inlet-channel of filter and their effectiveness was evaluated on the basis of water quality factors such as turbidity and particle counting. This study was conducted in she three steps of experiment: jar test. pilot plant test and real water treatment plant test (P plant in seoul). The experiment reult of the P water treatment showed that cationic polyamine was the most effective in the removal of particles and turbidity at the does of 0.25 mg/L. The turbidity without filer-aids showed in the range of 0.12 ~0.17 NTU during filtration and 0.14 NTU on the average. However. with addition of polyamine, the turbidity represented below(or less than) 0.1 NTU after 20 min in the start of filtration and kept 0.08 NTU on the average. On the other hand, as for number of particles, while no filter-aids led to the range of 111 ~270 per mL and 190 on the average, addition of polydmine led to 113 per mL on talc average, and kept below100 per mL after 20 min in the start of filtration.

• 상하수도학회지
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• 제22권6호
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• pp.633-640
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• 2008

In this research, the $3.6m^3/day$ scale pilot plant consisting preozonation, coagulation, flocculation, and ceramic membrane processes was operated for long term period to evaluate the validity of ceramic membrane filtration process for treating lake water containing high concentration manganese. The higher concentration of dissolved manganese($Mn^{2+}$) was effectively oxidized to the bigger insoluble colloidal manganese ($MnO^2$) by 1~2 mg/L ozone. The colloidal manganese reacted with coagulant (poly aluminium chloride, PAC) and then formed the big floc. Ceramic membrane rejected effectively manganese floc during membrane filtration. Dissolved organic carbon(DOC) removal was dependent upon $Mn^{2+}$ concentration. While average $Mn^{2+}$ concentration was 0.43 and 0.85 mg/L in raw water, DOC removal rate in preozonation was 26.5 and 13.5%, respectively. The decrease rate of membrane permeability was faster without preozonation than with preozonation while membrane fouling decreased with NOM oxidation by ozone. In conclusion, raw water containing high concentration of manganese can be effectively treated in preozonation-coagulation-ceramic membrane filtration system.

• Journal of Microbiology and Biotechnology
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• 제19권1호
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• pp.99-107
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• 2009

Strain PUPC1 produces an antifungal protease as well as plant growth promoting enzymes such as 1-aminocyclopropane-1-carboxylate (ACC) deaminase and phosphatase. Morphological, cultural, and physiological characteristics as well as 16S rRNA gene-sequence-based phylogenetic analysis confirmed the taxonomic affiliation of PUPC1 as Chryseobacterium aquaticum. The optimum growth of PUPC1 was observed at pH 6.0 and $30^{\circ}C$, and maximum protease production was observed in medium B amended with 1% tryptone, 0.5% sucrose, and 0.005% $MnCl_2$. The protease was purified by ammonium sulfate precipitation, Sephadex G-75 gel filtration chromatography, and electroelution from preparative SDS-PAGE. The protease had a molecular mass of 18.5 kDa. The optimum pH and temperature stability of the protease were pH 5.0-10.0 and temperature $40-70^{\circ}C$. Chryseobacterium aquaticum PUPC1 and its protease showed a broad-spectrum antifungal activity against phytopathogenic fungi. Strain PUPC1 also exhibited plant growth promoting traits. The objective of the present investigation was to isolate a strain for agricultural application for plant growth promotion and biocontrol of fungal diseases.

• 대한환경공학회지
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• 제22권5호
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• pp.895-905
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• 2000

본 연구는 여재가 모래와 무연탄인 복층 중력식 급속여과법으로 BNR(biological nutrient removal) 공정 유출수를 처리할 때 여과율의 변화에 따른 오염물질 제거효율 및 여층 깊이별 처리수질을 파악하기 위하여 수행되었다. Pilot scale의 4-stage BNR 공정 유출수를 200, 300 및 400 m/day의 여과율로 급속여과시킨 결과, 처리수는 2.6 NTU 이하의 탁도를 나타내어 우리나라의 중수도 제한수질인 5.0 NTU를 만족하였다. 여과율이 200, 300 및 400 m/day로 증가함에 따라 SS 제거효율은 각각 80.6, 75.4 및 68.9%로 감소하는 경향을 보였지만, 여과수는 모든 여과율에서 유입수의 수질변화에 큰 영향을 받지 않고 평균 1.3 mg/L의 SS 농도를 보였다. 생물학적 작용에 의하여 영양염류도 제거되었는데, 200, 300 및 400 m/day의 여과율에서 질산화효율이 각각 17.4, 18.8 및 14.3%, 그리고 탈질효율이 각각 32.3, 27.7 및 21.4%로, 질산화와 탈질이 동시에 일어났다. 여과주기의 후반기에는 여층 내의 DO가 결핍됨에 따라 인의 재용출이 일어남으로써 유출수의 T-P 농도가 유입수에 비하여 6.1~21.4% 증가하였다.

• Journal of Plant Biology
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• 제33권4호
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• pp.293-301
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• 1990

We have purified and characterized a deoxyribonuclease from zygotes of the eukaryotic green alga, Chlamydomonas reinhardtii and investigated effects of the polyamines, putrescine, spermidine and spermine on the purifed endonuclease-catalyzed cleavage of plasmid DNA. The enzyme has a molecular weight of about 37 kDa as measured by gel filtration and SDS-polyacrylamide gel electrophoresis. There is no requirement for a divalent cation. The activity is sensitive to ionic strength, as NaCl and KCl result in inhibition. The cleavage of plasmid DNA by the purified endonuclease was effectively inhibited by polyamines. The enzyme activity was inhibited more effectively by spermine than by spermidine. The inhibition by putrescine was lower than the other two polyamines.

• Journal of Plant Biology
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• 제33권4호
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• pp.325-332
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• 1990

Light membrane vesicles were isolated from the zucchini hypocotyl by floatation on ficoll density gradients and the proteins were solubilized with Triton X100. Three ATP-hydrolyzing enzymes were partially purified by ion-exchange and gel filtration chromatography and isoelectric focusing. There are plasma membrane-type ATPase whose activity was inhibited by vanadate but not by nitrate, tonoplast-type ATPase which was sensitive to nitrate but insensitive to vanadate and one having a phosphatase activity with a pI value different from that of an acid phosphatase. A fraction was obtained after DEAE-ion-exchange chromatography crossreacting with polyclonal antibodies against Ca2+ -ATPase from human erythrocytes.

• Journal of Preventive Medicine and Public Health
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• 제5권1호
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• pp.43-48
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• 1972

5 bed sand filter, applying biological oxidation, was designed and studied on the treatment of water works. Never using any coagulant agent (drugs), which may cause water pollution in pre-treatment of head water, the auther attempt a high rate filtration by the microorganism (nitrofication bacteria) end plant which populate in multi layer sand beds. The result are as follows : In order to evaluate the oxygen effect on filtration, oxygen was injected in aeration tank attached to each filter tank while filtration, and $NH_3$ was tested as a representaiive ingredient. It was found out that the aeration method was more effective, with over 33% of $NH_3$ removal capacity, than the anerobic and this 5 bed filter showed double removal capacity of $NH_3$ by comparing with conventional sand bed (2 stage bed). According to the examination of two kind of head water, pre-treated with coagulant agent and activated carton, the filtration capacity was affected by the polluted condition of head water, resulting that lower value of pollution and slower velocity of filtration showed more efficiency of $NH_3$ removal. In this experiment $NH_3$ content tested in treated water had a fairly good correlation with others.