• Korean Membrane Journal
• /
• 제11권1호
• /
• pp.21-28
• /
• 2009

We investigated the effect of organic materials on membrane fouling in advanced drinking water treatment by a hybrid module packed with granular activated carbon (GAC) outside multi-channel ceramic microfiltration membrane. Synthetic water was prepared with humic acid and kaolin to simulate natural water resouces consisting of natural organic matter and inorganic particles. Kaolin concentration was fixed at 30 mg/L and humic acid was changed as 2~10 mg/L to inspect the effect of organic matters. Periodic back-flushing using permeate water was performed for 10 sec per filtration of 10 min. As a result, both resistance of membrane fouling (Rf) and permeate flux (J) were influenced highly by concentration of humic acid. It proved that NOM like humic acid could be an important factor on membrane fouling in drinking water treatment. Turbidity and UV254 absorbance were removed up to above 97.4% and 59.2% respectively.

• Applied Biological Chemistry
• /
• 제41권5호
• /
• pp.384-389
• /
• 1998

제초제 propanil(3',4'-dichloropropionanilide)과 그 분해산물인 DCA(3,4-dichloroaniline)가 laccase, horseradish peroxidase(HRP) 및 birnessite에 의하여 중개된 oxidative coupling에 의하여 토양 유기물의 구성성분에 병합될 수 있는지를 알기 위하여 토양 유기물의 monomer들과의 반응성을 조사하였다. Propanil 또는 DCA가 단독으로 존재하는 반응조건에서는 산화환원촉매들에 의하여 이들의 전환이 거의 이루어지지 않았거나 상당히 낮은 수준이었다. 그러나 humic monomer들이 있을 때 laccase와 HRP의 경우 propanil은 syringic acid와 DCA는 catechol과 높은 전환율을 나타내었으며, birnessite의 경우 DCA는 protocatechuic acid와 높은 전환율을 나타내었다. DCA의 전환율은 laccase의 경우 catechol과 pH 8.0에서 24시간 동안 반응시킬 때, HRP의 경우 catechol과 pH 3.0에서 2시간 동안 반응시킬 때 가장 높았고, birnessite의 경우 protocatechuic acid와 pH 5.0에서 2시간 동안 반응시킬 때 가장 높았다. Humic monomer의 농도를 증가시킬수록 DCA의 전환율도 증가하였다. Humic monomer 대신 dissolved organic carbon(DOC)이 있을 때 laccase는 DCA를 거의 전환시키지 못 하였으나, HRP는 DCA의 전환율을 크게 증가시켰고, birnessite는 큰 영향을 미치지 않았다. DCA의 전환율은 laccase 단독으로 있을 때 보다 birnessite와 공존할 경우 약 5배 가량 증가된 반면, HRP와 birnessite가 공존할 경우에는 증가되지 않았다.

• Journal of the Korean Wood Science and Technology
• /
• 제29권3호
• /
• pp.104-111
• /
• 2001

There are some evidence that active enzymatic proteins, e.g. fungal laccase, exist in the naturally occured soil humus. This study was performed to investigate the covalent binding of fungal laccase to the humic acid-iron complex, and to measure laccase activity of immobilized ones. Seven methods were adopted to form the covalent binding of fungal laccase with soil humic acids complexed with iron. Using these seven methods it was possible to change the dimension of spacer arm between laccase and support, and also to regulate the mode of covalent binding of this enzyme. The spacer arm was regulated from 2C to 11C. There was not observed any straight relationship between the spacer arm longitude and the laccase activity after immobilization, but the binding mode more effective than the former. Three out of the seven methods gave the high activity of immobilized laccase, and which active products of laccase immobilization was stable up to 10 days after the process. It is indicated that natural soil condition might be prevented the laccase activation by the toxic influence of some phenolic humic compounds. It was shown, for the first time, the possibilities to obtain the high activity of fungal laccase by binding to humic acids, and especially in complex with iron.

• 한국지반환경공학회 논문집
• /
• 제7권4호
• /
• pp.5-13
• /
• 2006

본 연구는 지표수에서 휴믹산을 포함한 중금속을 제거하기 위해 $UV/TiO_2/H_2O_2$ 공정을 적용하여 각 실험인자에 대한 처리효율을 실험적으로 검토하였다. 휴믹산과 중금속을 제거하는데 있어 $UV/TiO_2/H_2O_2$ 공정은 $UV/TiO_2$ 공정보다 훨씬 더 높은 제거효율을 보여 주었다. $TiO_2$ 주입량과 UV 세기를 증가시킴에 따라 휴믹산과 중금속 제거율은 증가했다. 그러나 0.3 g/L 이상의 $TiO_2$ 주입량에서는 제거율이 감소했다. 산화제로 사용된 과산화수소의 첨가는 휴믹산과 중금속 제거에 있어 긍정적인 효과를 보여주었으며 특히 50 mg/L의 과산화수소 농도에서 가장 좋은 제거효율을 나타내었다.

• 한국토양환경학회지
• /
• 제4권1호
• /
• pp.13-23
• /
• 1999

본 연구에서는 기아상태에 있는 토양 미생물, Arthrobacter crystallopoietes cell의 2-hydroxypyridine대사능력의 변화 와 이 미생물의 대사능력에 대한 부식산의 영향에 대해 다루어졌다. 기질 2-HP에 대한 대수기 세포(exponential phase cell)는 적응기 세포(lag phase cell)와 비교할 때 기아상태에 있어서도 더 높은 2-HP대사능력을 보여 기아상태 3일 후 대수기 세포에서 2-HP반감기는 14시간으로 나타난 반면 적응기 세포의 경우 46.5시간으로 나타났다. 부식산은 기아상태에서 이 미생물 세포의 유도효소, 2-HP monooxygenase의 안정성을 높여주어 기아시간 2일 후 표준조건에서 기아상태에 있던 미생물의 효소활성이 처음의 1.5%로 남아 있는 반면 0.2% 부식산 용액에서 기아상태로 있던 미생물의 효소활성은 12%까지 남아 있었다. 기아시간 14일 후 까지도 부식산 용액 속에서 기아상태로 있던 이 미생물 세포의 2-HP대사능력은 표준 조건의 것에 비해 월등히 높아 2-HP반감기를 비교해 보면 표준 조건의 경우 43시간인 반면 부식산의 경우 1.25시간으로 나타났다.

• 대한화학회지
• /
• 제40권1호
• /
• pp.50-58
• /
• 1996

일정한 pH에서 Co(II), Ni(II), Sr(II), Cu(II), Fe(III) 및 U(VI) 등의 금속이온농도가 증가할 수록 흄산의 침적율이 증가하였으며, Sr

• 상하수도학회지
• /
• 제14권1호
• /
• pp.54-61
• /
• 2000

Recently, our circumstances are threatened by an accident that leakage of under ground storage tank and illegal dumping of synthetic organic compounds at chemical plants and many treatment methods, Activated carbon adsorption, Ozonization, Membrane filtration and Photocatalystic oxidation, are developed to remove such a synthetic organic compounds. And it has reported that Activated carbon adsorption have a great removal efficiency to nondegradable matters and organic compounds which have a high molecular weight. Comparing with other adsorbents, Activated carbon adsorption have a worse efficiency when ad desorption speed is low. Thus improved type of adsorbents was invented and one of those is Activated Carbon Filter. The purpose of this study was getting information about adsorption characteristic phenol which can be applied Activated Carbon Fiber and Granular Activated Carbon. In detail, With comparing removal characteristics of phenol in the presence Humic Acid using Activated Carbon Fiber(ACF) and Granular Activated. Carbon(GAC), it is to certify an effective application of Activated Carbon Fiber. At the range of this study, Batch test, Isotherm adsorption test and Factorial analysis, following conclusion were obtained from the results of this study. Batch test was carried to know time of adsorption equilibrium. In this study about time of adsorption equilibrium by ACF was faster than GAC's, for developed micropore of ACF. From the result of phenol adsorption test, High removal rate of adsorption is shown at pH 5. The result of lsotherm adsorption test, it has represented that the Freundlich's isotherm is most suitable one in others, that a ACF's adsorption capacity is more excellent than GAC's. Adsorption of phenol exiting humic acid is decreased getting raised humic acid concentration. Since ACF's micropore is developed at this time, an effect of high molecular humic acid is lower. Factorial analysis was carried to know about Main effect which was injection dosage of adsorbent in the range of this study.

• 멤브레인
• /
• 제22권6호
• /
• pp.415-423
• /
• 2012

탄소섬유 한외여과막 및 광촉매 혼성 수처리를 위해 관형 여과막 외부와 원통형 막 모듈 내부 사이 공간에 광촉매를 충전하였다. 광촉매는 PP (polypropylene) 구에 이산화티타늄 분말을 플라즈마 화학증착 공정으로 코팅한 것이다. 휴믹산과 카올린 모사용액을 대상으로 막오염을 최소화하기 위해 10분 주기로 10초 동안 물 역세척을 시행하였다. 기존 결과와 동일하게 휴믹산을 10 mg/L부터 2 mg/L로 변화시킴에 따라, 막오염에 의한 저항 ($R_f$)이 감소하여 2 mg/L에서 최대 총여과부피 ($V_T$)를 얻었다. 탁도와 휴믹산의 처리효율은 각각 97.1%와 74.2% 이상으로 휴믹산 농도의 영향을 받지 않았다. 그러나 기존 결과에서는 휴믹산의 농도가 증가할수록 휴믹산의 처리효율이 다소 증가하는 경향을 나타냈다.

• 한국근적외분광분석학회:학술대회논문집
• /
• 한국근적외분광분석학회 2001년도 NIR-2001
• /
• pp.1623-1623
• /
• 2001

Composting is a biological method used to transform the organic waste into stable, humified organic amendments. Humification is indicated as the key factor in improving the quality of compost, because of the importance of humic substances to soil ecology, fertility and structure, and their beneficial effects on plant growth The compost constituents vary widely, however, the degree of maturity is very important factor in compost quality. So this experiment carried out to determine the rapid estimation of the quality in cattle, pig, chicken and waste composts using near infrared reflectance spectroscopy(NIRS). Near infrared reflectance spectra of composts was obtained by Infra Alyzer 500 scanning spectrophotometer at 2-nm intervals from 1100 to 2500nm. Multiple linear regression(MLR) or partial least square regression (PLSR) was used to evaluate a NIRS method for the rapid and nondestructive determination of humic acid contents in composts. The results summarized that NIR spectroscopy can be used as a routine testing method to determine quantitatively the humic acid content in the compost samples ondestructively. Especially, we supposed that absorbance around 2300nm is related to humic acid as a factor of compost maturity. However the NIR absorption approach is empirical, it actually requires many combinations of samples and data manipulations to obtain optimal prediction.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제16권6호
• /
• pp.122-132
• /
• 2011

Mercury accumulates in biota mainly as methylmercury. In nature, methylmercury shows high affinity to organic matter and $CH_3Hg^+$-organic matter complexation affects the mobility and bioavailabiity of methylmercury. In this study, we examined the methylmercury binding sites in an aquatic humic acid as affected by the pH condition using Hg $L_{III}$-edge extended X-ray absorption fine structure (EXAFS). We evaluated methylmercury binding humic ligands using methylmercury-thiol, methylmerury-carboxyl, and methylmercury-amine complexation models. When $CH_3Hg^+$-to-humic reduced sulfur ratio is 0.3, we found that most of $CH_3Hg^+$ binds to thiol ligands at pH 5 and 7. At pH 7, however, some carboxyl or amine ligand contribution is observed, unlike at pH 5 where $CH_3Hg^+$ almost exclusively binds to thiol ligands. The carboxyl or amine ligand contribution may indicate that some types of thiol ligands in the natural organic matter have relatively low complexation constants or acid dissociation constants compared to those of some carboxyl or amine ligands. Analysis results indicate that ~0.2 fraction of methylmercury binds to amine or carboxyl ligands and ~0.8 to thiol ligands at pH 7.