• Environmental Engineering Research
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• 제12권5호
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• pp.224-230
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• 2007

The objectives of this study were to evaluate the change of molecular weight (MW) profiles in natural organic matter (NOM) through various treatment processes (coagulation, granular activated carbon (GAC), and ozonation) using high performance size exclusion chromatography based on ultraviolet absorbance and dissolved organic detection (HPSEC-UVA-DOC). In addition, relationships between MW profiles and disinfection by-production (DBP) formation were evaluated. Each treatment process results in significant different effects on NOM profiles. Coagulation is effective to remove high molecular weight NOM, while GAC is effective to remove low molecular weight NOM. Ozonation removes only a small portion of NOM, while it induces a significant reduction of UV absorbance due to breakdown of the aromatic groups. All treated waters are chlorinated, and chlorination DBPs such as trihalomethanes (THMs) and haloacetic acids (HAAs) are measured under formation potential conditions. Both THM and HAA formation potentials were significantly reduced through the coagulation process. GAC was more effective to reduce THM formation compared to HAA formation reduction, while ozonation showed significant HAA reduction compared to THM reduction.

• 한국환경과학회지
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• 제23권3호
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• pp.379-386
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• 2014

Adsorption and biodegradation performance of tetracycline antibiotic compounds such as ttetracycline (TC), oxytetracycline (OTC), minocycline (MNC), chlortetracycline (CTC), doxycycline (DXC), meclocycline (MCC), demeclocycline (DMC) on granular activated carbon (GAC) and anthracite-biofilter were evaluated in this study. Removal efficiency of seven tetracycline antibiotic compounds showed 54%~97% by GAC adsorption process (EBCT: 5~30 min). The orders of removal efficiency by GAC adsorption were tetracycline, demeclocycline, oxytetracycline, chlortetracycline, doxytetracycline, meclocycline and minocycline. Removal efficiencies of seven tetracycline antibiotic compounds showed 1%~61% by anthracite biofiltration process (EBCT: 5~30 min). The highest biodegradable tetracycline antibiotic compound was minocycline, and the worst biodegradable tetracycline antibiotic compounds were oxytetracycline and demeclocycline.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2002년도 봄 학술발표대회 발표논문집
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• pp.281-288
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• 2002

Crab shell 충진 칼럼을 이용한 수중 중금속의 연속적 제거에 있어서 다른 흡착제 (CER, GAC, Zeolite)와 비교 실험을 통하여 crab shell의 중금속 제거능을 알아보았다. 수중 $Pb^2+/{2+}$ 의 column을 이용한 연속적제거에 있어서 미세침전부분이 외부로 배출됨으로 칼럼 외부에 여과시스템의 도입함으로써 중금속 제거능을 높일 수 있을 것으로 판단된다. 중금속의 연속적 제거에 있어서 CER의 1,000 BVs까지의 전체 제거량은 0.35mmol/g, GAC는 0.17mmo1/g, zeolite는 0.16 mmol/g으로 나타났고 crab shell에 의한 중금속 제거량은 0.61 mmol/g으로 다른 흡착제보다 높은 제거효율을 보였다. 수중 중금속의 연속적 제거에 있어서 여러 흡착제의 제거 순서는 crab shell > CER > GAC > zeolite 로 나타났다. Crab shell의 경우는 파과점이 2,000 BVs에서 나타나므로 일반적인 폐수처리의 화학적 처리 후 잔존하는 저농도의 중금속을 제거를 위해 crab shell 충진 칼럼이 유용 할 것으로 판단된다. Crab shell의 재사용 가능성을 알아보기 위하여 crab shell을 이용한 중금속 제거공정에서 연속적인 중금속제거와 탈착과정을 통하여 보았을 때 1회에서 $Pb^2+/{2+}$제거된 량은 0.71 mmol/g 제거되었고 2회에서는 0.27 mmol/g, 3회에서는 0.02 mmol/g으로 급격하게 crab shell의 제거능이 떨어지는 것을 관찰 할 수 있다. 이는 crab shell이 재사용이 불가능 할 것으로 판단되나 다른 흡착제보다 월등한 제거효율을 보이므로 수중 중금속의 연속적 제거 흡착제 적합할 것으로 판단된다.

• 한국환경과학회지
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• 제24권1호
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• pp.65-71
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• 2015

This study accessed the adsorption characteristics of the 9 trihalomethanes (THMs) on coal-based granular activated carbon (GAC). The breakthrough appeared first for $CHCl_3$ and sequentially for $CHBr_2Cl$, $CHBr_3$, $CHCl_2I$, CHBrClI, $CHBr_2I$, $CHClI_2$, $CHBrI_2$, and $CHI_3$. The maximum adsorption capacity (X/M) for the 9 THMs with apparent breakthrough points ranged from $1,175{\mu}g/g$ (for $CHCl_3$) to $11,087{\mu}g/g$ (for $CHI_3$). Carbon usage rate (CUR) for $CHCl_3$ was 0.149 g/day, 5.5 times higher than for $CHCl_3$ (0.027 g/day).

• 한국수자원학회논문집
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• 제30권3호
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• pp.235-245
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• 1997

대청호 원수를 취수하여 정수하는 대청수도에서 이취미를 제거하고 THM(Trihalomethanes) 발생량을 줄이기 위하여 기존 표준정수공정에 오존과 활성탄여과공정을 추가한 pilot plant 실험을 수행하였다. pilot 실험결과 표준정수공정에서 DOC(dissolved organic carbon)는 약 25% 제거되었으나, 오존공정에서는 거의 제거되지 않았고, 30일이 지난 후 GAC(granular activated carbon)에서는 약 75%까지 제거되는 것으로 나타났다. 표준정수공정에서 이취미는 약 30%, 오존산화공정에서 약 60%정도 제거되었고, 활성탄여과에서 대부분 제거되었으나, Column 1과 2에서는 DOC와 같이 이취미물질도 파과(breakthrough) 되는 것으로 나타났다. 전염소처리 대신에 중1, 2염소처리를 도입할 경우 전염소처리와 비교하여 약 25%정도의 THM발생량이 감소하였으며, 후염소처리만할 경우 약 30%까지 감소하는 것으로 나타났다.

• 대한환경공학회지
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• 제22권10호
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• pp.1861-1867
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• 2000

활성탄 흡착법은 유해 유기화합물질을 처리하기 위한 최적기법이다. 강화되어 가는 각종 환경 기준을 만족시키고, 활성탄처리 비용절감을 위하여 RSTA의 최적화를 연구하였다. 실린더형 흡착탑과 RSTA의 비교실험에서는 동일 조건하에서 RSTA의 파과시간이 증가하였다. RSTA의 최적화를 위한 실험에서 최척 선속도는 19.10cm/min였으며, 최적각은 압력강하 실험과 최적 각도 결정 실험을 통해서 RSTA($3.0^{\circ}$)인 것으로 나타났다. 그리고 활성탄 주입량과 충전층수가 많을수록 흡착효율은 증가하였다.

• 한국환경농학회지
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• 제28권2호
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• pp.186-193
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• 2009

The removal efficiency of herbicide glyphosate in a drinking water treatment system was investigated. Four major processes of a drinking water treatment system were selected and experiments were performed separately including; treatments by sodium hypochlorite (NaOCl), a sedimentation process by PAC (polyaluminum chloride), ozonation and a GAC (granular activated carbon) treatment. In the sodium hypochlorite experiment, about 50% of the glyphosate was removed by 2 mg/L of hypochlorite and more than 90% was eliminated when 5 mg/L of NaOCl was applied. Also, AMPA, the main metabolite of glyphosate, was treated with hypochlorite. More than 30% of the AMPA was removed by 2 mg/L of hypochlorite and 50% by 5 mg/L. In the PAC experiment, it was determined that more than 60% could be removed. Further experiments were performed and the results indicated that the removed amount was dependent upon the amount of soil and upon the properties of the soil especially that of clay minerals. Ozonation could oxidize glyphosate to its byproducts at about a level of 50%. In contrast, when 1 mg/L of glyphosate was treated with GAC, the amount removed was negligible. The results of this experiment were conclusive. We confirmed that drinking water, which has been contaminated with water polluted with glyphosate can be effectively purified by the application of the drinking water treatment processes currently used.

• 상하수도학회지
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• 제20권6호
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• pp.813-822
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• 2006

Soluble manganese removal was analyzed as a function of filter media, filter depth, presence or absence of chlorination, and surface manganese oxide concentration in water treatment processes. Sand, manganese oxide coated sand (MOCS), sand+MOCS, and granular activated carbon(GAC) were used as filter media. Manganese removal, surface manganese oxide concentration, turbidity removal, and regeneration of MOCS in various filter media were investigated. Results indicated that soluble manganese removal in MOCS was rapid and efficient, and most of the removal happened at the top of the filter. When filter influent (residual chlorine 1.0mg/L) with an average manganese concentration of 0.204mg/L was fed through a filter column, the sand+MOCS and MOCS columns can remove 98.9% and 99.2% of manganese respectively on an annual basis. On the other hand, manganese removal in sand and the GAC column was minimal during the initial stage of filtration, but after 8 months of filter run they removed 99% and 35% of manganese, respectively. Sand turned into MOCS after a certain period of filtration, while GAC did not. In MOCS, the manganese adsorption rate on the filter media was inversely proportional to the filter depth, while the density of media was proportional to the filter depth.

• Membrane and Water Treatment
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• 제6권4호
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• pp.339-349
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• 2015

Experiments were carried out using granular activated carbon (GAC) adsorption techniques to treat wastewater contaminated with organic compounds caused by diverse human activities. Two techniques were assessed: adsorbent GAC prepared from coconut shell (GACC) and adsorbent GAC from palm shell (GACP). A comparison of these two techniques was undertaken to identify ways to improve the efficiency of the treatment process. Analysis of the processed wastewater showed that with GACC the removal efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD), turbidity, total suspended solids (TSS) and total dissolved solids (TDS) was 65, 60, 82, 82 and 8.7%, respectively, while in the case of GACP, the removal efficiency was 55, 60, 81, 91 and 22%, respectively. It can therefore be concluded that GACC is more effective than GACP for BOD removal, while GACP is better than GACC for TSS and TDS removal. It was also found that for COD and turbidity almost the same results were achieved by the two techniques. In addition, it was observed that both GACC and GACP reduced pH value to 7.9 after 24 hrs. Moreover, the optimal time period for removal of BOD and TDS was 1 hr and 3 hrs, respectively, for both techniques.

• 대한환경공학회지
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• 제35권7호
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• pp.457-463
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• 2013

본 연구는 수계에 잔류된 미량오염물질이 활성탄 여과공정을 통해 제거되는 메커니즘을 파악하고자 입상활성탄(GAC)을 이용하여 sulfonamide계 항생물질(SAs)에 대한 흡착제거 실험 및 Density functional theory (DFT)를 활용한 흡착 모델링 계산을 수행하였다. 활성탄 흡착실험결과 1시간 및 24시간 동안의 흡착 제거율은 각각 68.4~90.7% 그리고 99.0~99.9%로 나타났으며, 두 가지 경우 모두 흡착 제거율의 크기는 sulfamethazine (SMZ) > sulfathiazole (STZ) > sulfamethoxazole (SMTZ)의 순으로 높게 나타났다. DFT 흡착 모델링 계산 결과에서는, graphene 모형에 대한 SAs의 결합 형태는 SAs의 공통부분인 4-aminobenzenesulfonamide 고리 부분을 통하여 안정된 흡착형태를 나타내었으며, SMTZ의 경우에는 반대쪽 고리인 3-methyl-1,2-oxazol-5-amine 고리 부분과의 결합이 우세한 것으로 나타났다. 또한 흡착물의 형태가 보존되는 흡착모형에서의 흡착에너지는 SMZ, STZ, 그리고 STMZ가 각각 -4.91, -4.64, 그리고 -4.62 eV로 나타났다(흡착에너지 강도: SMZ > STZ > STMZ). 이는 흡착제거실험에서 측정된 흡착제거율 크기와도 일치되는 경향을 나타낸다. 또한, SAs 물질이 분해되면서 흡착될 때 발생될 수 있는 구조상의 특성 변화에 대한 정보를 나타내었다.