• Title/Summary/Keyword: K-powdered activated carbon

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Development of Optimum PAC Dose Prediction Program using $^{14}C$-radiolabled MIB and HSDM ($^{14}C$-radiolabeled MIB와 HSDM을 이용한 최적 PAC 투입량 예측프로그램의 개발)

  • Kim, Young-Il;Bae, Byung-Uk;Kim, Kyu-Hyoung;Hong, Hyun-Su;Westerhoff, Paul
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.10
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    • pp.1123-1128
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    • 2005
  • NIB(methylisoborneol) is an earthy/musty odor compound produced as a second metabolite by cyanobacteria and actinomycetes. MIB is not removed by conventional water treatment(coagulation, sedimentation, filtration) and its presence in tap water, even at low ng/L levels, can result in consumer complaints. PAC(powdered activated carbon) can effectively remove MIB when the correct dose is applied. But, since most operators in water treatment plants apply a PAC dose and then adjust that dose depending on direct observation (odor detection) after treatment, the result is often under-dose or eve,-dose. In this study, kinetic and isotherm tests using $^{14}C$-radiolabeled MIB were performed to determine coefficients for the HSDM(homogeneous surface diffusion model), including liquid film mass transfer coefficient($K_f$) and surface diffusion coefficient ($D_s$). The HSDM gave a reasonable fit and allowed prediction with the experimental data. Base on the HSDM, the authors developed an optimum PAC dose prediction program using the Excel spreadsheet. When the developed program was applied at two water treatment plants, the PAC dose based on the experience of operators in the water treatment plant was significantly different from that recommended by the newly developed program. If operators are willing to use the optimum PAC dose prediction program, it should solve dosing problems.

Odorous Gas Removal in Biofilter with Powdered Activated Carbon and Zeolite Coated Polyurethane Foam (분말활성탄 및 제올라이트 담지 폴리우레탄 담체를 이용한 바이오필터에서의 악취가스 제거)

  • Lee, Soo-Chul;Kim, Dong-Jin
    • Clean Technology
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    • v.18 no.2
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    • pp.209-215
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    • 2012
  • The performance and removal efficiencies of a pilot scale biofilter were estimated by using ammonia and hydrogen sulfide as the odorous gases. Expanded polyurethane foam coated with powdered activated carbon and zeolite was used as a biofilm supporting medium in the biofilter. Odorous gases from the sludge thickener of a municipal wastewater treatment plant were treated in the biofilter for 10 months and the inlet ammonia and hydrogen sulfide concentrations were 0.1-1.5 and 2-20 ppmv, respectively. The removal efficiencies reached about 100% at the empty bed retention time (EBRT) of 3.6-5 seconds except for the adaptation periods. The pressure drop of the biofilter caused by the gas flow was also low that the maximum attained was 31 mm $H_2O$ during the operation. Its stability was confirmed in the long term due to the fact that the biofilter and the polyurethane medium had a minimum plugging and compression. The microbial community on the medium is critical for the performance of the biofilter especially the distribution of ammonia oxidizing bacteria (AOB) and sulfur oxidizing bacteria (SOB). The distribution of Nitrosomonas sp. (AOB) and Thiobacillus ferroxidans (SOB) was confirmed by FISH (fluorescence in situ hybridization) analysis. The longer the operation time, the more microbial population observed. Also, the medium close to the gas inlet had more microbial population than the medium at the gas outlet of the biofilter.

Study on Removal of Artificial Radionuclide (I-131) in Water (물속의 인공방사성핵종(I-131) 제거율 연구)

  • Jeong, Gwanjo;Lee, Kyungwoo;Kim, Bogsoon;Lee, Suwon;Lee, Jonggyu;Koo, Ami
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.11
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    • pp.747-752
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    • 2014
  • Iodine-131, an artificial radionuclide, mostly exists as iodide ion ($^{131}I^-$) and iodate ion ($^{131}IO_3{^-}$) in the water, and When a short time contacted, it could not be removed by poly aluminum chloride (PACl) and powdered activated carbon (PAC). Although the removal rate of iodine-131 was not related with turbidity of raw water, it showed linear relationship with contact time with PAC. With the mixture of PACl (24 mg/L or more) and PAC (40 mg/L or more), about 40% of iodine-131 could be removed. Iodine-131 could be removed little by sand filtration, but approximately 100% by granular activated carbon (GAC), both virgin-GAC and spent-GAC. Microfiltration process could remove little iodine-131 while reverse osmosis process could remove about 92% of iodine-131.

Application of Newly PAC Selection Method Based on Economic Efficiency (경제성을 고려한 새로운 PAC 선정방법의 적용)

  • Kim, Young-Il;Bae, Byung-Uk
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.11
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    • pp.1141-1147
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    • 2006
  • In order to applicate a newly method for powdered activated carbon(PAC) selection based on economic efficiency, PAC adsorption tests were performed for removal of MIB and dissolved organic carbon(DOC) in drinking water supplies. The removal rate of MIB increased when the PAC dose increased. The Coal-based PACs were superior for adsorption of MIB compared to wood-based PACs. PAC adsorption of DOC and $UV_{254}$ were a little different for different PACs and types of raw water, but both were lower than adsorption of MIB. Among the tested PACs, the one called P-1000 was most effective for removal of MIB, DOC and $UV_{254}$. Most of the organics in the tested samples were proven by excitation emission matrix(EEM) results to be fulvic-like materials. Especially, fulvic-like materials, humic-like materials, and soluble microbial byproduct(SMP)-like materials decreased after contact with PAC. P-1000 which had the lowest MIB cost index(MCI) was selected as the optimum PAC for the target water. PAC efficiency and treatability, particle size and distribution, and the cost associated with PAC dosing for MIB removal according to DOC concentration should all be considered before making the final selection of the best PAC for the target water.

Effectiveness of Zeolite and Granular Activated Carbon Addition before Starvation for the Performance Recovering of the Sludge Settleability and Removal Efficiency (Starvation전 제올라이트 및 입상활성탄의 주입이 슬러지 침강성 및 오염물질 처리효율 회복에 미치는 영향)

  • Oh, Hye-Ran;Kim, Sang-Soo;Moon, Byung-Hyun;Yoon, Cho-Hee
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.3
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    • pp.234-240
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    • 2010
  • The effectiveness of adding powdered zeolite and granular activated carbon (GAC) before starvation into biological reactor for recovering its performances was investigated. Two types of carrier addition in Sequencing Batch Reactor (SBR) system for non-saline and saline wastewater were evaluated after starvation periods. During the experiment, settleablity (SVI), floc size, fractal dimension, $COD_{Mn}$, T-N, T-P removal efficiencies and recovery time were monitored. When the wastewater feeding was resumed after starvation period for 5days, the SVI increased at the beginning of resumption and then decreased with time in both types. And the larger the floc size and fractal dimension of floc, the more increased removal efficiency for $COD_{Mn}$, T-N and T-P was also. Its performance recovery was strongly correlated with floc size and fractal dimension of activated sludge. After resuming the wastewater feeding, the SVI, floc size, fractal dimension, $COD_{Mn}$, T-N, T-P removal efficiency of SBR with carrier improved and reached its initial value faster compared to those of SBR without carrier.

Assesment of Powdered Activated Carbon Effect on PAC+MF Hybrid Membrane Process (분말활성탄(PAC)+막여과(MF) 조합공정에서 PAC의 영향 평가)

  • Kim, Byung S.;Wang, Chang K.;Lim, Jae L.;Kim, Chung H.
    • Journal of Korean Society of Water and Wastewater
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    • v.22 no.5
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    • pp.517-522
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    • 2008
  • This study aims at an assessment of the effectiveness of taste & odor removal and transmembrane pressure changes in a pilot membrane plant(500m3/day) by adding PAC to MF process, and at providing a basis for applying it to the advanced water treatment process. The transmembrane pressure showed, in low turbidity of raw water, a tendency to decrease when PAC was injected at the Flux of 1, $1.5m^3/m^2{\cdot}d$, while it increased in high Flux($1.5m^3/m^2{\cdot}d$) in high turbidity of raw water. in addtion, it is shown that the fouling could be reduced more when PAC is injected together with appropriate amount of coagulant, than when PAC is solely injected. Taste & Odor-causing 2-MIB may not be detected in membrane filtered water, if the amount of PAC injection is increased in accordance with the increasing concentration of 2-MIB. Hence, PAC injection, as a pre-treatment process in MF membrane filtering, is supposed to be a suitable process for reducing fouling as well as for improvement effectiveness of taste & odor treatment.

Nitrogen removal characteristics of pigment wastewater using PAC-A/O process (PAC-A/O 공정을 이용한 안료폐수의 질소 제거 특성)

  • Jeong, Jongsik
    • Journal of Korean Society of Water and Wastewater
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    • v.32 no.1
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    • pp.19-25
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    • 2018
  • The objectives of this study were to evaluate the removal characteristics of total nitrogen, the influence factor of denitrification and the optimum operating condition in the pigment wastewater treatment using PAC-A/O process. The operating conditions of PAC-A/O process were mean BOD volumetric loading $0.86kgBOD/m^3/day$, mean F/M ratio 0.072~0.13 kgBOD/kgMLVSS/day and mean C/N ratio 3.47, respectively. The conditions of anoxic process in the field plant test were mean pH 8.3~8.7 and mean temperature $34.1{\sim}44.0^{\circ}C$. The ORP bending point knee was eventually appeared in the ORP -107 mV and $NO_3{^-}-N$ removal efficiency was increased according to the ORP decrease. In the ORP -107 mV below condition, the removal efficiency of T-N and $NO_3{^-}-N$ was 92.3~95.0% and 98.5~99.7%. Denitrification rate was calculated to be 1.581~1.791 mg $NO_3{^-}-N/gMLSS/hr$. The experimental results showed that the ORP control in the PAC-A/O process could be an effective method for treatment of pigment wastewater.

Study on Removal of Cesium in Water Treatment System (물속의 방사성핵종(세슘) 제거율 연구)

  • Jeong, Gwanjo;Son, Boyoung;Ahn, Chihwa;Lee, Suwon;Ahn, Jaechan;Kim, Bogsoon;Chung, Deukmo
    • Journal of Korean Society of Environmental Engineers
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    • v.38 no.1
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    • pp.8-13
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    • 2016
  • This study investigated the removal of a radioactive cesium ($Cs^+$) in the water at the water treatment processes. Since cesium is mostly present as the $Cs^+$ ion state in water, it is not removed by sand filtration, and coagulation with polyaluminum chloride (PACl), powdered activated carbon (PAC) and mixture of PACl and PAC. However, it is known that the removal rate of cesium increases as the turbidity increases in raw water. As the turbidity was adjusted by 74 NTU and 103 NTU using the surrounding solids near G-water intake and yellow soils, removal rate of cesium was about 56% and 51%, respectively. In case of a GAC filtration with supernatants after jar-mixing/setting was conducted, 80% of cesium is approximately eliminated. The experimental results show that it is efficient to get rid of cesium when the turbidity of the raw water is more than 80 NTU. In case of a GAC filtration, about 60% of cesium is removed and it is considered by the effect of adsorption. Cesium is not eliminated by microfiltration membrane while about 75% of cesium is removed by reverse osmosis.

The Removal of Styrene using Immobilized Microorganisms in Hydrogel Beads (미생물 고정화 복합고분자담체를 이용한 Styrene 제거)

  • Song, Ji-Hyeon;Ham, Eun-Yi
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.6
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    • pp.648-653
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    • 2006
  • As an alternative for the traditional materials packed in biofilters treating gaseous VOCs, a novel packing material has been developed and tested. In the packing material(named as Hydrogel Bead, HB), pollutant-degrading microorganisms were immobilized in hydrogel consisted of alginate, polyvinyl alcohol(PVA), and powdered activated carbon. A closed-bottle study showed that the HB rapidly removed gaseous styrene without the losses of adsorption and biodegradation capacity. Biofilter column experiments using the HBs also demonstrated that greater than 95% of removal efficiencies were found at an inlet styrene loading rate of $245g/m^3/hr$, which was higher biofilter performance than other elimination capacity reported earlier. Furthermore, when the inlet styrene concentration increased stepwise, the adsorption played an important role in overall styrene removals. The absorbed styrene was found to be biodegraded in the following low inlet loading condition. Consequently, the new HB material is able to successfully minimize the drawbacks of activated carbon(necessity of regeneration) and biological processes(low removal capacity at dynamic loading conditions), and maximize the overall performance of biofilter systems treating VOCs.

Characterization of Polyurethane and Soil Layers for In-situ Treatment of Landfill Leachate (매립지 침출수 현장 처리를 위한 폴리우레탄과 개질토의 특성 분석 실험에 관한 연구)

  • Park, Chan-Soo;Jung, Young-Wook;Park, Joong sub;Back, Won seok;Shin, Won sik;Chun, Byung sik;Han, Woo-Sun;Park, Jae-Woo
    • Journal of Korean Society on Water Environment
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    • v.23 no.2
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    • pp.281-286
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    • 2007
  • A chemical and biological permeable barrier with economic feasibility is suggested to treat landfill leachate in this study. The proposed composite layers consist of bentonite, and polyurethane (PU) foam that is mixed with powdered activated carbon (PAC) and inoculated with microorganisms from local wastewater treatment plant. Each layer is mixed with local sand, and yellow brown soil. Batch tests were conducted to investigate the sorptions of nitrate on the PU foam and PAC, and nitrification/denitrification rate of each layer material. Nitrification occurred in 30 minutes with initial ammonia concentration of 100 mg/L, and the concentration of nitrate attached in the PU foam increased after 270 minutes. Results of denitrification batch tests showed 76.6%, 87.3% and 88% of nitrate removal efficiency at 10%, 20% and 30% of the volume ratio of PU foam, respectively. The pH increased from 7 to 9.42, and alkalinity increased from 980 mg/L to 1720 mg/L during the denitrification batch tests. In the column experiments using the proposed composite layers with 20% of the volume ratio of the PU foam, about 96% of BOD, 63% of COD, 58.1~79.5% of total nitrogen were removed.