• Title/Summary/Keyword: sewage sludge

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Mixture treatment of food waste and sewage sludge using pilot scale anaerobic digester (Pilot scale 2단 혐기성 소화조를 이용한 음식물쓰레기와 하수슬러지의 혼합처리)

  • Park, Nam-bae;Lee, Heon-Mo;Lee, Byung-Heon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.7 no.2
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    • pp.47-55
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    • 1999
  • Recently, the treatment of that wastes according to increase of food waste has been a great problem of modern society for long time. This study was aimed to evaluate possibility for food waste and sewage sludge mixture treatment using pilot scale two-phase anaerobic digester. Pilot scale two-phase anaerobic digestion system was performanced at 1 : 9 mixture ratio of food waste and sewage sludge infield. The detention time of digester was 20days. The average COD and VS removal efficiencies in organic loading rate $3.03kg\;TCOD/m^3-day$ were 57.7 and 47.7%, and the gas production rate and methane content were $0.4m^3/kg$ VS-day and 65.3%, respectively. TS, VS and VS/TS(%) of mixing tank were 4.44%, 2.59% and 58.34%, respectively and TS. VS and VS/TS(%) of digester in steady state were 3.32%, 1.39% and 41.90%, respectively, Through this study. it was possible to accomplish effective mixture treatment of the sewage sludge and food waste.

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Emission Characteristics of Mercury and Heavy Metals from Coal and Waste Fuels (석탄과 폐기물 연료의 수은 및 중금속 배출 특성)

  • Ahmad, Tanveer;Park, Min;Keel, Sangin;Yun, Jinhan;Park, Jeong Min;Lee, Sang-Sup.
    • Resources Recycling
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    • v.26 no.2
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    • pp.33-38
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    • 2017
  • Waste can be utilized as secondary or alternative fuel. Solid recovered fuel (SRF) and dried sewage sludge were combusted to investigate heavy metal emissions from their combusiton in this study. Content of copper (Cu), chromium (Cr), cadmium (Cd), nickel (Ni), zinc (Zn), lead (Pb), arsenic (As) and mercury (Hg) of coal, SRF and dried sewage sludge were determined, respectively. Concentrations of these heavy metals in the combustion flue gas were also determined. As a result, emissions of gas-phase Cu, Cr, Cd, Ni, Zn, Pb and As compounds were found to be little. However, a significant amount of gas-phase Hg was emitted from combustion of coal, SRF and dried sewage sludge. While SRF showed a high mercury oxidation percentage in its combustion flue gas, dried sewage sludge showed a high level of gaseous mercury emission.

The Effects of Substitution Rate of Incinerated Sewage Sludge Ash on the Concrete Materials (건설재료로서 하수슬러지 소각재 적정 대체율 도출에 관한 연구)

  • Kim, Chun ho;Kim, Nam wook
    • Resources Recycling
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    • v.25 no.1
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    • pp.10-15
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    • 2016
  • In recent years, in terms of environmental protection and efficient use of the land, efficient utilization of byproducts and wastes generated in industrial areas are emerging. In this study, for the effective utilization of using ever increasing amount of utilizing sewage sludge incineration ash to increase sewage sludge, it is evaluated the use of as an construction material. After making concrete specimens, it is evaluated compressive strength, carbonation and environmental resistance. From the experimental results, compared with concrete without sewage sludge it is obtained satisfactory results for compressive strength and carbonation and results of the leaching test also satisfies the standard value. So, it is sufficient possibility using of concrete aggregate and the replacement rates is judged to be about 10%.

A study on the Optimization of Sewage Sludge-based Adsorbent Carbonization Condition for Improving Adsorption Capacity of Hydrogen Sulfide (H2S) (황화수소(H2S) 흡착성능 증진을 위한 하수슬러지 기반 흡착제 탄화조건 최적화 연구)

  • Choi, Sung Yeol;Jang, Young Hee;Kim, Sung Su
    • Applied Chemistry for Engineering
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    • v.29 no.6
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    • pp.765-771
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    • 2018
  • In this study, the optimization of carbonization conditions in manufacturing processes was performed to improve the absorption performance of sewage sludge based sorbent used for treating $H_2S$ out of all odorous substances generated by various environmental facilities. Adsorbents applied were manufactured from the sewage treatment plant under different carbonization conditions, such as temperature and heating rate, and the correlation between the adsorption performance and physical properties of the adsorbents was verified. As a result, the adsorption performance of sludge at $900^{\circ}C$ with a heating rate of $10^{\circ}C/min$ was the best, and the SEM and BET analysis revealed that specific surface area and characteristics of pore (size, volume) were major parameters for the adsorption. In addition, the effect of K ions used for improving the adsorption performance of the optimum carbonization condition sorbent was insignificant for the sewage sludge based sorbent.

A Study on the Development of Activated Carbons from Sewage Sludge (하수슬러지를 이용한 활성탄 개발에 관한 연구)

  • Lee, Taek-Ryong;Chung, Chan-Kyo;Joe, Young-Cheon
    • Clean Technology
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    • v.15 no.1
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    • pp.31-37
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    • 2009
  • This study deals with the production process of activated carbons from the sewage sludge char by chemical activation reaction. KOH and NaOH were used as activating agents, which react well with carbon. From the experiments, it was found that activated carbons made with KOH treatment had better physicochemical properties in terms of iodine number and BET value than those made with NaOH treatment. It was also found that the optimal deposition ratio of an activating agent to the sewage sludge char was 75 wt% of KOH and 50 wt% of NaOH. Activated carbons were washed out by distilled water after neutralization with 5 M hydrochloric acid solution. The activated carbons that were produced from a sewage sludge char at this optimal conditions have BET surface areas of approximately $600m^2/g$.

The Effect of Ozone of the Improvement of Dehydration in Treatment of Sewage Sludge Measuring SRF (SRF측정에 의한 하수슬러지의 탈수 개선을 위한 오존 효과)

  • 황상용;손종렬;이용성
    • Journal of Environmental Health Sciences
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    • v.19 no.4
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    • pp.44-50
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    • 1993
  • This paper has concentrated on estimating the improvement of sludge dewaterability for the application of ozone in sewage treatment plant sludge. The experiment for the study was conducted by batch reactor, contacting ozone (5.0 g O$_3$/hr/l) to waste sludge and measured the Specific Resistance to Filtrate (SRF) varying pH, pressure and reaction time of ozone. And then checked the dissolved solids concentration of flitrate. The results of experiment were as follows: 1. When the total solids concentration of excess sludge was 9, 000 mg/l, the optimum injection rate of ozone was 5.0 g O$_3$/hr/l, and then pressure was 50 cm Hg for the measuring SRF. 2. In the range of pH 3~5, the effect of ozone injection was excellent, but it was unsatisfactory in the range of pH 9~11. Therefore, the ozone injection by acidifying pH level was effective in improving the dewaterability of sludge. 3. It was estimated that the dissolved solids concentration of flitrate was increased in proportion to the injection rate of ozone.

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A Study on Nonylphenol, Octylphenol, and Di (2-ethylhexyl)phthalate in Sewage Sludge (하수슬러지 중 Nonylphenol, Octylphenol, Di (2-ethylhexyl)phthalate 의 연구)

  • Kim, Jong-Hun
    • Analytical Science and Technology
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    • v.15 no.5
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    • pp.451-458
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    • 2002
  • Determination were performed for the presence of three common environmental endocrine disrupting compounds (EDC), namely nonylphenol (NP), octylphenol (OP), di (2-ethylhexyl)phthalate in sewage sludge from 67 wastes plants, using Soxhlet extraction and GC/MS-SIM. NP and DEHP were detected in almost every sludges but OP was not detected. The range and mean value for NP of all sludge samples were nd~593, $62{\mu}g/g$ dry and the two statistic values for DEHP of those were 13~4733, $1176{\mu}g/g$ dry respectively. DEHP content was 20 times greater than NP in sludges. Concentrations of NP and DEHP in sludge from individual area were increased as following order ; Jeolla South and North Province (Cheju) < Chungcheong South and North Province (Kwangwon) < Gyungsang South and North Province < Wide City < Kyunggi Province.

Comparison of Sewage Sludge Solubilization through Different Pretreatment Methods (전처리 방법에 따른 하수슬러지 가용화 비교연구)

  • Kwon, Jae-Hyun;Kim, Bong-Jun;Kim, Min-Kyu;Yeom, Ick-Tae;Kim, Hyung-Soo
    • Journal of Korean Society of Water and Wastewater
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    • v.17 no.4
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    • pp.567-573
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    • 2003
  • The pretreatment process was carried out to solubilize the sewage sludge for enhancing its biodegradability using alkaline treatment, ultrasonic treatment(15kHz), ozone treatment and different combination of these three methods: alkaline followed by ultrasonic as well as ozone, and ultrasonic followed by alkaline. The solubilization efficiency was evaluated based on the SCOD/TCOD ratio and VSS/TS ratio. In results, the proper condition of alkaline treatment was shown as 30meq/l of NaOH, pH 12 and 3hours of reaction time. Solubilization efficiency increased to 17% from initial 2% based on SCOD/TCOD ratio under this condition. In ultrasonic treatment, the higher ultrasonic power, the longer treatment time and the lower sludge volume resulted in higher solubilization respectively. There was a rapid increase in solubilization efficiency after 20 minute, then it was measured as 32% of SCOD/TCOD ratio in 1 hour at a ultrasonic power of 1,300W with 1/sludge. Solubilization efficiencies in combined treatment using alkaline and ultrasonic were 47-53% higher than single treatment at a sonicated time of 1 hour. Ozone treatment followed by alkaline treatment also represented the enhanced solubilization compared to ozone treatment. Therefore, ultrasonic or ozone treatment assisted by alkaline could achieve the short treatment time as well as high solubilizetion efficiency.

A Study on Volume Reduction of Waste Sludge by Aerobic Thermophilic Bacteria (호기성 호열미생물에 의한 하수슬러지 감량화 효율에 관한 연구)

  • Bae, Yoon-Sun;Kim, Soon-Young;Nam, Duck-Hyun;Park, Chul-Hwi;Kim, Jin-Su;Takada, Kazu
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.4
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    • pp.497-505
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    • 2005
  • Domestic Sewage Treatment Plants are mostly based on biological treatment, in which large amounts of excess sludge are generated and occupy about 40 ~ 60% of the total sewage treatment costs. Several methods for sludge treatment has been so far reported as upgrading biodegradation of sludge; heat treatment, chemical treatment, including thermo-alkali and ozone, mechanical treatment including ultrasonic pulverization. But, it has a limitation in case of reducing the amount of excess sludge which are already producted. In this study, application of excess sludge reduction process using thermophilic aerobic bacteria for activated sludge was examined. The research was carried out two different stage. one for a biological wastewater treatment and the other for a thermophilic aerobic solubilization of the waste sludge. A portion of excess sludge from the wastewater treatment step was into the thermophilic aerobic sludge solubilization reactor, in which the injected sludge was solubilized by thermophilic aerobic bacteria. The solubilized sludge was returned to the aeration tank in the wastewater treatment step for its further degradation. Sludge solubilization reactor was operated at $63{\pm}2^{\circ}C$ with hydraulic retention time(HRT) of 1.5 ~ 1.7 day. Control group was operated with activated sludge process(AS) and experiment group was operated with three conditions(RUN 1, RUN 2, RUN3). RUN 1 was operated with AS without sludge solubilization reactor. RUN 2 were operated with AS with sludge solubilization reactor to examine correlation between sludge circulation ratio and sludge reduction ratio by setting up sludge circulation ratio to 3. RUN 3 was operated with sludge circulation ratio of 3 and MLSS concentration of 1,700~2,000mg/L to examine optimum operation condition. The quantity of excess sludge production was reduced sharply and in operation of RUN 3, sludge The quantity of excess sludge production was reduced sharply and in operation of RUN 3, sludge solubilization ratio and sludge reduction ratio were 53. 7%, 95.2% respectively. After steady state operation, average concentration of TBOD, SBOD, $TCOD_{Cr}$, $SCOD_{Cr}$, TSS, VSS, T-N, T-P of effluent were 4.5, 1.7, 27 .8, 13.8, 8.1, 6.2, 15.1, 1.8mg/L in the control group and were 5.6, 2.0, 28.6, 19.1, 9.7, 7.2, 16.1, 2.0mg/L in the experimental group respectively. They were appropriate to effluent standard of Sewage Treatment Plants.

Phytoplankton as Standard Test Species for Marine Ecotoxicological Evaluation (해양생태독성평가를 위한 표준시험생물로서의 식물플랑크톤에 관한 연구)

  • Park Gyung-Soo;Lee Sang-Hee;Lee Seung-Min
    • Journal of Environmental Science International
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    • v.14 no.12
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    • pp.1129-1139
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    • 2005
  • A series of experiments was conducted to identify the potential of five phytoplankton species as standard test species for marine ecotoxicological tests. The candidate phytoplankton species are Skeletonema costatum, Heterosigma akashiwo, Prorocentrum micans, Isochrysis galbana, and Tetraselmis suecica. Salinity tolerance and sensitivity on potassium dichromate as a reference material were identified. Toxicity of eleven ocean dumped sewage sludges and four red tide expellent extracts were estimated by the inhibition of population growth rates (PGR) of marine diatom S. costatum, While most species revealed relatively weak tolerance on salinity, T. suecica demonstrated the highest salinity tolerance ranged from $5\~35$ psu and the others $15\~35$ psu. H. akashiwo revealed the highest sensitivity as 72h $IC_{50}$=0.76mg/L and T. suecica the lowest as 72h $IC_{50}$=8.89mg/L on potassium dichromate. Sludge extracts from industrial waste, domestic sewage and livestock farm waste sludge showed high toxicity as 72h $IC_{50}$<$2\%$ and lowest toxicity from filtration bed sludge as 72h $IC_{50}$=$30.50\%$ NOEC (No Observed Effective Concentration) of sludge extract ranged from <$0.4\%$ to $1.6\%$ and this indicated high phytotoxicity of ocean dumped sewage sludge. The test sensitivity of phytoplankton PGR inhibition was much higher than those of marine rotifer Brachionus plicatilis mortality test and bioluminescent inhibition test by marine bacteria Vibrio fischeri, and comparable with the sea urchin (Strongylocentrotus intermedius) fertilization test. As a result the phytotoxicity test using phytoplankton PGR inhibition ($IC_{50}$) must be a useful tool for marine phyto-toxicological evaluation of ocean dumped materials.