• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.865-872
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• 2009

Continuous operation of aerobic sludge digestion reactor was attempted for 279 days. Anaerobic digester sludge, the target material of the experiment, was pretreated by sodium hydroxide at $40^{\circ}C$ for 120 minutes, and the pretreated sludge was fed to 5 L CSTR (continuous stirred tank reactor). Reactor performance was affected by properties of input sludge and HRT (hydraulic retention time). 6 days of HRT showed best and stable performance, and under this condition, removal rates of $NH_3$-N, SCOD, TKN, TCOD, SS, and VSS were 97.4%, 81.7%, 68.7%, 61.4%, 50.6%, and 47.0%, respectively. 73.9% of SS in anaerobic digester sludge was reduced by pretreatment and aerobic digestion. Effluent sludge had low soluble COD of 350 mg/L. This implied the sludge was stabilized and suitable for use as liquid fertilizer. Nitrification took place when HRT was higher than 4 days. $NO_3$-N concentration was as high as 658 mg/L while $NH_3$-N was as low as 20 mg/L.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.2
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• pp.192-200
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• 2016

A characteristics of microwave drying-gasification was analyzed for converting a dewatered sewage sludge generated a wastewater treatment plant. Gas (60%) was the largest component of the product of microwave gasification, followed by sludge char (33%) and tar (2%). The main components of the producer gas were hydrogen (33%) and carbon monoxide (40%), and there was some methane and hydrocarbons ($C_2H_4$, $C_2H_6$, $C_3H_8$). Larger nitrogen and smaller oxygen amounts were generated. Gravimetric tar generated $414g/m^3$. This means a total tar which is a heavy hydrocarbons from the volatile organic substance in the sewage sludge. Selected light tars were benzene, anthracene, naphthalene, pyrene, showing lower concentrations as 2.62, 0.37, 0.49, $0.28g/m^3$, respectively. Sludge char has larger meso pores which is a mean pore size of $50.85{\AA}$ and has high adsorptivity. An amount of adsorption was $228.71cm^3/g$, showing higher quantity than acommercial adsorbers. This indicates that the gas obtained from the microwave gasification of wet sewage sludge can be used as fuel, but the heavy tar in the gas must be treated. Sludge char can be used as a tar reduction adsorbent in the process, and then burns as a solid fuel.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.1
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• pp.85-92
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• 2010

In this study, odorous compounds emitted from various wastewater treatment were treated with using the non-thermal plasma reaction, and the effluent gas from the plasma reactor was introduced to a waste sludge reactor to achieve simultaneous sludge reduction. Hydrogen sulfide, the model odorous compound, was removed at 70% using the plasma reaction, and greater than 99% removal efficiency was observed when treated by the sludge reactor. In addition, the sludge reactor showed a high efficiency of ozone removal. As ozone reacted with sludge, oxidation with organic matters took place, and total COD decreased by 50~60% and soluble COD increased gradually. As a result, the integrated process consisting of the non-thermal plasma and the sludge reactor can be successfully applied for the simultaneous treatment of malodorous gas and waste sludge.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.228-231
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• 2012

In this work, the mixture of sewage sludge incubated in an anaerobic bioreactor for 35 days and paperboard sludge was treated in a batch anaerobic digester equipped with a ultrasonicator, and methane production during the treatment was investigated. The Soluble Chemical Oxygen Demand (SCOD) increased with increasing the amplitude of ultrasonicator, which help solubilizing paperboard sludge more effectively. The optimum amplitude of ultrasonicator for the enhancing methane productivity was found to be $142.5\;{\mu}m$ and the methane production amount increased as the anaerobic digestion period became longer. In addition, the anaerobic digestion was performed with various biomass (6000, 9000 and 12000 mg/L) and methane production increased with higher cell mass. These results will be used as valuable data to enhance the methane production from anaerobic digestion of the high concentration of organic wastes containing the paperboard sludge and sewage sludge.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1359-1367
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• 2008

We analyzed the physical and chemical properties such as proximate analysis, ultimate analysis, heating values, thermogravimetric analysis, and combustion test for the organic sludges generated from paper and beverage manufacturing industries in the industrial complex. The average water and combustible content of the organic sludges from paper and beverage manufacturing industries were 66.07% and 14.67%, 54.98% and 26.77%, respectively. From the ultimate analysis of the organic sludges, C, H, O, N, and S compositions were 21.75%, 3.42%, 32.70%, 0.63%, and 0.30%, respectively. For beverage manufacturing industries, C, H, O, N, and S compositions were 39.88%, 4.28%, 23.20%. 2.65%, and 0.35%, respectively. According to the results of investigating the lower heating values by Dulong's equation, 1 sludge(T company) was on the range of over 2,000 kcal/kg. This sludge could be directly applied to industries which try to use the energy by direct incineration. From the TGA test, the minimum combustion temperature of A company's sludge was about $700^{\circ}C$ for direct use for energy and that of 3 sludges(C, I, and T company) were at least over $800^{\circ}C$.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.2
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• pp.35-45
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• 1999

The effect of compost to force the cultivation using various soil and vegetation was investigated 5 times in the field for 4 years. Sewage sludge compost was validated to be useful fertilizer for the growth of a plant. and the optimal amendment amounts of compost to soil depended on the kinds of soil and vegetation, and the organic contents of compost. In the case of compost with high organic content. the optimal amended compost weight was 0.12t/are in fertile-dark brown(eutrophic) soil, 0.2t/are in sandy soil(trophic) and 0.4t/are in infertile-dark brown(oligotrophic) soil, respectively. In the case of compost with low organic content. on the other hand, the amentments of compost up to 0.6t/are was allowable without negative effect on the applied vegetation. Consequently, it can be believed that the sewage sludge compost is useful fertilizer, if keep the optimal amendment amounts(0.4t/are. year) to improve soil on cultivation of vegetation.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.113-120
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• 1985

A filed experiment was carried out to investigate the effects for growth, yield of red lopper (Saelona) and properties of soil by beer sewage sludge application to the sandy loam which fertility was common. The results obtained were summerized as follows. 1. Growth of red pepper in sludge plot was very poor by drought in early stage, but color of loaves was green and growth strength was better than nontreated plot after rainfall in last stage. There were no significant differencies between plant height, number of branch on main stem and stem height in sludge and standard plot. 2. Yield of matured red pepper per plant in NPK+, and PK+ sludge 1200kg, 2400kg and 4800kg/10a plot were less than those in standard plot respectively. 3. Ratio of dry weight of matured red pepper in NPK+, and PK+ sludge 1200kg, 2400kg and 4800kg/10a were high than those in standard plot appreciably. 4. Sewage sludge application (1200kg/10a. N=51kg) was available as nitrogen source of organic fertilizer considerably, but there were some growth inhibition by excess of amount applied. 5. Sewage sludge application decreased the pH of the soil and increased the content of organic matter and exchangeable babe in the soil appreciably.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.4
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• pp.95-103
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• 2015

The purpose of this study was performed to quantitatively measure the thermal conductivity of poultry slaughter waste with variation of reaction temperature for optimal design of thermal hydrolysis reactor. We continuously quantified the thermal conductivity of dehydrated sludge related to the reaction temperature. As the reaction temperature increased, the dehydrated sludge is thermally liquefied under high temperature and pressure by the thermal hydrolysis reaction. Therefore, the bond water in the sludge cells comes out as free water, which changes the dehydrated sludge from a solid phase to slurry of a liquid phase. As a result, the thermal conductivity of the its sludge was more than 2.11 times lower than that of the water at $20^{\circ}C$. However, the thermal conductivity of the sludge approached to $0.677W/m{\cdot}^{\circ}C$ of water at $200^{\circ}C$, experimentally substantiating liquefaction of the dehydrated sludge. Therefore, we confirmed that the change in physical properties due to thermal hydrolysis appears to be an important factor for heat transfer efficiency. And the thermal conductivity function related to reaction temperature was derived to give the boundary condition for the optimal design of the thermal hydrolysis reactor. The consistency of the calculated function was 99.69%.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.4
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• pp.65-74
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• 2002

This Study was investigated operating condition of pyrolysis processing for sludge disposal in sewage treatment plant. Important parameters studied include running time of pyrolysis, run time of dry and pyrolysis processing, water content of sewage sludge, solids amount of sewage sludge(TS%), condition of pyrolysis temperature. Most degradation reaction of sewage sludge are first order, it assumed first order and elucidated the kinetics. This was the basis of characteristics analysis of sludge degradation mechanism. Also, with the increasing of temperature, how the yield of oil and char product change was observed, and the distribution of gas product components was observed. Main components of gas and carbon product are a little difference with pyrolysis temperature, but it consist of $CH_4$, $C_2H_4$, $C_3H_8$, $C_4H_{10}$, toluene, $C_6H_6$, $SO_2$, CO etc. The gas of $C_1-C_4$ yield increased along with degradation temperature of $670^{\circ}C$ and oil yield decreased of $C_6H_6$ and $C_6H_5OH$ with temperature of $600^{\circ}C$. Particularly, low value added char yield 134kg/t at $670^{\circ}C$, but increased to 194kg/t at pyrolysis temperature of $600^{\circ}C$. In the result of elementary analysis on it, it is mainly composed of carbon. From this fact, in pyrolysis of sludge, it comfirmed that carbonization reaction occur at high temperature well.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.3
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• pp.101-109
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• 2006

Earthworms(Eisenia fetida) were fed with paper mill sludge produced from P&G or Yuhan Kimberly paper manufacturing factory, or cow dung manure. Turnover rate of feed into earthworm biomass and excreting rate on each feed were investigated on dry weight base. Biomass of earthworm population was increased on paper mill sludge, but it was fallen to death on cow dung manure, which had high electrical conductivity and low redox potential. When P&G paper mill sludge was supplied to adult, elder juvenile or younger juvenile for 84 days, turnover rate of feed into earthworm biomass was 0.48, 0.40 and 0.76%, respectively, and on Yuhan Kimberly paper mill sludge 0.26, 0.45, 0.42%. When P&G paper mill sludge was supplied to adult, elder juvenile or younger juvenile, excreting rate was 49.02, 54.32 and 55.39%, respectively and on Yuhan Kimberly paper mill sludge 32.22, 41.86, 40.69%, and on cow dung manure, 73.73, 57.89. 76.38%.