• Clean Technology
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• v.15 no.4
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• pp.265-272
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• 2009

In this study the experiments on the static adsorption of benzene were carried out using activated carbon made from sewage sludge. The experiment was performed at 303.15 K, 318.15 K and 333.15 K under the pressure up to 7.999kPa. Isothermal adsorption curves were obtained using Langmuir isotherm, Freundlich isotherm and Toth isotherm for comparison. Based on fitting the adsorption quantity of Benzene (q), the isothermal adsorption curves obtained from Langmuir isotherm and Toth isotherm showed the higher accuracy. Although there was little difference in accuracy between result from Langmuir isotherm and that from Toth isotherm, the adsorption quantity of Benzene (q) was expressed in terms of Langmuir isotherm because less parameters were required for Langmuir isotherm than for Toth isotherm. Moreover SEM images of the activated carbon from sewage sludge and the commercial activated carbon were taken to observe the pore size development. The results showed that the perforation development of the commercial activated carbon (DARCO A.C., SPG-100 A.C.) was better than that of activated carbon from sewage sludge. Adsorption quantity of benzene on commercial activated carbon was confirmed to be higher than that on activated carbon from sewage sludge. However the maximum adsorption quantity of benzene on activated carbon from sewage sludge was close to that on SGP-100 A.C. at 303.15K. Therefore, we may conclude that it is feasible to commercialize the process to manufacturing activated carbon from sewage sludge.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.367-369
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• 2005

방사선 처리에 의한 슬러지의 기초 물성 변화 및 탈수율 증진에 대한 실험을 수행하였다. 또한 슬러지의 자원화를 위하여 슬러지 이용 퇴비를 제조하여 품질을 평가하였다. 방사선을 조사한 슬러지는 입자 내부에 존재하는 일부 수분이 유출되어 최종 탈수 케이크의 함유 수분이 약 7% 정도 감소하였으며, 이는 방사선 조사가 최종 슬러지 발생량을 저감시킬 수 있는 한 가지 방법임을 시사 하여준다. 슬러지를 이용한 퇴비화 실험을 통하여 방사선 처리를 한 퇴비의 품질이 비조사 퇴비에 비하여 퇴비 품질이 향상되었음을 입증하였다.

• Journal of the Korean GEO-environmental Society
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• v.15 no.9
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• pp.5-12
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• 2014

Anaerobic digestion was investigated for the stabilization of sludge, decrease of volatile solids, production of biogas for wastewater sludge. In this study, total solids and volatile solids, elemental analysis were conducted to determine characteristics of various types of sludges and investigate the feasibility of biogas production of Municipal Wastewater Sludge (MWS), Industrial Wastewater Sludge (IWS), mixed sludge (Mix), and Municipal Wastewater Sludg Cake (MWSC). Total solids, volatile solids, and C/N ratio were determined in the range of 11.2~20.6 %, 62.1~83.1 % of TS and 4.96~8.33 %. Using the biochemical methane potential (BMP test), mixed sludge and wastewater sludge finished the methane production within approximately 20 day and 16~17 day. Sludge cake finished within 10 day. Mixed sludge produced 395.5 mL $CH_4$ per g of Volatile Solid (VS) and resulted in the highest methane production. For carbon dioxide production, five sludges had similar value of accumulated carbon dioxide production except for sludge cake.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1083-1091
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• 2000

The objective of this study is to develop effective and economical treatment processes for the removal of non-biodegradable organics by reusing the sludge generated from Fenton's Oxidation Process. It was found that about 50% of coagulants and 50% of catalyst can be reduced by reusing the sludge generated from Fenton's Oxidation Process. It was also found that the amount of sludge generation can be reduced in coagulation process and Fenton's Oxidation Process. From the results of bench-scale test, it was found that the average removal efficiency increased to 8.5% and the amount of sludge generation was reduced up to 35% by reusing the sludge as coagulant. The average organic removal efficiency increased to 5.3% and the amount of sludge generation was reduced up to 14% by reusing the sludge as catalyst in Fenton's Oxidation. It can be concluded that the reuse of sludge generated from Fenton's Oxidation Process would be reduced cost of chemical consumption and Fenton's sludge treatment.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.3
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• pp.279-290
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• 2004

Sludge quantity has increased at "A"water treatment plant due to deterioration of raw water quality and GAC installation. Increased sludge resulted in overloading on sludge handling facilities. The object of this study is to survey sludge quantity and capacity of sludge handling facilities at "A"water treatment plant. Measured quantity of sedimentation sludge considerably exceeded the design capacity of sludge holding basin. Sludge holding basin was properly designed, but low concentration of sludge discharged from sedimentation basin caused production of large volume of the sludge. Timer operated control system for sludge withdrawal unit and leakage through a control valve were suspected to cause the low concentration. Augmentation of the control system by a turbidity meter and addition of a new control valve successfully reduced the sludge volume enough to satisfy the design capacity of sludge holding basin. Unlike sedimentation sludge, measured quantity of washwater was considerably less than the design capacity of washwater basin because it was over-designed.

• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.264-270
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• 2016

This Study is to into fuel using a torrefation reaction to food waste. When the fuel of only food waste alone, fuel value is was performed at a ratio of sewage sludge constant attempts to prevent low. Mixing ratios of food waste and sewage sludge, 10:0, 8:2, 6:4, 5:5. Regardless mixing ratio, it was possible to confirm that decreases the moisture content of 10% or less at a reaction temperature of $240^{\circ}C$ or higher. As the ratio of the reaction temperature and the sewage sludge is high, the fixed carbon content is increased. It was measured at up to 36%(mixing ratios6:4, reaction temperature $270^{\circ}C$) from the initial 1.1%. From the reaction temperature $240^{\circ}C$ satisfied with 3000Kcal/Kg or more is a SRF criteria shows the calorific value. It was possible to obtain a heating value that is increased from the raw sample approximately sextuple. As reaction temperature is heightened, Van krevelen Diagram moved to the range of Lignite range. It was possible to obtain high fuel ratio and 5,500Kcal/kg or less of a combustility index as the sewage sludge mixing ratio becomes high. Increase the fixed carbon content, than those food waste alone solid fuel into and improved fuel costs, it is necessary to ensure that the quality of the fuel is improved.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.2
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• pp.35-45
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• 1996

In order to investigate the possibility of treating nightsoil sludge, the growth trend experiments with vermicompsting was performed and the stability of worm castings was evaluated by the analysis of minerals according to growth periods. Survival rate(SR) of earthworms decreased as earthworms grow up to 7 weeks. The growth period of the earthworms could be classified into two phases on the basis of the ratios of cast to feed ingested(ID). The growth period of the earthworms up to 3 weeks, the high percentage of dry weight of feed ingested(ID) is mainly utiliz-ed to an increase in fresh weight of earthworms, and after the 3 weeks, it is utilized to cast production in this experiment, respectively. The highest values of increasing rate(IR) and biomass of the earthworms(BE) were obtained at 3 weeks and those were 10.59mg/day and 14.48g, respectively. Between the increasing rate(IR) and biomass of the earthworms(BE), a highly positive correlation coefficient(p<0.001) ap-peared. The highest values of biomass of the earthworms(BE) and cast production(CW) were obtained at 3 and 7 weeks, respectively. All the concentrations of minerals except calcium(Ca) in worm castings was lower than the values in nightsoil sludge. It was considered that the major portion of minerals in nightsoil sludge may have been retained in the bodies of earthworms. And these values were lower than the regulated levels in organic fertilizers that the regula-tion standards. In conclusion, the worm castings are very stable for the use as soil conditioner or organic fertilizers.

• Applied Chemistry for Engineering
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• v.25 no.5
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• pp.510-514
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• 2014

In this work, the effect of torrefaction on the basic characteristic of sewage sludge was studied to evaluate the energy potential as a solid fuel. Torrefaction experiments were performed at temperatures of $150{\sim}600^{\circ}C$. The torrefied sewage sludge was characterized by the energy yield, ash content, volatile fraction and high heating value (HHV). The gaseous products from torrefaction of the sewage sludge were also analyzed. Thermogravimetric analysis was carried out for the kinetic analysis of sewage sludge torrefaction. From this work, it was found that the ash content increased with an increase of the torrefaction temperature while the energy yield, HHV and volatile fraction decreased. It was also found that the emission of carbon monoxide and hydrocarbon gases started at $300^{\circ}C$ by the thermal degradation of volatile components in the sewage sludge.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.8
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• pp.578-582
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• 2011

Aerobic digestion of organic sludge generates stabilized slurry which could be used as a nitrogen-rich liquid fertilizer. In this study, the effects of air supply rate and eggshell addition on the sludge fertilizer efficiency were examined. Sludge from a wastewater treatment plant in a food industry was fed to a lab-scale aerobic digester, and the fertilizer efficiency was assessed by the growth of cucumber. Increase of air supply rate up to 200 mL/L/min enhanced the fertilizer efficiency as well as the nitrification efficiency. The addition of eggshell, a potassium-rich leftover, in fertilizer application was also beneficial to the cucumber growth. A proper control of air supply rate and the use of an inexpensive additive would guarantee the quality of sludge liquid fertilizer.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.3
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• pp.82-90
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• 2009

Disintegration of sewage sludge (SS) was investigated by batch experiments using mechanical pre-treatment. Mechanical disintegration of SS increased the amount of soluble chemical oxygen demand (SCOD), protein and carbohydrate due to the break-up of cell walls. The mechanical disintegration incorporated with alkaline pre-treatment demonstrated higher amount of SCOD compared with mechanical one only. In terms of anaerobic biodegradability, mechanical pretreatment enhanced the anaerobic biodegradation of SS, leading to the methane production improvement. The improvement in BMP for SS treated with mechanical and alkaline-mechanical pre-treatments were 24.1% and 44.5%, respectively. This result suggested that disintegration of SS was effective for improving anaerobic biodegradability.