• 상하수도학회지
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• 제23권4호
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• pp.499-505
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• 2009

Many other countries have investigated the residual sludge treatment process to save the existing water resource and produce the high suspended solid concentration sludge. There are various methods for concentrating residual sludge, but the membrane system has received the most interest for its efficiency. The objective of this study was to evaluate the application of membrane filtration system for the residual sludge treatment. The experiment equipment was composed of Lab scale Crossflow tubular membrane filtration system. Generally, crossflow operation mode demands high electric cost mainly for the pump energy. So to cut off electric cost, very low Crossflow velocity was used in this experiment. Results confirmed that suspended solid concentration of residual sludge could be concentrated to 57,000mg/L in low Crossflow velocity tubular membrane system,. This concentration can be directly injected into the dehydrator. Based on the results, we know that the Crossflow tubular membrane system should be replaced conventional residual sludge treatment system.

• Environmental Engineering Research
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• 제13권3호
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• pp.112-118
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• 2008

Residual solid in excess sludge treated by hydrothermal reaction was investigated as raw material for its recycling. Treated excess sludge and residual solid were also focused on their content change during hydrothermal reaction. Two kinds of excess sludge, obtained from a local food factory and a municipal wastewater treatment process, were tested under various conditions. Following hydrothermal reaction, depending on the reaction conditions, biodegradable substrates in treated excess sludge appeared to increase. The separated residual solid was a composite composed of organic and inorganic materials. The proportion of carbon varied from 34.0 to 41.6% depending on reaction conditions. Although 1.89% of hazardous materials were detected, SiO2 (Quartz) was a predominant constituent of the residual solid. X-ray diffraction (XRD) experiments revealed that the residual solid was of a partially amorphous state, suggesting that the residual solids could be easily converted to stable and non harmful substances through a stabilization process. Thus, this technology could be successfully used to control excess sludge and its reuse.

• 자원리싸이클링
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• 제7권1호
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• pp.41-49
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• 1998

알루미늄계 응집제를 사용한 수처리시 발생하는 슬러지를 산으로 처리하여 응집제를 회수하는 방안과 그로 인한 잔류 슬러지의 부피 및 질량감소, 탈수성질의 변화, 그리고 산처리시의 영향요인 등에 관해 논의하였다. 회수된 응집제의 특성은 알루미늄의 함량, 응집 효율성, 잔류 불순물들에 의해 평가될 수 있다. 산처리후 발생하는 잔류 슬러지의 처리방법 및 실제 공정 운영에의 적용사례 등에 관해서도 논의하였다.

• Environmental Engineering Research
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• 제24권2호
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• pp.202-210
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• 2019

In order to maximize the utilization of sewage sludge, a waste from wastewater treatment facility, the residual sewage sludge generated after lipid and carbohydrate extraction for biodiesel and bioethanol production was used to produce bio-oil by pyrolysis. Thermogravimetric analysis showed that sludge pyrolysis mainly occurred between 200 and $550^{\circ}C$ (with peaks formed around 337.0 and $379.3^{\circ}C$) with the decomposition of the main components (carbohydrate, lipid, and protein). Bio-oil was produced using a micro-tubing reactor, and its yield (wt%, g-bio-oil/g-residual sewage sludge) increased with an increase in the reaction temperature and time. The maximum bio-oil yield of 33.3% was obtained after pyrolysis at $390^{\circ}C$ for 5 min, where the largest amount of energy was introduced into the reactor to break the bonds of organic compounds in the sludge. The main components of bio-oil were found to be trans-2-pentenoic acid and 2-methyl-2-pentenoic acid with the highest selectivity of 28.4% and 12.3%, respectively. The kinetic rate constants indicated that the predominant reaction pathway was sewage sludge to bio-oil ($0.1054min^{-1}$), and subsequently to gas ($0.0541min^{-1}$), rather than the direct conversion of sewage sludge to gas ($0.0318min^{-1}$).

• 펄프종이기술
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• 제35권1호
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• pp.27-32
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• 2003

To understand the chemical structure of sewer sludge in comparison with commercial compost and charcoal used as a soil improver, it was carried out to analyse their ash contents and metal ions, and to elucidate the chemical structure of their residuals after a sequential treatment of alcohol-benzene(1:2) extraction in Soxhlet, 3% HCl reflux and 79% H₂SO₄ hydrolysis, using CHNS analyzer and solid C-13 NMR spectrometer. The results obtained were as follows: 1. Ash content of sludge was about 46% that is higher than those of compost (17%) and charcoal (4%). 2. The residual of sludge after a sequential treatment of HCl and H₂SO₄ hydrolyses had high ash content about 23%, too. 3. The sludge seems to be suitable to the soil improver because the content of heavy metal ions in sludge was near the compost and below the organic fertilizer standard. 4. Elemental composition of sludge residual after HCl-H₂SO₄ hydrolyes was C/sub 56/H/sub 91/O/sub 12/N₂S = (C/sub 6/H/sub 10/O/sub 5/)/sub 7/(C/sub 6/H₄)/sub 7/C₂H/sub 43/O₂N₂S, similar to C/sub 103/H/sub 122/O/sub 33/N/sub 6/S = (C/sub 6/H/sub 10/O/sub 5/)/sub 6/(C/sub 6/H₄)/sub 10/C/sub 7/H/sub 22/O₃N/sub 6/S of compost. 5. The sludge residual had proved to have both considerable aliphatic and aromatic groups, but the compost residual to have mainly aliphatic groups and the charcoal to have mainly aromatic groups, through the peak analysis of solid C-13 NMR charts. 6. So, the sewer sludge is proved to have a considerable amount of aromaticity like in woody biomass containing lignin.

• 상하수도학회지
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• 제25권5호
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• pp.777-782
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• 2011

The residual treatment facilities in WTP(water treatment plant) play an important role in solid-liquid separation. At present, it is difficult to solve problems related with thickening and dewatering of WTP sludge, and discharging waste water to river. The quantity of residuals generated from water treatment plants depends upon the raw water quality, dosage of chemicals used, performance of the treatment process, method of sludge removal, efficiency of sedimentation, and backwashing frequency. Sludge production by the physical separation of SS(Suspended Solid) occurs under quiescent conditions in the primary clarifier, where SSs are allowed to settle and to consolidate on the clarifier bottom. Raw primary sludge results when the settled solids are hydraulically removed from the tank. In this study, Drawing characteristics of the sludge thickening in the thickener of Water Treatment Plants was simulated by Using CFD(Computational Fluid Dynamics.

• 한국초전도ㆍ저온공학회논문지
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• 제23권3호
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• pp.20-25
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• 2021

Milking parlor wastewater contains high concentration suspended solid (SS), nitrogen, and/or phosphate as well as organic compounds. A new biological wastewater process by magnetic separation, magnetic activated sludge (MAS) process, was applied to milking parlor wastewater treatment process. A three step wastewater treatment process of coagulation sedimentation / ammonia stripping (C/S), magnetic activated sludge process and contact oxidation (CO) was proposed for removal of these pollutants. First step, C/S process recovered 96% TN and 96% PO₄^3--P as resource for fertilizer from the wastewater. 81% biochemical oxygen demand (BOD) in wastewater was removed after MAS process. As a results, all pollutant concentrations satisfied Japanese effluent standards. Most of residual BOD and SS were removed by the CO process. It was estimated that the proposed process could reduce the process space to 1/7.

• 청정기술
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• 제19권4호
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• pp.355-369
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• 2013

재생 원료인 바이오매스를 이용한 에너지 생산에 있어서 경제성은 가장 중요한 인자 중 하나이다. 이러한 관점에서 슬러지 혐기소화에 의해 생산되는 바이오가스는 다른 바이오매스에 비해 매우 저렴하며 처분 비용 절감으로 얻는 이익이 부가적으로 발생하기 때문에 경제성이 매우 높다. 슬러지 혐기소화에서 기질의 가수분해 속도는 전체 소화 성능을 결정짓는 인자이며 혐기소화 속도를 향상시키기 위한 슬러지 전처리 기술이 많이 개발되었다. 슬러지 전처리는 생물학적, 열 가수분해, 초음파, 기계적 방법 등 다양한 기술이 실제 시설에 적용되었다. 전처리는 슬러지 가용화를 촉진하고 고형물을 감소시키면서 바이오가스 생산을 늘리는 등 혐기소화 효율을 향상시켰다. 본문에서는 전처리 방법의 기술적 특성을 소개하고 각 전처리 방법의 에너지 수지와 경제성을 비교하여 적절한 전처리 기술을 선정하기 위한 기준을 마련하고자 하였다. 조사 결과 고온 혐기소화와 열 가수분해가 가장 경제성이 높고 다음으로 Cell rupture$^{TM}$, OpenCEL$^{TM}$, MicroSludge$^{TM}$, 초음파의 순서로 평가되었다. 경제성 평가에 있어서 슬러지의 최종 처분 비용이 가장 큰 요소가 되며 따라서 최종 처분 슬러지의 수분 함량이 경제성 평가에 결정적인 역할을 하였다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.238-244
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• 2005

This study performs the pilot-plant experiments to evaluate the effect of the oxygen enrichment on the co-incineration of municipal solid waste and organic sludge from a wastewater treatment facility. The design capacity of the stoker-type incinerator pilot-plant is 150 kg/h. Combustion chamber temperatures were measured as well as the stack gas concentrations, i.e., NOx, CO, and the residual oxygen. The maximum ratio of organic sludge waste to the total waste input is 30%. Also the oxygen-enriched air with 23% of oxygen in supplied air is used for stable combustion. As the co-incineration ratio of the sludge increased up to 30% of the total waste input, the primary and the secondary combustion chamber temperature was decreased $to900^{\circ}C$ (primary combustion chamber), $750^{\circ}C$(secondary combustion chamber), respectively, approximately $200^{\circ}C$ below the incineration temperature of the domestic waste only (primary: $1,100^{\circ}C$, secondary: $950^{\circ}C$). However, if the supplied air was enriched to 22% oxygen content in air, the incinerator temperature was high enough to burn the waste mixture with 30% sludge, which has the heating value of 1,600 kcal/kg.

• 상하수도학회지
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• 제21권6호
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• pp.709-715
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• 2007

The dewaterability of a sludge can be characterized by two ways: the residual moisture content in the sludge cake after dewatering process, and the filtration of the sludge. Time to filter (TTF) represents filtration processes that are special cases of the flow through a solid matrix concept. TTF characterizes a resistance to filtration. The sludge resistance, in turn, can be subdivided into resistances associated with the solid phase and the liquid phase to evaluate the effect of each of the two phases on sludge dewaterability. In order to determine the dewatering characteristics of the water sludge samples, TTF and zeta potential were measured. For these studies cationic polymer was chosen for water sludge dewatering experiments. The zeta potential of thickener sludges neared from minus values to zero values till 4 days after sampling. The dewaterability of thickener sludges using cationic polymer was deteriorated according to the increase of detention time. As the detention time was increased from 4 to 10 days, the optimal dose of the polymer was increased from 4 to 8mg/L. Therefore, the optimal detention time plays an important part for the dewaterability of a sludge.