• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.192-195
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• 2003

The hight density sludge process (HDS) is a process that has been developed to achieve greatly increased sludge densities compared to those resulting from conventional pH modification systems. This study was carried out to apprehend variation of sludge properties and removal of metals during recycling of the sludge. The principal neutralization and settlement took place in neutralization beaker and mass cylinder. Sludge was recycled, as a volumetric ratios of 20%, 40% and 60%. The pH was controlled in neutralization tanks near 9.5. The average lime consumption rate was about 10g per L of AMD. The increment of sludge density was correlated with the volumetric ratios of recycled sludge.

• 한국응용과학기술학회지
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• 제9권1호
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• pp.31-40
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• 1992

This study is on the biodegradability of the activated sludge, which used to biodegrade Linear Alkylbenzene Sulfonate(LAS), synthetic detergents and sufactants. The activated sludge in waste water treatment plant is used to the test of biodegradation of anionic surfactants and nonionic surfactants, but it have the periodic change of the biological propety to the lapse of the time. For the puropse of controlling and adjusting of the activated sludge in biodegradation test, we collected microorganisms from the sewage plant and the soil, and then, made the activated sludge in semicontinuous aeration chamber. From determined biodegradation data, and the degree of biodegradability to the LAS, we confirmd the standardized synthetic activated sludge which have more stable biodegradability than the sewage activated sludge. In continuous biodegradation test, LAS(dodecene-1) was biodegraded more than 99%, In 7days by the standardized activated sludge.

• 한국유체기계학회 논문집
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• 제9권5호
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• pp.22-27
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• 2006

Sedimentation phenomenon of suspended solids occurs by the gravitational force. Pollution particles are separated from slowly flowing waste water in clarifier. Recently, the sludge suction collector is Preferred rather than the scraper type sludge collector due to the enhancement of the clarifier efficiency. The sludge suction collector is usually operated by the user's experiences without any scientific and/or technical consideration. To evaluate the performance of sludge suction collector, the three dimensional numerical simulation was conducted by the finite volume method. To analyze the performance, the velocity vectors and the suction flow rates of the orifices were investigated. The result showed that each suction flow rate through out the collector was equivalent in the sludge suction collector and the efficiency of suction collector was good to remove high concentrated sludge in clarifier.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1851-1856
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• 2004

Sedimentation phenomenon of suspended solids occurs by the gravitational force. Pollution particles are separated from slowly flowing wastewater in clarifier. Recently, the sludge suction collector is preferred rather than the scraper type sludge collector due to enhancement of the clarifier efficiency. The sludge suction collector is usually operated by the user's experiences without any scientific and/or technical consideration. To evaluate the performance of sludge suction collector, the three dimensional computer simulation was conducted by the finite volume method. To analyze the performance, the velocity vectors and the suction flow rates of the orifices were investigated. The result showed that each suction flow rate through out the collector was equivalent in the sludge suction collector and the efficiency of suction collector was good to remove high concentrated sludge in clarifier.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.415-420
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• 2003

Sedimentation phenomenon of suspended solids occurs by the gravitational force. Pollution particles are separated from slowly flowing wastewater in clarifier. Recently, the sludge suction collector is preferred rather than the scraper type sludge collector due to enhancement of the clarifier efficiency. The sludge suction collector is usually operated by the user's experiences without any scientific and/or technical consideration. To evaluate the performance of sludge suction collector, the three dimensional computer simulation was conducted by the finite volume method. To analyze the performance, the velocity vectors and the suction flow rates of the orifices were investigated. The result showed that each suction flow rate through out the collector was equivalent in the sludge suction collector and the efficiency of suction collector was good to remove high concentrated sludge in clarifier.

• Environmental Engineering Research
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• 제24권2호
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• pp.191-201
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• 2019

Petroleum industry produces one of the popular hazardous waste known as Petroleum Sludge. The treatment and disposal of petroleum sludge has created a major challenge in recent years. This review provides insights into various approaches involved in the treatment, and disposal of petroleum sludge. Various methods used in the treatment and disposal of petroleum sludge such as incineration, stabilization/solidification, oxidation, and bio-degradation are explained fully and other techniques utilized in oil recovery from petroleum sludge such as solvent extraction, centrifugation, surfactant EOR, freeze/thaw, pyrolysis, microwave irradiation, electro-kinetic method, ultrasonic irradiation and froth flotation were discussed. The pros and cons of these methods were critically considered and a recommendation for economically useful alternatives to disposal of this unfriendly material was presented.

• 한국전기전자재료학회논문지
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• 제14권10호
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• pp.861-867
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• 2001

In this paper, in order to investigate the catalytic effect of the sludge exhausted from waterworks on NO$_{x}$ removal, we measure NO removal characteristics with and without sludge pellets in BaTiO$_3$-sludge packed-bed reactor of plate-plate geometry. NO initial concentration is 50 ppm balanced with air and a gas flow rate is 5ι/min. Gas temperature is changed from 25 to 10$0^{\circ}C$ to investigate the role of sludge pellet on removing active oxygen species and NO$_2$. BaTiO$_3$pellets is filled for coronal discharge at upstream of reactor and sludge pellets is filled for catalytic effect at downstream of reactor. The volume percent of sludge pellets to BaTiO$_3$pellets is changed from 0% to 100% and AC voltage is supplied to the reactor for discharging simulated gases. In the results, when sludge pellets is put at the downstream of plasma reactor, NO removal rate is slightly increased. However, NO$_2$and $O_3$ as by-products during NO removal is significantly decreased from 51ppm without sludge pellets to 5 ppm with sludge pellets and from 50 ppm without sludge pellets to 0.004ppm with sludge pellets, respectively. Therefore, NO$_{x}$(NO+NO$_2$) removal rate is increased up to 93%. It is thought that sludge pellet maybe react with active oxygen species and NO$_2$ generated by corona discharge in surface of BaTiO$_3$pellets, the then NO$_2$O$_3$as by-products are considerably decreased. When we increase gas temperature from room temperature to 10$0^{\circ}C$, NO removal rate is decreased, while NO$_2$ concentration is independent on gas temperature. These result suggest that the removal mechanism of active oxygen species and NO$_2$in sludge pellet is not absorption, but chemical reaction. Therefore we expect that sludge pellets exhausted for waterworks could be used as catalyst for NO$_{x}$ removal with high removal rate and low by-product.oduct.

• Journal of the Korean Wood Science and Technology
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• 제27권2호
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• pp.23-30
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• 1999

한지제지 공정 중에서 발생하는 백색슬러지와 흑색슬러지를 각각 일정비율(10:90, 20:80, 30:70, 40:60)로 목재 섬유와 혼합하고 PMDI, 요소 및 폐지수지를 이용하여 목표비중 0.60, 0.75, 0.90 별로 복합보드를 제조한 결과 전반적으로 볼 때 백색슬러지를 20% 정도까지 혼합하고 PMDI 수지를 적용하면 통상적인 보드와 유사하거나 오히려 더 좋은 치수안정성을 가지는 것으로 판단된다. 또한 흑색슬러지의 경우는 요소수지를 사용하거나 PMDI 수지의 첨가량을 증가시켜 조절한다면 20%의 슬러지 첨가량까지는 치수안정성 면에서 통상적인 보드와 큰 차이가 없는 보드를 제조할 수 있다고 믿어진다.

• 상하수도학회지
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• 제22권5호
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• pp.551-559
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• 2008

An experimental study was carried out to evaluate the potential of flotation process for the secondary clarifier of an activated sludge process. Flotation techniques, applied in this study, include electrofloation (EF) which generated fine bubbles smaller than $35{\mu}m$ in average and diffuser flotation (DF) which generated fine bubbles smaller than $55{\mu}m$ in average. The batch experiments were done with activated sludge displaying various characteristics. It was shown that the efficiency of solids/liquid separation was reduced as the diluted sludge volume index ($DSVI_{30}$) of activated sludge increased. The dependency, however, gradually decreased as the gas to solids (G/S) ratio increased. Thickening efficiency of EF was more than 2~10 times and DF process was more than 1.5~5 times as compared with gravity sedimentation (GS). Stable sludge blanket was maintained regardless of sludge settleability when the G/S ratio was 0.019 in the EF. On the other hand, Serious deterioration in the sludge blanket was observed in the DF depends on G/S ratio and sludge settleability. And For EF and DF, the suspended solids concentration of effluent was not nearly influenced on settleability of activated sludge and more clear than GS. A biological nutrient removal (BNR) process, combined with EF as a secondary clarifier was operated for three months. The mean MLSS (mixed liquid suspended solids) concentration in the reactor and mean solids concentration of return sludge were estimated to be 5,340 mg/L and 16,770 mg/L, respectively. The water quality of effluent was considerably stable and low value was accomplished, that was, standard suspended solids concentration $0.07{\pm}0.51mg/L$ and standard turbidity $1.44{\pm}0.56NTU$. The EF could be applicable for enhancement of efficiency of activated sludge system as well as improvement of the water quality of effluent.

• 대한환경공학회지
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• 제36권2호
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• pp.103-108
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• 2014

하수슬러지의 해양투기 규제에 따른 처리대안으로 석탄화력발전소 보조연료로서의 활용이 제안되고 있다. 슬러지를 석탄과 혼합하여 사용한다면 연료의 조성변화로 인하여 산성가스의 배출특성이 달라질 것으로 예상된다. 본 연구에서는 국내 하수처리장 7곳에서 발생한 하수슬러지를 수거하여 석탄과 혼합한 뒤 실험실 규모의 연소로에서 연소시킨 후 배출되는 질소산화물($NO_x$), 이산화황($SO_2$), 염화수소(HCl), 염소($Cl_2$) 가스를 분석하였다. $NO_x$는 슬러지 혼합에 따른 배출농도 변화가 가장 작았고, $SO_2$는 슬러지를 혼합하여 연소하였을 때 석탄 연소가스와 비교하여 높은 배출농도 증가를 보였다. HCl + $Cl_2$는 슬러지의 염소함량에 따라 서로 다른 배출농도를 보였다.