• KSBB Journal
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• v.11 no.5
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• pp.577-585
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• 1996

Effects of various factors on the phenol degradation by activated sludge immobilized with the photo-crosslinked resin were investigated. The optimum pH on the degradation of phenol in both free and immobilized activated sludge was 7. When the pH of the reaction was varied from 5 to 10, the relative activity of the phenol degradation by the immobilized activated sludge was higher than that by the free activated sludge. A higher rate of phenol degradation was observed when a bead size was smaller. The phenol degradation in the free activated sludge was inhibited at the 3000 mg/L of phenol, while that in the immobilized activated sludge was maintained at the same concentration for 28 hrs without an inhibition. The degradation rates of phenol were not directly proportional to the increasing amount of immobilized beads dosage, but the phenol degradation was made in a rather short time than that for a free sludge system. The relative activities of the immobilized activated sludge after 7 runs of repeated reactions increased about 8 times as that of the first reaction. The activities for the phenol degradation remained stable for at least 80 days when the immobilized activated sludge was stored at an aerobic condition in the wastewater containing phenol. The loading rate as high as 5.59 kg-pheno1/㎥.d could have been achieved during the continuous treatment of phenol by the immobilized activated sludge.

• Journal of Life Science
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• v.9 no.6
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• pp.692-697
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• 1999

For further removal of non-biodegradable CODs and color in biologically treated distillery waster water, we selected a chemical treatment with Fe(III) and cationic polymers and then another chemical treatment with Fenton reagent. We developed Pregenerated Bubble Flotation(PBF) to effectively remove the chemical sludge from each chemical reaction process. The flotation unit was constructed with hydraulic loading rate, 7 ㎥/$m^2$.hr. The CODMn and suspended solids (SS) in biologically treated distillery waste water were reduced by the first PBF from 310-1096 mg/L to 141-303 mg/L and from 160-990 mg/L to 48-385 mg/L, respectively. Again, after the Fenton reaction process, floated SS was skimmed off at the top of the flotation unit and the final effluent was directly discharged without any tap water dilution. The quality of final effluent can be below 40 mg/L-CODMn but IISan Distilery has been maintained effluent quality of 73 mg/L-CODMn and 10-80 mg/L-SS. The chemical cost was saved by more than 30% as compared with that of prior process.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.22-27
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• 2004

The activated paper mill sludge was treated with WF and some additives (sodium sulfide, nickel nitrate, ethyl acetate) for methane fermentation at $35^{\circ}C$. Optmum C/N ratio was 60 out of three conditions (20, 30 and 60). The Period of 40% of methane content possibly ignition, was 2 days shorter than with non-treatment during 10 days. Nevertheless, the total amount of methane production showed the 1/8 level of control far the same period. The yield and content of methane were increased by the addition of sodium Sulfur and ethyl acetate. Sulfur was an essential factor in methane fermentation of paper mill sludge.

• Journal of the Korean GEO-environmental Society
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• v.13 no.8
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• pp.75-84
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• 2012

In this paper, strength and leaching characteristics of water sludge-added lightweight soils(WALS) considering reinforcing materials(waste fishing net, glue treated waste fishing net and geogrid) and layer(1 or 2 layer) were investigated using unconfined compression test and leaching test. Several specimens of water sludge-added lightweight soil consisted of water sludge, cement, and bottom ash were prepared according to flowability. Reinforcing material added into these specimens were waste fishing net and geogrid. A glue treated waste fishing net was also added in order to increase interlocking between soil mixture and waste fishing net. Strength increased in the order of WALS reinforced by waste fishing net, glue treated waste fishing net, and geogrid. Strength of specimen with double layer-reinforcing material was greater than that of specimen with single layer reinforcing material. Leaching result of WALS was also satisfied with standard of ministry of environment.

• Microbiology and Biotechnology Letters
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• v.32 no.2
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• pp.158-165
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• 2004

This study concerns the succession process of protozoa populations in two activated sludge pilot plants. Protozoa populations with similar structures developed and succeeded each other in two plants. It was observed that initial sludge inoculum did not influence the protozoan composition but shorten the period of the plant stabilization. It seemed the protozoan in aeration tank was come from the influent. The composition of the influent sewage influenced the structure of protozoa in the pilot plants. The flagellates was very abundant during the initial starting phase. These rapidly decreased after growth peak. Then sarcodina, ciliates were increased in succession. In ciliates, free-swimming forms appeared at first and crawling forms and stalked forms were followed. After 36 days from the start, the sludge stabilization phase was characterized by a populations of ciliates dominated by stalked and crawling type and low value of effluent BOD was achieved.

• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.63-75
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• 1999

This study was performed to investigate applicabilities of sewage sludge and papermill sludge as carbon sources in biologically treating abandoned acidic mine drainage, and effects of limestone. In spite of ranging average 3.3 in influent pH, SRB(Sulfate Reducing Bacteria) was well grown. because effluent pH was maintained by alkalinity a little under for whole stages. TCODcr was high in effluent with washing out in early stage. but its concentration was low with passed time and did not cause the problem of secondary pollution. Removal rate of Mn was remarkably low, but in case of heavy metals such as Fe, the fixation trends showed high as the volume of ${SO_4}^2$ reduction increased. In case of mixing sewage sludge and papermill sludge, when their mixing ratio were 1 : 1 and 2 : 1 respectively, rate of ${SO_4}^2$ reduction and removal rate of heavy metals were high. The mixing ratio 1 : 1 was considered as the most appropriate, because degradability of swewage sludge under short time was higher than that of papermill sludge. As a result of investigating efficiencies of limestone and biological treatment, biological treatment excelled limestone in neutralization and removal rate of heavy metals.

• Journal of the Korean Ceramic Society
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• v.39 no.12
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• pp.1138-1142
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• 2002

Slag cement and supersulfated slag cement were fabricated by mixing blast furnace slag and ordinary portland cement and adapted to solidify/stabilize heavy metal contained hazardous waste sludge. In case of slag cement, it showed continuous increase of their compressive strengths, which is attributed to the formation of the C-S-H, ettringite and monosulfate with STS sludge. However, BF and COREX sludge has a different shape and composition. therefore, adequate compressive strength could not be achieved with this slag cement. In case of the mixture of the each sludge like the STS-BF or the STS-COREX, the compressive strength over the standard level for disposing the wastes could be obtained with slag cement. The supersulfated slag cement that contain accelerators was very effective in solidifying the COREX sludge, which was difficult to solidify using different cement and obtained high compressive strength only for 3 days.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.187-194
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• 2011

In compliance with an international law about the ocean dumping of the sludge, the proper sewage treatment process which occurs from the wastewater treatment process has been becoming problem. Generally the sewage and the sludge are controlled from anaerobic condition when the sewage is treated and land filled, where the methane$(CH_{4})$ and the nitrous oxide $(N_{2}O)$ from this process are discharged. Because these gases have been known as one of the responsible gases for global warming, the wastewater treatment process is become known as emission sources of green house gases(GHG). This study is to suggest a new approach of estimate and environmental assessment of greenhouse gas emissions and sludge emissions from wastewater treatment processes. It was carried out by calculating the total amounts of GHG emitted from biological wastewater treatment process and the amount of the sludgegenerated from the processes. Four major biological wastewater treatment processes which are Anaerobic/Anoxic/Oxidation$(A_{2}O)$, Bardenpho, Virginia Initiative Plant(VIP), University of Cape Town(UCT)are used and GPS-X software is used to model four processes. Based on the modeling result of four processes, the amounts of GHG emissions and the sludge produced from each process are calculated by Intergovernmental Panel on Climate Change(IPCC) 2006 guideline report. GHG emissions for water as well as sludge treatment processes are calculated for environmental assessment has been done on the scenario of various sludge treatments, such as composting, incineration and reclamation and each scenario is compared by using a unified index of the economic and environmental assessment. It was found that Bardenpho process among these processes shows a best process that can emit minimum amount of GHG with lowest impact on environment and composting emits the minimum amount of GHG for sludge treatment.

• Resources Recycling
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• v.7 no.1
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• pp.41-49
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• 1998

This papcr covcrs ihe recovery process of aluminum coagulant by acidic exlraclion which can develop the dewaterability'of residual sludge solids and ihc reduclion ot sludge valumc and mass. Simultmeously, variables affecting acidic extaction of aluminum arc discussed It is represented that the characteristics of recovcrcd coagulant is assessed mth rcspcct to aluminum content. coagulalion effeaiveness, and trace contaminants. The treatment methods of residual sludge solid following acidic extraction arc also d~scussed. Fillally, we suggest some cases in which the results from laboratory can he applied to the fullscale operation and future domestic mosoect of it.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.363-369
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• 2006

본 연구의 목적은 하수슬러지로부터 외부탄소원을 회수하여 하수의 질소 및 인 처리를 위한 최적의 pH선정과 감마선 조사의 적용가능성을 조사하는 것이었다. 연구 결과, 외부탄소원의 회수 가능성을 평가할 수 있는 index인 SCOD의 값은 비조사된 하수슬러지에서는 pH13에서 SCOD 간이 6590mg/L이고, 가용화율 SCOD/TCOD값은 57.8%로 최대의 탄소원을 회수할 수 있음을 확인하였고, 동일 pH에서는 경우에는 조사선량이 증가할수록 SCOD/TCOD값이 증가하였다. 알칼리 가수분해가 산처리 보다는 슬러지 탄소원을 회수할 수 있는 더 적정한 처리방법이고, 알칼리의 전처리에 감마선 조사한 하수슬러지의 탄소원 회수율은 pH 13, 조사선량 20kGy에서 SCOB/TCOD 최대의 값인 59% 분석되었다.