• Journal of Korean Society of Water and Wastewater
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• v.9 no.2
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• pp.84-96
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• 1995

The dewatering characteristics of the sewage sludge was investigated through the experimental observations and model simulations. The activated sludge and the anaerobically digested sludge were examined for the dewaterability evaluation within the pressure range of $0{\sim}10^6N/m^2$. Modified Buchner funnel test and compression test by the consolidometer were conducted to evaluate average specific resistance, porosity, and moisture percentage of filter cake. Shirato's technique of compression-permeability test was followed for the pressure range lower than about $10^2N/m^2$. The flocculation effects on sludge dewatering was also examined for ferric chloride and polymeric flocculant. The application of hydrated lime which can be used for flue-gas desulfurization showed improved moisture percentage, and was thought to have positive feasibility in combined system of sludge dewatering and incineration. Determined characteristic constants were applied to Tiller's cake filtration model to simulate liquid pressure distribution and porosity distribution in cake. Model simulations showed a sharp drop of the porosity close to the cake-medium interface for the highly compressible material such as the activated sludge and the anaerobically digested sludge.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.2
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• pp.102-111
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• 1998

Large amount of sludge have been generating in the process of water and wastewater treatment in urban area, and it has been making many environmental problems. Currently almost of sludge is landfilled, and since sludge is difficult to handle and dehydrate, the permeated water from the filled-in ground contaminate the surrounding soil and groundwater which may cause serious environmental and sociological problems. The organic component in sludge can be almost removed through the heat treatment process, and the final product is called artificial soil or artificial media according to the temperature control. To produce artificial media using sludge, chabazite and lime were used as an additive, and the mixture of sludge & additives was thermally treated in the firing kiln at about 800~1, 100。C for about fifteen minutes. The physical and chemical characteristics of the produced artificial media were analyzed, and it showed that it can be used as an artificial media for plant production or soil conditioner for farmland. The concentrations of the toxic heavy metals in the artificial media were lower than the soil quality standard for farmland. The characteristics of produced artificial media, using the mixture of sludge and additives through the heat treatment, is similar to the natural chabazite and soil. The analyzed result of the mineral composition of artificial media showed that it has a characteristics similar to natural stable soil, so the produced artificial media may be applied to farmland or water culture without causing adverse effect. Therefore this study showed that the above process can be a feasible alternative for sludge treatment.

• Membrane Journal
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• v.11 no.4
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• pp.170-178
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• 2001

PVC microfiltration membrane was prepared by phase immersion method and applied to membrane bioreactor (MBR) contained activated sludge. The hydrophilicity of membrane and the pore size increase with the amount of additive(PVP) ducting the preparation of membrane. Permeation characteristics and the membrane fouling behavior were investigated by varying the internal environment in MBR using the prepared membranes. When there is a sludge bulking in MBR caused by microorganism, membrane fouling was accumulated. The cake layer resistance, R$_{c}$, of membrane increased in the order of CP-0 > CP-1.0 > CP-1.5. Rc increased up to 3.5~7 fold where the sludge bulking occurred in MBR. CP-1.5 seems to be appropriated membrane on the basis of the surface characteristics and the flux. The average flux of all the test membrane was 12(${\pm}$2) L/$m^2$hr whereas the COD removal efficiency was 98.8%. The ratio of bulking sludge and the type and the size of microorganism in operating MBR accelerate the membrane fouling and flux decline. It is concluded that the characteristic of membrane filtration depends on the hydrophilicity of membrane, the internal environment of MBR reactor and the growth factor of sludge.

• Journal of Korean Society of Water Science and Technology
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• v.26 no.6
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• pp.73-80
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• 2018

In this study, the solids removal characteristics using T-P sludge generated from PACl coagulation were analyzed by laboratory scale and full scale experiment. As the amounts of T-P sludge injection into the raw sewage influent increased at the rate of 0, 1, 2, 3, 4 %, the suspended solids concentrations after 20 minutes setting test decreased to 210, 137, 91, 64, 43 mg/L, respectively. The filtration time required for dewatering test of the raw sewage influent decreased to 982, 728, 658, 581, 492 sec for 0, 1, 2, 3, 4% of T-P sludge injection, respectively. As the amounts of PACl coagulant into the effluent from final setting tank increased at 0, 10, 20, 30, 40 mg/L, the required filtration times for T-P sludge increased into 12.3, 41.7, 53.7, 67.2, 79.5 sec and the dewaterability of T-P sludge decreased. After T-P sludge returned into the primary settling tank on J-si sewage treatment plants, the effluent concentrations of COD, SS, T-N and T-P from primary settling tank into bioreactor decreased by 35.9, 27.9, 22.2, and 52.6% due to the coagulation effects of the T-P sludge. Finally, it was found that the return of T-P sludge into the primary settling tank could result into the sludge reduction having a lower water content of 3.03% p than in case of the only T-P sludge dehydration.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.412-420
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• 1999

A controlled column study using elution development and miscible displacement was conducted to assess heavy metal transport characteristics in sludge-untreated soil ("Control"), soil treated with an equivalent of sludge 50 and 100 dry ton $ha^{-1}$ ("Soil-Sludge mixtures"), and sewage sludge ("Sludge"). The elution curves (ECs) and the breakthrough curves (BTCs) for Cd, Cu and Zn in sludge 50 and 100 dry ton $ha^{-1}$ treated soils are not different from the sludge-untreated soil, The ECs for Cd, Cu and Zn in soil column which received a pulse of 10 mg of each Cd, Cu and Zn were similar to those of Cd, Cu and Zn in soil column which had no Cd, Cu and Zn added, but were very different with the ECs for Cd, Cu and Zn in soil column which received a pulse of Cd, Cu and Zn containing 50 mg of each metal. On the other hand, the BTCs for Cd, Cu and Zn in soil columns that were eluted with 500 and $1000mg\;L^{-1}$ of mixed solution of Cd, Cu and Zn were similar to each other, but were distinctly different with the BTCs for Cd, Cu and Zn in soil column that was eluted with $100mg\;L^{-1}$ mixed solution of Cd, Cu and Zn. Sewage sludge applied at rates of 50 and 100 dry ton $ha^{-1}$ did not affect the transport characteristics of this calcareous soil. The apparent mobility for this sludge treated soil and sludge is: Cd >Zn>Cu. The transport characteristics of Cd and Zn are similar to each other, but are different from those of Cu.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.6
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• pp.431-435
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• 2000

The goal of this research is to compare the metal binding characteristics of an anoxic selector activated sludge system and a conventional activated sludge system. Metal biosorption by biomass harvested from experimental systems was determined by a series of batch experiments. Heavy metals studied in this research were zinc, cadmium, and nickel. The sorption isotherm showed that the selector sludge had significantly higher sorption capacity than did the control sludge. Metal biosorption behavior closely followed a Freundlich isotherm model for equilibrium concentrations. ECP contents of biomass estimated by alkali extraction technique showed that ECP levels in the selector sludge significantly higher than that in the sludge harvested from the conventional system, indicating that the higher metal sorption capacity of selector sludge may be due to the selection of the ECP-producing bacteria (i.e., Zoogloea sp.) by the selector system.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.599-605
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• 1999

An experimental investigation was carried out to study the feasibility of using the stabilized sludge, as a backfill and cutoff-water materials for embanckment structures. for stabilizing of sludge, hydrated lime and quick lime was used as additive , and a series of tests was performed on the sludge and the stabilized sludge to examine their physical properties, compaction, compressive strength, hydraulic conducivity and consolication characteristics. From the test results, the physical and mechanical properteis of the stabilized sludge weremore improved as compared with the sludge. Especially from the viewpoint of physical porperty , consolidation or settlement and cutoff-water , quick lime is more effective than the hydraged lime as tabilizatio addtivie. But , viewpoint of compaction and shear strength, hydrated lime is more effective than the quick lime as stabilization additive. As a result of this study, it was founded that the stabilized sludge can be developed the backfill and cutoff-water materials , improved the stabilizing method of sludge.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.493-496
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• 2005

The Re-mi-con sludge water has been investigated because of environmental pollution and disposal cost. So, sludge water is partially reused as mixing water. However, if sludge water is reused too much that would influence the quality of concrete. KS specification limits the amount of sludge content up to 3$\%$ of cement weight. In this study, the effect of re-mi-con sludge on the characteristics of concrete is compared to raise the reuse ratio of re-mi-con sludge. From the test results, as blending ratio of re-mi-con sludge increases, workability is decreases. However, the re-mi-con sludge water have a minor effect on the strength development, the drying shrinkage and the resistance of freeze and thawing. Also, the existing model codes of drying shrinkage do not coincide with the test results of this study.

• Journal of the Speleological Society of Korea
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• no.82
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• pp.8-12
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• 2007

In this paper, we have investigated the characteristics of the magnetic abrasive using sludge on polishing of internal finishing of seamless stainless steel tube applying magnetic abrasive polishing. Either green carborundum(GC) grain was used to resin sludge at a low temperature, and the sludge of magnetic abrasive powder was synthesized and crushed into 200 meshes. Surface roughness was measured before and after polishing, and more than 38% of improvement of surface roughness was achieved when grain was used under a specific condition. Even though some degree of surface roughness due to deeper scratches still exist, but the result showed a prospective magnetic abrasive polishing using sludge with green carborundum grains.

• Journal of Environmental Science International
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• v.5 no.4
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• pp.525-533
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• 1996

Chemical characteristics of the industrial wastewater sludge, degradation of the sludge in soil and CO2 generation and changes of nitrogen in soil treated with the sludge were investigated. The results obtained were summarized as follows: 1. Degradation rate of the sludge in soil was 26% at natural temperature, and 33% at incubation temperature at 12 weeks after treatment. 2. T-C, T-N and the C/N ratio of sludge in soil was 16.0%, 0.63% and 26, respectively, at natural temperature, and 15.0%, 0, 65% and 23, respectively, at incubation temperature at 12 weeks after treatment. 3, Camulative CO2 generation in soil treated with l%, 3% and 5% of sludge was 284, 440 and 512 mg/100 g, respectively, at natural temperature, and 440, 558 g and 654 mg/100g, respectively, at incubation temperature at 12 weeks after treatment. 4, Changes of :norganic nitrogen in soil treated with l%, 3% and 5% of sludge were 7.8, 12.8 and 16.3 mg/100g, respectively, at incubation temperature at 12 weeks after treatment. Mineralization ratio of organic nitrogen in soil treated with 1%, 3% and 5% of sludge was 10.7%, 13.6% and 15.2%, respectively, at incubation temperature at 12 weeks after treatment. 5. Chanties of pH in soil treated with 1%, 3% and 5% of Industrial wastewater sludge were in the range of 6.7~7, 5 at natural temperature, and 6.1~7.9 at incubation temperature at 12 weeks after treatment.