• Proceedings of the Korean Environmental Health Society Conference
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• 2002.04a
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• pp.26.1-28
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• 2002

Entrapped media with cellulous triacetate in which actived sludge was applied to induce operation factors and sewage treatment on site. The results are summarized as follows; The treatment efficiency of entrapped media is 92％, 90％ and 80％ at the size of 5mm, 7mm, and 12mm, respectively. Also, treatment efficient rate was increased by the packed amount of media in less than 30％ packed, while in more than 40％ packed that was decreased. It takes 10day to reach the steady states and it is less than the existing activated sludge method. The slopes of oxygen consumption rate are almost parallel both in the entrapped media and free sludge. When organic loading rate is less than 1.0 kg/㎥. d on site, it is achieved good removal rate independent of changes of loading rate.

• Journal of the Korean Society of Industry Convergence
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• v.16 no.2
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• pp.35-39
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• 2013

This paper synthesized the new copper removal agent(PW-2001) and investigated removal efficiency of copper, COD, calcium, SS and sludge amounts. Removal efficiency of copper were 96.1% and 99.1% with the lime and PW-2001, respectively while COD removals reached up to 38% and 69.6% with the use of lime and PW-2001. The concentrations of calcium and SS with PW-2001 were decreased 2.68 and 4.95 times lower than those with lime. Amount of sludge with PW-2001 was 60% smaller than lime. Quantity of PW-2001 needed for coagulation only reached 58.7, compared to lime standard quantity(100), and total cost of copper removal with PW-2001 was saved 25% more than lime.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.109-112
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• 2005

As civilization progresses amount of sewage sludge continues to increase from a sewage disposal plant with a huge expenditure of water resources. So It is necessary to reduce the high costs of sewage disposal and the pollution of the environment and also a unit cost of artificial lightweight aggregate by continual recycling. The purpose of this study is to put artificial lightweight aggregate concrete to practical use by using sewage sludge and clay

• Journal of Environmental Health Sciences
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• v.28 no.1
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• pp.79-84
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• 2002

Entrapped media with cellulous triacetate in which activated sludge was applied to induce operating factors and sewage treatment on site. The results are summarized as follows; The treatment efficiency of entrapped media is 92%, 90% and 80% at the size of 5mm, 7mm, and 12mm, respectively. Also, treatment efficient rate was increased by the packed amount of media in less than 30 % packed, while in more than 40 % packed that was decreased. It takes 10 day to reach the steady states and it is less than the existing activated sludge method. The slopes of oxygen consumption rate are almost parallel both in the entrapped media and free sludge. When organic loading rate is less than 1.0 kg/m$^3$ㆍd on site, it is achieved good removal rate independent of changes of loading rate.

• Resources Recycling
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• v.3 no.3
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• pp.12-20
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• 1994

Difficulties lies on using the dust from iron making process as a raw material for sintering process mainly because of high amount of Zn or alkali content and its ultra fine characteristics. To eliminate these toxic influence, new fluxing materials were tested and could get a very successful results. This fluxing materials, Calcium-ferrite of magnesio-ferrite were made from various waste materials such as lime stone sludge, bag filter dust, waste EP dust and dolomite sludge by simple way of pre-sintering. Sintering behavior as a fluxing materials was revealed to be good in any aspects and new concept of total recycling system could be established.

• Corrosion Science and Technology
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• v.20 no.1
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• pp.22-25
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• 2021

In the past, Alloy 600 nickel-based alloys have been widely used in steam generators. However, most of them have been replaced by thermally treated alloy 690 tubes in recent years because mill annealed alloy 600 materials are known to be susceptible to stress corrosion cracking. Unlike this general perception, some steam generators using mill annealed alloy 600 tubes show excellent performance even though they are designed, manufactured, and operated in the same way. Therefore, various analyses were carried out to determine causes for the degradation of steam generators. Based on the general stress corrosion cracking mechanism, tube material susceptibility, residual stress, and sludge deposits of steam generators were compared to identify factors affecting stress corrosion cracking. It was found that mill annealed alloy 600 steam generator tubes showed higher resistance to stress corrosion cracking when the amount of sludge deposits on tube surface was smaller and residual stress generated during the fabrication was lower.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.7
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• pp.746-751
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• 2006

In this study, drying and carbonization experiment was conducted in a fluidized bed reactor according to the variations in gas velocity, particle size, and reactor temperature. As a result, the weight loss rates of sludge by drying in the fixed bed and fluidized bed type dryer showed that drying in the fluidized bed was about 6 times faster than drying in the fixed bed, and the weight loss rates of sludge by carbonization in the fixed bed and fluidized bed type reactor showed that carbonization in the fluidized bed was about 4 times faster than drying in the fixed bed. This implies that carbonization in the fluidized bed was completed within 10 minutes. Although the amount of char decreased with the increase of carboniration temperature, the amount of char became similar at upper 873K. Also, the amount of char decreased with increasing gas velocity. Consequently, it could be efficient that slow fluidization should be maintained within the range of fluidization in case of fluidized carbonization of sewage sludge at 873K.

• Economic and Environmental Geology
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• v.38 no.5 s.174
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• pp.579-585
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• 2005

Cheap and environmental sound biosorbent was made for the adsorption of arsenate using an waste activated sludge. The biosorbents were methylated in 9hours and 24 hours respectively for the better adsorption of arsenate. The amount adsorbed of arsenate(V) increased with increasing methylation time. The specific arsenate adsorption was 0.06mmol As(V)/g biomass when the biosorbent was methylated in 24 hours. The methylated biosorbents were also studied with pH 5, 7 and 9. The pH of the solution affect the amount of adsorption of arsenate of the biosorbent even though it was methylated. The specific arsenate adsorption of the biosorbent at pH 5 was best and it was three times greater than the amount of arsenate adsorbed at pH 9.

• Journal of Soil and Groundwater Environment
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• v.26 no.6
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• pp.18-26
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• 2021

Soil aggregation begins with flocculation of clay particles triggered by interfacial reactions of polyvalent cation such as Ca²⁺ and Fe³⁺, and they are also known as important elements to control the mobility of arsenic in soil environment. The objective of this study was to investigate the feasibility of CMDS (coal mine drainage sludge) for soil loss reduction and stabilization of arsenic-contaminated soil in a 37% sloped farmland under rainfall simulation. The amount of soil loss decreased by 43% when CMDS was applied, and this result was not significantly different from the case of limestone application, which yielded 46% decrease of soil loss. However, the relative amount of dispersed clay particles in the sediment CMDS-applied soil was 10% lower than that of limestone-applied soil, suggesting CMDS is more effective than limestone in inducing soil aggregation. The concentrations of bioavailable arsenic in CMDS amended soil decreased by 46%~78%, which was lower than the amount in limestone amended soil. Therefore, CMDS can be used as an effective amendment material to reduce soil loss and stabilize arsenic in sloped farmland areas.

• Korean Journal of Environmental Agriculture
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• v.23 no.4
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• pp.211-219
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• 2004

Three sludge types from pharmaceutical byproducts and one sludge type from cosmetic waste-water sludge as raw materials of compost were used in a field based concrete pot ($4\;m^2$, $2\;m{\times}2\;m$) for investigating damage of red pepper cultivation. These sludges and pig manure (1 Mg/10a, dry basis) were incorporated into the upper of clay loam soil prior to transplanting with red pepper. Changes in concentration and properties of heavy metal for both of soil and plant were investigated 4 times during of red pepper growth. Plant height and stem diameter of red pepper in sludge treatments except to Pharmaceutical sludge 3 were poor than those of NPK treatment. This result were regarded as an effect of incompleted decomposition sludge which has a lot of organic matter concentration. Amount of total As was increased rapidly Jul. 8. in soil, total Zn Cu Pb Cd were in harvest time, and 1 N-HCl extractable Zn Cu Pb Cd As were in harvest at middle stage and then decreased. Amounts of nitrogen in plant (leaf and stem) were high in Phamaceutical Sludge 1 and fig Manure treatment in early and middle stage because of organic matter and nitrogen concentrations and characteristics. Amounts of Zn, Pb, and Ni in leaf and amount of Zn and Pb in stem were increased in harvest time so that we need to have a concern in detail. Total yield of red pepper was Pig Manure > Phamaceutical Sludge 3 > Phamaceutical Sludge 1 > NPK > Phamaceutical Sludge 2 and Cosmetic Sludge treatment was decreased considerably to compare to others. Amounts of Zn and Cu in green and red pepper in harvest time were higher than the other heavy metals. Finally these results can use to utilize that finding damage on crop for authorization and suitability estimation of raw material of compost.