• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.1
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• pp.178-184
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• 2007

In the present work, the vermicomposting index was investigated using leakage water from sludge to develop the process of mechanization and automation in the earthworm-cast treatment. The in situ sewage sludge was used batch and continuous experiments. Due to different treatment processes, the physico-chemical characteristics of liquid extracted from sludge was the similar change pattern. However, some items, such as Oxidation Reduction Potential (ORP), pH, Electrical Conductivity (EC) and $NH_3-N$, showed the distinct changes between pre- and post-vermicomposting. Also, The ORP and EC were the best parameters for the vermicomposting index. These results offered that the present vermicomposting technology was an actual earthworm-cast treatment.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.2
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• pp.153-159
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• 2006

It is a serious task to the decommissioning of the uranium conversion plant that the demolition of the lagoon sludge. The main component of the sludge is ammonium nitrate and that is the very explosive material. Therefore, the bio-denitrification is a attractive process to remove the nitrate. In this work, some process variables was tested such as incubation temperature, nitrate concentration, electron donor, C/N ratio, seeding ratio, and pH with an anaerobic bacteria as Pseudomonas halodenitrificans. The results would be used as basic data to the continuous bio-denitrification process.

• Journal of Soil and Groundwater Environment
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• v.7 no.2
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• pp.13-22
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• 2002

Soil washing by surfactants is a technology to enhance mobilization and subsequent degradation of oil pollutants by reducing the surface tension of pollutants which is combined with soil. In this study, biosurfactant, rhamnolipid was produced from Pseudomonas aemginosa ATCC 9027 which had an excellent biodegradable activity in soil without causing secondary pollution. Effects of chemical surfactants on the removal of diesel from diesel-contaminated soil were compared to those of biosurfactants including rhamnolipid. Diesel removal efficiency by rhamnolipid extracted from P. aeruginosa culture broth was over 95% in both batch and column washing test in 5,000ppm diesel-contaminated soil with 1% surfactants after washing for 24 hours. On the contrary, the results of chemical surfactants were below 50∼80%, The chemical surfactants with HLB value(8∼15) showed more then 75% efficiency of diesel removal. But, when the HLB values were below 8 or over 15. their efficiency were observed as less then 60% of diesel removal. Rhamnolipid, biologically produced surfactants, may also be promising agent for enhancing diesel removal from contaminated soil.

• Polymer(Korea)
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• v.26 no.1
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• pp.121-127
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• 2002

We investigated uranium adsorption and adsorption process characteristics in brine water, changing column bed height packed with amidoximated polypropylene-g- acrylonitrile (AOPP-g-AN) fibrous ion-exchanger. Swelling ratios of AOPP-g-AN in fibrous ion-exchanger were 8.54g/g $H_2O_2$ and 8.87 g/g for $H_2O_2$ solvent respectively. Ion exchange capacity increased with degree of graft and showed the maximum, 3.99 meq/g at 100% degree of graft. In batch process, uranium adsorption had reached an initial equilibrium in 10 min with the adsorption rate of 9.5 mg/min. Finial adsorption capacity was 3.95 meq/g, and pH effect could not be observed. In continuous process, adsorption capacity depended on various packing ratios and showed the maximum, 3.92 meq/g at L/D=1. In L/D<2, breakthrough curve was shown two step by channeling flow and ununiform adsorption. Breakthrough time and adsorption capacity were 26 min and 3.63 meq/g, respectively, in brine water adsorption. When compared with actual brine water and model solution, there was no significant difference of adsorption characteristics.

• Resources Recycling
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• v.6 no.4
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• pp.11-16
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• 1997

The wastewater resulted from the process of developing and fuing for x-ray film manufachlring contains a lot of silvercomponent. The average concentation of silver-component is about 1,500 mgA. The wastewater contained silver-component is toxic when it is discharged to the natural ecosystem. So that we must to do pretreatment of wastewater prior to discharge. There are electrolysis. chemical precipitation, and metallic replacement as conventional lreabent proccss of fixer wastewater of x-ray film. Adsorption of silver-component in x-ray fkcr wastewater was carricd out this study. 'Ille manganese dioxide (MDO) reagent and the recovered manganese dioxide (RMDO) from the waste dry-cell were used for adsarbents. Adsorption of silvercomponent was wrried out at the batch and continuous type experimental equipment. The adsorption experiment results were obtained bom silver-component have some diifcrences according to adsorhents. The adsorption results of manganese dioxide reagent (MDO) were better ihan those of waste dry-ccU (RMDO), but the manganese dloxide recovered fmm waste dry-cell (RMDO) will be able la recognized as good adsorbent too.

• KSBB Journal
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• v.15 no.1
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• pp.42-48
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• 2000

Urokinase (UK), a thrombolytic enzyme used to clear catheters obstructed by blood clots, can be also used industrially in the recombinant protein purification system to cleave a fusion protein linked with a certain fragment of GST. We have immobilized UK by covalent attachment to activated Sepharose 6B-Cl gels and evaluated its performance to cleave a fusion protein of hGH and GST. The Sepharose gels were activated by etherification with glycidol (2,3-epoxypropanol) and further oxidized with periodate resulting in glyceryl-Sepharose gels. After the activation treatment, surface density of the aldehyde groups was 7-30 $\mu$mol-aldehde/mL-gel. Immobilization yield was higher than 99% at high pH (10.5), and the immobilized UK maintained ca. 80% specific activity of the soluble UK. In a column reaction the cleavage yield heavily depended on the feed rate, and it was nearly 86% of that from soluble UK. And the immobilized UK was successfully regenerated by unfolding and refolding with 6M GuHCl. After cleavaging reaction, the monomeric hGH was purified by using expanded bed adsorption chromatography.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.10
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• pp.694-702
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• 2013

The purpose of this study is to evaluate a de-watering filtrate treatment and the possibility of securing biological treatment capacity by changing the structure of the secondary clarifier. Accordingly, the column test was conducted to determine the effect of polymer in the de-watering filtrate on sludge sedimentation. Also, the characteristics of de-watering filtrate processing was evaluated through batch test and continuous processing operation. The results showed that sludge settling velocity increased with higher polymer concentration, and that effluent SS concentration was found to decrease. Regarding processing characteristics of de-watering filtrate, the removal efficiency of TSS and TBOD5 increased as the length of secondary clarifier was longer. Also, comparing injections into anoxic tank and secondary clarifier, de-watering filtrate by continuous infusion treatment process showed stability in both conditions. Therefore, by modifying the structure of secondary clarifier, efficient processing of de-watering filtrate is expected to be possible and processing capacity of small sewage treatment plants is considered to be improved.

• Journal of Soil and Groundwater Environment
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• v.13 no.1
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• pp.60-66
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• 2008

Laboratory soil washing experiments with HCl or EDTA were conducted to remediate lead-contaminated soil in a firing range. After lead bullets were removed by standard sieve #18 (1.0 mM), Pb concentrations were measured by EPA Method 3050B (9,443 mg/kg) and Korea Standard Test (4,803.5 mg/kg). The results of the batch test showed that the removal efficiency curve was logarithmic and approximately 90% of lead in soil was removed, when HCl was used. In case of EDTA, the removal efficiency increased proportionally to the concentration of EDTA, up to 98% lead removal with 0.1M EDTA. High mixing strength resulted in increase of removal efficiency and kinetics showed that the most lead was extracted in 10 min.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.1
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• pp.31-38
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• 2008

Animal carcasses have always been and continue to be a major burden in animal production. The main aim of this study is to evaluate the feasibility of thermophilic anaerobic digestion for animal carcasses. A batch test using ground meat and organ as the model substrate showed that animal carcasses arehighly biodegradable at thermophilic anaerobic condition. The volatile solids (VS) destruction and $CH_4$ yieldranged from 52.7 to 58.5% and from 220 to 243 mL/g VS, respectively, at initial substrate VS in the range of 1.5~7.7%. However, high ammonia concentration inhibited continuous operation at substrate VS above 2.5%. As ammonia is formed during the degradation of proteineous organic materials, the major constituent of animal carcasses, the only way to reduce the ammonia concentration would be dilution. Co-digestion with other waste stream without high nitrogen content is recommended as an economically feasible approach for thermophilic digestion of animal carcass.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.2
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• pp.77-88
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• 1988

This research investigated the effect of COD/N ratio on nitrogen removal, and the use of organics in raw wastewater as a carbon source for denitrification in SBR(Sequencing Batch Reactor) systems. Four laboratory scale reactors were operated in three modes. Only the difference between modes were; Mode I operated in aerated condition during fill while Mode II in anoxic condition and Mode III operated on two fills per cycle in anoxic condition. When COD/N ratio increased, total nitrogen removal efficiencies increased from 8.7 to 57.7 percent in Mode I, from 28.9 to 83.2 percent in Mode II and from 42.7 to 97.8 percent in Mode III, respectively. COD removal efficiencies ranged from 93 to 98 percent throughout the study. SBR operation in Mode III of feeding twice per cycle in anoxic condition was an effective operating method for nitrogen removal and nitrogen concentration in effluent can be estimated using influent COD and nitrogen concentrations.