• Journal of Korean Society of Water and Wastewater
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• v.13 no.3
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• pp.29-35
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• 1999

The purpose of this study is to remove the organics, nitrogen and phosphorus using biosorption for the domestic sewage. The new process using biosorption is based on the methods of contact-stabilization, which remove the organics by absorbing them to the surface of the microorganism in the activated sludge. This process consists of biosorption reactor, biosorption clarifier, nitrifying reactor, nitrifying clarifier, denitrifying reactor, phosphorus uptake(polishing) reactor and final clarifier. The efficiency of removal could be reached 91% for organics, 76% for nitrogen, 90% for phosphorus in Eujungbu pilot plant. We operated the plant which irrigated $10m^3$ per day for sewage. During our operation the HRT(Hydraulic Retention time) was maintained for 10.5hr, but it could be reduced as 8.5hr according to our operation results.

• Resources Recycling
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• v.26 no.6
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• pp.58-64
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• 2017

Leaching of black dross with HCl solution was conducted to find a suitable process to recover valauble materials. In this work, the leaching behavior of the components was compared between black dross and the residues after water treatment. All the components except $TiO_2$ in the black dross were dissolved by HCl solution in the experimental ranges. Treatment of the black dross with water to recover the salts has negative effect on the leaching of $Al_2O_3$, MgO and $SiO_2$. The reactions occuring during the leaching were discussed. At an optimum leaching condition of 3 M HCl and $90^{\circ}C$, the leaching percentage of $Al_2O_3$, MgO and $SiO_2$ was 85, 100 and 40%, respectively.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.11a
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• pp.114-117
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• 2004

• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.130-133
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• 2008

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1164-1173
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• 1996

Treating methods and characteristics of waste from a nuclear fuel powder conversion plant were studied. To recovery or treat a trace uranium in liquid waste, the ammonium uranyl carbonate(AUC) filtrate must be heated for $CO_2$ expelling, essentially. Uranium content of final treated waste solution from fuel powder processes for a heavy water reactor(HWR) could be lowered to 1 ppm by the lime treatment after the ammonium di-uranate(ADU) precipitation by simple heating. Otherwise, in case of the waste from fuel powder processes for a pressurized light water reactor(PWR), it is result in 0.8 ppm as a form of uranium peroxide such as $UO_4{\cdot}2NH_4F$ compounds. Optimum condition was found at $101^{\circ}C$ by the simple heating method in case of HWR powder process waste. And in case of PWR powder process waste, optimum condition could be obtained by precipitating with adding hydrogen peroxide and adjusting at pH 9.5 with ammonia gas at $60^{\circ}C$ after heating the waste In order to expelling $CO_2$. As the characteristics of recovered uranium compounds, median particle size of ADU was increased with pH increasing in case of HWP waste. Also, in case of uranium proxide compound recovered from PWR waste, the property of $U_3O_8$ power obtained after thermal treatment in air atmosphere was similar to that of the powder prepared from AUC conversion plant.

• Journal of the Korean GEO-environmental Society
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• v.16 no.5
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• pp.27-33
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• 2015

Manganese in sludge precipitated during water treatment might be soluble again in effluent from sludge thickener. If that happens, the manganese concentration of effluent from water treatment plant will exceed the limit for clean reservation. In this study the influence of pH on Mn concentration of effluent from sludge thickener of water treatment plant was investigated. When the pHs of sludge solutions increased with alkaline materials such as NaOH, KOH, CaO, $Ca(OH)_2$, $CaCO_3$, the Mn concentrations of sludge solutions decreased under the limit. The Mn concentration of effluent from sludge thickener could be controlled with waste limestones from beneficiation process at limestone mine as an alkaline material.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.255-261
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• 2004

Experiments using ozone are presented for the water purification and wine quality improvement. Advanced oxidation process results reveal water treatment by both ozone and UV radiation increases quality of the takju prepared using a Korean conventional nuruk than with ozone-treatment or convectional method only. Water quality was enhanced by ozone treatment, resulting in 85% reduction of hardness, and 30% increase in total glucose produced due to increased conductivity and biodegradability of water. Although initially decreased slightly due to oxidation of takju, higher than expected ethanol production was observed, with ozone plus UV treatment resulting in 20% higher production compared with other methods.

• 수도
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• v.24 no.5 s.86
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• pp.16-28
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• 1997

As sewerage works has become one of the major public works in Korea, the employment of advanced and more appropriate sewerage technology has become essential to improve the efficiency of sewerage works. During last 10 years, the Korean Government has made tremendous amount of investment on sewerage works so that treatment plants in 58 cities have treatment capacity which is equivalent to 52.8% of total daily sewage generation in Korea. This remarkable development, however, has heavily depended on one technology, the conventional activated sludge process as more than 95% of the existing plants employ this process, Recently, the Korean Government and local authorities have plans to introduce more appropriate sewage treatment technologies and research and development in this area has become very active. To encourage employing new and appropriate technologies, however, the proper technology evaluation and verification program for new process is needed. The public sector should play a key role in this program since the sewerage works is one of the major public works. In this paper, the technology evaluation and verification programs related with sewerage facilities in the US and Japan are briefly reviewed. The Innovatived and Alternative Technology programs which was operated by US EPA until recently and Environmental Technology Verification(ETV) program which was commenced in 1995 are introduced. The technology verification programs operated in Japan and also in Korea are also reviewed in this paper to propose a future direction for development of the appropriate evaluation and verification system.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.1
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• pp.47-55
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• 2015

Recently, the production of taste and odor (T&O) compounds is a common problem in water industry. Geosmin is one of the T&O components in drinking water. However, geosmin is hardly eliminated through the conventional water treatment systems. Among various advanced processes capable of removing geosmin, adsorption process using granular activated carbon (GAC) is the most commonly used process. As time passes, however GAC process changes into biological activated carbon (BAC) process. There is little information on the BAC process in the literature. In this study, we isolated and identified microorganisms existing within various BAC processes. The microbial concentrations of BAC processes examined were $3.5{\times}10^5$ colony forming units (CFU/g), $2.2{\times}10^6CFU/g$ and $7.0{\times}10^5CFU/g$ in the Seongnam plant, Goyang plant and Goryeong pilot plant, respectively. The dominant bacterial species were found to be Bradyrhizobium japonicum, Novosphingobium rosa and Afipia broomeae in each plants. Removal efficiencies of $3{\mu}g/L$ geosmin by the dominant species were 36.1%, 36.5% and 34.3% in mineral salts medium(MSM) where geosmin was a sole carbon source.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.2
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• pp.131-143
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• 2018

Phosphorus (P) is a limited, essential, and irreplaceable nutrient for the biological activity of all the living organisms. Sewage sludge ash (SSA) is one of the most important secondary P resources due to its high P content. The SSA has been intensively investigated to recover P by wet chemicals (acid or alkali). Even though $H_2SO_4$ was mainly used to extract P because of its low cost and accessibility, the formation of $CaSO_4$ (gypsum) hinders its use. Heavy metals in the SSA also cause a significant problem in P recovery since fertilizer needs to meet government standards for human health. Therefore, P recovery process with selective heavy metal removal needs to be developed. In this paper some of the most advanced P recovery processes have been introduced and discussed their technical characteristics. The results showed that further research is needed to identify the chemical mechanisms of P transformation in the recovery process and to increase P recovery efficiency and the yields.