• 한국농공학회논문집
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• 제47권3호
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• pp.69-76
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• 2005

An Absorbent Biofilter System (ABS) combined with the recirculation process was investigated for the feasible application in additional removing of organics (BOD, SS) as well as nutrients (TN, TP) from small Community wastewater in Korea. Polyurethane biofilter media with high porosity and large surface area were /used for the aerobic system. A part of treated wastewater was recirculated into the anoxic septic tank to promote removal of nutrients. The concentrations of BOD and SS of treated wastewater satisfied the regulations for small on-site wastewater treatment facility (10 mg/L) during the overall experimental period. The effluent concentrations of BOD and SS were decreased with enhancement of removal efficiencies of 95.7 and $96.7\%$. The nitrogen and phosphorus removal efficiencies by the recirculation increased to $52.9\%\;and\;43.2\%$ in average during the overall experimental period, respectively. With the improvement, these values were increased as much as additional 42 and $18\%$ compared with those of non-recirculation. The rates of nitrification and denitrification were enhanced showing $65\~77\%\;and\;42\~92\%$, respectively. The described process modification is a low cost and effective method of enhancing nitrogen and phosphorus removal, especially on existing systems without changing major design components of a treatment facility.

• 공업화학
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• 제24권1호
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• pp.38-43
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• 2013

ETA (ethanolamine)는 원자력 발전소 2차계통의 pH 조절제인 암모니아 대체 물질로 2001년부터 이용되고 있다. 환경적 측면에서 난분해성 유기물이며 현재 운영 중인 원자력 발전소 폐수처리설비로 처리가 불가능하다. 본 연구는 현장 시료를 사용하여 N와 COD 제거하기 위한 최적 공정과 사용 약품에 대하여 조사하였다. 폐수 중에 다량 함유되어 있는 ammonium ion은 diffused aeration system을 이용하여 95% 이상을 제거하고 혼합과산화물(sodium persulfate/sodium percarbonate)을 사용하여 산화시키고 응집제를 사용하여 물리 화학적으로 처리 후 90% 이상의 제거효과를 얻을 수 있었다.

• 한국물환경학회지
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• 제38권6호
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• pp.282-291
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• 2022

Since the efficiency of wastewater treatment using microalgae differs depending on the metabolic characteristics of the species, it is important to understand the characteristics of target algae prior to the application in wastewater treatment. In this study, for the application of Arthrospira platensis to wastewater treatment, which is a filamentous alkaliphilic cyanobacteria, basic species specificity was identified and the possibility of application to wastewater treatment was investigated. As a result of the species specificity investigation, the specific growth rate between pH 7.0 and 11.0 showed the highest value near pH 9 at 0.25/day. The reason for the relatively low growth(0.08/day) at pH 11 was thought to be the CA(carbonic anhydrase) enzyme that is involved in carbon fixation during photosynthesis has the highest activity at pH 8.0 to 9.0, and at pH 11, CA activity was relatively low. In addition, A. platensis showed optimal growth at 400 PPFD(photosynthetic photon flux density) and 30℃, and this means that cyanobacteria such as A. platensis have a larger number of PS-I(photosystem I) than that of PS-II(photosystem II). It was speculated that it was because higher light intensity and temperature were required to sufficiently generate electrons to transfer to PS-I. Regarding the applicability of A. platensis, it was suggested that if a system using the synergistic effect of co-culture of A. platensis and bacteria was developed, a more efficient system would be possible. And different from single cocci, filamentous A. platensis expected to have a positive impact on harvesting, which is very important in the latter part of the wastewater treatment process.

• 한국농공학회지
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• 제39권3호
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• pp.64-71
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• 1997

Floating aquatic plant system using water hyacinth was applied to examine feasibility as a wastewater treatment system for the industrial complex in rural area. The wastewater from the industrial complex does not likely contain toxic pollutants because the industries which generate wastewater with toxic compounds are not allowed to move in. Pilot plant was installed at Baeksuk Nongkong Danzi in Chunahn-City, Chunchungnam - Do , and field study was performed during summer and fall of 1996. Hydraulic loading rate was 0. $0.19m^3/m^2$.day. The effluent concentration of DO was higher than influent, and it implies that 0.6m depth reactor was reaerated enough to increase DO level. The influent concentration of BOD varied significantly from less than 30 to 120mg/${\ell}$ during the study period, however, effluent concentrations were generally lower than the water quality standard and removal efficiency was up to 85%. The influent concentration of COD also showed wide variation from less than 40 to 160mg/${\ell}$ and effluent concentration was higher than water quality standard when influent concentration was over l00mg/${\ell}$. The influent concentrations of T-N and T-P were lower than water quality standard and no further treatment was required, and these compounds were also removed in the system. Although some improvement and refinement are still required, overall* the floating aquatic plant system was proved to be feasible to apply to treat wastewater from industrial complex in rural area.

• 상하수도학회지
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• 제24권1호
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• pp.33-40
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• 2010

Individual sewage treatment system is classified into a sewage treatment system which treats all the domestic sewage and a water-purifier tank which treats only effluent flushing from the toilet. The number of registered manufacturers has increased rapidly since 2001. As a result, price competition has increased among the manufacturers and has caused the problems such as the inappropriate production of individual sewage treatment system, the unreasonable permit for building completion and the shortage of the professional technology of the community's public officials in charge. This study collected the problem cases that are related with existing individual sewage treatment system and operation. Efficient improvement plan for the stable supply, installation, maintenance of individual sewage treatment system were suggested.

• 환경위생공학
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• 제23권3호
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• pp.39-46
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• 2008

In order to study the estimate of $CH_4$ emission factors in the municipal wastewater treatment plants, the active sludge process, 5-stage process, Denipho process, and SBR process were investigated. When active sludge process, 5-stage process, and Denipho process were used in wastewater treatment plant, the $CH_4$ emission factors were 2.88, 1.61, and 0.57 g-$CH_4/kg$-BOD, respectively. On the other hand, in the case of SBR process, it was 4.14 g-$CH_4/kg$-BOD. These results indicate that SBR process was effective for $CH_4$ emission in municipal wastewater treatment plants. Using the above processes, the methane emission factor and amount of waste water sludge were $4.78m^3/t$ and $12,204,506m^3/yr$, respectively. The remove of BOD was a range of $93.91{\sim}98.63%$.

• 한국환경과학회지
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• 제8권1호
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• pp.75-81
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• 1999

In recent years increasing production and disposal of wastewater have caused an accelerated eutrophication of receiving waters. Therefore, in order to alleviate the detrimental impact of wastewater discharge, there is an increasing demand for removing the main nutrients, nitrogen and phosphorus, as well as the organic content of the waste water prior to disposal. This is effectively achieved by extended conventional treatment technology. However, the working expenses and energy requirements of such advanced treatment systems are rather high. So in a sparsely populated rural community is required development of wastewater treatment system combined with the regional characteristics. In this study, the systems are planted with Reeds and Amaryllis In A.C and estimated purification potential of system. The results obtained are as follows. BOD removal rate is 20% in the early stage, the last removal rate is 35% in A.C process and is 65% in Amaryllis+A.C process and is 50% in Reed+A.C process. T-N removal rate by Amaryllis is average 2.6g/$m^3$ㆍd, T-N removal rate by Reed is average 1.76g/$m^3$ㆍd. T-P removal rate by Amaryllis is average 0.27g/$m^3$ㆍd, T-P removal rate by Reed is average 0.25g/$m^3$ㆍd. BOD removal rate constant with retention time is 1.4494(1/d), T-N removal rate constant is 0.5428(1/d), T-P removal rate constant is 0.5287(1/d).

• 한국환경복원기술학회지
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• 제5권4호
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• pp.31-38
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• 2002

The rate of sewage treatment in South Korea was 68% in the late 1999. Sewage treatment is mostly made near big cities such as Seoul and Busan, and it is little in rural areas. Wastewater from households goes to streams directly without treatment in rural areas and pollutes streams. It is necessary to improve the progress for treatment of nutrients such as N and P which cause eutrophication in streams and lakes, because sewage treatment system in South Korea focuses on treatment of basic organic matters. Therefore it will contribute to improve discharged water quality if small sewage treatment systems by aquatic plants and microbes are introduced to rural areas where are not connected to local sewage treatment facility. This experiment was conducted to find out the best way using aquatic plants and microbes to purify wastewater from households through individual sewage treatment system. Phragmites communis, Iris pseudoacorus, Acorus calamus var. angustatus, Typha orientalis and Oenanthe javanica were used for this experiment. BOD, COD, SS, T-N and T-P were analyzed following standard methods for wastewater. The result shows that wastewater was roughly purified through pebbles and sands, and highly purified through aquatic plants and microbes especially in T-N and T-P. Iris pseudoacorus is the most effective in reduction of COD and BOD level. This system will work even in winter when plants die because microbes will be still working.

• 공업화학
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• 제27권1호
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• pp.1-9
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• 2016

미세조류와 박테리아의 공배양 시스템은 두 미생물종이 공생적 관계가 있다면 한 배양기에서 BOD와 영양염류의 동시 제거가 가능하다. 이때 영양염류는 미세조류의 바이오매스 성분으로 전환된다. 이 총설은 미세조류와 박테리아의 공생적 혼합배양을 이용한 하폐수처리, 특히 질소와 인의 제거에서의 중요성과 최근의 연구동향을 살펴보았다. 미세조류는 광합성을 통해 산소를 발생시키고 박테리아는 이 산소를 전자수용체로 이용하여 유기물의 산화분해에 활용할 수 있다. 호기성 박테리아가 유기물을 산화할 때 발생되는 $CO_2$는 미세조류의 탄소원으로 섭취되어 탄소동화작용에 사용된다. 미세조류와 박테리아의 공배양은 상호 이익이 될 수도 있고 저해가 될 수도 있으므로 지속적인 영양염류 제거를 위해서는 상호 이익이 되는 공생적 관계가 필수적으로 요구된다. 이를 위해서는 하폐수처리에 사용되는 상용적인 두 미생물 종의 선택이 중요하다.

• 한국물환경학회지
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• 제21권2호
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• pp.132-140
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• 2005

The pilot test of a new alternative for small wastewater treatment system has been conducted for two years. It consists of a hybrid bioreactor and the expert system including the process control logic, PLC system, and HMI for the process automation. In order to monitor and remote control its status, the real-time data was transferred from the on-site control center to the central station via a wireless local area network. More efficient and stable performances were observed at automatic operating mode compared with the manual. On an average, COD, SS, T-N and T-P concentrations in the effluent from the hybrid bioreactor were less than 14, 7, 12 and 0.9 mg/L, respectively. According to the result from pilot tests, the quality of treated wastewater with sand filtration was enough to be utilized again.