Numerical analysis using commercial CFD code was carried out to develop the drag force type vertical axis hydraulic turbine for the improvement of the production efficiency of small hydro energy at low flow velocity condition. Blade pressure changes and internal flows were analyzed according to the presence or absence of the hydraulic turbine blade holes at flow velocity of less than 1.0~3.0 m/s. According to the numerical results, the pressure and flow velocity is severly affected by the flow velocity in turbine blade with no holes, while the influence of flow velocity is comparatively decreased in turbine blade with holes. It is also found that the pressure and flow velocity on the blade surface with holes are evenly distributed with no singular location and it is believed that forming a hole in the blade may be helpful in terms of structural safety.

유기성폐기물(음식물, 하수슬러지 등)은 2005년부터 육상 직매립이 금지되었고, 2006년에 발효된 런던협약에 따라 2013년 1월부터 해양투기 또한 금지되어 폐기물의 처리 및 재활용이 시급한 실정이다. 따라서, 이러한 유기성 폐기물의 효과적인 자원화 방법 중 하나인 혐기성소화가 각광받고 있는 실정이며, 혐기성소화조에서 발생되는 바이가스는 일반적으로 CH4 50~90%, CO2 10~50%, 소량의 H2S 및 NH4로 알려져 있다. 이러한 바이오가스의 정제방법으로는 탄소흡착법, 막분리법 등이 있으나 높은 운전비용과 공정구성의 어려움, 2차 폐기물 발생 등 많은 문제를 일으키고, CO2의 재활용이 아닌 폐기시키고 있어 자원순환적인 측면에서 바람직하지 못하다. CH4의 전환방법중 하나인 CO2 methanation반응은 1M의 CO2와 4M의 H2가 반응하여 1M의 CH4와 2M의 H2O가 생성되는 반응이다. CO2는 열역학적으로 매우 안정된 물질로, 반응에 필요한 에너지를 공급하기 위해서는 수소 등과 같은 높은 에너지의 환원제를 같이 반응에 참여시켜 주어야 한다. 그러나 열역학적 평형으로 인해 전환이 제한되는 경우가 많아, 적절한 반응속도와 선택도를 달성하기 위해 촉매가 요구되며, CO2 methanation 반응에 사용되는 촉매는 주로 Ni, Fe, Al 등 금속계 촉매가 주를 이루고 있다. 따라서 본 연구에서는 바이오가스의 정제효율을 높이기 위하여 CO2 methanation 촉매를 다양한 조건에 따라 제조하였으며 각각의 촉매별 CO2 전환율을 평가하였다.

인과 질소는 하천, 호소 등의 부영양화의 주요 인자로 작용하고 있고 특히 하수 중의 인 농도가 1 mg/L 이상일 경우 조류의 급증식이 일어날 수 있다. 현재 우리나라 하수처리 공정은 인을 기준치 이하로 제거하기 위해 총인 처리 공정을 운영하고 있으나, 이 과정에서 제거된 인은 슬러지와 혼합되어 폐기처분되고 있다. 인은 무한자원이 아닌 유한자원으로 비료, 금속표면처리 세정제를 비롯하여 다양한 용도로 사용될 수 있으며, 우리나라의 경우 전량 수입에 의존하고 있다. 최근 인광석 매장량의 한계로 인하여 인을 회수하여 재이용하는 기술이 반드시 필요한 실정이고, 그 대안으로 축산폐수, 혐기성발효액, 하수처리 시 발생되는 인을 유용한 자원으로 회수하는 방법에 관한 연구가 활발히 이루어지고 있다. 그러나 기존의 연구된 인결정은 100㎛ 이하의 미세 결정으로 고액분리 및 탈수에 어려움이 있다. 본 연구에서는 인제거 기술 중 화학적 침전법 중 하나인 MAP(Magnesium Ammonium Phosphate) 법을 적용하여 부천시와 공동으로 부천시 소재 공공하수처리장에서 발생되는 탈수여액내의 인을 회수하고자 하였으며 다양한 실험조건(pH, 약품, 주입량, Seed적용)에 따라 인회수 및 입상화의 최적 조건을 도출하고 연속반응조를 통하여 2mm 이상의 크기로 입상화가 가능함을 확인하였다. Jar-test 실험결과 pH 9, 몰비 1~9(Mg2+/PO4-P) 범위에서 PO4-P가 55%~90% 제거되었으며, 생성된 결정화물을 seed로 사용하여 최적 약품투입량 도출결과 pH9, 몰비1 조건에서 6회 재사용시 seed 미적용 대비 PO4-P 제거율이 36% 상승하였다. 도출된 조건을 이용하여 2단 상향류(내경이 1.1cm, 1.8cm) 반응조와 침전조로 구성된 Lab Scale 반응조에서 선속도를 변화시켜 입상화를 유도하였다. 입상화시 PO4-P 제거율은 70%~84%, NH3-N 제거율은 20%~28%로 나타났으며, 내경 1.1cm의 반응조 하부에는 2mm~1.5mm, 내경 1.8cm의 반응조 상부에서는 0.6mm~1.2mm로 입상화되었다. 본 연구에서 미립 결정화물을 연속 순환을 통하여 선속도에 따른 입상화를 확인한 결과, 2mm 이상의 인 결정화물의 생성이 가능함을 입증하였다. 이를 통해 탈수 및 건조에 소요되는 에너지를 최소화하고 고순도 입상화로 비료 가치를 향상시켜 경제성 확보가 가능할 것으로 사료된다.

국내 하수처리장에서는 방류수에 총인 규제의 강화에 대응하기 위해 응집제와 여과 혹은 가압 부상 등의 방법을 이용하여 인을 물리·화학적으로 처리고 있으며, 사용되는 응집제는 주로 황산반토, PAC(poly aluminum chloride)등을 이용되고 있다. 그리고 처리 과정에서 발생되는 슬러지(이하에서는 총인 슬러지라고 함)는 별도로 탈수하거나 처리장의 여건에 따라 소화 슬러지와 통합하여 탈수하여 처분되고 있는 실정이다. 총인 슬러지에는 다량의 알루미늄과 인이 함께 함유되어 있으며, D시 하수처리장에 발생되는 총인 슬러지를 대상으로 하여 분석한 결과, 알루미늄이 150~220g/kg, 총인이 16~23g/kg정도 함유되어 있는 것으로 나타났다. 이와 같은 함유량은 다량의 응집제를 사용하는 정수 공정에서 발생되는 슬러지의 알루미늄 함유량(110~140g/kg)에 비해서도 높은 값임을 알 수 있다. 따라서 본 연구에서는 D시의 하수처리장 중에서 총인 슬러지를 별도로 탈수 처리하고 있는 처리장의 슬러지를 대상으로 비료의 원료로 사용할 수 있는 인과 응집제로 재사용을 위한 알루미늄의 회수를 위한 기초적 조건을 검토하고 회수한 응집제의 인의 회수능과 분리 회수한 인의 순도에 대한 검토를 실시하였다. 회수한 응집제의 경우는 황산반토와 유사한 인의 제거능을 보였으나, Hydroxylapatite의 형태로 회수한 인의 경우는 알루미늄과의 완전한 분리가 이루어지지 않아 중량 단위로 인에 비해 3배 이상의 알루미늄이 되어 있는 것으로 나타났지만, 총인 슬러지에 있어서 인의 함유량이 알루미늄의 약 10배 정도임을 감안한다면, 약 70%의 알루미늄을 제거한 알루미늄과 결합되어 있을 가능성이 높은 Hydroxylapatite를 얻을 수 있었다.

The efficiencies of Gang-Byeon sewage treatment facilities, which are based on GPS-X modelling, were analysed and used to design recycle water treatment processes. The effluent of an aeration tank contained total kjeldahl nitrogen (TKN) of 1.8 mg/L with both C-1 and C-2 conditions, confirming that most ammonia nitrogen (NH3 +-N) was converted to nitrate nitrogen (NO3 --N). The concentrations of NH3 +-N and NO3 --N were found to be 222.5 and 227.2 mg/L, respectively, with C-1 conditions and 212.2 and 80.4 mg/L with C-2 conditions. Although C-2 conditions with higher organic matter yielded a slightly higher nitrogen removal efficiency, sufficient denitrification was not observed to meet the discharge standards. For the total nitrogen (T-N) removal efficiency, the final effluent concentrations of T-N were 293.8 mg/L with biochemical oxygen demand (BOD) of 2,500 mg/L, being about 1.5 times lower than that (445.3 mg/L) with BOD of 2,000 mg/L. Therefore, an external carbon source to increase the C/N ratio was required to get sufficient denitrification. During the winter period with temperature less than 10 , the denitrification efficiency was dropped rapidly even with a high TKN concentration (1,500 mg/L). This indicates that unit reactors (anoxic/aerobic tanks) for winter need to be installed to increase the hydraulic retention time. Thus, to enhance nitrification and denitrification efficiencies, flexible operations with seasons are recommended for nitrification/anoxic/denitrification tanks.

This study aimed to evaluate changes in the TN and TP removal efficiencies, depending on whether or not a settling process is applied, in a sequencing batch reactor (SBR) process with a membrane bioreactor (MBR). Nutrient removal was considered in terms of developing an advanced water treatment system for ships in accordance with water quality standards set forth by 227(64). For these purposes, the TN and TP concentrations in the inflow and outflow water were measured to calculate the TN and TP removal efficiencies, depending on whether or not a settling process was used. Water discharged from a bathroom, which was constructed for the experiment, was used as the raw water. The experiment that included a settling process was conducted twice, and the operating conditions were: aeration for 90 min, settling for 30 min, agitation for 15 min, and settling for 15 min for one experiment; and aeration for 150 min, settling for 45 min, agitation for 15 min, and settling for 15 min in the other. Operating conditions for the experiment that did not include a settling process were: aeration for 180 min and agitation for 60 min. The concentration of the mixed liquor suspended solids (MLSS) in the reactor was 3,500 mg/L, while the aeration rate was 121 L/min and the water production rate was 1.5 L/min. For the two experiments where a settling process was applied, the average TN removal efficiencies were 44.39% and 41.05%, and the average TP removal efficiencies were 47.85% and 46.04%. For the experiment in which a settling process was not applied, the average TN removal efficiency was 65.51%, and the average TP removal efficiency was 52.51%. Although the final nutrient levels did not satisfy the water quality standards of MEPC 227(64), the TN and TP removal efficiencies were higher when a settling process was not applied.

Comprehensive evaluation by the old sewage treatment plant residual value, investments are needed, such as adequacy of established objective criteria, such as after maintenance or abolition of sustainable operations. In this study, we propose a comprehensive evaluation items of evaluating structural measures to determine whether the abolition of the old sewage treatment plant.

절화 국화 ‘백설’의 상온 및 5℃ 저장시 Promalin 50mg.L-1 처 리는 절화 후 초기 개화를 억제시키고 품질을 증진시키는 좋은 작 용을 함을 알 수 있었다. 이러한 효과는 상온 저장시 더욱 효과적이 었으며 상품성 손실과 관계되는 생체중 유지에 작용하여 선도유지 에 좋은 전처리제임을 확인할 수 있었다. 또한 Promalin 50mg.L-1 분무 전처리는 절화 국화의 에틸렌 발생을 억제시키는 경향을 나타 내었으며 호흡급등형 패턴을 나타내고 있음을 알 수 있었다.

본 연구의 핵심은 다양한 환경기초시설, 치수관련 시설물 등의 지자체별 개별적 건설과 운영에 따른 예산의 낭비와 비효율적 운영을 지양하는데 있다. 다음으로는 인접 지자체간의 협력적 운영을 통하여, 저출산 고령화 시대에 맞는 수자원시설의 효율성을 강화하여 규모의 경제를 달성하는 방안을 찾는데 있다. 지자체간의 협력을 유도하기 위해서는 관련시설의 투자비용의 합리적 배분이 필요하다. 이러한 합리적 비용배분의 방법으로 비례법, 샤플리방법, 분리비용잔여편익 산출법 등을 제안하고 있다. 지자체별로 건설 중인 하수처리장시설을 사례대상으로 하여 구체적인 적용방법을 제시하고 있다. 본 연구결과의 정책적인 시사점으로는 합리적 비용배분을 통하여 관련 지자체간의 갈등을 사전에 차단하는 동시에, 정부의 환경기초시설에 대한 지자체별 국고보조 방식보다는 유역의 협력적 예산으로 전환하는 것도 바람직한 정책으로 판단된다.

Investigation of flowing time, flower structure, microspore density, microspore vitality and microspore-derived embryo (MDE) formation rate according to the light quality treatment on broccoli donor plant was accomplished. The material was 08-8-3 line yielding high MDE production rate having 4.0 ± 0.5 mm flower bud length. The donor plant was cultivated with light quality treatment of red LED light, red+blue+white LED light and fluorescent light. The light intensity was 50 μ molm-2s-1 and photoperiod was 16/8 hours (light/dark). The flowering time was fastest at red LED light treatment compared to the other light treatment condition. 100.0, 36.4 and 18.2% of flower bud with longer stigma length than floral leaf which reported high MDE production rate were found under red LED light, Red+Blue+White LED light and fluorescent lights respectively. The microspore density and MDE production rate per single flower bud was highest at Red LED light. Suitable flower bud and high MDE production rate could be achieved in a short period if using LED light to broccoli donor plant cultivation. The above result is thought to be very useful for the development of a new cultivar of broccoli and other many crops including Brassica using haploid breeding technology. This journal was supported by the National Research Foundation

This study aimed for evaluating the applicability of the two stage dual media filtration system in field water treatment plant. The field plant of two stage and dual media filtration system was operated for 2 months. Average iron concentrations of the settled water, existing filtered water and second stage filtered water was 0.041 mg/L, 0.007 mg/L and 0.005 mg/L, respectively. Removal efficiency of iron concentration in the second stage is appropriately 35% more than in existing filtered water. Also removal efficiency of residual chlorine in the dual media filtration system is relatively 42.3% more than in existing filtered water due to adsorption of activated carbon, but the removal of ammonia nitrogen by adsorption is insufficient. Average concentrations of THM and chloroform in the settled water are 0.033 mg/L, 0.026 mg/L, respectively and in existing filtered water are 0.023 mg/L and 0.023 mg/L. Average concentrations of THM and chloroform in the dual media filtration system are 0.008 mg/L and 0.013 mg/L. Therefore removal efficiency of THM concentration in second stage is more than 66.4% in existing filtrated water. Also removal efficiency of chloroform in the dual media filtration system is more than 50.0% in existing filtered water because of the adsorption of activated carbon. In this case backwashing period in dual stage system is 4～5 days, but in existing filtration system is 1～2 days.

In a pilot-scale dyeing wastewater treatment using two-type fluidizing media, each thickness of biofilm was 15 and 30 μm, respectively. The numbers of protozoa inhabited in small-size (PEMT A) and big-size (PEMT B) media were 7.5 x 104 and 1.25 x 105 cells/ml, respectively, and dominant species were Entosiphon sulcatus var sulcatus in PEMT A and Chlamydomonas reinhardtii in PEMT B, respectively. Flask experiments using the two media revealed that the percentages of color removal were 25.8% in PEMT A and 27.1% in PEMT B after 72-h cultivation, indicating the necessity of bioaugmentation. Experiments for bioaugmentation effect on color removal were carried out in the pilot-scale treatment for 75 d by three-step operation under the control of wastewater loading rate and microbial input rate. Dye degradation occurred mainly in the second reaction tank, and the attachment of augmented dye-degrading microorganisms to media took at least 35 d. Final value of chromaticity in effluent was 227, meeting the required standard. Therefore bioaugmentation onto media was good for color treatment. In summary, thickness of biofilm formed on the media depended upon the size of media, resulting in different ecosystem inside the media. Hence, this affected microbial community and color treatment further. Accordingly, the reduction of operation cost is expected by efficient color-treatment process using bioaugmented media.

The objectives of this paper are the characterization of the pretreatment of wastewater by microfiltration (MF) membranes for river maintenance and water recycling. This is done by investigation of the proper coagulation conditions, such as the types and doses of coagulants, mixing conditions (velocity gradients and mixing periods), pH, etc., using jar tests. The effluent water from a pore control fiber (PCF) filter located after the secondary clarifier at Kang-byeon Sewage Treatment Plant (K-STP) was used in these experiments. Two established coagulants, aluminum sulfate (Alum) and poly aluminum chloride (PAC), which are commonly used in sewage treatment plants to treat drinking water, were used in this research. The results indicate that the optimal coagulation velocity gradients (G) and agitation period (T) for both Alum and PAC were 200-250 s-1 and 5 min respectively, but the coagulation efficiencies for both Alum and PAC were lower at low values of G and T. For a 60 min filtration period on the MF, the flux efficiencies (J/J0 (%)) at the K-STP effluent that were coagulated by PAC and Alum were 92.9 % and 79.9 %, respectively, under the same coagulation conditions. It is concluded that an enhanced membrane process is possible by effective filtration of effluent at the K-STP using the coagulation-membrane separation process.

This study was conducted to select plant growth regulators effective at ginseng berry set inhibition to help root growth in Korean ginseng (Panax ginseng C. A. Meyer). PGRs (ethephon, gibberellic acid, maleic hydrazide, coumarin) were applied to field grown 5-year-old Korean ginseng between one and two times, before and during bloom in 2009, 2010. The number of treatment was more effective in ginseng berry set inhibition when used two times compared with one time in GA 1,000 ppm, MH (5,000, 10,000 ppm), coumarin (5,000, 10,000 ppm) treatment. According to treatment period of plant growth regulator, ginseng berry set inhibition rate from 20days before flowering date to 5days after blooming was the highest in MH 5000 ppm showing 99.9% and the lowest in GA 100 ppm showing 32.8%. The spray treatments of Ethephon (50, 150 ppm) and MH (5,000, 10,000 ppm) from 20 days before the flowering bloom up to 5 days before, and coumarin (5,000, 10,000 ppm) from 20 days to 6 days and before blooming that induced the inhibitory effect more than 90% after 12 weeks. Considering ginseng berry set inhibition characteristics and treatment period ethephon and coumarin was important about applied period but, MH treatment appeared to effective ginseng berry set inhibition regardless of treatment period.

White light and compound light were found to be the ideal light sources for improving the functionality and ornamental value of indoor plants and reducing the cost of maintenance, but because compound light hinders people from recognizing the original color of plants and makes their eyes easily tired, white light was considered the optimal light satisfying all of the ornamental value, economic efficiency and functionality resulting from plant growth. On the other hand, in the results of examining physiological changes before and after treatment on fine dust PM10 and carbon dioxide removal capacity in a closed chamber under an artificial light source, the patterns of carbon dioxide and fine dust removal were similar among the treatment groups according to light condition, but according to plant type, the removal rate per unit leaf area was highest in Spathiphyllum and lowest in Dieffenbachia. In the experiment on dust and carbon dioxide removal, the photosynthetic rate was over 2 times higher after the treatment, and the rate increased particularly markedly under compound light and white light, suggesting that the photosynthetic rate of plants increases differently according to light quality. These results show that light quality has a significant effect on the photosynthetic rate of plants, and suggests that plants with a high photosynthetic rate also have a high carbon dioxide and dust removal capacity. In conclusion, the photosynthetic rate of foliage plants increased under white and blue light that affect photosynthesis and the increased photosynthetic rate reduced carbon dioxide and fine dust, and therefore white and compound light were found to be the optimal light sources most functional and economically efficient in improving ornamental value and indoor air quality.

The covered stream of cities are considered an odor source. Also, the public do not want a wastewater treatment plant(WWTP) near their properties due to the emission of odor emanating from such sources, although they play an important role in urban development. The purpose of this study is to analyze the pattern distribution of the odorous compounds from the Nambu WWTP and Youngho stream in Busan. odor sampled four times were analyzed by instrumental analysis method and indirect olfactory method. The kinds of offensive odorous compounds examined are acetaldehyde, propion aldehyde, hydrogen sulfide, methyl mercaptan, dimethyl sulfide and ammonia. Also, Concentration of air pollutants has been calculated by ISCST3 models. At the result of this study, The Nambu WWTP releases sulfur compounds. And the major odorous were hydrogen sulfide (1,475 ppb) and acetaldehyde (95 ppb) at Youngho stream. The stink which residents feel will point out the Nambu WWTP mainly if the odor is removed with the improvement of a Youngho stream. Accordingly, we should pay more attention to appropriate components to processes in odor reducing plan at Nambu WWTP.

To develop anti-acidosis and anti-diabetes agentsfrom natural products, the inhibitory activities of Brazilian plant extracts against microbial -amylase and -glucosidase were evaluated. Among 100 different ethanol extracts tested, those of Acacia jurema Mart., Anacardium humile A. St.-Hil., Cedrela odorata L., and Guazuma ulmifolia Lam showed good inhibitoryactivities toward both enzymes. In addition, an extract of Plumeria drastica Mart. showed specific inhibition of -amylase, whereas that of Eugenia uniflora L. demonstrated strong inhibition of the enzyme. IC50 values of -amylase inhibition suggested that the extract of A. humile A. St.-Hil., which has been used as an anti-diabetes medicine in Brazil, had potent inhibitory activity. The IC50 for the A. humile A. St.-Hil. extract () was similar to that of acarbose (). This activity of A. humile A. St.-Hil. was not reduced by heat or acid treatment. Moreover, treatment with HCl (0.01 M) for 1 h increased the inhibitory activity from 57.5% to 81.2%. Also, the extract did not cause hemolysis of human red blood cells at levels up to 1 mg/mL. The results indicate that the extract of A. humile A. St.-Hil. is potentially useful as an anti-acidosis and anti-diabetes agent.

To acquire preliminary data for the control of total nitrogen (TN) in S sewage treatment plant, which processes merging food waste and sewage, the effect of reject water on the total nitrogen in the effluent was examined in this study. Water quality data for the plant during the winter period were applied to calculate the mass balance. It was calculated that at least more than 231 kg/d TN should be removed to control the TN concentration in the effluent. Assuming 18 ppm as the goal TN concentration in the effluent, about 941 kg/d TN should be removed from this plant. Approximately 10% more TN should be removed than at present to achieve this result. It was observed that dewatering the filtrate had a considerably greater effect on the total nitrogen in the effluent than the reject waters. The dewatered filtrate contained 1,399kg/d TN. The contribution of the dewatered filtrate to the TN concentration in the effluent was 0.183, which was 7 to 23 times greater than the other reject waters. In addition, the amount of total nitrogen from the reject water, with the exception of the dewatering filtrate, was lower than the amount of TN that should be removed from S sewage treatment plant. Therefore, it was concluded that one of the most effective methods for controlling the TN concentration in effluent was the removal of the TN contained in the dewatering filtrate.

Activated sludge sewage treatment processes are difficult to be controlled because of their complex and nonlinear behaviour, however, the control of the dissolved oxygen level in the reactors plays an important role in the operation of the facility. For this reason, this study is designed to present a system which accurately measures DO, MLSS, pH and ORP in the aeration tank to alleviate situations above and provide the automatization of a sewage treatment plant (STP) using new DO control system. The automatic control systems must be guaranteed the accuracy. Therefore, the proposed automatic DO control system in this study could be commercial applications in the aeration tanks by means of operating cost analysis and user-friendly for operation and maintenance. We could get accurate data from the lab tank which has water quality checker because there was no vortex and air bubble during the measurement process. Improvement of confidence in the lab tank enabled effective and automatic operation of sewage treatment plants so that operation costs and manpower could be saved. If this result is put in place in every sewage treatment plant nationwide for practical purposes, it is estimated to cost 18.5 million dollars in installing the lab tank and to save 9.8 million dollars in management cost a year, except for cost saved by automation.