간행물
상하수도학회지 KCI 등재 Journal of the Korean Society of Water and Wastewater
- 발행기관 대한상하수도학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1225-7672 (Print)2287-822X (Online)
- 수록기간 1993 ~ 2023
- 주제분류 공학 > 건축공학 공학 분류의 다른 간행물
- 십진분류KDC 539DDC 628
권호리스트/논문검색
제31권 제5호 (2017년 10월) 11건
1.
2017.10
구독 인증기관 무료, 개인회원 유료
RuO2 is a common active component of Dimensionally Stable Anodes (DSAs) for chlorine evolution that can be used in wastewater treatment systems. The recent improvement of chlorine evolution using nanostructures of RuO2 electrodes to increase the treatment efficiency and reduce the energy consumption of this process has received much attention. In this study, RuO2 nanorod and nanosheet electrodes were simply fabricated using the sol-gel method with organic surfactants as the templates. The obtained RuO2 nanorod and nanosheet electrodes exhibit enhanced electrocatalytic activities for chlorine evolution possibly due to the active surface areas, especially the outer active surface areas, which are attributed to the increase in mass transfers compared with a conventional nanograin electrode. The electrocatalytic activities for chlorine evolution were increased up to 20 % in the case of the nanorod electrode and 35% in the case of the nanosheet electrode compared with the nanograin electrode. The RuO2 nanorod 80 nm in length and 20-30 nm in width and the RuO2 nanosheet 40-60 nm in length and 40 nm in width are formed on the surface of Ti substrates. These results support that the templated RuO2 nanorod and nanosheet electrodes are promising anode materials for chlorine evolution in future applications.
4,000원
2.
2017.10
구독 인증기관 무료, 개인회원 유료
The 4th Industry Revolution was advocated by Klaud Schwab who is founder of World Economic Forum at the Davos Forum in 2016, and there are big differences on ICT based 4th Industry revolution in the aspects of speed, scope and impact compared with the 3rd Industry revolution. Creating new industries and values through technology such as internet of things, cloud, big data, and artificial intelligence are included in the meaning of The 4th industry revolution. In this article, the direction of change to water technology in response to the 4th Industry revolution is surveyed. 4G Water Infra should minimize environmental impact under the consideration of sustainable development and advanced technologies. To solve the existing water infra problems, it is common and fundamental that the intake water from nature can be regarded as borrowed from nature and it should be returned to natural state with improved water quality. Government, academic organizations and industries should prepare and collaborate together in order to help our country with outstanding capabilities in infrastructure construction and ICT to lead the 4G water technology development.
4,000원
3.
2017.10
구독 인증기관 무료, 개인회원 유료
In this paper, we investigate the characteristics of membrane fouling caused by water temperature in the Membrane bioreactor(MBR) process and try to derive the membrane fouling control by chemical enhanced backwashing(CEB). The extracellular polymeric substances(EPS) concentration was analyzed according to the water temperature in the MBR, and the membrane fouling characteristics were investigated according to the conditions, with sludge & without sludge, through a lab-scale reactor. As shown in the existing literature the fouling resistance rate was increased within sludge with the water temperature was lowered. However, in the lab-scale test using the synthetic wastewater, the fouling resistance increased with the water temperature. This is because that the protein of the EPS was more easily adsorbed on the membrane surface due to the increase of entropy due to the structural rearrangement of the protein inside the protein as the water temperature increases. In order to control membrane fouling, we tried to derive the cleaning characteristics of CEB by using sodium hypochlorite(NaOCl). We selected the condition with the chemicals and the retention time, and the higher the water temperature and the chemical concentration are the higher the efficiencies. It is considered that the increasing temperature accelerated the chemical reaction such as protein peptide binding and hydrolysis, so that the attached proteinaceous structure was dissolved and the frequency of the reaction collision with the protein with the chemical agent becomes higher. These results suggest that the MBRs operation focus on the fouling control of cake layer on membrane surface in low temperatures. On the other hand, the higher the water temperature is the more the operation strategies of fouling control by soluble EPS adsorption are needed.
4,000원
4.
2017.10
구독 인증기관 무료, 개인회원 유료
A dimensionally stable anode based on the RuO2 electrocatalyst is an important electrode for generating chlorine. The RuO2 is well-known as an electrode material with high electrocatalytic performance and stability. In this study, sonoelectrodeposition is proposed to synthesize the RuO2 electrodes. The electrode obtained by this novel process shows better electrocatalytic properties and stability for generating chlorine compared to the conventional one. The high roughness and outer surface area of the RuO2 electrode from a new fabrication process leads to increase in the chlorine generation rate. This enhanced performance is attributed to the accelerated mass transport rate of the chloride ions from electrolyte to electrode surface. In addition, the electrode with sonodeposition method showed higher stability than the conventional one, which might be explained by the mass coverage enhancement. The effect of sonodeposition time was also investigated, and the electrode with longer deposition time showed higher electrocatalytic performance and stability.
4,200원
5.
2017.10
구독 인증기관 무료, 개인회원 유료
In this study, we divided the process operation scenarios into three categories based on raw water temperature and turbidity. We will select and operate the process operation scenario according to the characteristics of the raw water. The number of algae in the DAF treated water has been analyzed to be less than 100 cells/mL. These results indicated that the DAF process is effective in removing the algae. In addition, the scenario of the integrated management decision algorithm of the DAF process was developed. DAF pilot plants (500 m3/day) process has shown a constantly sound performance for the treatment of raw water, yielding a significantly low level of turbidity (DAF treated water, 0.21~1.56 NTU).
4,000원
6.
2017.10
구독 인증기관 무료, 개인회원 유료
In recent years there have been large increases in the hydraulic loading rates used to design dissolved air flotation (DAF) facilities for drinking water applications. High rate DAF processes are now available at loading rates of 20 to 40 m3/m2·h. This research evaluated dissolved air flotation as a separation method for algae and organic compounds from water treatment plants. During the service period of 2016. 5. to 2017. 6., DAF pilot plants (500 m3/day) process has shown a constantly sound performance for the treatment of raw water, yielding a significantly low level of turbidity (DAF treated water, 0.21～1.56 NTU). As a result of analyzing the algae cell counts in the influent source, it was expressed at 100-120 cells/mL. In DAF treated water, the removal efficient of alge cell counts was found to be upto 90%. The stable turbidity and algae removal were confirmed by operating the high rate DAF process under the condition of the surface loading rate of 30 m3/m2·hr.
4,000원
7.
2017.10
구독 인증기관 무료, 개인회원 유료
In this study, a model was developed to predict for Disinfection By-Products (DBPs) generated in water supply networks and consumer premises, before and after the introduction of advanced water purification facilities. Based on two-way ANOVA, which was carried out to statistically verify the water quality difference in the water supply network according to introduce the advanced water treatment process. The water quality before and after advanced water purification was shown to have a statistically significant difference. A multiple regression model was developed to predict the concentration of DBPs in consumer premises before and after the introduction of advanced water purification facilities. The prediction model developed for the concentration of DBPs accurately simulated the actual measurements, as its coefficients of correlation with the actual measurements were all 0.88 or higher. In addition, the prediction for the period not used in the model development to verify the developed model also showed coefficients of correlation with the actual measurements of 0.96 or higher. As the prediction model developed in this study has an advantage in that the variables that compose the model are relatively simple when compared with those of models developed in previous studies, it is considered highly usable for further study and field application. The methodology proposed in this study and the study findings can be used to meet the level of consumer requirement related to DBPs and to analyze and set the service level when establishing a master plan for development of water supply, and a water supply facility asset management plan.
4,000원
8.
2017.10
구독 인증기관 무료, 개인회원 유료
The small-scale sewage treatement system with A2/O process was applied to evaluate applicability for Mongolian sewage, It was designed to have 10 m3/d flowrate and installed in Ulaanbaatar, Mongolia. During over 6month operation BOD, COD, TN, TP removal efficiency were measured and operation condition was optimized. In addition, MLSS concentration its internal circulation rate and DO were adjusted properly. BOD, COD showed average 88 perecent of removal and TN and TP achieved 81 percent and 88 percent removal efficency, respectively. Maxium influent concentration of BOD, COD, TN and TP was 214 mg/L, 300 mg/L, 24.3 mg/L and 5 mg/L respectively, which were decreased to 4.1 mg/L, 5.6 mg/L, 1.3 mg/L and 0.15 mg/L by the test system. This study show possibility tham small-scale sewage treatment system could be a useful system for scattered sewage wastewater treatment.
4,000원
9.
2017.10
구독 인증기관 무료, 개인회원 유료
This study aimed to investigate growth rate and nutrient consumption of Chlorella vulgaris according to different light irradiation interval. Applied light irradiation intervals were 12 hr, 4 hr, 1 hr, and 1 min. The light source was flexible LED(Blue:Red=1:1), light intensity was 200 PPFD and Light/Dark cycle was 1:1. As a result, growth rate and nutrient removal efficiencies showed no significant differences depending on the light irradiation interval. Considering the reproduction characteristics of applied microalgae cultures of this study, this is thought to be one of the possible reasons of above results. Because Chlorella vulgaris performs an asexual reproduction and it is known that there is no significant relationship between light irradiation interval and growth rate, including nutrient consumption in case of asexual reproduction.
4,000원
10.
2017.10
구독 인증기관 무료, 개인회원 유료
This study derived the unit of industrial water usage reflecting the latest industry trends. Available for establishing plans such as the master plan for water supply system and analyzed changes in the basic unit by a comparison with the current basic unit values. This study analyzed 4,038 samples with a sampling error of less than 1.5 % at the 95 % confidence level after removing outliers according to a log-normal distribution. As a result, the unit of industrial water usage per site area in the whole manufacturing industry was 7.11 m3/1,000m2/d. The ten industrial categories (C10, C13, C20, C21, C22, C25, C27, C30, C32, C33) showed a similar unit value compared to before, and the four industrials categories (C11, C17, C22, C31) showed a more unit value than before. With regard to the nine industrial categories (C14, C15, C16, C18, C19, C24, C26, C28, C29), the unit value decreased. Cases that companies examined before were the same as the companies examined in this study were analyzed. The result that the changes in the unit industrial water usage were reasonable was obtained. However, in some industrial categories (C17, C14, C24, C29), the unit value was changed by a small number of companies with large-scale water use or unit value of sampling had a large deviation. It was considered necessary to survey them periodically. The unit of industrial water usage derived by the survey in this study reflects the current industrial trends in 2016. Water use in manufacturing companies has continuously changed by the development of manufacturing technologies and simplification of manufacturing processes. In order to deal with this, it is considered necessary to survey the usage of industrial water periodically from a long-term perspective.
4,200원
11.
2017.10
구독 인증기관 무료, 개인회원 유료
A real scale leakage test facility was developed to study the leak signal characteristics of water supply pipelines, and then leak tests were carried out. The facility was designed to overcome the limited experimental circumstances of domestic water supply pipeline experimental facilities. The length of the pipeline, which was installed as a straight line, is 280m. Six pipes were installed on a 70m interval with different pipe material and diameters that are DCIP(D200, D150, D100, D80), PE(D75) and PVC(D75).The intensity of the leakage is adjusted by changing the size of the leak hole and the opening rate of ball valve. Various pressure conditions were simulated using a pressure reducing valve.To minimize external noise sources which, deteriorate the quality of measured leak signal, the facility was built at a quiet area, where traffic and water consumption by customers is relatively rare. In addition, the usage of electric equipment was minimized to block out noise and the facility was operated using manual mode. From the experimental results of measured leakage signal at the facility, it was found that the signal intensity weakened and the signal of high frequency band attenuated as the distance from the water leakage point increased.
4,200원
