• 한국식품영양학회지
• /
• 제33권3호
• /
• pp.287-298
• /
• 2020

When producing rice products, it is very important to select suitable raw materials. Therefore, in this study, the quality characteristics of 16 rice cultivars were quantified to determine the criteria for evaluating the machinability of raw rice. The L value, which can affect the color of porridge prepared from rice, was the greatest for Hwaseonchalbyeo (84.17). The water-binding capacity, related to water interaction, was high in Hyangcheola (113.2%), and water solubility was high in Shingil (22.3%). Dodamssal (42.3%, 70.7 RVU) and Hwaseonchalbyeo (4.7%, 27.8 RVU) showed lower final viscosity compared to the cultivars in which the amylose content was medium groups (16.4~21.2%, 173.6~277.2 RVU). Specifically, cultivars with high or low amylose content had a low viscosity. The characteristics of the distribution of raw rice quality data were confirmed through 11 histograms. Furthermore, amylose content vs. water solubility, water solubility vs. peak viscosity, and peak viscosity vs. final viscosity showed high correlations (r=0.542, -0.569, and 0.836 respectively, p<0.01), and clear cultivar discrimination by the standard error of the mean (0.765~10.811). In conclusion, amylose content, water solubility, and peak viscosity were considered the most suitable characteristics for the quality evaluation of raw rice.

• 환경위생공학
• /
• 제5권2호
• /
• pp.15-21
• /
• 1990

Current analyses of tap water in Seoul metropolitan area prove the water is still safe, despite the Pollution of raw water source. However, it also significantly suggests that a feasibility study of apply, additional advanced technology to existing water treatment processes is needed in order to cope with future pollution. Also, the monitoring of water quality within private, multi-household buildings is important as the monitoring of public water distribution system.

• 상하수도학회지
• /
• 제8권3호
• /
• pp.26-33
• /
• 1994

To slove the problems by the scum, which causes operational and water quality problems in water treatment plants, several researches were conducted based on the site investigations on twelve large water treatment plants, biological and chemical analysis of scum, analyzing raw water quality data. Two types of scum, which are from scum and floe scum, can be classified based on the analysis and site investigations. The major parameter generating floe scum was indicated as fine bubbles dissolved in the water. The fine bubbles dissolved in the water can be generated by over-saturated air in the water, adding aluminum surface as the coagulant, conducting the break point pre-chlorination and so on. The water spray method, which is one of the physical treatment methods for removing scum, was selected for conducting experiments on the removal efficiency in the flocculation basin of the real water treatment plant. The water spray method was successfully applied for removing scum with the advantages of using spiral nozzles in case of using the raw water rather than the cleaned water.

• 한국물환경학회지
• /
• 제22권5호
• /
• pp.831-837
• /
• 2006

The present study applies wavelet transform for the extraction of various periodicities which are included in TOC and pH time series of water quality and rainfall data. The primary objective of the present study is to detect the relationships between the respective data through the correlation analysis using the approximation components which are decomposed by wavelet transform. The results reveal the approximation components of TOC and pH in the 5th level of wavelet transform can explain more than 99% of the whole energy for the raw data respectively and there are considerably high correlation between the approximation components of the respective data used for the study even through no significant correlation between the raw data has been detected.

• 한국환경과학회지
• /
• 제20권5호
• /
• pp.575-580
• /
• 2011

This study characterized water quality of groundwater and purified water used for drinking water in 30 schools in Gyeongsangbukdo Province. The results of the study showed that 43% of groundwater and 45% of purified water were not suitable for drinking. Among them, microbial contaminations were the most serious problem. In raw groundwater, the exceeding rates of total colony counts was the highest in August (53.6%). Purified water samples showed higher rate of exceeding drinking water standard for total colony counts while showing lower rate of exceeding drinking water standard for total coliforms and fecal coliforms in March and August. Overall, proper managements for microbial contaminations are required for both groundwater and purified water. Furthermore, special attention should toward students not to drink water when groundwater or purified water exceeds the drinking water quality standard.

• 상하수도학회지
• /
• 제18권5호
• /
• pp.588-597
• /
• 2004

In this research, we investigated the variation of transmembrane pressure and permeate water quality with pre coagulation and sedimentation with iron based coagulant and chlorination of feed water for PVDF (polyvinylidene fluoride) based MF membrane filtration. NaCIO was fed to the membrane module with dosage of 0.5mg/L and maintained during filtration. To observe the effect of raw water, three types of raw and processed waters, including river surface water, coagulated water and coagulated-settled water, were applied. In case of river surface water, the transmembrane pressure increased drastically in 500 hours of operation. On the contrary, no significant increase in transmembrane pressure was observed for 1,200 hours of operation for coagulated water and coagulated-settled waters. The turbidity of permeate was lower than a detection limit of equipment for all raw waters. The removal efficiency of humic substances of coagulated water and coagulated-settled water was approximate ten times of that of surface river water. And, the removal efficiency of TOC and DOC was approximate two times of that of surface river water. From the results of plant operation, stable operation was maintained at $0.9m^3/m^2{\cdot}day$ filtration flux through the combination of pre-coagulation and pre-chlorination. However, the water quality of permeate was the best when pre-coagulation-sedimentation process was combined with pre-chlorination.

• 한국환경과학회지
• /
• 제11권11호
• /
• pp.1157-1163
• /
• 2002

The effective removal of microcystins by chlorination was investigated on a laboratory scale. With an initial chl.a concentration of more than 1,000 $\mu\textrm{g}$/ℓ, the required chlorine dose for the effective removal of microcystins from the raw water was more than 8.0 mg/ℓ. Whereas, a chlorine dose of 3.0 mg/ℓcould effectively remove microcystins from raw water containing a chl.a concentration of less than 1,000 $\mu\textrm{g}$/ℓ. The microcystin removal was more effective below pH 8.0, plus the optimum pH range was unrelated to the concentration of toxic algal material. Although chlorination is one of the most effective methods for reducing the toxin from blue-green algae, it causes cell lysis and toxin release. However, it was demonstrated that the released cell lysates and toxins could be effectively removed by a higher dose of the oxidant. The highest removal efficiency of dissolved microcystins(initial concentration: 280 $\mu\textrm{g}$ L$\^$-1/) was with a chlorine dose of 5.0 mg/ℓ.

• 상하수도학회지
• /
• 제20권4호
• /
• pp.509-518
• /
• 2006

Although final water of domestic water treatment plants almost contains highly corrosive characteristics, the countermeasures for eliminating internal corrosion of pipeline system have not been conducted yet by controlling water quality in plants. The technologies of internal corrosion control are to control water quality parameters(pH, Alkalinity, and Calcium Hardness etc.) and to use corrosion inhibitor. Under the conditions of domestic water treatment, first of all, the technologies of adjusting water quality parameters has to be considered. Otherwise, The technology of using corrosion inhibitor is favorably thought to be applied with the technology of adjusting water quality parameters in accordance with the result of availability for water treatment process. Since the technology of adjusting water quality parameter influences on other water treatment processes, the guideline of water quality management to be apt for water quality characteristic is required to be estabilished. While the selection of proper chemicals and technologies is dependent upon the raw water characteristics and water treatment process, typically, the technology of $Ca(OH)_2$ & $CO_2$ additions is considered more effective than other technologies in order to adjust pH and Alkalinity, increase $Ca^{2+}$ and form $CaCO_3$ film

• 한국식품조리과학회지
• /
• 제33권1호
• /
• pp.65-71
• /
• 2017

Purpose: This study was carried out to investigate the availability of raw Astragalus membranaceus as a food ingredient. Methods: Raw and dried A. membranaceus water extracts were used to examine the free radical scavenging activity, polyphenol and flavonoid contents, and antimicrobial activity. Also, the sensory characteristics of each water extracts were evaluated. Results: The free radical scavenging activity and total polyphenol and flavonoid contents of raw A. membranaceus extracts were higher than those of dried A. membranaceus extracts. The antimicrobial activities of raw and dried A. membranaceus extracts were examined against several food borne illness-causing microorganisms using the paper disc diffusion method. Inhibition zones were observed in Staphylococcus aureus subsp. aureus, Bacillus subtilis, Pseudomonas aeruglnosa, Salmonella enterica subsp. enterica, Escherichia coli and Bacillus cereus treated with raw extracts. Inhibition zones were observed in B. subtilis, P. aeruglnosa and S. enterica subsp. enterica treated with dried extracts. Raw A. membranaceus extracts had higher scores than dried extracts in sensory evaluation. Conclusion: Raw A. membranaceus was better in antioxidative, antimicrobial activities, and sensory characteristics than dried one.

• 대한토목학회논문집
• /
• 제29권5B호
• /
• pp.419-427
• /
• 2009

기존의 WTP를 이용한 수질개선 관련 편익산정 연구들은 특정 하천에 대하여 '모든 종류의 물놀이 가능한 2급수로 개선', '수영가능수준으로 개선' 등을 설문대상으로 하여 지불의사를 산정한 다음, 해당 유역의 가구수를 곱하여 편익으로 산정하였다. 이는 특정 수자원개발사업에 대한 편익이 아니며, 설문작성 과정에서 수질개선 정도에 대한 객관적인 설명이 부족하고, 단순화되었기 때문에 설문응답자들에게 설문대상재화에 대한 정보를 전달하는데 미흡한 점이 있었다. 따라서 본 연구에서는 수자원개발사업시 상수도 원수수질개선에 대한 편익/비용분석에 적용할 수 있는 편익산정방법론을 제시하였다. 본 연구에서는 수도권을 대상으로 하여 용수를 사용하는 소비자의 BOD 개선정도별 지불의사(WTP)를 설문을 조사하고, 설문결과를 통계분석하여 수질개선-지불의사 관계식을 도출하였다. 사례연구로서 낙동강수계의 내성천 지방2급하천 구간에 계획한 송리원 다목적댐을 대상으로 적용하였다. 방류시나리오별 연평균편익산정 결과, 연평균계획방류량($4.79m^3/s$) 방류시 5,980 백만원, 풍수기(7~10월)를 제외한 기간의 계획방류량($7.22m^3/s$) 방류시 8,663 백만원, 수질악화기 계획방류량($10.72m^3/s$) 방류시 11,905 백만원, 최대계획방류량($13.54m^3/s$) 방류시 14,502 백만원으로 산정되었다. 본 연구에서 개발된 가구소득별 수질개선 (BOD)-지불의사(WTP) 관계식을 이용함으로써 수질개선사업에 대한 원수수질편익을 산정할 때 수질개선정도에 상관없이 쉽게 편익을 산정할 수 있을 것으로 판단된다.