• Title/Summary/Keyword: characteristics of water quality

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Detection of Perchlorate in Nakdong River and Removal Characteristics of Perchlorate by Granular Activated Carbon Process (낙동강 수계에서의 Perchlorate 검출 및 활성탄 공정에 의한 제거특성)

  • Son, Hee-Jong;Jung, Chul-Woo
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.4
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    • pp.438-443
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    • 2007
  • This study was done to investigate perchlorate contamination in Nakdong river. The perchlorate was detected in Nakdong river and ranged from ND to $82.1{\mu}g/L$. The highest concentration was observed in Wheguan. The perchlorate concentration was decreased with the down stream of Nakdong river. Three different virgin activated carbons made of each coal(Calgon), coconut(Samchully) and wood(Picabiol) based activated carbon(AC) were tested for an adsorption performance of perchlorate in a continuous adsorption column. Breakthrough behavior was investigated that the breakthrough points of coal, coconut and wood based AC as 2,300 bed volumn(BV), 719 BV and 288 BV respectively. Adsorption capacity(X/M) of real, coconut and wood based AC was observed. The experimental results of adsorption capacity showed that coal based AC was highest$(768.2{\mu}g/g)$, coconut based AC was intermediate$(299{\mu}g/g)$ and wood based AC was lowest$(99.2{\mu}g/g)$. Moreover, carbon usage rates(CURs) for coal, coconut and wood based AC had been shown as 0.71 g/day, 2.16 g/day and 3.45 g/day respectively. The constant characteristic of the system, k of coal, coconut and wood based ACs were found to be 307.2, 102.5 and 94.2, respectively.

Quality Characteristics of Mackerel Surimi Prepared by Alkaline Washing under Reduced Pressure (감압 알칼리 수세하여 제조한 고등어 Surimi의 품질 특성)

  • Park, Hyung-Sun;Park, Sang-Woo;Yang, Seung-Taek
    • Korean Journal of Food Science and Technology
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    • v.30 no.5
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    • pp.1120-1127
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    • 1998
  • An attempt was made in this study to investigate the optimum condition of washing for preparation of mackerel surimi by alkaline washing of 1, 3, 5, and 7 times under atmospheric (760), 660, and 560 mmHg pressure. The qualities of surimis were examined by analyzing the factors such as water content, crude lipid, pH, volatile basic nitrogen (VBN), expressible drip, protein extractability, $Mg^{2+}-$, $Ca^{2+}-$ and EDTA-ATPase activity, transglutaminase (TGase) activity, gel strength and color. The contents of moisture, crude lipid, pH and VBN in surimis prepared by alkaline washing under atmospheric, and reduced pressure went up to $72.0{\sim}72.9%$, $4.8{\sim}5.7%$, $6.9{\sim}7.0$ and $6.7{\sim}7.0\;mg/100\;g$, respectively. Protein extractability, ATPase activity and TGase activity were highest in surimis prepared by alkaline washing under 560 mmHg. Gel strengths of surimi setting gel and cooked gel from five times washing under 560 mmHg were 420 g cm (atmospheric, 330 g cm) and 485 g cm (atmospheric, 412 g cm), respectively. For the preparation of mackerel surimi, optimum washing condition was five times washing under 560 mmHg.

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Effect of dietary supplement with fermentation feed on the physicochemical properties of pork (발효 사료 첨가가 돼지고기의 이화학적 특성에 미치는 영향)

  • Park, W.J.;Sung, C.K.;Kim, G.J.
    • Korean Journal of Agricultural Science
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    • v.24 no.1
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    • pp.41-49
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    • 1997
  • The results on the chemical characteristics of the pork fed with fermented feeds are summarized as follows; 1) The pork treated with fermented feeds had lower fat and higher protein content than control pork in proximate compositions. It is considered to be the improvement of the quality. 2) It was not recognized to the difference of oxidation level among the sample porks. 3) Oleic acid was the highest concentration in the components of fatty acid of pork. The rate of the saturated and unsaturated fatty acids is 38.8 % : 59.9 % in the ordinary meat, 40.8 % : 57.8 % in the a high-grade meat, and 36.3 % : 62.0 % in the pork treated with fermented feeds. In addition, the essential fatty acid content of them is 14 %, 11.2 %, and 16.7%, respectively. 4) Glutamic acid was the highest composition in total amino acids and the essential amino acid content was 39% in both an ordinary meat and the pork treated with fermented feeds, and 14 % in high-grade meat. 5) It was no difference in the inorganic content among the samples. The water holding capacity by extraction meat juice was higher to 92 % in the pork treated with fermented feeds and 15.6 % in a loss in quantity by heating than others. Thus, the pork bred with fermented feeds was evaluated to be good in terms of processing and cooking.

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Evaluation on HACCP prerequisite-program performance within general hospital foodservice operations (종합병원 급식소의 HACCP 선행요건 관리 수행도 평가)

  • Song, Yoon-Ji;Bae, Hyun-Joo
    • Journal of Nutrition and Health
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    • v.49 no.1
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    • pp.43-50
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    • 2016
  • Purpose: This study was conducted to examine prerequisite-program performance of the hospital foodservice operation and develop measures for improvement of prerequisite-program performance. Methods: Data were collected through surveys administered to 168 hospital dieticians in the Seoul, Incheon, Gyeonggi-do, Daegu, and North Gyeongsang areas. Out of total questionnaires, 65 questionnaires were usable and the response rate was 38.7%. Statistical analyses were performed using the SPSS program (ver 20.0) for ${\chi}^2-test$ and one-way ANOVA. Results: According to the result of the prerequisite-program evaluation, the percentage of 'appropriate', 'needs to be improved', and 'inappropriate' was 44.6%, 47.7%, and 7.7%, respectively. The score for the 'inappropriate' group was significantly lower than that of the 'appropriate' group or 'needs to be improved' group on the food safety management (p < 0.001), preparation facility management (p < 0.001), water management (p < 0.001), and storage transportation management (p < 0.05) parts. Holding rate of foodservice facility and equipments in the 'appropriate' group were significantly higher than in the others on convection oven (p < 0.01), air conditioner (p < 0.01), three-compartment sink (p < 0.01), hot-holding equipment (p < 0.01), cold-holding equipment (p < 0.05), exclusive thawing refrigerator (p < 0.05), and sterilizer for sanitary shoes (p < 0.05) items. Conclusion: To improve the quality of hospital foodservice, foodservice managers and HACCP specialists should develop and implement a prerequisite-program and a HACCP plan considering the characteristics of the hospital foodservice operation.

Long-term Changes of Fish Ecological Characteristics on the Gwanpyeong Stream Development and the Necropsy-based Health Assessments (관평천 개발에 따른 장기간 어류 생태적 특성 변화 및 해부학적 건강도 평가)

  • Oh, Ja Yun;Lee, Sang-Jae;An, Kwang-Guk
    • Korean Journal of Environment and Ecology
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    • v.34 no.4
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    • pp.282-293
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    • 2020
  • This study investigated a long-term variation trend of water quality, fish compositions, and ecological health conditions in the Gwanpyeong stream located in the nearby Daejeon metropolitan city to understand the impact of urban development projects on the aquatic ecosystem. The sampling was made in four surveys (2009, 2010, 2016, 2019) before and after urbanization. The urban development was conducted in 2008, resulting in the stream's ecological disturbance, and the stream restoration was conducted in 2012. Thus, stream monitoring was conducted to analyze the ecological trends before and after the restoration. The multi-metric models for Fish Assessment Index(FAI) and necropsy-based Health Assessment Index(HAI) were applied in the fish community and organ-level, respectively, to assess the ecological health of the stream. Minimum turbidity and chlorophyll-a(Chl-a) occurred in the mid-stream(St. 2), and this was probably due to rapid current velocity in the riffle zone. We collected 18 fish species, and the dominant species was Zacco platypus (40.6%). In 2016 immediately after the stream restoration, the relative proportions of sensitive species and insectivore species were the highest along with highest values in the species diversity and species richness index, resulting in the best condition in the ecological health, based on FAI model values. However, the ecological health, based on the FAI, became worse in the latest survey conducted in 2019. The analysis of the HAI model based on the organ-level approach showed skin erosion in the fish of upper stream, kidney defects in downstream, and the liver and gill defects observed in all sites, indicating that the anatomical health was also affected.

Effect of Dietary Supplemention with Probiotics, Illite, Active Carbon and Hardwood Vinegar on the Performance and Carcass Characteristics of Broiler (사료내 생균제, 일라이트, 활성탄 및 목초액의 첨가가 육계의 성장 능력 및 도체 특성에 미치는 영향)

  • Kim, Y.J.
    • Korean Journal of Poultry Science
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    • v.34 no.3
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    • pp.165-172
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    • 2007
  • We investigated the effects of dietary supplements of probiotics, illite, active carbon and hardwood vinegar on growth performance, feed intake, and pH, shear force, sensory evaluation, meat color and fatty acid composition of meat in broilers. Two hundred broilers were fed diets for five weeks containing 0.2% of probiotics (T1), and 1% of Illite (T2), 1% active carbon (T3), or 1% hardwood vinegar (T4). Body weight gain was higher in T1 and T4 groups fed the starter diet but was the lowest in C and T4 for finishing period (P<0.05). Feed efficiency was not significantly different. In proximate composition, crude fat content of chicken meat were decreased lower in all treatment groups than control, but moisture, crude protein and crude ash were not significantly different. Cooking loss was decreased in T3 and T4 and WHC (water holing capacity) was increased in T3 and T4 groups compared to the other groups. In sensory evaluation, T4 tended to improve the hardness. Redness $(a^*)$ and yellowness $(b^*)$ were no difference between the all treatment groups, lightness $(L^*)$ were higher in T1, T2, T3 and T4 groups than control group (P<0.05). Stearic acid content was lower in T1, T2, T3 and T4 groups, but oleic acid contents were higher in T1, T2, T3 and T4 groups (P<0.05). These results showed that supplementing broiler diets with 1.0% hardwood vinegar may noticeably improve the meat quality of broiler.

Analysis of Processing Conditions on Maesil Kochujang Production Using Response Surface Methodology (반응표면 분석을 이용한 매실첨가 고추장의 품질특성)

  • Lee, Min-Ji;Lee, Jun-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.5
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    • pp.629-635
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    • 2007
  • Response surface methodology (RSM) was used for the analysis and optimization of the production process of Kochujang added with Maesil extract. The process variables were the amount of Maesil extract ($0{\sim}8%$) and red pepper powder ($6{\sim}10%$). pH and all color characteristics (L*-, a*-, and b*-value) decreased but titratable acidity and water activity increased with the addition of Maesil extract. Amino nitrogen content appeared to decrease with the addition of red pepper powder. The highest sensory flavor score was obtained when 2.20% Maesil extract and 8.62% red pepper powder were blended, the highest sensory taste score with 6.63% Maesil extract and 9.50% red pepper powder, and the highest sensory color score with 7.80% Maesil extract and 8.62% red pepper powder respectively. The point chosen as representative of the optimal area corresponds to $X_1=3.60%,\;X_2=10%\;and\;X_1=4.08%,\;X_2=9.96%$ for physicochemical and sensory quality, respectively.

Physical and Sensory Properties of Chiffon Cake Made with Rice Flour (쌀가루로 제조한 쉬폰케이크의 물리적.관능적 품질특성)

  • Kim, Ji-Na;Shin, Weon-Sun
    • Korean Journal of Food Science and Technology
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    • v.41 no.1
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    • pp.69-76
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    • 2009
  • This study was conducted to evaluate the physicochemical and sensory characteristics of chiffon cakes made with rice flour ranging from 20-100% in place of wheat flour. The water binding capacity of the rice flour was greater than that of the wheat flour and its fat binding capacity was lower than that of the wheat flour. The batter stability data indicated that the 100% treatment was better than the control, and specific gravity values and specific loaf volumes were lower in the samples with added rice flour. Texture analysis found no significant differences in hardness, adhesiveness, cohesiveness, gumminess, and chewiness between the control and the 100% treatment. In the case of crust color, the rice flour-added chiffon cakes did not show any significant differences for their 'a' values. In addition, their crumb color was not significantly different in terms of both their 'L' and 'a' values. According to the sensory evaluation, there was no significant difference in overall acceptability between the control and the rice flour-added chiffon cakes. The highest sensory scores were obtained by the 100% treatment for overall acceptance and moistness. However, flavor, cohesiveness, and brittleness were not significantly different. These study results show that wheat flour could be replaced by rice flour up to 100% in chiffon cake.

Effects of Dietary Energy Level on Growth and Meat Quality of Korean Black Goats (사료의 에너지 수준이 육성기 흑염소의 발육과 육질에 미치는 영향)

  • Choi, S.H.;HwangBo, S.;S. W. Kim;Kim, Y.K.;Sang, B.D.;Myung, J.H.;Hur, S.N.;Jo, I.H.
    • Journal of Animal Science and Technology
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    • v.49 no.4
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    • pp.509-514
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    • 2007
  • This study was conducted to investigate the optimal energy level at growing Korean black goat from April 20 to November 6, 2006. Forty male Korean black goat were divided into four treatments and were fed with concentrate feed containing ME 2.4, 2.6, 2.8 and 3.0 Mcal/kg with CP 15% and rice straw. Average daily gains of were 59.8, 65.4, 73.2 and 77.2 g/day in groups fed with ME 2.4, 2.6, 2.8 and 3.0 Mcal/kg diet, respectively. There was a tendency to increase ADG as the ME level of concentrate feed grew. Dressing percentage were 49.73, 48.64, 50.19 and 51.36% in each group, and were increased as the ME level grew. Meat percentage ranged between 53.1 and 55.3%, and were almost constant. Ranges of crude fat contents and water holding capacity were and 57.9~59.0%, which were increased as the ME level grew. On the other hand, shear force were between 2.8 and 3.1 kg/cm2, which were decreased as the ME level grew. These results suggest that the optimal energy level at growing goat's concentrate is ME 3.0 Mcal/kg.

Analysis of Factors Affecting Retention Time in Grassed Swale (식생수로에서 유하시간에 영향을 주는 인자 분석)

  • Paek, Seoungbong;Gil, Kyungik
    • Journal of Wetlands Research
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    • v.17 no.3
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    • pp.303-310
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    • 2015
  • Recently the water quality management policy gives priority to management the point source. Point pollution sources have definite emission points and are discharged to one point through a pipe. But Nonpoint pollution source (NPS) has uncertain pathway, pollutant load and runoff characteristics unlike point pollution sources, making them difficult to manage. Thus, the Korea government plans to develop and equip facilities that help reduce NPS so as to manage them more easily. But removal efficiency of Best Management Practice (BMPs) is in influenced by rainfall, hydrologic condition like natural phenomenon, so factors of removal efficiency are difficult. Thus there is a need for multilateral research about many factors that affect removal efficiency for removal facility design of proper non-point pollution. In this research, mapping, vegetation coverage and retention time were investigated in the case of factors that affect removal efficiency in grassed swale, a nature-type non-point removal facility. Grassed swale obtained changed of coverage using Braun-Blanquet within swale and retention time was obtained from point that rainfall effluent enters into swale to the time that first outflow starts. Besides, correlation analysis was obtained using pearson correlation analysis method. As a result, it was shown that removal efficiency increases as retention time is longer in grassed swale and that retention time increases as vegetation coverage is higher.