• Title/Summary/Keyword: Concentrated Water

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Investigation on the Pollutant Delivery Characteristics using Physically Based Watershed Model (물리적 기반의 유역모형을 이용한 오염물질 유달 특성 규명)

  • Kim, Chul-Gyum;Kim, Nam-Won
    • Journal of Korean Society on Water Environment
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    • v.25 no.2
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    • pp.256-267
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    • 2009
  • A method of estimating pollutant delivery ratios considering watershed physical and meteorological characteristics and flow conditions using SWAT-K watershed model was described, and pollutant delivery characteristics during dry and rainy seasons, for monthly and seasonally, and with flow regimes were investigated for the Chungju dam watershed. Delivery ratios for sediment, T-N, and T-P showed higher values over 100% during dry and winter seasons with low pollutant loads and flows, and showed relatively uniform ones under 100% during rainy and summer seasons with concentrated loads and flows. It was found that mainly wet flows during summer seasons played very important roles in investigating the delivery characteristics of total or nonpoint pollutant loads, because more than 90% of total loads were influenced by nonpoint source, and discharged with the flows. From the results, we could find out the delivery characteristics with various watershed and flow conditions which are difficult to consider by actual measurement, and could get a foothold of estimating more reasonable and scientific allocated loads for water quality standard using the reliable method of estimating delivery ratios with a watershed model.

Design of Residual Treatment Process with Filter Backwash Recycle System (역세척수 회수시스템이 포함된 배출수처리공정의 설계)

  • Bae, Byung-Uk;Choi, Kyung-Hwan
    • Journal of Korean Society on Water Environment
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    • v.28 no.1
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    • pp.109-114
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    • 2012
  • In this study, both sedimentation and thickening experiments were conducted for residuals produced from an advanced water treatment plant for more accurate and practical design of residual treatment train. In order to design a backwashed residual sedimentation basin (SRSB) in the filter backwash water recycle system, two kinds of backwash waters, one from sand filter (SFBW) and the other from GAC adsorption bed (GACBW), were separately collected and their surface loading rate measured. In addition, in order to design a gravity thickener, batch thickening tests were conducted for concentrated residuals taken from sedimentation basin and their limiting solid flux ($SF_{L}$) measured. From the experimental results and consideration of the seasonal characteristics of the residual, surface loading rate of $70m^{3}/m^{2}{\cdot}d$ was proposed as a design parameter for SRSB and solid loading rate of 20 kg $TS/m^{2}{\cdot}d$ was proposed as a design parameter for gravity thickeners. Finally, the material mass-balance was made for the design of each unit process in the residual treatment train.

Seasonal Succession Characteristic of Phytoplankton Community in Lake Doam (도암호에서 식물플랑크톤 군집의 계절적 천이 특성)

  • Joung, Seung-Hyun;Park, Hae-Kyung
    • Journal of Korean Society on Water Environment
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    • v.26 no.4
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    • pp.673-680
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    • 2010
  • Environmental factors and phytoplankton community in Lake Doam were monthly investigated at 3 stations from April 2009 to November 2009. During the study period, the concentrated rainfalls occurred at between July and August and then the TP and turbidity were sharply increased in in-lake. A total of 91 phytoplankton species was classified and these were consisted of 38 Bacillariophyceae, 35 Chlorophyceae, 10 Cyanophyceae, and 8 other species. Bacillariophyceae and Chlorophyceae were dominated during the seasonal succession of phytoplankton community, especially summer season. Bacillariophyceae was dominated from spring season to summer season and Chlorophyceae was dominated at summer season and autumn season. However, the dominance of Cyanophyceae generally developed at summer season in eutrophic water was not observed. From the analysis of correlation coefficient between environmental factors and phytoplankton cell number, we confirmed that there was a negative correlation between turbidity and cyanobacteria cell number (P<0.01). This result indicated that turbid water acts as the inhibitor of the cyanobacteria growth than other phytoplankton community.

Increase of treatment amount of thermophilic oxic process considering calorie/water (C/W) ratio (칼로리/수분 (C/W)비를 고려한 고온호기 처리법에서의 처리량 증가)

  • Jeon, Kyoung-Ho;Choi, Dong-Yoon;Song, Jun-Ik;Park, Kyu-Hyun;Kwag, Jung-Hoon;Kim, Jae-Hwan;Kang, Hee-Sul
    • Journal of Korean Society of Water and Wastewater
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    • v.24 no.2
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    • pp.203-210
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    • 2010
  • The signification of calorie/water (C/W) ratio was investigated in the treatment of highly concentrated organic wastes by thermophilic oxic process (TOP). Swine waste was used in this study. When C/W ratio was 1.6, most of swine waste was decomposed and all water was evaporated in the 24-h injection cycle. To improve treatment efficiency of TOP treating swine waste, the effect of shortening the swine waste injection cycle was examined. The shortening of injection cycle was conducted to stimulate the activity of thermophilic bacteria. A high temperature in the reactor was maintained by shortening of the injection cycle. When the swine waste injection cycle was shortened, the C/W ratio was fixed at 1.6. As a result, by shortening the swine waste injection cycle from 24-h to 12 and 6-h, the maximum loading rate of swine waste per day could be improved 1.9 and 3.5 times, respectively.

Effect of Artificial Aeration System on Water Quality of Yeoncho Lake (연초호의 인공 순환 장치 운영에 의한 수질 개선 효과 분석)

  • Seo, Dong-Il;Hwang, Hyun-Dong;Lee, Eun-Hyoung;Heo, Woo-Myung
    • Journal of Korean Society of Water and Wastewater
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    • v.18 no.3
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    • pp.357-365
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    • 2004
  • Effect of artificial circulation on amelioration of water quality in Yeoncho Lake was analyzed using summer data between 1991-2002. Two sites, intake tower area where aeration systems are concentrated in and near the inlet of reservoir were selected for comparison in this study. Summer averages between may and september Showed that aeration system might be beneficial in the improvement of water quality of BOD5, COD, and TN while Chl-a concentration and transparency did show opposite pattems. Wilcoxon's singed rank test for matched pair indicated slight increase of BOD5 and COD concentrations in the vicinity of intake tower while other variables did not show any significant differences from data of inlet of reservoir. During the study, it was found that the following subjects need to be investigated for more detailed analysis. 1) Dynamic pollutant loading from outside and inside the lake, 2) Biological, Chemical and Physical lake data when aeration systems are in and not in operation and 3) Radius of influence of aeration system.

The Development of Socioeconomic drought Risk Assessment Methodology with a Focus of Residential Water Scarcity (이상가뭄 저감대책을 위한 사회경제적 위험도 평가기법 개발: 생활용수 물부족을 중심으로)

  • Lee, Sangeun;Yoon, Sun-Kwon
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.3
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    • pp.381-393
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    • 2015
  • This study is carried out in order to propose a drought risk assessment methodology. This methodology is required to deal with practical questions that a variety of stakeholder often raise in the course of discussions on mitigation measures. With a focus on the socioeconomic aspect of drought, more particularly, residents' hardship from water scarcity, it suggests basic concepts and a system of methods in order to assess hazard, exposure, vulnerability and risk. The case study shows a considerable possibility of the methodology in evaluating potential levels of damages in a certain area, in identifying the boundary of districts where risk is disproportionately concentrated, and also in understanding the underlying risk factors of those districts. The authors think that the proposed methodology is able to offer risk information in terms of socioeconomic damages, and therefore contribute to reducing information gaps that policy-makers are currently encountered with.

The Causes of Bolt Breakage During the Tightening of Impellers in Water Jet Propulsion Systems (워터제트 추진기 임펠러 체결용 볼트파손 원인 분석 연구)

  • Jung, Sang-Jin;Oh, Shini Il;Hur, Jang-Wook
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.10
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    • pp.48-53
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    • 2019
  • A water jet propeller is a key component that generates propulsion during the start of a naval vessel. When failure or breakage occurs, the vessel cannot operate. Recently, a flow analysis and structural analysis were conducted to understand the cause of damage to a bolt on a water jet. In particular, the stress and strain acting on the fastening bolt (impeller shaft and tail shaft) were examined to determine the extent of misalignment between the impeller shaft and the tail shaft of the water jet propeller. The study determined that stress and strain were concentrated on the impeller shaft and the tail shaft bolt. The alignment of the propeller impeller shaft and the tail shaft increased significantly in response to the tail shaft bolt. Failure of the tail shaft bolt fastening can lead to misalignment between the impeller shaft and the tail shaft.

Investigation of water qualities and microbials on the flow-through olive flounder, Paralichthys olivaceus farms using coastal seawater and underground seawater in Jeju (연안해수와 지하해수를 사용하는 제주 넙치 양식장의 수질과 미생물 변동)

  • KIM, Youhee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.58 no.1
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    • pp.59-67
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    • 2022
  • This study assessed the levels of water qualities and microbials contamination of inland olive flounder farms in Jeju in the summers from 2015 to 2017. Three farms (A-C) located in a concentrated area using mixing coastal seawater and underground seawater and one farm (D) located in an independent area using only coastal seawater were selected. Total ammonia nitrogen (TAN) reached a maximum of 0.898 ± 1.024 mg/L as N in the coastal seawater of A-C, which was close to the limit of the water quality management goal of the fish farm. TAN in the influent from A-C was up to three times higher than that of D, so that the discharged water did not spread to a wide range area along the coast and continued to affect the influent. TAN of the effluent in A-C increased by 2.7-4.6 times compared to the influent, resulting in serious self-pollution in the flounder farm. Heterotrophic marine bacteria in the influent of A-C was about 600 times higher than D, and the discharge of A-C was increased by about 30 times compared to the influent.

Choline chloride-Glycerol (1:2 mol) as draw solution in forward osmosis for dewatering purpose

  • Dutta, Supritam;Dave, Pragnesh;Nath, Kaushik
    • Membrane and Water Treatment
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    • v.13 no.2
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    • pp.63-72
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    • 2022
  • Choline chloride-glycerol (1:2 mol), a natural deep eutectic solvent (NADES) is examined as a draw solution in forward osmosis (FO) for dewatering application. The NADES is easy to prepare, low in toxicity and environmentally benign. A polyamide thin film composite membrane was used. Characterization of the membrane confirmed porous membrane structure with good hydrophilicity and a low structural parameter (722 ㎛) suitable for FO application. A dilute solution of 20% (v/v) NADES was enough to generate moderate water flux (14.98 L m-2h-1) with relatively low reverse solute flux (0.125 g m-2h-1) with deionized water feed. Application in dewatering industrial wastewater feed showed reasonably good water flux (11.9 L m-2h-1) which could be maintained by controlling the external concentration polarization and fouling/scaling mitigation via simple periodic deionized water wash. In another application, clarified sugarcane juice could be successfully concentrated. Recovery of the draw solute was accomplished easily by chilling utilizing thermo responsive phase transition property of NADES. This study established that low concentration NADES can be a viable alternative as a draw solute for dewatering of wastewater and other heat sensitive applications along with a simple recovery process.

Effects of Guizibokryungwhan Herbal-Acupuncture on the Intravascular Coagulation Induced by Endotoxin in Rats (계지복령환약침(桂枝茯笭丸藥鍼)이 Endotoxin으로 유발(誘發)된 흰쥐의 혈전증(血栓症)에 미치는 영향(影響))

  • Yi, In-Ho;Lee, Kyung-Sub;Song, Byoung-Key
    • Journal of Pharmacopuncture
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    • v.2 no.1 s.2
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    • pp.51-62
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    • 1999
  • This study was designed to investigate the effects of Guizibokryungwhan Herbal-acupuncture on the intravascular coagulation. At first 36 mice were divided normal group(n=6) and experimental group(n=30). Normal group had no treatment and experimental group was induced intravascular coagulation by injected endotoxin 0.5mg/kg into the caudal vein. The experimental group was divided Sample-A(n=12), Sarnple- B(n=12) and control group(n=6). Control group was administrated normal saline. Sample-A was injected Guizibokryungwhan Herbal-acupuncture manufactured by extraction method and Sample-B was injected Guizibokryungwhan Herbal-acupuncture manufactured by water-alcohol method. Then Sample-A and Sample-B was injected high and low concentration. All treatments were done to Kwanwon acupuncture point once a day for 5 days s.c.. The results were following. 1. Compared with the control group, the platelet count was significantly increased in high-concentrated Sample-A and Sample-B group. 2. Compared with the control group, the concentration of fibrinogen was significantly increased in all experimental groups. 3. The prothrombin time was sjgnificantly shortened in high-concentrated Sample-A and Sample-B group as compared with the control group. 4. The activated partial thromboplastin time was significantly shortened in high-concentrated Sample-A group as compared with the control group. 5. The Guizibokryungwhan Herbal-acupuncture has a concentration-dependent effects on the intravascular coagulation.