• 한국물환경학회지
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• 제26권1호
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• pp.44-51
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• 2010

A lab-scale apparatus for turbid water transport control was tested and examined. The channel had a dimension of $100cm{\times}30cm{\times}15cm$ (length${\times}$hight${\times}$width). And the turbidity water was prepared using two types of particles, bentonite and loess. The channel equipped with filamentous mat was operated under various shock load conditions. In the control channel, instantly, turbid water mixed with the clean water inside the channel and turbidity prevails the entire channel. While in the mat-equipped channel, it increases only at the bottom. Overall, the filamentous mat gave capture efficiency of 70~90% compared with the control group. The capture efficiency of turbid particles decreased with increased input turbidity flux. The result of experimental run on how turbid particles are separated in the mat channel shows that settling, filtration and attachment are the main processes. Meanwhile, turbidity was diffused from the channel bottom due to turbidity gradient before and after mat zone. The particle size before mat zone was lightly coarser than that after mat zone.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 춘계학술발표논문집
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• pp.888-890
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• 2009

This study presented a lab-scale apparatus for turbidity control in the lakes or reservoirs. Overall, the filamentous mat had a capture efficiency of 70~90% compared with the control group. Generally, the capture efficiency decreased with improved input turbidity flux. However, the attachment and sedimentation were thought to be the main processes for turbidity water retention and removal. Thus, the increase of hydraulic detention time in the mat zone is very important to improve the capture efficiency of the turbidity water.

• 한국식품영양과학회지
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• 제23권4호
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• pp.660-665
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• 1994

Treatment of rice-washing wastewater was considered under various pH levels and chitosan concentrations. Compared with the control test, addition of chitosan at the various concentrations did not noticeably enhanced turbidity reduction at pH 4 and 5 , but greatly enhanced at above pH 6. However, reduction of turbidity in the wastewater, irrespective of chitosan concentrations, was the greatest at pH 4 and became lower by increasing pH. Suspended solids in the wastewater were the most effectively recovered by pH adjustment of the wastewater to 4 followed by centrifugation, with over 99% reduction in turbidity . Different concentrations of suspended solids in the wastewater and various kinds of acids used for p/H adjustment did not affect turbidity reduction. Increasing storage periods of the wastewater resulted in lower reductions in turbidity.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.282-285
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• 1996

In the water purification plant, the raw water is promptly purified by injecting chemicals. The amount of chemicals is directly related to water quality such as turbidity, temperature, pH and alkalinity. At present, however, the process of chemical reaction to the turbidity has not been clarified as yet. Since the process of coagulant dosage has no feedback signal, the amount of chemical can not be calculated from water quality data which were sensed from the plant. Accordingly, it has to be judged and determined by Jar-Test data which were made by skilled operators. In this paper, it is concerned to model and control the coagulant dosing process using jar-test results in order to predict optimum dosage of coagulant, PAC(Polymerized Aluminium Chloride). The considering relations to the reaction of coagulation and flocculation, the five independent variables(turbidity, temperature, pH, Alkalinity of the raw water, PAC feed rate) are selected out and they are put into calculation to develope a neural network model and a fuzzy model for coagulant dosing process in water purification system. These model are utilized to predict optimum coagulant dosage which can minimize the water turbidity in flocculator. The efficacy of the proposed control schemes was examined by the field test.

• 한국생산제조학회지
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• 제25권3호
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• pp.237-243
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• 2016

Recently, technologies that produce biofuels from microalgae are being studied worldwide. It is necessary to significantly reduce the production costs of biofuels from microalgae for economic reasons. In this study, the growth curve of the microalgae was obtained using the batch-culture method, and the specific growth rate was predicted using the regression method. Based on the culture conditions of the estimated specific growth rate, the turbidity of the microalgae in the flat panel photobioreactor (PBR) was measured. Furthermore, an on-off control scheme was applied to the flat panel PBR in order to culture the microalgae continuously on the basis of turbidity. The parameters of the on-off control system were displayed by LabView. The on-off scheme of peristaltic pump was controlled based on the turbidity in the PBR. In addition, the turbidity values of growth curves were compared and analyzed in the continuous culture process using the on-off controller.

• 제어로봇시스템학회논문지
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• 제3권6호
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• pp.644-651
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• 1997

In the water purification plant, chemicals are injected for quick purification of raw water. It is clear that the amount of chemicals intrinsically depends on water quality such as turbidity, temperature, pH and alkalinity. However, the process of chemical reaction to improve water quality (e.g., turbidity) by chemicals is not yet fully clarified nor quantified. The feedback signal in the process of coagulant dosage, which should be measured (through the sensor of the plant) to compute the appropriate amount of chemicals, is also not available. Most traditional methods focus on judging the conditions of purifying reaction and determine the amounts of chemicals through manual operation of field experts using Jar-test data. In this paper, a systematic control strategy is proposed to derive the optimum dosage of coagulant, PAC(Polymerized Aluminium Chloride), using Jar-test results. A neural network model is developed for coagulant dosing and purifying process by means of six input variables (turbidity, temperature, pH, alkalinity of raw water, PAC feed rate, turbidity in flocculation) and one output variable, while considering the relationships to the reaction of coagulation and flocculation. The model is utilized to derive the optimum coagulant dosage (in the sense of minimizing turbidity of water in flocculator). The ability of the proposed control scheme validated through the field test has proved to be of considerable practical value.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.75-78
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• 1995

In this paper it is concerned to develop control method using jar-test results in order to predict the optimum dosage of coaglant, PAC(PoliAluminum Chloride). Considering the relations with the reactions with the reaction of coagulation and flocculation, the five independent variables ( e, g, turbidity of raw water, water turbidity in flocculators, temperature, pH, and alkalynity) are selected out of parameters and they are put into calculation to develop a neural network model for PAC dosing process in water purification system. This model is utilized to predict optimum dosage of PAC. That is, the optimum dosage of PAC is searched in neural network model for PAC dosing process to minimize the water turbidity in flocculators. This searching is implemented by means of expert heuristics. The efficacy of the proposed contorl schemem and feasibility of acquired neural network model for PAC dosing contorl in water purification system is evaluated by means of computer simulation.

• 한국수자원학회논문집
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• 제40권8호
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• pp.601-615
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• 2007

선택취수 방법은 성층화된 저수지로부터 공급되는 방류수의 수온, 용존산소농도, 탁도 등의 수질을 제어하고, 하천의 생태계 서식환경을 개선하기 위해 널리 사용되고 있다. 최근 우리나라에서도 하류의 탁수피해 저감을 위해 다단 취수가 가능하도록 기존의 취수시설을 개량하였거나 계획하고 있는 댐들이 늘고 있다. 이 연구의 목적은 대청댐에 선택취수 시설을 도입하였을 경우 하류의 탁수 제어 효과와 저수지 수질에 미칠 영향을 평가하는데 있다. 다양한 선택취수 조건이 방류수 탁도와 저수지 수질 변화에 미치는 영향을 모의하기 위해 선행연구에서 보정 검증한 2차원 폭 방향 평균 수리 및 부영양화 모델을 사용하였다. 연구결과, 2년 연속$(2004\sim2005)$ 수문조건에서 표층수의 선택취수를 통한 댐 하류의 탁수 장기화 저감 효과는 미미한 것으로 평가되었다. 또한 하류에 깨끗한 물을 공급하기 위해 표층수를 과다하게 취수 할 경우, 높은 농도의 인을 포함하고 있는 중층 탁수를 유광대로 유입하게 하는 결과를 초래하여 호수역의 조류 성장을 증가시킬 우려가 있는 것으로 나타났다.

• Journal of the Korean Wood Science and Technology
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• 제44권5호
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• pp.743-749
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• 2016

균일한 품질의 방부처리 목재 생산을 위해서는 방부약액의 농도관리가 필요하다. 아직까지 목재방부처리 현장에서 농도관리를 위하여 간편하게 방부약액의 농도를 측정할 수 있는 방법은 개발되어 있지 않다. 본 연구에서는 ACQ 목재방부제를 대상으로 비교적 손쉽게 측정할 수 있는 탁도를 이용하여 농도를 예측할 수 있는 방법을 검토하였다. 탁도가 현저하게 작은 알칼리성의 ACQ 약액에 20%의 인산 용액을 첨가하면 백색의 현탁 물질이 생성되며 탁도가 증가한다. 인산 용액의 최적 첨가량은 약액의 탁도가 최고치에 도달하는 pH 7 수준이며, 첨가량이 많아지면 약액의 산성화와 함께 탁도가 급격하게 떨어지고 약액은 투명해진다. ACQ 약액의 농도와 탁도 간에는 정(正)의 상관을 가지며 고도의 유의성이 인정되었다. 농도와 탁도로부터 유도된 회귀방정식을 사용하여 산출한 현장 채취 약액의 예측 농도 값과 적정법으로 측정한 실측 농도 값 간의 농도 차이에는 t 검정 결과, 유의성이 인정되지 않았다. 따라서 탁도와 회귀방정식을 이용하여 ACQ 현장 약액의 농도 관리가 가능할 것으로 예상된다.

• 한국환경과학회지
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• 제19권8호
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• pp.931-940
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• 2010

The Raw water from Deer Creek (DC) reservoir and Little Cottonwood Creek (LCC) reservoir in the Utah, USA were collected for jar test experiments. This study examined the removal of arsenic and turbidity by means of coagulation and flocculation processes using of aluminum sulfate and ferric chloride as coagulants for 13 jar tests. The jar tests were performed to determine the optimal pH range, alum concentration, ferric chloride concentration and polymer concentration for arsenic and turbidity removal. The results showed that a comparison was made between alum and ferric chloride as coagulant. Removal efficiency of arsenic and turbidity for alum (16 mg/L) of up to 79.6% and 90.3% at pH 6.5 respectively were observed. Removal efficiency of arsenic and turbidity for ferric chloride (8 mg/L) of up to 59.5% at pH 8 and 90.6% at pH 8 respectively were observed. Optimum arsenic and turbidity removal for alum dosages were achieved with a 25 mg/L and 16 mg/L respectively. Optimum arsenic and turbidity removal for ferric chloride dosages were achieved with a 20 mg/Land 8 mg/L respectively. In terms of minimizing the arsenic and turbidity levels, the optimum pH ranges were 6.5 and 8for alum and ferric chloride respectively. When a dosage of 2 mg/L of potassium permanganate and 8 mg/L of ferric chloride were employed, potassium permanganate can improve arsenic removal, but not turbidity removal.