• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.257-260
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• 2002

The main purpose of this research is to find suitable treatment methods of wastewater effluent for artificial recharge. For this purpose, we search the effluent quality of wastewater treatment plant and possibility of additional filtration process. Particles ranged 2 ~ 5 ${\mu}{\textrm}{m}$ and 15~20 ${\mu}{\textrm}{m}$ in "T" WWTP(Waste Water Treatment Plant) effluent were relatively dominant. In dual-media filtration system operation, head-loss development of column 1 was about two times faster than column 2, and head-loss development within 5 cm from surface was very important factor in operation, Conclusively, for the stable filtration and running time of 1.5~2 day, influent turbidity must keep 5 NTU or below, and filtration system must operated at 280 m/day or below. After filtration of WWTP effluent, water quality reached satisfactory level. This water has potential of agricultural reusing, flushing water in building, recharging water to river or stream at dry season and artificial recharge of ground water.und water.

• 한국막학회:학술대회논문집
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• 한국막학회 1997년도 제5회 하계 Workshop (97 한,카 국제공동 Workshop, 고도 수처리를 위한 막분리 공정)
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• pp.21-35
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• 1997

As environmental regulations become more stringent, water, used either as drinking water or as industrial process water, becomes increasingly better in its quality. As a result, an increasingly more advanced water treatment technology is required. It is believed that membrane technology will be able to satisfy such a requirement. The heart of the membrane technology is membrane. The advancement in water treatment technology using membranes, therefore, depends on the development of novel membranes which are superior in performance to the currently available membranes. In this paper, a brief review will be made how the recent progress in surface science, such as surface modification and surface characterization, has aided to improve the performance of the membranes used for water treatment. Some suggestions will also be made regarding the future direction of the research in this area.

• Korean Membrane Journal
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• 제11권1호
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• pp.21-28
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• 2009

We investigated the effect of organic materials on membrane fouling in advanced drinking water treatment by a hybrid module packed with granular activated carbon (GAC) outside multi-channel ceramic microfiltration membrane. Synthetic water was prepared with humic acid and kaolin to simulate natural water resouces consisting of natural organic matter and inorganic particles. Kaolin concentration was fixed at 30 mg/L and humic acid was changed as 2~10 mg/L to inspect the effect of organic matters. Periodic back-flushing using permeate water was performed for 10 sec per filtration of 10 min. As a result, both resistance of membrane fouling (Rf) and permeate flux (J) were influenced highly by concentration of humic acid. It proved that NOM like humic acid could be an important factor on membrane fouling in drinking water treatment. Turbidity and UV254 absorbance were removed up to above 97.4% and 59.2% respectively.

• Coupled systems mechanics
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• 제4권2호
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• pp.157-172
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• 2015

Control of potable water treatment plant (PWTP) is nowadays based on experience. The aim of this article is to show that model based control of treatment process is more efficient than process operation based on experience. Stimela environment is used for modeling of processes of potable water treatment. Application of the model was conducted on PWTP "Crkvice" in Zenica (BiH). This plant has used conventional rapid sand filters. By effective application of the model it is determined the optimal filter run time for different input turbidity of raw water. This results in the possibility of reducing the consumption of backwashing water, lower costs for its pumping and reducing the amount of coagulants. In the existing practice, based on experience, these benefits are not used.

• 상하수도학회지
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• 제23권1호
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• pp.39-46
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• 2009

A method to improve water treatment efficiency by coagulant overdosing for high pH raw water at a drinking water treatment plant (WTP) which had no pH adjusting facilities was investigated. Poly aluminum chloride (PACl) was used for coagulant, and turbidity removal efficiency was evaluated as a function of PACl dosage increases. pH and turbidity of supernatant of jar-tester were 7.10 and 0.50 NTU respectively, when the turbidity, pH, alkalinity, water temperature, conductivity of raw water were 1.75 NTU, 9.38, 46.5 mg/L, $6.4^{\circ}C$, $400{\mu}s/cm$, respectively. Turbidity of settled water was reduced from 2.18 NTU to 0.28 NTU (87% reduction) when PACl dosage was increased from 16 mg/L to 45 mg/L at a full scale WTP. This can be attributed to the recovery of coagulant efficiency by pH reduction with the increase of coagulant dose, however coagulation efficiency was reduced with the formation of Al(OH)4- by PACl addition at higher pH. Coagulant overdosing was proven to be a rapid and effective method for high pH raw water, which can be applied at drinking WTP.

• 한국세라믹학회지
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• 제54권2호
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• pp.114-120
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• 2017

In underdeveloped countries, many people suffer from water shortage due to the absence of water supply service. Although water purifiers have provided support in such situations, it is not easy to maintain water filters without a continuous supply of consumable filters. To obtain a sustainable drinking water source, appropriate technology of water treatment is necessary. Herein, a low cost water purification system was developed using natural raw materials. A non-electric water treatment system was developed using filtration through an Onggi filter, which is a type of Korean traditional earthenware with a microporous surface. The porosity and flux of the prepared Onggi filter were 29.06% and 31.63 LMH, respectively. After purification of water with total dissolved solids of 10.4 mg/L and turbidity of 100 NTU, the total dissolved solids and turbidity of the water treated using the Onggi filter decreased by 12% and 99.8%, respectively.

• 한국어병학회지
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• 제34권2호
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• pp.225-231
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• 2021

In biofloc culture for olive flounder, Paralichthys olivaceus, the possibility of antibiotics treatment was investigated against edwardsiellosis. After inducing edwardsiellosis by immersion in Edwardsiella tarda 1.2 × 10⁵/mL suspension, the survival trends on various biofloc water management and some physiological changes were observed. For biofloc water management, six types of water treatments were carried out, which were no exchange without antibiotics as negative control, the exchange to stored biofloc water, the exchange to stored biofloc water with 20% flow-through, the exchange to fresh biofloc water, half fresh biofloc water and half sea water, and the complete flow-through. There was no significant physicochemical change on water qualities in any type. The exchange to fresh biofloc water was shown the highest survival ratio as 72.3%, and in case of stored biofloc water with 20% flow-through, the survival ratio was also significantly high as 62%. Plasma glucose, cholesterol, total protein, calcium, and magnesium were analyzed as physiological index. Mostly, there was no significant change, but plasma cholesterol showed an initial decrease in low survival group, and an initial increase with high survival group. Consequently, antibiotic treatment against a bacterial disease during biofloc culture is possible as long as the biofloc water management follow along properly.

• 상하수도학회지
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• 제28권4호
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• pp.479-489
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• 2014

Membrane backwashing waste shows seasonally different characteristics and it has bad settleability differently from general backwashing waste in water treatment plant. When chemicals was injected to membrane backwashing waste, the settleability was better than chemicals was not injected. However, when settled lower sludge was not discharged, flowing sludge continuously was concentrated over a certain surface and floatation penomena occurred according to flowing velocity. When the lower sludge was discharged continuously in the thickener to prevent floatation penomena of turbidity materials, the depth of sludge surface was the least and the settleability increased.

• Advances in environmental research
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• 제4권3호
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• pp.155-172
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• 2015

In this study, a complete set of recirculating cooling water system and the required instruments were built in a semi-industrial-scale and a 50 g/h ozone generation plant and a chlorine system were designed for cooling water treatment. Both chlorination and ozonation treatment methods were studied and the results were analyzed during two 45-days periods. The concentrations of ozone and chlorine in recirculating water were constant at 0.1 mg/lit and 0.6 mg/lit, respectively. In ozone treatment, by increasing the concentration cycle to 33%, the total water consumption decreased by 26% while 11.5% higher energy efficiency achieved thanks to a better elimination of bio-films. In case of Carbon Steel, the corrosion rate reached to 0.012 mm/yr and 0.025 mm/yr for the ozonation and chlorination processes, respectively. Furthermore, consumptions of the anti-corrosion and anti-sedimentation materials in the ozone cooling water treatment were reduced about 60% without using any oxidant and non-oxidant biocides. No significant changes in sediment load were seen in ozonation compared to chlorination. The Chemical Oxygen Demand of the blow-down in ozonation method decreased to one-sixth of that in the chlorination method. Moreover, the soluble iron and water turbidity in the ozonation method were reduced by 97.5% and 70%, respectively. Although no anaerobic bacteria were seen in the cooling water at the proper concentration range of ozone and chlorine, the aerobic bacteria in chlorine and ozone treatment methods were 900 and 200 CFU/ml, respectively. The results showed that the payback time for the ozone treatment is about 2.6 years.

• 한국물환경학회지
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• 제22권5호
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• pp.905-912
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• 2006

In this paper, simulation methods of the system dynamics model developed by Das et al. (1997) for activated-sludge wastewater treatment plants are illustrated in an attempt to determine the operating rules and the policies related to capacity expansion of an activated-sludge wastewater treatment plant. For existing conditions, the analyses were performed by varying activated-sludge return rate to observe changes in effluent water quality and treatment efficiency. The effluent water quality is also analyzed for various average daily inflow conditions and activated-sludge return rates. As a result, without expanding the aeration tank, maximum average daily inflow that can satisfy the effluent water quality standard of BOD $0.02kg/m^3$ was determined as $2,840m^3/hr$, subject to 100% of activated-sludge return rate while other factors remain constant. When the activated-sludge return rate is less than 100%, expansion of the aeration tank is necessary and minimum sizes of the aeration tank to satisfy the effluent water quality standard were determined for various activated-sludge return rates. In addition, the total operating and maintenance as well as unit treatment cost regression equations for activated-sludge wastewater treatment plants are suggested by using the cost data that are obtained from Water and Wastewater Division, Ministry of Environment. The regression analyses showed that the economies of scale phenomena exist in the operating and maintenance costs of activated-sludge wastewater treatment plants.