• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.661-666
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• 2005

Wastewater reuse are exposed public health risk by pathogens. Therefore, this study was examined for microbial risk assessment after irrigation as treated wastewater in paddy rice plots. Five treatments were used: biofilter effluent, UV disinfected water, pond treatment, wetland treatment and conventional irrigation water. Risk assessment was calculated based on the beta-Poisson model by concentration of E. coli from 2003 to 2005. Monte-Carlo simulation (n=10,000) was used to estimate the risk characterization of uncertainty. The risk range was from $10^{-5}$ to $10^{-8}$ except biofilter effluent was $10^{-4}$ in June. The USEPA(1992) has recommended that risk of < $10^{-4}$ is acceptable level of safety for potable waters. In 2005, risk value was lower than 2003, 2004 because of the first irrigation for plowing water is lower E. coli concentration used tap water. It is shown that the first irrigation water quality was important for wastewater irrigation in paddy. UV disinfection and natural treatment used pond and wetland were thought to be an effective for wastewater reuse.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.2
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• pp.289-294
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• 2006

A pilot scale non-woven fabric filter separation activated sludge system was investigated for practical application on domestic wastewater reclamation and reuse. The system was operated in A/O (Anaerobic/Oxic) process with submerged filter module in the aerobic compartment. In the test of two types of filter materials ($70g/m^2$ and $35g/m^2$), the initial flux (0.42m/d) could be maintained for about three months by regular air backwashing of $70g/m^2$ filter at 0.3m water head. The removal efficiency of organic matter by the system was BOD 93.3%, CODcr 96.3%, SS 96.7%. The effluent quality was 7.8mg/L, 12mg/L and 5mg/L for BOD, CODcr and SS, respectively. The water quality was enough to meet a standard for domestic reuse without human contact. T-N removal efficiency was 49.9% at internal recycle rate 2Q and C/N ratio 3.3. The removal efficiency of T-P was 50% with average effluent concentration, 2.6mg/L.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.535-539
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• 2006

GIS-based integrated management system was developed for the treated wastewater to be reused as agricultural water. The major scopes of this research includes developing different types of system such as connecting data of wastewater treatment plants to data of hydraulic structures and paddy field ; separating spatial data into the watershed boundary and the agricultural water boundary ; and estimating applicable site for reuse. This system can enable to provide more scientific support to manage information of effluent and agricultural data utilizing GIS techniques.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.479-484
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• 2005

A GIS-based integrated system for reuse of effluent from wastewater treatment plants was developed in this study. The GIS-supported program classified attribute data which the effluent's quantity and quality and agricultural thematic map data according to the 5 big river basin area. From the database, showing the spatial variation of the water quality of the effluent, thereby proposing proper mitigation strategies over the watershed. Also, this system enables the users who is going to reuse the reclaimed water for their paddies to provide of all the wastewater treatment plant data and agricultural structures and thematic map data.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.3
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• pp.305-314
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• 2014

A pilot plant (Q=5 $m^3/d$) study was implemented for small and medium sized personal wastewater treatment plant effluent to evaluate MBR and A/O processes utilizing self-sufficient energy composed of wind and solar energy. The removal efficiencies of BOD, SS, turbidity and color were sufficient for legal water quality standards for gray water. However, those of nitrogen and phosphorus could not meet legal regulations which suggested that further removal of those contaminants were needed for reuse of the treated water. Self-sufficient energy rate was 100 % for the pilot plant due to excessive design capacity. In this research, wind and solar energy system was applied considering geological characteristics, which significantly improved energy self-sufficiency. Substantial improvement on energy self-sufficiency can be obtained by optimized investment and operation at a full scale wastewater treatment plant.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.259-262
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• 2003

Surveyed effluent capacities for potential wastewater resources through the surveying of the sewage treatment plants its capacity is up to 10,000 tonnes per day located 4 provinces (kyunggi, gangwon, chungbuk, chungnam) in this year. The total effluent capacities in this provinces are 423 thousand $m^3/day$, which may be used to irrigated paddy fields of 2,310ha A GIS database for wastewater resource inventory was developed for 4 provinces (kyunggi, gangwon, chungbuk, chungnam) to explore the feasibility of the wastewater reuse for drought mitigation. And it is to be extended to the other wastewater treatment plants.

• Journal of Korean Society on Water Environment
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• v.21 no.3
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• pp.289-296
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• 2005

Purpose of this research is to quantitatively and qualitatively investigate the blow down wastewater produced from Yeosu Industrial Complex. Approximately, 38,325,000 tons/year of wastewater is produced, processed and finally discharged. Six representative companies, namely, A, B, C, D, E, F were chosen for this study. Each company produce over 5,000 tons/day of wastewater. In total, 6,844 tons/day of blow down water is produced from these six companies, put together. However, companies A and C produce about 24% and 37% of blow down water, respectively. It was found that the blow down water had favorable qualities, except for its high conductivity, ranging from 230 to $1,700{\mu}s/cm$. It was evident that, this water can be suitable for reuse, for industrial purposes, if a suitable treatment, for example, RO membrane process is adopted to remove high conductivity.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.6
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• pp.477-487
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• 2021

Due to the global climate change, Korean peninsula is has been experiencing flooding and drought severely. It is hard difficult to manage water resources sustainably, because due to intensive precipitation in short periods and severe drought has increased in Korea. Reused water from the wastewater treatment plant (WWTP) could be a sustainable and an alternative water source near the urban areas. In order to understand the patterns of water reuse in Korea, annual water reuses data according to the times and regional governments were investigated from 2008 to 2019. The reused water from WWTP in Korea has been mainly used for river maintenance flow and industrial use, while agricultural use of water reuse has decreased with time. Metropolitan cities in Korea such as Seoul, Busan, Daegu, Ulsan, and Incheon have been mainly used reused reusing water for river maintenance flow. Industrial water reuse has been limitedly applied recently for the planned industrial districts in Pohang, Gumi, Paju, and Asan. By using the collected annual water reuse data from the domestic sewerage statistics of sewerage, the optimistic and pessimistic future estimations of for future annual water reuse were suggested from 2020 to 2040 on a five year interval for every five years.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.289-296
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• 2010

The purpose of this study is to evaluate various pre-treatment methods and proprieties of water quality for wastewater reuse using reverse osmosis (RO) processes. Secondary effluents were sampled from wastewater treatment plants and lab scale pre-treatments and RO filtration test were conducted systematically. Specifically, different types of pre-treatments, such as coagulation, microfiltration and ultrafiltration, were employed to evaluate the removal efficiency of particle and organic matters which may affect the membrane fouling rate. RO process was later added to eliminate trace amounts of remaining organic matters and salt from the raw water for wastewater reclamation. The permeate through the RO process satisfied water quality regulations for industrial water uses. The experimental results showed that the initial fouling tendency differed not only by the feed water properties but also by the membrane characteristics. Membrane fouling was greater for the membranes with large surface roughness, regardless of the hydrophobicity and zeta potentials. Thus both careful consideration of pre-treatment options and proper selection of RO membrane are of paramount importance for an efficient operation of wastewater treatment.

• Environmental Engineering Research
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• v.21 no.4
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• pp.350-354
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• 2016

There is an urgent need to identify more reliable indicator systems for human pathogenic viruses in water reuse practice. In this study, we determined the response of different bacteriophages representing various bacteriophage groups to different ultraviolet (UV) technologies in real wastewater in order to identify more reliable bacteriophage indicator systems for UV disinfection in wastewater. Bacteriophage ${\varphi}X174$ PRD1, and MS2 in two different real wastewaters were irradiated with several doses of both low pressure (LP) and medium pressure (MP) UV irradiation through bench-scale UV collimated apparatus. The inactivation rate of ${\varphi}X174$ by both LP and MP UV was rapid and reached ${\sim}4{\log}_{10}$ within a UV dose of $20mJ/cm^2$. However, the inactivation rates of bacteriophage PRD1 and MS2 were much slower than the one for ${\varphi}X174$ and only ${\sim}1{\log}_{10}$ inactivation was achieved by the same UV dose of $20mJ/cm^2$. Overall, the results of this study suggest that bacteriophage MS2 could be a reliable indicator for human pathogenic viruses for both LP and MP UV disinfection in wastewater treatment processes and water reuse practice.