• Journal of Environmental Health Sciences
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• v.22 no.1
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• pp.99-106
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• 1996

The purpose of this study is to observe a specific removal efficiency of synthethetic wastewater which is managed by upflow submerged type at porous media which was sinteringed on a comparative low temperature 600$\circ$C, was annexed slag and humus soil with main material kaolinite. Observing removal efficiency quality of each media, a mixed media of kaolinite and humus soil by gravity percent 60, 40% respectively showed the most excellent removal utility, and applied predictive models for suspended culture kinetics without consideration diffusion limitation, and when analyzed kinetic which had been processed by this study the removal efficiency accompanied by carbon, nitrogen, phosphorous volumetric loading rate variation standed for a comparative large change rate 61~71%, it means the selection of the most proper load factor had a great effect on the highly removal efficiency, yield coefficient(Y) and specific microbial attach equation showed 1.53 mgVSS/mgCOD, $m_p=10039.4\times ((S_0)/(6.75+S_0))$ repectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.3
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• pp.250-256
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• 2017

This study investigated the removal efficiency of organic matter and nitrogen from fish farm effluent by hydraulic retention time (HRT) using an upflow biological filter (ANR system) reactor. The recycling time and influent flow in the reactor were controlled to 14.8, 7.4, 5.5 and 3.2 h to evaluate HRT. In addition, each reactor was coupled to a fixed bed upflow filter charged with media. The results showed that removal efficiency was ${\geq}95%%$ with an HRT of 5.5 h, and nitrification efficiency was reduced to 81% with an HRT of 3.2 h, although nitrification efficiency temporarily decreased due to the shock load as HRT decreased. Total nitrogen removal rate was also reduced to about 65% with an HRT of 3.2 h, which was considered a washout effect of nitrifying and denitrifying microorganisms by increasing the shearing force to the filter media, which decreased organic matter and nitrogen removal efficiency.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.562-564
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• 2002

Noise reduction and a simplification of a precision measurement system has been performed by changing analog output mode of a load cell into digital output mode. Usually, analog output signal of a few $\mu V$ from a load cell are amplified by amp and acquired by A/D converter. If the distance from a load cell to a DAS(Data Acquisition System) increases, more noise signals are mixed. So, a microprocessor has been integrated into a load cell so that the amplification and A/D conversion of output signals could be done in close proximity to the lode cell for the reduction in mixing of noise. Obtained data from the load cell like this manner are transferred to a computer with digital values(of TTL level). To simplify the configuration of a multi-channel DAS, RS-485 communication system has used for data transfer.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.851-860
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• 2012

In this study, to evaluate the abatement of runoff pollution loads by the road sweeping(cleaning), various investigations are implemented at the sample area of the highway. As the results of evaluating the removal efficiency of pollutants along road cleaning, TSS showed about 78 % of the removal efficiency and COD showed 49 % of removal efficiency through the operation of cleaning vehicle of vacuum suction method. In case of TN and TP, they showed the relatively-lower removal efficiency by 30~35 %. TSS removal efficiency along the number of cleaning appeared about 60 % in case of one time of cleaning and the additional removal effect did not appear though the number of cleaning increased to two times. With running speed of cleaning vehicle, TSS removal ratio is lessened from 60 % to 20 % when cleaning vehicle speed up to 20 km/hr from 6 km/hr. It seems that the reasons why the removal efficiencies are inversely proportional to its speed are related to the lower vacuum efficiencies and the disturbed particles on the road. In the pollutant build-up analysis, it is showed that it takes more time to the critical pollutant build-up in the shoulder than the center of the road. It is also showed that the proper cleaning cycle is recommended as 4~6 dry weather days without rainfall events.

• Journal of Environmental Health Sciences
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• v.26 no.4
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• pp.9-14
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• 2000

In this study, the removal efficiencies of organics, nitrogens and phosphorus from municipal wastewater using $A^2$/O process were investigated. BO $D_{5}$ removal efficiencies were indicated 95% and 94% with HRT of 12 hr and 10 hr, respectively. CO $D_{Cr}$ average removal efficiency and concentration of effluent were indicated 87% and 34mg/$\ell$. SS average removal efficiency and concentration of effluent were indicated 93% and 4~17mg/$\ell$. T-N removal efficiency and concentration of effluent were shown as 60~80% and below 15mg/$\ell$. In aerobic basin, removal efficiency of N $H_4$-N was shown over 97% with N $H_4$-N volume load 0.16kg N $H_4$-N/㎥.d and in anoxic basin, denitrification efficiency was indicated over 80% with return sludge rate 0.5Q and internal recirculation rate 2.5Q. Removal efficiency and effluent concentration of phosphorus were shown over 80% and below 2 mg/$\ell$ with return sludge rate 0.5Q.Q.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.850-862
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• 2007

This study was carried out to survey the actual conditions of wastewater treatment facilities to obtain basic data for the management of wastewater from industrial complexes in Chungcheongnam-do province. Wastewater production flow per site area by watersheds was $49.2m^3/km^2/d$ for Sapgyoho, $8.1m^3/km^2/d$ for Anseongcheon, $5.7m^3/km^2/d$ for Seohae, and $2.9m^3/km^2/d$ for Geumgang. Sapgyoho showed 75% of the total production flow, which was the highest value, Geumgang showed 4% of total flow, which was the lowest value. Average total extra rate as production flow/capacity flow in the wastewater treatment facilities for industrial complex is 49%. Considering by watersheds, the extra rates of Seohae, Geumgang, Anseongcheon, and Sapgyoho, are 73%, 65%, 62%, and 33% respectively. This means that the design of capacity flow in wastewater treatment facilities was too large. Effluent concentration of wastewater treatment facilities did not exceed discharge limit mostly. The removal efficiency rate for water quality item was 90% in BOD, 70% in COD, 80% in SS, 30 to 80% in TN, and 20 to 90% in TP, so the organic removal was good, but the nutrient removal was low and interval of variation was high. The removal efficiency rate of the agricultural was industrial complexes is lower than the national and local complexes. The construction cost of the wastewater treatment facilities in Chungcheongnam-do was $1,756Won\;per\;m^3$, treatment cost was $189Won\;per\;m^3$, and they were about two times and 1.2 times higher than the nation-wide cost, respectively. The treatment cost consists of 39% for man power, 21% for chemical, 16% for power, 11% for sludge treatment, and 13% for others.

• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.306-310
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• 2009

Packed-bed reactor for removing ammonia was tested at different loading rates. Nitrifiers for ammonia removing was encapsulated in gel media which consisted of polyethlene glycol, alginate and activated carbon. The removal efficiency was nearly 100% when ammonia loading was $12g/m^3/hr$, and the maximum elimination capacity (EC) achieved on this study was $18g/m^3/hr$. The initial microbial portion of nitrifiers in the media was about 82% and it was increased to more than 90% at the end of the operation. Short-term shock loading test was carried out to survey the stability of the media. The inlet loading rates were varied from 2 to $20g/m^3/hr$. The packed-bed reactor overcame the shock loading i.e. removal efficiency recovered rapidly from about 80% to almost 100% within 6 hrs. The results of Live/Dead cell test showed that nitrifiers maintained there activity in the encapsulated media during the test and also against ammonia shock load.

• The Korean Journal of Ecology
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• v.19 no.5
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• pp.487-496
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• 1996

This study was conducted to investigate pollutant loading, were quality and plant distribution of 8 streams which are tributaries of the Youngsan River. The nitrate reductase activity (NRA) and nutrient removall capacity of the most frequently occurring aquatic plants on streamside were also determined. As a result, the pollutant loading appeared to be correlated with the area of watershed, while the water quality was related to the land use pattern of each steam. The aquatic plants were distributed differently among the streams; Hydrilla verticillata - Potamogeton crispus, Numphoides peltata - Hydrocharis dubia and Polygonum thunbergii - Phragmites japonica were dominant at the Orye Chon, Jungan Chon, Whangryong River and Jiseok Chon, while potamogeton crispus - Lemma paucicostata, Zizania latifolia - Phragmites communis were dominant at the Youngam Chon and Munpyeong Chon. Persicaria hydropiper and Echinochloa crus-galli var. oryzicola were dominant at Kwangju Chon which was polluted with domestic wastewater. >From the measurement of leaf NRA for dominant species, the highest value of NRA was shown by the Polygonum thunbergii, followed by Oenanthe javanica > Phragmites communis > Zizania latifolia > Lemma paucicostata. The highest nitrogen and phosphorus removal capacity was found in Phragmites communis.

• Journal of Korean Society on Water Environment
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• v.20 no.3
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• pp.269-274
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• 2004

The performance of a newly designed wastewater treatment process equipped with an anaerobic and two intermittent aeration tanks operated alternately was investigated. During the experimental period, several types of cyclic operating schedules with different aeration and non aeration time were examined for the optimization. At all modes, the removals of organic matter and SS were highly achieved. With respect to T-N removal, however, the cycle length for aeration on/off affected the efficiencies. At the optimal operating mode, the ORP bending point indicating the disappearance of nitrate was observed. Considering the influent wastewater characteristics and cyclic operating schedules, it can be suggested that T-P removal is much more BOD/T-P ratio and/or its load dependant rather than the aeration on/off time. The results obtained from pilot-scale test showed the competitive advantage of this alternating process through an omission of nitrate recycle and operational flexibility against influent load variations when comparing with other continuous flow processes.

• Korean Chemical Engineering Research
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• v.52 no.2
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• pp.240-246
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• 2014

A semi-pilot biofilter inoculated with the microbes consortium of Bacillus cereus DAH-1056 and Arthrobacter sp. KDE-0311 was operated under various operating conditions in order to treat malodorous waste air containing both hydrogen sulfide and ammonia. When both hydrogen sulfide and ammonia contained in malodorous waste air were treated simultaneously by semi-pilot biofilter inoculated with Thiobacillus sp. IW and return-sludge, the removal efficiencies of hydrogen sulfide and ammonia were ca. 80% and ca. 50%, respectively. On the other hand, in this study, the removal efficiencies of hydrogen sulfide and ammonia were ca. 90% and ca. 60%, respectively. Therefore, the removal efficiencies of hydrogen sulfide and ammonia were enhanced by ca. 13% and 20%, respectively, compared to the semipilot biofilter inoculated with Thiobacillus sp. IW and return-sludge. In addition, in this study, the maximum elimination capacities of hydrogen sulfide and ammonia were enhanced by ca. 15% ($8g/m^3/h$) and 10~17% ($3{\sim}5g/m^3/h$), respectively. In this study, it was observed either that in case of even a same inlet load of hydrogen sulfide, a higher concentration of hydrogen sulfide causes more difficulties in treating ammonia containing in waste air than a lower one, or that in case of even a same inlet load of ammonia, a lower concentration of ammonia results in higher removal efficienciy and elimination capacity than a higher one. Even though hydrogen sulfide and ammonia were treated simultaneously by a biofilter in this study, the maximum elimination capacity of hydrogen sulfide in this study exceeded or was similar to that in previous study of biofilter treating only hydrogen sulfide. In addition, this study showed the higher maximum elimination capacity of ammonia than other previous investigation of biofilter treating hydrogen sulfide and ammonia simultaneously.