• Journal of Environmental Science International
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• v.9 no.4
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• pp.351-367
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• 2000

Air-lift biofilm reactor should be an admirable process substituting conventional activated sludge process, because of its small area requirement as well as high volumetric loading capacity and stability against loading and chemical shocks. However most of the past research on the performance of ABR was focused on the sewage treatment. This research studied the applicability of ABR to treat high strength wastewater. A bench-scale ABR was operated to treat high strength synthetic wastewater, tannery wastewater and petrochemical wastewater, and its applicability was conclusive In case of synthetic wastewater, ABR showed good performance in which the substarate removal efficiency was higher that 80% even under short HRT(1.4 hr) and high volumetric loading rate(9.3 kgCODcr/$m^3$.day). When ABR was applied to treat tannery wastewater, it was suggested that the maximum volumetric loading rate and F/M ratio should be 7.7kgCODcr/$m^3$.day, 0.76 $day^{-1}$, respectively. And high substrate removal efficiency over than 90 % was observed with 4,000 mgCODcr/L of petrochemical wastewater. Even though effluent concentration was quite high, ABR should be applicable to treat the high strength wastewater, because of its high loading capacity.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.6
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• pp.647-655
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• 2008

Sewer Rehabilitation Project (SRP) is planed, designed and constructed to perform its intended performance as sewerage delivery systems. Recently, a subject of performance evaluation methodology development for SRP has become a great deal of concern among researchers in Korea. From the view point of Sewage Treatment Plant (STP), however, the estimation of improvement efficiency for SRP is in lack of reliability due to the fact that affections for the treatment efficiency and operating condition are not reflected on SRP design and construction. In this study, statistical methodology was used in the analysis of data, which are taken during 1,186 days ($1^{st}$ Jan. 2005 - $31^{th}$ Mar. 2008) from the influent, effluent and operating conditions of full-scale STP($25,000m^3/d$). Then the effect of SRP on the influent characteristics and operating conditions changing was compared and evaluated. Results from the statistical evaluation show that SRP causes characteristic changes in influent and exerts a significant effect especially on the performance of STP.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.2
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• pp.15-29
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• 2016

This study investigated the environmental and economical assessment for sewage sludge treatment options including biogasification, incineration, carbonization, drying, and solidification. Considering B/C ratio for an anaerobic digestion treatment, for $270,000m^3/d$ (over $1,150m^3/day$), B/C was 1, as the moisture content increased to 95 %, B/C was 1 for $100000m^3/d$ (capacity of $400m^3/day$). Anaerobic digestion+solidification was the most economically feasible, then Anaerobic digestion+incineration and anaerobic digestion+drying were the next economically feasible and then anaerobic digestion+carbonization was the least economically feasible. If anaerobic digestion efficiency was improved to 45%, the treatment costs for anaerobic digestion+carbonization, anaerobic digestion+incineration and anaerobic digestion+drying were decreased to 3,000~5,000 won/t and the costs for anaerobic digestion+solidification was decreased to 2,000~3,000 won/t due to increasing of the beneficial cost of the biogas production.

• Journal of Satellite, Information and Communications
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• v.9 no.2
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• pp.96-100
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• 2014

Recently, the management system of wastewater treatment facility has magnified due to the stringent regulations for the protection of the environment, and a sewage treatment plant efficiency and research of the car development are activated in large facilities or industrial park. however, the existing sewerage disposal system and specific water quality monitoring network reliability for real-time transmission of this building is insufficient. In this paper, we proposed a local wireless network design for sludge multi meter data collection and control for measuring the concentration of the sludge efficiently. Also, the collected data over the local wireless network to transmitted to the central monitoring system and accumulate the data in real time to calculate statistics is possible to monitor the status of the sewage treatment facilities. The proposed system uses a short-range wireless networks of IEEE 802.15.4 and configures an IEEE 802.11 network which can monitor real-time status in central system. Also, we install a sludge multimeter and communication network in sewage treatment facilities and confirm the usefulness of the proposed technique by demonstrating its effectiveness.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.433-441
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• 2014

It has been known that sewage containing high-concentration nitrogen affects the efficiency of municipal wastewater treatment plants harmfully. Therefore, research has been actively conducted to treat sewage containing high-concentration nitrogen. The current study has analyzed organic compounds, conducted foaming tests, and operated a laboratory-level nitritation reactor with the subjects of anaerobic digester supernatant and livestock wastewater which are the typical kinds of sewage containing high-concentration nitrogen. According to the results of analyzing organic compounds, soluble inert components form the largest part of anaerobic digester supernatant while particle biodegradable components occupy the most part of livestock wastewater. About the retention time proper for the reaction of nitritation, anaerobic digester supernatant shows 2 days while livestock wastewater indicates 6 days. It seems that the difference in the proper retention time is resulted from the difference of properties in organic compounds and ammonium nitrogen concentration. In addition, livestock wastewater's reactor foam is generated comparatively more than anaerobic digester supernatant's, but it tends to be eliminated faster. It is expected that the findings of this study can be utilized as foundational data afterwards in applying the reaction of nitritation to municipal wastewater treatment plants.

• KSBB Journal
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• v.22 no.2
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• pp.102-108
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• 2007

A sewage was treated using a vertical flow zeolite-filled reed bed. The sewage from the student dormitory of Changwon National University was fed into the reed bed for 10 minutes every 6 hours at the hydraulic load of $314L/m^3{\cdot}$day. The filtering height of the reed bed was 100 em and the zeolite mixture was filled in the reed bed. The mixture consisted of the same volume of two types of zeolite: 0.5$\sim$1 mm and 1$\sim$3 mm in diameter. Annual average removal efficiency was 88 89.9%, $COD_{Cr}$ 86.1 %, $COD_{Mn}$ 81.2%, T-N 34.0%, $NH_4^+$-N 97.3% and T-P 34.6%. T-N of effluent was mostly $NO_3^-$-N and the concentration of $NO_2^-$-N in effluent was lower than 0.1 mg/L. All removal efficiencies did not show a remarkable seasonal change. The ranking of phosphorous fractions fixed to the zeolite in column test was Ca-P > Fe-P > reductant soluble Fe-P > occluded P > saloid P > AI-P at all depths of the filter. All phosphorous fractions except for AI-P reduced at deeper filter layer, while their content ratios increased at deeper filter layer. Organic matter content was the highest at the highest layer (0$\sim$5 cm from the top of the filter) and only small differences were observed at the deeper filter layer than 5 em from the top. Organic matter content increased at all depths of the filter with the operating time.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.6
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• pp.309-316
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• 2016

In this study, sewage was fed with up flow direction into a reactor equipped with a screw to circulate media that had lower specific gravity than water. It was observed that the media in the reactor could be circulated by a screw with reverse flow of the sewage feeding from the top to the bottom direction. Under these conditions, concentrations of inflow and outflow pollutants were measured at the filtration unit. Experimental results revealed stable circulation of the media with a screw in the reactor. Circulation of the media in the reactor showed more efficiency in removing the pollutants (particulate matters and organics) than no circulation. The maximum removal efficiencies of suspended solid (SS), chemical oxygen demand (CODmn), and total phosphorus (T-P) were 96%, 72% and 65%, respectively. Improvements for SS, CODmn and T-P removals with circulation of media were 52.38%, 43.14% and 118.12% respectively, compared to those without circulation.

• Journal of Environmental Science International
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• v.21 no.12
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• pp.1495-1501
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• 2012

In this study, an experiment was conducted on influent water with low concentrations of organic matter, such as river water or secondary treatment water of a sewage treatment plant, according to HRT changes by using aerobic biofilm. In the biofilm process, as the biofilm increases in thickness, the inner membrane can be low in oxygen transfer rate and become anaerobic conditions, while the detachment of biomass from biofilm occurs. To overcome these limitations in the detachment of microorganisms in biofilm, the yarn, which was made from poly propylene(PP), was weaved and manufactured into a tube. Then, a test was carried out by injecting air so that the interior of the biofilm could create aerobic conditions. The results of the experiment showed that the removal efficiency of $TCOD_{cr}$ reached 66.1~81.2% by HRT 2hr, and 50.9 ~61.8% after HRT 1 hr. The removal efficiency of $SCOD_{cr}$ was 45.9 to 55.1% by HRT 1hr, and 26.1% in HRT 0.5hr, showing the highest removal efficiency in HRT 1hr. The SS removal efficiency was at 81.8 to 94.6%, and the effluent SS concentration was very low, indicating less than 2.2 mg/L in all HRT's. As a result, the $SCOD_{cr}$ and $NH_4{^+}$-N that were removed per specific surface area and attached to microbial biofilm showed the highest efficiency in HRT 1hr with 8.37 $gSCOD_{cr}/m^2{\cdot}d$, 2.93 $gNH_4{^+}-N/m^2{\cdot}d$. From the result of reviewing the characteristics of biofilm growth, microorganisms were found to be attached, and increased by 36 days. Later, they decreased in number through detachment, but showed a tendency to increase again 41 days later due to microbial reproduction.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.6
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• pp.743-752
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• 2009

One of the major problems associated with operation of domestic sewer lines involves hydraulic problems such as insufficient conveyance capacity, exceeding maximum velocity, and deficiency of minimum velocity. It has also been pointed out that influent concentration lower than design concentration of pollutants, which is mainly caused by unidentified inflow and infiltration, degrades the operational efficiency of many sewage treatment plants (STPs). A computer-added analysis method supporting a coupled simulation of sewage quality and quantity is essentially required to evaluate the status of existing STPs and to improve their efficiency by a proper sewer rehabilitation work. In this study, dynamic water quality simulations were conducted using MOUSE TRAP to investigate the principal parameters that governs the changes of BOD, ${NH_4}^+$, and ${PO_4}^{3-}$3- concentrations within the sewer networks based on data acquired through on-site and laboratory measurements. The BOD, ${NH_4}^+$ and ${PO_4}^{3-}$3- concentrations estimated by MOUSE TRAP was lower than theoretical pollution loads because of sedimentation and decomposition in the sewer. The results revealed that sedimentation is a most important factor than other biological reactions in decreasing pollutant load in the sewers of C-city. The sensitivity analysis of parameters pertaining to water quality changes indicated that the effect of the BOD decay rate, the initial DO concentration, the half-saturation coefficient of dissolved BOD, and the initial sediment depth is marginal. However, the influence of settling rate and temperature is relatively high because sedimentation and precipitation, rather than biological degradation, are dominant processes that affect water quality in the study sewer systems.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.471-478
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• 2012

The objective of the study is to find a way to utilize MSWI slag as filter material and to verify it. To do so, stability as filter material was tested, and used Ju-Munjin filter sand as control group to run actual filtering experiment to analyze filtering efficiency. According to result, MSWI slag is usable within designated waste acceptable standards. Also, it showed similar level of filtering capability to filter sand. Thus, MSWI slag could help to save and recycle resources if used as filtering material instead of filter sand As result of filtering test, SS and COD showed about same level of filtering capability similar to standard filter sand. MSWI slag has shown 26.96% higher with T-N, and 6.55% higher with T-P compared to standard filter sand. Also, remove efficiency comparison result with No. 40#(0.43mm) and mixed diameter showed equal or greater filtering capability.