• 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 Korean Society of Environmental Engineers
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• v.32 no.5
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• pp.437-442
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• 2010

This work was initiated both to maximize purity of calcium fluoride sludge and to minimize water content in the settled sludge. The sludge was produced in the process of fluoride removal of semiconductor wastewater by the addition of $Ca^{2+}$ ion. Fludized bed reactor(FBR) using calcium fluoride as a seed was adapted. Optimum pH and molar ratio of $Ca^{2+}/F^-$ were determined in lab-scale study. The experimental results showed that fluoride removal was increased as pH and molar ratio of $Ca^{2+}/F^-$ increased, with the best removal of 79.8% in an optimum condition. In the optimum point of fluoride removal, very low ${PO_4}^{3-}$-P removal of 9.3% was observed. It indicates forming $CaF_2$ crystal of high purity, when side reaction of calcium with phosphate was minimized. In addition, water content of settled sludge was 19.3%, which is relatively low compared to other fluoride removal processes. Consequently, the FBR process proposed in this study was very effective in fluoride removal, producing good sludge of high purity and less water content.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.4
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• pp.112-117
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• 2002

This study was conducted to induce the optimal composting conditions of pig manure mixed with sawdust and dried paper-mill sludge in the composting for production of high quality compost. Pig manure contains high water content and How C/N ratio because of comparatively high nitrogen content than sawdust and dried paper-mill sludge. Therefore the addition of dried paper-mill sludge and sawdust to the raw materials helps controlling the C/N and the water content of compost pile. The composting system used in the experiment was agitated static bed system. The physical properties of the mixed raw materials was not good at the working conditions in the early stage of composting. The temperature of compost heap reaches at $60^{\circ}C$within 5 day after starting composting in P-2 treatment mixed with pig manure and sawdust(56.6 : 43.4). Then the water content of P-2 was 58%. The pH in all treatments were slowly decreased as the composting was proceeded. Although the changes of T-C and T-N were not extended because of the short composting experiment period. Reduction rates of T-C in treatments were 5-12% without special difference. By considering the efficiency of composting in each of five treatments with pig manure the optimal water contents was about 57% level. Mixing a sawdust as a bulking agent was more positive than dried paper-mill sludge from a viewpoint of compost quality.

• Journal of Korean Society on Water Environment
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• v.22 no.3
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• pp.527-533
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• 2006

Tetracycline is one of the mostly used antibiotics around the world. The purpose of this study was to evaluate the fate of two different types of tetracycline resistant bacteria in biological wastewater treatment plants. Tetracycline resistant enterics and heterotrophic bacteria were monitored under two different lab-scale experimental conditions. Tetracycline resistant enteric bacteria showed the lower percentages of total enteric bacteria and net specific growth rate in the monitored activated sludge system as compared to tetracycline resistant heterotrophic bacteria. Therefore, total enterics, potentially E.coli, might not be the best indicator microorganism for evaluating the antibiotic resistant bacteria in biological wastewater treatment plant.

• Korean Journal of Environmental Agriculture
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• v.23 no.4
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• pp.211-219
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• 2004

Three sludge types from pharmaceutical byproducts and one sludge type from cosmetic waste-water sludge as raw materials of compost were used in a field based concrete pot ($4\;m^2$, $2\;m{\times}2\;m$) for investigating damage of red pepper cultivation. These sludges and pig manure (1 Mg/10a, dry basis) were incorporated into the upper of clay loam soil prior to transplanting with red pepper. Changes in concentration and properties of heavy metal for both of soil and plant were investigated 4 times during of red pepper growth. Plant height and stem diameter of red pepper in sludge treatments except to Pharmaceutical sludge 3 were poor than those of NPK treatment. This result were regarded as an effect of incompleted decomposition sludge which has a lot of organic matter concentration. Amount of total As was increased rapidly Jul. 8. in soil, total Zn Cu Pb Cd were in harvest time, and 1 N-HCl extractable Zn Cu Pb Cd As were in harvest at middle stage and then decreased. Amounts of nitrogen in plant (leaf and stem) were high in Phamaceutical Sludge 1 and fig Manure treatment in early and middle stage because of organic matter and nitrogen concentrations and characteristics. Amounts of Zn, Pb, and Ni in leaf and amount of Zn and Pb in stem were increased in harvest time so that we need to have a concern in detail. Total yield of red pepper was Pig Manure > Phamaceutical Sludge 3 > Phamaceutical Sludge 1 > NPK > Phamaceutical Sludge 2 and Cosmetic Sludge treatment was decreased considerably to compare to others. Amounts of Zn and Cu in green and red pepper in harvest time were higher than the other heavy metals. Finally these results can use to utilize that finding damage on crop for authorization and suitability estimation of raw material of compost.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.171-176
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• 2000

A wastewater treatment pond system was developed for treatment and recycling of dairy cattle excreta of $5\;m^1$ per day. The wastes were diluted by the water used for clearing stalls. The system was composed of three ponds in series. A submerged gas collector for the recovery of methane was installed at the bottom of secondary pond with water depth of 2.4m. This paper deals mainly with performance of methane fermentation of secondary pond which is faclutative one. The average $BOD_5$, SS, TN, and TP concentrations of influent into secondary pond were 49.1, 53.4, 48.6, and 5.3 mg/l, and those of effluent from it were 27.9, 45.7, 30.8, 3.2 mg/l respectively. Methane fermentation of 2.4-meter-deep secondary pond bottom was well established at $16^{\circ}C$ and gas garnered from the collector at that temperature was 80% methane. Literature on methane fermentation of wastewater treatment ponds shows that methane bacteria grow well around $24^{\circ}C$, the rate of daily accumulation and decomposition of sludge is approximately equal at $19^{\circ}C$, and activities of methanogenic bacteria are ceased below $14^{\circ}C$. The good methane fermentation of the pond bottom around $16^{\circ}C$, about $3^{\circ}C$ lower than $19^{\circ}C$, results from temperature stability, anaerobic condition, and neutral pH of the bottom sludge layer. It is recommended that the depth of pond water could be 2.4m. Gas from the collector during active methane fermentation was almost 83% methane, less than 17% nitrogen. Carbon dioxide was less than 1% of the gas, which indicates that carbon dioxide produced in bottom sludges was dissolved in the overlaying water column. Thus a purified methane can be collected and used as energy source. Sludge accumulation on the pond bottom for a nine month period was 1.3cm and annual sludge depth can be estimated to be 1.7cm. Design of additional pond depth of 0.3m can lead to 15 - 20 year sludge removal.

• 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 of Water and Wastewater
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• v.20 no.1
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• pp.115-121
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• 2006

The purpose of this study was to investigate applicability of pretreatment on the existing biological treatment for domestic wastewater reclamation. From Jar Tests, it was found that optimum dosage of coagulant was PAC 0.5mg/L and $FeCl_3$ 180mg/L for urban sewage. In this study, PAC 0.5mg/L was selected considering sludge production and the amount of coagulant required. In a continuous experiment performed with combining chemical coagulation and biological treatment, a considerable removal efficency was obtained in term of BOD, SS, T-N, T-P and ABS. When the raw sewage was supplied into the pre-chamical treatment facility, the removal of BOD and SS was 48.3% and 81.1%. However T-N removal was very low which means T-N consists of $NH_3-N$ mostly. T-P was almost completely recluced by the chemical addition. The effluent BOD & SS was 57~76 and 21~43mg/L, which could reduce the size of biological treatment facility. From the cost estimation pre-chemical treatment could save around half of the area required for biological treatment with post ceagulation.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.11a
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• pp.452-455
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• 2000

There are increasingly important financial incentives and environmental consideration to improve the effluent quality of wastewater from domestic and industrial users. The activated sludge process is a widely used biological wastewater treatment process. The activated sludge process is complicated due to the many factors such as the variation of influent flowrate and concentration, the complexity of biological reactions and the various operation conditions. Nowadays, not only suspended solids and residual carbon, but also nitrogen and phosphorous concentration of the effluent water must be taken into account for the design and operation of wastewater treatment plants. Also, the effluent quality to be met are more stringent. Therefore, an intelligent control approach is required in order to successful biological nitrogen removal. In this paper, the strategies for dosage of extra carbon in the anoxic zone and DO concentration in the aerobic zone are presented and evaluated through the simulation using the denitrification layout of the IWA simulation benchmark implemented by Matlab$\^$/5.3/Simulink$\^$/3.0. The control strategy to achieve sufficient denitrification rates in an anoxic zone. Methanol is used as an external extra carbon source. The external extra carbon source is required for the nitrogen removal process because nitrogen and organic concentration are fluctuated in the influent flowrate. The dissolved oxygen is calculated by So concentration in the activated sludge model NO.1. The air flowrate of each aerobic reactor is intelligently controlled to achieve the predefined setpoints. Air flowrate is adjusted by the fuzzy logic controller that includes two inputs and one output. The objective function for the optimization procedure is designed to improve effluent quality and reduce the operating cost.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.4
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• pp.591-598
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• 2012

Denitrification is an important biological mechanism in wastewater treatment process because this process is technically to remove nitrogen from water to air. There have been lots of study about denitrification engineering and molecular biological research about denitrifying bacteria, respectively. However, combination of these researches was unusual and rare. This study is about the correlation between quantity of denitrifying bacteria and denitrification potential, and consists of NUR batch test as analysis method of denitrification potential and quantitative molecular analysis for denitrifying bacteria. Three reactors (A/O, MLE and A/O of nitrogen deficiency) are operated to get activated sludge with various denitrification potential. All samples which were acquired from reactors were measured denitrification potential by NUR test and NUiR test. Also, Real-time PCR was conducted for quantification of denitrifying bacteria composition in activated sludge. The various denitrification potentials were measured in the reactors. The denitrifiaction potential was the highest in MLE process and the reactor of the nitrogen deficiency showed the lowest. Genomic DNA of activated sludge was obtained and consequently, real-time PCRuse the primer sets of nirK and nirS　were conducted to quantify genes involving denitrification reductase production. As the result of real-time PCR, nirK gene showed more significant influence on denitrification potential comapred with nirS gene.