• Applied Chemistry for Engineering
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• v.4 no.3
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• pp.564-568
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• 1993

By measuring the COD (chemical oxygen demend) of dish washing detergents being sold at market and pollutants connected with domestic sewage, we compared the amounts of water pollutants of one with other and carried out the experiments of ultimate biodegradation as against these samples. Also we combined our experimental results and circumstances of water pollution and wastewater treatments to the sewage system, compared the effects of synthetic detergent on water pollution with soap and the other pollutants and investigated results of our research.

• Journal of Environmental Health Sciences
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• v.33 no.5
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• pp.422-427
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• 2007

The purposes of this study were to investigate the concentration of total coliforms in sewage effluents during the period from August 2004 to October 2005. The removal efficiency range of multi-tube method and plate count method were $31.3{\sim}99.5%$ and $66.8{\sim}99.2%$, respectively. Though a correlation between the multi-tube method and the plate count method in the same sample is low, not only is an experimental procedure very simple, but the time required also is short. The seasonal correlation between methods showed more sensitive spring and summer than autumn and winter. So the study indicated plate count method can be used in rapid and reliance identification of total coliform more than the multi-tube method.

• Journal of Environmental Science International
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• v.6 no.1
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• pp.17-24
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• 1997

The objective of this study was to examine the transient response to hydraulic shocks in an Inverse fluidized bed bioflm reactor(IFBBR) for the treatment of apartment sewage. The hydraulic shock experiments, when the system were reached at steady state with each HRT 12, 7, and 4hr, were conducted by chancing twice HRT per day during 3days. The SCOD, SS, DO, and pH of the effluent stream were increased with hydraulic shock, but easily recovered to the steady state of pre-hydraulic shock condition. In spite of hydraulic shock, there were not much variation of biomass concentration, biofilm thickness and biofilm dry density.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.204-207
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• 2003

This study has been conducted for the purpose to develop a new technology using the carbonization process for establishing the resources circulation system for sewage sludge and enabling the sludge amount and volume to be reduced sanitarily and safely. Besides, it is thought that the effective value of the carbonized sludge is much greater even though there is any limitation to its applicable fields or use since it is not a product that is intentionally produced like any existing materials for conventional uses.

• Journal of Environmental Health Sciences
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• v.35 no.1
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• pp.58-63
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• 2009

This study investigated improvement to sludge dewaterability and coagulation for sewage treatment plant sludge by using sodium hypochlorite solution (NaOCl), ferric sulfate [$Fe_2(SO_4)_3$] and zeolite. The specific resistance to filtration(SRF), chloride, pH and turbidity were used to evaluate the sludge dewatering behaviors. The results of study were as follows: By varying the amount of NaOCl added the optimum result in terms of enhancement for pretreatment occurred when 34 mg/l of NaOCl was injected. When the total solids concentration of the sludge was 10,000 mg/l, the optimum ferric sulfate dosage for the sludge dewaterability was 150 mg/l and the corresponding SRF was $1.7{\times}10^7sec^2/g$. It was observed that injecting zeolite into sludge was effective in improving the dewaterability of sludge.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.387-392
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• 2006

There have been several problems in treating shipboard sewage due to special environmental conditions of ship, such as limited space, rolling and pitching, change of temperature and so on. It was suggested that Sequence Batch Reactor (SBR) might be suitable process for overcome these problems in terms of small size, high capacity of treating wastewater and full automation. In this study a SBR process was employed for biological treatment of organic wastes in the shipboard sewage. This process was able to remove nitrogen and phosphorus as well as organic matter efficiently. More than 95% of chemical oxygen demand(COD) were removed. In addition, about 97% of total nitrogen (T-N) was reduced. The total phosphorus(T-P) reduction averaged 93%. A disturbance operation caused by the treatment of Methylene Blue Active Substances(MBAS) was not observed.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.3
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• pp.373-382
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• 2013

In this study, a biological odor treatment system was proposed to remove odor(foul smell) materials causing several problems in the closed sewage treatment plant. This odor treatment system was composed of a two-step biofilter system in one reactor. The two-step biofilter reactor was constructed with natural purification layer in upper part and artificial purification layer in lower part. The reed grasses of water purification plants were planted in the surface area and mixed porous ceramic media were filled with the lower part of biofilter reactor. By using the above experimental apparatus, the ammonia gas removal efficiency was attained to 98.3 % and the hydrogen sulfide gas removal efficiency was appeared more than 97.7 % which shows more effective than the conventional odor removal process.

• Korean Chemical Engineering Research
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• v.55 no.6
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• pp.822-829
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• 2017

As a method to reduce the total phosphorus in sewage treatment plant, we applied the integral type slow mixing/sedimentation fiber filtration system to compare the control methods for the sewage effluent and the reject water. It was analyzed that about 92.4 kg T-P/day should be removed in order to satisfy the final concentration of phosphorus of 0.2 mg T-P/L, which is reinforced effluent standard. Therefore the total phosphorus removal efficiency should be 96% for sewage effluent and 69.2% for reject water (dehydrated filtrate) respectively. The system operation cost to achieve the target of total phosphorus removal efficiency was assessed. It has been found that the treatment cost of the reject water containing high concentration of phosphorus with a low flow rate is reduced to about 1/2.4 of the coagulant cost and about 1/120 of the electricity cost, compared to that of the sewage effluent treatment. Also the economics of the integral type slow mixing/sedimentation fiber filtration system and the general coagulation and sedimentation system were compared. It was evaluated that the development system was more economical because the installation area of the integral type slow mixing/sedimentation fiber filtration system was about 1/7 smaller than that of the general coagulation and sedimentation system, and the annual operation cost including the required amount of coagulant and electricity cost of the development system was lowered about 1/1.7 than that of the general system.

• Journal of Power System Engineering
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• v.21 no.5
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• pp.55-62
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• 2017

In this study, the water content and the low calorific value of the dried sludge are analyzed by using a vertical cylinder type indirect heating type dryer for evaluatation of energy source value. The vertical cylindrical thin film dryer was an Okadora Pilot Plant, and the dryer was indirect heating vertical thin film type. The internal standard consisted of 500 mm in diameter and 700 mm in height. In the drying experiment, 10 kg of dehydrated sewage sludge was added to the dryer and the total amount of the sludge was adjusted to 27 times by variable of the time, the number of revolutions and the steam temperature. The results of analysis of the 27th experiment component of the dried product showed that the average low calorific value of about 11.2 MJ/kg and the water content of 6%. This is satisfy the fuel use standard of the thermal power plant of the sludge.

• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.676-681
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• 2008

The evaluation of the effluent water quality of sewage treatment plant is one of the most important factor in calculating total maximum daily loads (TMDLs). Current method to calculate 95% upper limit of effluent water quality of sewage treatment plant assuming normal distribution of data needs to be implemented in case of non-normal distribution. We have investigated the applicability of percentile ranking method as a non-parametric statistical analysis in case of non-normal distribution of data.