• Journal of Environmental Health Sciences
• /
• v.40 no.4
• /
• pp.322-329
• /
• 2014

Objectives: The purpose of this study was to investigate the effect of BIO-CLOD on advanced wastewater treatment for enhanced removal efficiency and meeting the stringent discharge water requirements of wastewater treatment plants. Methods: Two experimental apparatuses consisting of anaerobic, anoxic and aeration tanks were operated. One included a BIO-CLOD cultivation tank. Organic and nutrient parameters and removal efficiency were analyzed by pH, BOD, CODcr, SS, T-N and T-P. Results: The average removal efficiencies of BOD, COD and SS from the apparatus with BIO-CLOD tank installation were 95.5%, 88.6% and 92.9%, respectively, and these were higher than the results from the apparatus without BIO-CLOD. The average TP removal efficiency with BIO-CLOD tank marked 56.0%, higher than the 47.3% from the apparatus without one. BIO-CLOD showed a higher performance for TN removal at 49.6%, compared to the result without BIO-CLOD of 34.3% Conclusion: By reaction with BIO-CLOD, ammonia removal was effective in the aeration tank, as was phosphorus release in the anaerobic tank. Phosphorus luxury uptake and nitrification in aeration tank proceeded smoothly. The application of BIO-CLOD can improve the decrease of odor and settleability of activated sludge in a wastewater treatment plant, as well as increase the removal efficiency of organic and nutrient materials in water.

• 한국석유지질학회:학술대회논문집
• /
• autumn
• /
• pp.40-49
• /
• 1999

The chemical compositions of natural gases and isotopic compositions of hydrocarbon gases were analyzed to characterize the properties of the gases which were found in the exploratory wells from offshore Korea, as well as those dissolved in the ground water onshore in the Pohang area. Natural gases from the offshore area mainly consisted of hydrocarbon gases $(97.98{\~}100{\%})$. The gases were composed of methane $(90{\~}96{\%})$ and minor amounts of heavier components up to $C_{6+}$ Hydrocarbon gases extracted from the groundwater in the Pohang area consisted of methane $(27{\~}376420 ppm)$ and ethane $(19{\~}127 ppm)$. The total amount of hydrocarbon gases was related to the lithology and geological factors surrounding the reservoir. The quantity of the hydrocarbon gases tended to Increase in the Tertiary reservoirs and in the reservoirs where the Tertiary formations were thickly distributed. According to the methane contents, composition of hydrocarbon gases, and stable isotope data, gases from offshore wells are identified as thermogenic in origin, generated during catagenesis stage of the oil window. On the otherhand, based on the methane content $(>99.9\%)$ and isotopic composition $(\delta^{13} C^;\; -73.1{\sim}\;-43.22{\%}_{\circ})$, it is interpretated that the gases from the Pohang area are predominantly composed of biogenic origins, which were generated by the methanogenic bacterial processes under low temperatures and anoxic conditions.

• Journal of Korean Society on Water Environment
• /
• v.22 no.6
• /
• pp.1014-1021
• /
• 2006

SMMIAR (Submerged Moving Media Intermittent Aeration Reactor) Process is a very efficient system which remove ammonia to nitrogen gas in one reactor. In this study, we determined the diversity of ammonia oxidizing bacteria and denitrifying bacteria using specific PCR amplification and the clone library construction. An ammonia monooxygenase gene(amoA) was analyzed to investigate the diversity of nitrifiers. Most of amoA gene fragments (27/29, 93%) were same types and they are very similar (>99%) to the sequences of Nitrosomonas europaea and other clones isolated from anoxic ammonia oxidizing reactors. ANAMMOX related bacteria have not determined by specific PCR amplification. A nitrite reductase gene(nirK) was analyzed to investigate the diversity of denitrifying bacteria. About half (9/20, 45%) of denitrifiers were clustered with Rhodobacter and most of others were clustered with Mesorhizobium (6/20, 30%) and Rhizobium (3/20, 15%). All of these nirK gene clones were clustered in alpha-Proteobacteria and this result is coincide with other system which also operate nitrification and denitrification in one reactor. The molecular monitoring of the population of nitrifiers and denitrifiers would be helpful for the system stabilization and scale-up.

• Journal of Korean Society on Water Environment
• /
• v.18 no.4
• /
• pp.435-440
• /
• 2002

A pilot scale SBR (effective volume, $20m^3$) for the treatment of piggery wastewater treatment was performed with three different kinds of wastewater; fermenter effluent, scraper type and slurry type. The react phase in SBR was performed by sub-cycle operation consisting of repeated short cycle of anoxic-aerobic step. The fermenter effluent was characterized by the rapid nitrification and $NO_X-N$ accumulation due to depletion of organic matter in wastewater. The scraper type wastewater showed appropriate nitrogen removal efficiency, however, a poor response capacity for high loading rate often resulted in increased nitrogen concentration in effluent. Moreover, severe P release was the most serious problem in scraper type wastewater. SBR treated slurry type wastewater with high nitrogen removal efficiency to satisfy effluent quality requirement. It was thought that high concentration of organic matter in slurry made it possible to uptake P during SBR operation, where P concentration of 140mgP/l was decreased to 8mgP/l. As results, SBR was suitable to treat slurry type wastewater which has been discharged to the ocean till now.

• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.6
• /
• pp.907-915
• /
• 2011

In this study, the SBR and MLE process was performed for a removal of the RO retentate and the nitrogen removal efficiency was evaluated. The inflow-rate of two processes was set a 10 L/day. The SBR process was operated a two cycle as HRT per one cycle was 12hr and the HRT of the anoxic and aerobic tank was respectively 7.5 hr and 16.5 hr. The methanol was injected for an effective denitrificaion owing to a low C/N ratio of the RO retentate. The two processes were effectively performed for nitrogen removal, but the average removal efficiency of the SBR process was about 94.93% better performance than the MLE process. Therefore, the SBR process demonstrated a good performance more than the MLE process for nitrogen removal of the RO retentate. The kinetic of SNR and SDNR was observed respectively 0.051 kg $NH_{3}-N/kg\;MLVSS{\cdot}dayg$ and 0.287 kg ${NO_3}^--N/kg\;MLVSS{\cdot}day$, which will be useful to design for the wastewater treatment system with a RO retentate.

• Journal of environmental and Sanitary engineering
• /
• v.17 no.3
• /
• pp.52-59
• /
• 2002

Pilot-scale PSSBR(Phase Separated Sequencing Batch Reactor) was operated to evaluate requirement of external carbon sources(${\Delta}gCOD/{\Delta}gNO_3^{-}-N$) in denitrification. Methanol and fermented food waste were used as external carbon sources. Methanol and fermented food waste were fed to the anoxic state of first reactor and concentration were 50 and 40 mgCOD/L on the basis of concentration in reactor, respectively. In case that external carbon source was not used, average $NO_3^{-}-N$ concentration in effluent was 22.49 mg/L. When methanol and fermented food waste were fed, average $NO_3^{-}-N$ concentration in effluent were 10.13 mg/L and 6.3 mg/L, respectively and requirement of external carbon sources were 4.04 and 2.5 ${\Delta}gCOD/{\Delta}gNO_3^{-}-N$, respectively. Fermented food waste was better than methanol in denitrification efficiency. Therefore fermented food waste could be one of the excellent external carbon sources for nitrogen removal in biological nutrient removal process.

• Journal of Chest Surgery
• /
• v.24 no.1
• /
• pp.1-7
• /
• 1991

This report describes our 10-year experience with intracardiac repair in 42 patients older than 16 year with tetralogy of Fallot. The mean age was 22.0$\pm$5.18 years[range 16~41]. The preoperative clinical manifestations were cyanosis & clubbing[93%], frequent URI [55%], anoxic spell[40%], pulmonary tuberculosis[21%], tuberculous empyema[7%], chronic renal failure[7%], congestive heart failure[7%] and subacute bacterial endocarditis [2%], etc. The previous shunt procedure for palliation had been performed in 7 patients. The type of VSD were typical perimembranous type[67%], total canal defect[28%] and combined type[5%]. The right ventricular outflow tract obstruction were combined type[69%], infundibular type[21%] and valvular type[10%]. Transannular patch was used in 50% of patients. Associated cardiovascular anomalies were ASD[33%], PFO[31%], Rt. aortic arch[10%], Lt. SVC[10%], single Rt. pulmonary artery, single Lt. coronary artery, ASI, proximal stenosis of Rt. pulmonary artery and anomalous systemic venous return, etc. Hospital mortality was 7.1%[3 cases]in overall. The causes of hospital deaths were revealed low cardiac output & acute renal failure[2 cases], postoperative bleeding[1 case]. There were 2 late deaths 3 & 68 months after surgery. Residual intracardiac shunt was detected in 2 patients. one patient was successfully reoperated and another patient had Qp /Qs ratio less than 1.5.

• Journal of Korean Society on Water Environment
• /
• v.22 no.2
• /
• pp.230-237
• /
• 2006

The operational parameters and control strategies of a tertiary wastewater treatment process a biological filtration system were investigated. The biological filtration system consisted of a nitrification filter (Fiter 1) and a polishing filter with anoxic and aerobic parts (Filter 2). SS, T-C-BOD, and T-N in effluent were kept stable at less than 3, 5 mg/L, and 5 mgN/L, respectively, under a HRT in Filter (filter-bed) of 0.37~2.3 h. T-N at the outlet of Filter 2 were about 1~5 mgN/L under the condition of LV of 50~202 m/d. Methanol addition was controlled based on the COD/N ratio or McCarty's equation. Constant COD/N ratio control results in excess addition under large diurnal fluctuation of $NOx^--N$, and McCarty's equation can be used to add appropriate amount of methanol. Control of methanol addition by on-line nitrate measurement, control of aeration by on-line DO measurement, and control of backwashing by head loss measurement are successfully operated. These results proved that this process prove the easy-maintenance and cost-effectively treatment is attainable.

• Journal of Korean Society of Water and Wastewater
• /
• v.27 no.6
• /
• pp.815-826
• /
• 2013

Using a developed mathematical model and calibrated kinetic constants, numerical experiments for a aerobic digestion of wastewater sludge by SBR aerobic digestion process combined with ultrasonication (USSBR) were performed in this study. It simulated well the phenomena of the decomposition of particulate organics and the release of organic nitrogen and transformation. To achieve 40 % of particulate organics removal, USSBR process requires only 6 days of SRT and 14 W/L of ultrasonic power whereas SBR aerobic digestion process requires 12 days of SRT. Based on the model simulation results, an empirical equation was presented here. This equation will be used to predict digestion efficiency for the given variables of SRT and ultrasonic power dose. USSBR aerobic digestion process can reduce the nitrogen concentration. The optimal operation strategy for the simultaneous removal of solids and soluble nitrogen in this process is estimated to 7 days of SRT with 14 W/L of ultrasonic power dose while anoxic period was 6 hours out of 24 hours of cycle time. In this condition, 40 % of particulate organics as well as 36 % of total nitrogen will be removed and the soluble nitrogen concentration of the centrate will be lower less then 40 mg/L.

• Korean Journal of Ecology and Environment
• /
• v.38 no.spc
• /
• pp.39-43
• /
• 2005

The dynamics of water quality with the storm events were analyzed in a small reservoir for irrigation, Lake Wangkung. Water quality of the inflowing stream fluctuated seasonally with the variation of flow rate. Thermal stratification was consistent from April to October below 2 m depths and anoxic layer was developed below 2 m depth in summer. The unique feature of temperature showed that thermal stratification was disrupted by a heavy rain event during monsoon, but hypolimnetic hypoxia were reestablished after a few days. Phosphorus and nitrogen increased immediately following storm events. The marked increase may be due to the input of P-rich storm runoff from the watershed. Internal phosphorus loading can be one of the explanations for TP increases in summer. When there was a storm, total populations of phytoplankton and zooplankton was reduced immediately following the storm, indicating possible flushing of algae and zooplankton. After a lag period of low-density the plankton population bloomed to a peak again within five days after the storm. Turbid water in lake became clear again which coincided with the time of the phytoplankton buildup. The results demonstrate that water quality is regulated greatly by rainfall intensity in Lake Wangkung.