• Archives of Plastic Surgery
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• 제38권6호
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• pp.875-878
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• 2011

Purpose: Absorbable implants are frequently used to fix facial bone fractures, because they are radiolucent and compatible with magnetic resonance imaging (MRI). Despite their increasing usage, however, there have been few reports about their long-term side-effects. In this paper, a case in which absorbable implants led to a foreign body reaction 17 months after their insertion is presented. Methods: A previously healthy 19-year-old male fell from a flight of stairs and visited the authors' hospital with right periorbital pain. Zygomaticomaxillary fracture involving right orbital floor was detected via a facial bone computed tomography (CT). Internal fixation with absorbable implants was followed by open reduction. 17 months after the surgery, the patient complained of localized periorbital swelling. Removal of the granulomatous lesion including the absorbable implants along with their biopsy and culture was performed. Results: The granulomatous lesion around the implants was firm and extended into the maxillary sinus. The histologic finding showed a microabscess with a foreign body reaction. Methicillin-sensitive Staphylococcus aureus growth was confirmed in the culture. No definite abnormal symptoms ensued after the complete removal. Conclusion: A microabscess-forming granulomatous lesion around the absorbable implant can cause delayed symptomatic foreign body reaction despite its rare occurrence. Complete removal of the lesion including implants is expected to have a successful outcome if it is encountered.

• Journal of Korean Neurosurgical Society
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• 제48권4호
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• pp.383-387
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• 2010

Complete removal of three-compartment trigeminal schwannomas is a challenge to neurosurgeons. To expand exposure of each compartment, the combination and modification of skull base approaches are necessary. The 61-year-old woman was admitted with chronic headache. Preoperative magnetic resonance imaging showed $47{\times}50{\times}40\;mm$-sized tumor originating primarily in the middle cranial fossa extended to the posterior and the infratemporal fossa. We performed operation in five stage; 1. Zygomatic osteotomy, 2. Inferior temporal fossa plate removal and foramen ovale opening, 3. Cavernous sinus opening, 4. Tailored anterior petrosectomy, 5. Meckel's cave opening. Combination of skull base surgery should be concerned according to the patient. In this study, extradural basal extension with zygomatic osteotomy, interdural posterior extension with tailored anterior petrosectomy, and intracavemous exploration are reasonable options for remodeling three-compartment lesion into a single compartment. Tailoring of bone resection and exploring through natural pathway between meningeal layers accomplish single-stage operation for complete removal of tumors.

• 한국물환경학회지
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• 제31권6호
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• pp.619-624
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• 2015

This study experimentally determined the effect of titanium tetrachloride (TiCl₄) concentration ([TiCl₄]) (0.25-0.55 mM) and initial pH (3-11) on phosphorus (P) removal in synthetic wastewater (2 mg P/L). The P removal efficiency increased when [TiCl₄] increased. The P removal efficiency showed a parabolic trend with an inflection point at pH 7. At the molar ratio of TiCl₄ and P>6.2, the P removal efficiency was over 90% and the residual P concentration was less than 0.2 mg/L. Within the design boundaries, the complete P removal could be achieved at 7.0≤initial pH≤8.5 and 0.43≤[TiCl₄]≤0.55 mM. The final pH was over 5.8 at initial pH≥7.7 and [TiCl₄]≥0.35 mM. The results showed that TiCl4 was effective in P removal in water so that it could be an alternative chemical for P removal.

• Environmental Engineering Research
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• 제23권1호
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• pp.92-98
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• 2018

Suitability of aluminium-based water treatment sludge (WTS), a waste product from water treatment facilities, was assessed for removal of heavy metals from an electroplating wastewater which had high concentrations of copper and chromium along with other heavy metals. Batch tests with simulated wastewater in single- and multi-metal solutions indicated the influence of initial pH and WTS dose on removal of six metals namely Cu(II), Co(II), Cr(VI), Hg(II), Pb(II) and Zn(II). In general, removal of cationic metals such as Pb(II), Cu(II) and Zn(II) increased with increase in pH while that of anionic Cr(VI) showed a reduction with increased pH values. Tests with multi-metal solution showed that the influence of competition was more pronounced at lower WTS dosages. Column test with diluted (100 times) real electroplating wastewater showed complete removal of copper up to 100 bed volumes while chromium removal ranged between 78-92%. Other metals which were present in lower concentrations were also effectively removed. Mass balance for copper and chromium showed that the WTS media had Cu(II) and Cr(VI) sorption capacities of about 1.7 and 3.5 mg/g of dried sludge, respectively. The study thus indicates that WTS has the potential to be used as a filtration/adsorption medium for removal of metals from metal-bearing wastewaters.

• 상하수도학회지
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• 제21권1호
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• pp.83-89
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• 2007

A biological anoxic-aerobic reactor filled with porous media was operated in lab scale for the advanced wastewater treatment. The experiments were conducted for 6 months with three HRTs (4, 6, 8hr) and temperature of $23{\sim}25^{\circ}C$. Some other experimental conditions were as follows; nitrification reactor (MLSS 4,500mg/L, DO 3.3mg/L, $23{\sim}28^{\circ}C$), denitrification reactor(MLSS 8,000mg/L, ORP -100mV, Temp.$19{\sim}23^{\circ}C$). Average removal efficiencies of SS, $BOD_5$, $COD_{Cr}$, T-N, and T-P were 97.8%, 95.5%, 94.5%, 80.2%, and 60.6%, respectively. The reactor filled with porosity media showed stable removal capacity for organics and nutrients. Fast and complete nitrification and denitrification were accomplished. Maintaining high MLSS with porous media in the nitrification and denitrification reactor appears to enhance the nitrogen removal process. For the higher T-P removal, some coagulant addition process will be needed.

• 한국환경과학회지
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• 제25권7호
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• pp.905-916
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• 2016

The characteristics of phenol removal and $UV_{254}$ matters variance were investigated and compared by the variation of operating factors (NaCl concentration, air flow rate, initial phenol concentration) in electrochemical reaction (ER) and dielectric barrier discharge plasma reaction (DBDPR), respectively. The phenol removal rate was shown as $1^{st}$ order both in ER and DBDPR. Also, the absorbance of $UV_{254}$ matters which means aromatic intermediates was analyzed to investigate the complete phenol degradation process. In ER, the phenol degradation and aromatic intermediates production rates increased by the increase of NaCl concentration. However, in DBDPR, the variation of NaCl concentration had no effect on the degradation of phenol and $UV_{254}$ matters. Air flow rate had a little effect on the removal of phenol and the variation of $UV_{254}$ matters in ER. The phenol removal rate in ER was a little higher than that in DBDPR. The produced $H_2O_2$ and $O_3$ amounts in ER were 2 times and 10 times higher than those in DBDPR. The chlorine intermediates ($ClO_2$ and free chlorine) were produced in ER, however, they were not produced in DBDPR.

• 한국환경보건학회지
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• 제23권3호
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• pp.121-129
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• 1997

This study was performed to delineate the removal phenol in solutions using of ozone, ozone/$H_2O_2$ and ozone/GAC. The disinfection by-product of phenol by ozonation, hydroquinone, was analyzed and it's control process was investigated. The followings are the conclusions that were derived from this study. 1. The removal efficiency of phenol by ozonation was 58.37%, 48.34%, 42.15%, and 35.41% which the initial concentration of phenol was 5 mg/l, 10 mg/l, 15 mg/l, and 20 mg/l, respectively. 2. The removal efficiency of phenol by ozonation was 42.95% at pH 4.0 and 69.39% at pH 10, respectively. The removal efficiencies were gradually increased, as pH values were increased. 3. With the ozone/$H_2O_2$ combined system, the removal efficiency of phenol was 72.87%. It showed a more complete degradation of phenol with ozone/$H_2O_2$ compared with ozone alone. 4. When ozonation was followed by filtration on GAC, phenol was completely removed. 5. Oxidation, if carried to completion, truly destroys the organic compounds, converting them to carbon dioxide. Unless reaction completely processed, disinfection by-products would be produced. To remove them, ozone/GAC treatment was used. The results showed that disinfection by-product of phenol by ozonation, hydroquinone, was completely removed. These results suggested that ozone/GAC should also be an appropriate way to remove phenol and its by-product.

• 한국환경과학회지
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• 제16권1호
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• pp.45-53
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• 2007

This study was carried out to investigate the variation of organic, nitrogen and phosphorus in $(AO)_2$ SBBR process according to the variation of operating cycle at the high TOC concentration. The operation time in anoxic (anaerobic) time to oxic time was 1:1. Three lab-scale SBBRS were fed with synthetic wastewater based on glucose as carbon source, The variation of total TOC removal was similar each other irrespective of operation time, however, the TOC concentrations in SBBRs showed a little difference according to the operating condition. In SBBR, complete nitrification was not occurred at all reactors, however, R3 showed a higher nitrification than R2. And in SBBR, the variation of operating time more affected at phosphorus removal than nitrogen removal. R2 which had the shortest time at the 1st aeration time showed the lowest phosphorus release and uptake efficacy.

• 한국환경농학회지
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• 제39권2호
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• pp.89-94
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• 2020

BACKGROUND: Persistent organic contaminants such as dichlorodiphenyltrichloroethane (DDT) are often found in agricultural soils decades after it was banned in Korea. This study uses hemoglobin and hemoglobin-containing blood meal to reduce the residual DDT in soil. METHODS AND RESULTS: Hemoglobin or blood meal with or without hydrogen peroxide (H₂O₂) was mixed with the DDT-spiked soil prepared for this study, and samples were taken over 14 d-degradation period to measure the residual DDT concentrations. With only hemoglobin, DDT was completely removed after 14 d, while with both hemoglobin and H₂O₂, 73%, on average, removal was observed. Similarly, the blood meal removed 73% of DDT, but with H₂O₂, the DDT removal was only 39%. The lower DDT removal in the presence of H₂O₂ can be attributed to the adverse effects of reactive species. Hemoglobin was more effective than blood meal for DDT removal in a given time; however, with additional blood meal injection, complete DDT removal was achieved. CONCLUSION: Overall, this study shows that the blood meal that is used as a fertilizer can potentially be used to remove residual contaminants such as DDT in agricultural soil.

• Journal of Electrochemical Science and Technology
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• 제8권2호
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• pp.124-132
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• 2017

The performance of electrolytic processes using copper and catalyzed electrodes for enhanced nutrient removal with various catalyzers and combinations of electrodes was evaluated. The catalyzed electrodes removed more ammonia nitrogen than the copper electrode, but higher ammonia removal was achieved using a Pt/Ti anode. On the other hand, electrolysis using the Pt/Cu anode consumed less energy and cost less. During electroreduction, nitrate was better removed by a pair of copper electrodes than by the catalyzed electrodes. During electrolysis of synthetic wastewater, ammonia removal not only increased owing to direct oxidation at the anode, but was also influenced by indirect oxidation at the cathode. Platinum-coated copper and titanium cathodes actively produced oxidizers and thus removed more ammonia than a pure metal cathode. Although phosphorus was removable irrespective of the type of catalyzer, electrocoagulation using the copper electrode achieved complete removal of phosphorus in a period of less than 10 min.