• Title/Summary/Keyword: Refractory organic

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Treatment of Refractory Organics in Dyeing Wastewater by Using Cell Immobilized Pellets (고정화담체를 이용한 염색폐수의 난분해성 유기물질 처리)

  • Han, Duk-Gyu;Bae, Woo-Keun;Cho, Young-Jin;Won, Ho-Shik;Lee, Yong-Woo
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.9
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    • pp.917-922
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    • 2005
  • The wastewaters from textile and dyeing industries are difficult to treat due to its high pH, temperature, color intensity and non-biodegradable organic contents. This study investigated the removal of recalcitrant organics in a dyeing wastewater by using a packed bed reactor (PBR) that contained cell-immobilized pellets. The feed, obtained from an effluent of a biological treatment plant, had $SCOD_{Cr}$ of 330 mg/L and $SBOD_5$ of 20 mg/L on average. In immobilizing the cells to a Polyethylene Glycol(PEG) based medium, activated sludges from either a sewage treatment plant or an industrial wastewater treatment plant were used. When the empty bed contact time (EBCT) was above 8 hrs in the PBR, the $COD_{Cr}$ removal efficiency was over 50% and the $COD_{Mn}$ concentration was 72 mg/L or lower on average, which was substantially lower than the discharge standard of 90 mg/L. The results indicated that the optimum EBCT in the PBR was 8 hrs. The PBR with cell-immobilized pellets was effective as an advanced treatment process after an activated sludge process for treating dyeing wastewaters.

Assessment and Treatment of Depression in the Medically III (신체질환 환자들에서 우울증의 평가 및 치료)

  • Koh, Kyung-Bong
    • Korean Journal of Psychosomatic Medicine
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    • v.9 no.2
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    • pp.111-132
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    • 2001
  • Depression in the medically ill is a common clinical problem that primary physicians and psychiatric consultants encounter. Treatment of such patients begins with a careful evaluation of the patient's medical and psychiatric conditions. The assessment of depression in the medical patients requires a multidimensional approach. Psychological instruments are also used as a method of assessment in these patients. First of all, what the therapists have to do is to find and remove organic causes. Psychosoical treatment includes dealing with the patient's resistance and despondency relevant to physical diseases. For biological treatment, it is important to select appropriate antidepressants. Therapists should be familiar with the side effects of the antidepressants as well as the patient's primary depressive symptoms, pharmacokinetics and pharmacodynamics of the available agents. In addition, special attention should be paid to the potential for drug-illness and drug-drug interactions. Tricyclic antidepressants can be still effectively used for patients with pain disorder, although a variety of new antidepressants such as selective serotonin reuptake inhibitors (SSRI), bupropion and venlafaxine could have more benefits in depression of the medically ill. However, electroconvulsive therapy can be recommended for refractory cases of depression in patients with medical illness.

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Removal of Ammonia Nitrogen and Organics from Piggery Wastewater Using BACC Process-I. Comparison of Activated Sludge Process (BACC를 이용한 축산폐수의 암모니아성 질소 및 유기물의 제거 I. 활성슬러지 공정과의 비교)

  • 성기달;류원률;김인환;조무환
    • KSBB Journal
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    • v.16 no.2
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    • pp.133-139
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    • 2001
  • To treat piggery wastewaters containing refractory compounds including nitrogen, biological treatments were investigated. In biological treatment, the removal efficiencies of organics and nitrogen by the activated sludge process and bioreactor using a BACC (Biological Activated Carbon Cartridge) media filled with granular activated carbon were examined. The results were as follows; in the biological process, when the approximate influent BOD concentration of 620 mg/L, through dilution, was treated by the activated sludge process, the process should be operated at a HRT of over 8 days to maintain an effluent BOD concentration of lower than 100 mg/L. In the treatment of piggery wastewater using a BACC bioreactor, when the HRT was 200 hours, the BOD, COD(sub)cr, and TKN removal efficiency of the effluent were 94, 75 and 64.3%, respectively. Comparing the BACC bioreactor with the activated sludge process, when the volumetric loading rate was 0.3 g BOD/L.day, the specific substrate removal rate of BOD was 0.14 g BOD removed/L.day in the activated sludge process which compared with 0.27 g BOD removed/L$.$day in the BACC bioreactor. The BACC bioreactor showed on average a 2-fold higher removal rate and was superior to the activated sludge process in wastewater treatment in terms of variations of loading time and high loading time. Therefore, the BACC process can effectively treat piggery wastewater containing high concentrations of nitrogen and organic compounds.

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Decomposition of Sulfamethoxazole by Catalytic Wet Peroxide Oxidation (촉매습식과산화(CWPO)를 이용한 설파메톡사졸의 분해)

  • Kim, Dul Sun;Lee, Dong-Keun;Kim, Jin Sol
    • Clean Technology
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    • v.24 no.4
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    • pp.293-300
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    • 2018
  • Sulfamethoxazole (SMX) is sulfaamide-based synthetic antibiotics, which are widely prescribed pharmaceutical compound to treat bacterial infections in both human and animals. Most of them are not completely decomposed as refractory substances. The environmental impact of pharmaceuticals as emerging contaminants has generated severe concerns. In this study, catalytic wet peroxide oxidation (CWPO) of SMX was carried out with $Cu/Al_2O_3$ catalyst and investigated the optimum reaction conditions of temperature, dosage of catalyst and concentration of $H_2O_2$ to completely decompose the SMX. It was observed that SMX was completely decomposed within 20 min using 0.79 mM $H_2O_2$ and 6 g $Cu/Al_2O_3$ catalyst at 1 atm and $40^{\circ}C$, but SMX was not fully mineralized and converted to intermediates as hydroylated-SMX, sulfanilic acid, 4-aminobenzenesulfinic acid and nitrobenzene. After that these are completely mineralized through organic acid. We proposed the decomposition reaction path ways of SMX by analyzing the behavior of these intermediates. To investigate the durability of heterogeneous catalyst, decomposition of SMX was observed by continuously recycling catalysts. When the heterogeneous catalyst of 10 wt% $Cu/Al_2O_3$ was continuously reused 5 times, decomposition of SMX was a little lowered, but the activity of catalyst was overall very stable.