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Degradation of residual pharmaceuticals in water by UV/H2O2 advanced oxidation process (UV/H2O2 고도산화기술을 이용한 수중 잔류의약물질 제거)

  • Park, Chinyoung;Seo, Sangwon;Cho, Ikhwan;Jun, Yongsung;Ha, Hyunsup;Hwang, Tae-Mun
    • Journal of Korean Society of Water and Wastewater
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    • v.33 no.6
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    • pp.469-480
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    • 2019
  • This study was conducted to evaluate the degradation and mineralization of PPCPs (Pharmaceuticals and Personal Care Products) using a CBD(Collimated Beam Device) of UV/H2O2 advanced oxidation process. The decomposition rate of each substance was regarded as the first reaction rate to the ultraviolet irradiation dose. The decomposition rate constants for PPCPs were determined by the concentration of hydrogen peroxide and ultraviolet irradiation intensity. If the decomposition rate constant is large, the PPCPs concentration decreases rapidly. According to the decomposition rate constant, chlortetracycline and sulfamethoxazole are expected to be sufficiently removed by UV irradiation only without the addition of hydrogen peroxide. In the case of carbamazepine, however, very high UV dose was required in the absence of hydrogen peroxide. Other PPCPs required an appropriate concentration of hydrogen peroxide and ultraviolet irradiation intensity. The UV dose required to remove 90% of each PPCPs using the degradation rate constant can be calculated according to the concentration of hydrogen peroxide in each sample. Using this reaction rate, the optimum UV dose and hydrogen peroxide concentration for achieving the target removal rate can be obtained by the target PPCPs and water properties. It can be a necessary data to establish design and operating conditions such as UV lamp type, quantity and hydrogen peroxide concentration depending on the residence time for the most economical operation.

Description of Feeding Apparatus and Mechanism in Nemopilema nomurai Kishinouye (Scyphozoa: Rhizostomeae)

  • Lee, Hye-Eun;Yoon, Won-Duk;Lim, Dong-Hyun
    • Ocean Science Journal
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    • v.43 no.1
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    • pp.61-65
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    • 2008
  • Feeding apparatus, mechanism and passage of ingested prey were described for Nemopilema nomurai (Scyphozoa: Rhizostomeae). N. nomurai medusae without central mouths have developed complicated canal systems connecting the tip of the tentacle and oral arm to the gut cavity. The number of junctions in the canal system increases with the bell diameter. The prey is gathered by paralyzing nematocyst at the tentacles and by adhering cirri at the oral arms and scapulets. They are engulfed into the terminal pore located at the oral arms and scapulets, and entered into the gut cavity via the canal system. The estimated digestion time is 1 hour and 20 min. The diameter of terminal pore is always about 1 mm, implying that they could not eat prey larger than that pore size. On the other hand, ephyrae have central mouths and could swallow prey as large as adults could. Exploitation of the same size of food by adult and ephyra implies that N. nomurai can affect seriously the whole food web, massively ingesting micro- and mesozooplankton and cutting the energy transfer toward the higher level of carnivores.

A study on the testing method of discolored tap water by spectrophotometer (분광측색계에 의한 착색 수돗물 시험방법 연구)

  • Dongheon Kim;Jonggeum Lee;Jiyoon Oh;Gitae Kim;Hangbae Jun
    • Journal of Korean Society of Water and Wastewater
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    • v.37 no.4
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    • pp.187-202
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    • 2023
  • This study focuses on the application of a new measurement method that quantifies the residual color of filtered water using a spectrocolorimeter after filtering the discolored substances. It was confirmed through the color and turbidity cross-test that the discolored substances cannot be measured effectively with the current legal color and turbidity test method. Therefore, the National Institute of Environmental Research's filter testing method, which involves filtering the sample through 0.45 ㎛ filter and visually inspecting the color, was improved. A membrane filter colorimetry (MFC) method was established by measuring the color difference (ΔE*ab(65)) of the filtered filter using a spectrophotometer and expressing it as filter color unit (FCU). Using the MFC method, the FCU for reference materials such as iron and manganese, as well as field samples, was measured. The results showed a high correlation with turbidity, and the color difference patterns varied depending on the type of reference materials and field samples. This indicates that the MFC method is an effective new measurement method of discolored tap water.