The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform

Jae Hak Cheong - One of the best experts on this subject based on the ideXlab platform.

  • calculation of risk based detection limits for radionuclides in the Liquid Effluents from korean nuclear power plants
    Journal of Nuclear Science and Technology, 2017
    Co-Authors: Jae Hak Cheong
    Abstract:

    ABSTRACTIn order to review if present detection limits of radionuclides in Liquid Effluent from nuclear power plants are effective enough to warrant compliance with regulatory discharge limits, a risk-based approach is developed to derive a new detection limit for each radionuclide based on radiological criteria. Equations and adjustment factors are also proposed to discriminate the validity of the detection limits for multiple radionuclides in the Liquid Effluent with or without consideration of the nuclide composition. From case studies to three nuclear power plants in Korea with actual operation data from 2006 to 2015, the present detection limits have turned out to be effective for Hanul Unit 1 but may not be sensitive enough for Kori Unit 1 (8 out of 14 radionuclides) and Wolsong Unit 1 (9 out of 42 radionuclides). However, it is shown that the present detection limits for the latter two nuclear power plants can be justified, if credit is given to the radionuclide composition. Otherwise, consideratio...

Chin Kui Cheng - One of the best experts on this subject based on the ideXlab platform.

  • photocatalytic restoration of Liquid Effluent from oil palm agroindustry in malaysia using tungsten oxides catalyst
    Journal of Cleaner Production, 2017
    Co-Authors: Yoke Wang Cheng, Ying Shi Chang, Chin Kui Cheng
    Abstract:

    In the current work, the photocatalytic treatment of palm oil mill Effluent over tungsten oxides photocatalyst under ultraviolet-irradiation was evaluated. Characterization of fresh and used tungsten oxides photocatalyst was accomplished via X-Ray Diffraction, Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis, Ultraviolet–Visible Light Diffuse Reflectance Spectroscopy, and Fourier Transformed-Infrared Spectroscopy. Photocatalytic treatment of palm oil mill Effluent was conducted to determine the effects of catalyst loading, longevity, and recyclability of the tungsten oxides photocatalyst, as well as the effect of pH alteration on palm oil mill Effluent. During the photocatalytic reaction, the collected Liquid sample was tested for chemical oxygen demand, pH, and colour intensity while the gaseous sample was analyzed via gas chromatography. The optimum catalyst loading was 0.5 g/L, corresponds to highest photocatalytic degradation (51.15%) and decolourization (96.21%). The pH alteration on palm oil mill Effluent has negligible effect on its photocatalytic degradation with UV/WO3 system. For longevity study, the optimum reaction time was 16 h, which achieved 84.70% photocatalytic degradation and 98.28% photocatalytic decolourization. From the recyclability study, it can be concluded that the tungsten oxides photocatalyst is suitable for photocatalytic decolourization of palm oil mill Effluent, but not suitable for photocatalytic degradation. In addition, analysis of the gaseous product showed that the photocatalytic treatment has successfully degraded the organic pollutants in the Liquid Effluent into methane and carbon dioxide.

  • restoration of Liquid Effluent from oil palm agroindustry in malaysia using uv tio2 and uv zno photocatalytic systems a comparative study
    Journal of Environmental Management, 2017
    Co-Authors: Maksudur R Khan, Sk Safdar Hossain, Chin Kui Cheng
    Abstract:

    In this study, we have employed a photocatalytic method to restore the Liquid Effluent from a palm oil mill in Malaysia. Specifically, the performance of both TiO2 and ZnO was compared for the photocatalytic polishing of palm oil mill Effluent (POME). The ZnO photocatalyst has irregular shape, bigger in particle size but smaller BET specific surface area (9.71 m2/g) compared to the spherical TiO2 photocatalysts (11.34 m2/g). Both scavenging study and post-reaction FTIR analysis suggest that the degradation of organic pollutant in the TiO2 system has occurred in the bulk solution. In contrast, it is necessary for organic pollutant to adsorb onto the surface of ZnO photocatalyst, before the degradation took place. In addition, the reactivity of both photocatalysts differed in terms of mechanisms, photocatalyst loading and also the density of photocatalysts. From the stability test, TiO2 was found to offer higher stability, as no significant deterioration in activity was observed after three consecutive cycles. On the other hand, ZnO lost around 30% of its activity after the 1st-cycle of photoreaction. The pH studies showed that acidic environment did not improve the photocatalytic degradation of the POME, whilst in the basic environment, the reaction media became cloudy. In addition, longevity study also showed that the TiO2 was a better photocatalyst compared to the ZnO (74.12%), with more than 80.0% organic removal after 22 h of UV irradiation.

Pushpito Kumar Ghosh - One of the best experts on this subject based on the ideXlab platform.

  • efficient recovery of potassium chloride from Liquid Effluent generated during preparation of schoenite from kainite mixed salt and its reuse in production of potassium sulfate
    Industrial & Engineering Chemistry Research, 2006
    Co-Authors: Rohit Harshadray Dave, Pushpito Kumar Ghosh
    Abstract:

    Although bittern of oceanic origin can be utilized for the production of K2SO4 via kainite (KCl·MgSO4·2.75H2O) and schoenite (K2SO4·MgSO4·6H2O) double salts, certain limitations are encountered in practice. These include (i) difficulties in obtaining pure schoenite from crude kainite and (ii) the requirement of KCl in the K2SO4 forming process. When schoenite is prepared from kainite through a simple reaction-cum-leaching process and the Liquid Effluent is desulfated with CaCl2 as part of a scheme to coproduce magnesia (Ghosh et al. U.S. Patent Publication No. 2005/0220698 A1, 2005 (Notice of Allowance); International Patent Publication No. WO 2005/063626 A1, July 14, 2005), the composition of the resultant Effluent is found to be ideally positioned in the phase diagram for direct recovery of sylvinite (NaCl/KCl). The intermediate steps of carnallite crystallization and decomposition, encountered during sylvinite preparation from Dead Sea brine and desulfated oceanic bittern, are avoided as a result. In t...

G. Timothy Jannik - One of the best experts on this subject based on the ideXlab platform.

  • Risk-based radioactive Liquid Effluent monitoring requirements at the U.S. Department of Energy's Savannah River Site
    Health physics, 2002
    Co-Authors: G. Timothy Jannik, Peter D. Fledderman
    Abstract:

    For Department of Energy (DOE) facilities, clear regulatory guidance exists for structuring radiological air emissions monitoring programs. However, there are no parallel regulations for radiological Liquid Effluent monitoring programs. In order to bridge this gap and to technically justify Liquid Effluent monitoring decisions at DOE's Savannah River Site, a graded, risk-basked approach has been established to determine the monitoring and sampling criteria to be applied at each Liquid discharge point.

  • Proposed radioactive Liquid Effluent monitoring requirements at the Savannah River Site
    1994
    Co-Authors: G. Timothy Jannik, W.h. Carlton, B.c. Blunt
    Abstract:

    Clear regulatory guidance exists for structuring a radiological air monitoring program, however, there is no parallel guidance for radiological Liquid monitoring. For Department of Energy (DOE) facilities, there are no existing applicable federal regulations, DOE orders, or DOE guidance documents that specify at what levels continuous monitoring, continuous sampling, or periodic confirmatory measurements of radioactive Liquid Effluents must be made. In order to bridge this gap and to technically justify and document Liquid Effluent monitoring decisions at DOE`s Savannah River Site, Westinghouse Savannah River Company has proposed that a graded, dose-based approach be established, in conjunction with limits on facility radionuclide inventories, to determine the monitoring and sampling criteria to be applied at each potential Liquid radioactive Effluent point. The graded approach would be similar to--and a conservative extension of--the existing, agreed-upon SRS/EPA-IV airborne Effluent monitoring approach documented in WSRC`s NESHAP Quality Assurance Project Plan. The limits on facility radionuclide inventories are based on--and are a conservative extension of--the 10 CFR 834, 10 CFR 20, and SCR 61-63 annual limits on discharges to sanitary sewers. Used in conjunction with each other, the recommended source category criteria levels and facility radionuclide inventories would allow for the best utilization of resources andmore » provide consistent, technically justifiable determinations of radioactive Liquid Effluent monitoring requirements.« less

Rohit Harshadray Dave - One of the best experts on this subject based on the ideXlab platform.

  • efficient recovery of potassium chloride from Liquid Effluent generated during preparation of schoenite from kainite mixed salt and its reuse in production of potassium sulfate
    Industrial & Engineering Chemistry Research, 2006
    Co-Authors: Rohit Harshadray Dave, Pushpito Kumar Ghosh
    Abstract:

    Although bittern of oceanic origin can be utilized for the production of K2SO4 via kainite (KCl·MgSO4·2.75H2O) and schoenite (K2SO4·MgSO4·6H2O) double salts, certain limitations are encountered in practice. These include (i) difficulties in obtaining pure schoenite from crude kainite and (ii) the requirement of KCl in the K2SO4 forming process. When schoenite is prepared from kainite through a simple reaction-cum-leaching process and the Liquid Effluent is desulfated with CaCl2 as part of a scheme to coproduce magnesia (Ghosh et al. U.S. Patent Publication No. 2005/0220698 A1, 2005 (Notice of Allowance); International Patent Publication No. WO 2005/063626 A1, July 14, 2005), the composition of the resultant Effluent is found to be ideally positioned in the phase diagram for direct recovery of sylvinite (NaCl/KCl). The intermediate steps of carnallite crystallization and decomposition, encountered during sylvinite preparation from Dead Sea brine and desulfated oceanic bittern, are avoided as a result. In t...