Department of Safety, Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, 2 Jhuoyue Road, Nanzih, Kaohsiung, 811, Taiwan.
Graduate Institute of Environmental Engineering, National Taiwan University, 71 Chou-Shan Road, Taipei, 106, Taiwan.
Environ Sci Pollut Res Int. 2018 Feb;25(6):5095-5104. doi: 10.1007/s11356-017-9321-x. Epub 2017 Jun 1.
Among various adsorbents studied, sulfur-impregnated activated carbon is one of the most promising adsorbents for mercury removal from flue gas. However, a large amount of spent activated carbons containing high content of mercury are generated after adsorption. To make the adsorption a more viable option, the regeneration and reuse of the spent activated carbon should be considered. The purpose of this study is to develop a novel technique for bioregeneration of sulfur-impregnated activated carbons after adsorption of mercury from flue gases by sulfur-oxidizing bacteria. The optimal operating parameters for this bioregeneration process were studied using central composite design (CCD) and response surface methodology (RSM). Results showed that the sulfur oxidation rate was increased with increasing activated carbon dosage. Furthermore, the increase of inoculum size only caused a slight increase of sulfur oxidation rate in the bioregeneration. The maximum mercury removal efficiency of more than 50% was obtained at 10% (w/v) activated carbon dosage and 20% (v/v) inoculum size. After the bioregeneration process, Brunauer-Emmett-Teller (BET) surface area and micropore volume of spent activated carbon increased due to the bio-oxidation of mercury bearing sulfur on the surface of activated carbons.
在研究的各种吸附剂中，载硫活性炭是从烟道气中去除汞最有前途的吸附剂之一。然而，吸附后会产生大量含有高含量汞的废活性炭。为了使吸附更可行，应考虑废活性炭的再生和再利用。本研究的目的是开发一种通过硫氧化细菌从烟道气中吸附汞后再生载硫活性炭的新技术。使用中心复合设计（CCD）和响应面法（RSM）研究了该生物再生过程的最佳操作参数。结果表明，随着活性炭用量的增加，硫的氧化速率增加。此外，接种量的增加仅导致生物再生中硫氧化速率略有增加。在 10%（w/v）活性炭用量和 20%（v/v）接种量下，可获得超过 50%的最大汞去除效率。生物再生后，由于载汞硫在活性炭表面的生物氧化，废活性炭的比表面积和微孔体积增加。
