Wu Li-Chun, Chung Ying-Chien
Department of Industrial Engineering and Management, China Institute of Technology, Taipei, Taiwan, Republic of China.
J Air Waste Manag Assoc. 2009 Mar;59(3):258-65. doi: 10.3155/1047-3289.59.3.258.
Activated carbon (AC) is widely used as an effective adsorbent in many applications, including industrial-scale air purification systems and air filter systems in gas masks. In general, ACs without chemical impregnation are good adsorbents of organic vapors but poor adsorbents of low-molecular-weight or polar gases such as chlorine, sulfur dioxide (SO2), formaldehyde, and ammonia (NH3). Impregnated ACs modified with metallic impregnating agents (ASC-carbons; e.g., copper, chromium, and silver) enhance the adsorbing properties of the ACs for simultaneously removing specific poisonous gases, but disposal of the chromium metal salt used to impregnate the ACs has the potential to result in situations that are toxic to both humans and the environment, thereby necessitating the search for replaceable organic impregnating agents that represent a much lower risk. The aim of this study was to assess the gas removal efficiency of an AC in which the organic impregnating agent triethylenediamine (TEDA) largely replaced the metallic impregnating agent chromium. We assessed batch and continuous adsorption capacities in situ for removing simulated hydrogen sulfide (H2S), trichloromethane (CHCl3), NH3, and SO2 gases. Brunauer-Emmet-Teller measurements and scanning electron microscopy analyses identified the removal mechanism by which TEDA-impregnated AS-carbon (dechromium ASC-carbon) adsorbs gases and determined the removal capacity for H2S, CHCl3, NH3, and SO2 to be 311, 258, 272, and 223 mg/g-C, respectively. These results demonstrate that TEDA-impregnated AS-carbon is significantly more efficient than ASC-carbon in adsorbing these four gases. Organic TEDA-impregnating agents have also been proven to be a reliable and environmental friendly agent and therefore a safe replacement of the hazardous chromium found in conventional ASC-carbon used in removing toxic gases from the airstream.
活性炭（AC）作为一种有效的吸附剂，在许多应用中被广泛使用，包括工业规模的空气净化系统和防毒面具中的空气过滤系统。一般来说，未经化学浸渍的活性炭是有机蒸汽的良好吸附剂，但对于低分子量或极性气体，如氯气、二氧化硫（SO₂）、甲醛和氨（NH₃），则是较差的吸附剂。用金属浸渍剂（ASC-碳；例如铜、铬和银）改性的浸渍活性炭可增强活性炭对同时去除特定有毒气体的吸附性能，但用于浸渍活性炭的铬金属盐的处理有可能导致对人类和环境都有毒的情况，因此有必要寻找风险低得多的可替代有机浸渍剂。本研究的目的是评估一种有机浸渍剂三乙烯二胺（TEDA）在很大程度上替代金属浸渍剂铬的活性炭的气体去除效率。我们原位评估了去除模拟硫化氢（H₂S）、三氯甲烷（CHCl₃）、NH₃和SO₂气体的间歇和连续吸附容量。Brunauer-Emmet-Teller测量和扫描电子显微镜分析确定了TEDA浸渍的AS-碳（脱铬ASC-碳）吸附气体的去除机制，并确定其对H₂S、CHCl₃、NH₃和SO₂的去除容量分别为311、258、272和223 mg/g-C。这些结果表明，TEDA浸渍的AS-碳在吸附这四种气体方面比ASC-碳效率显著更高。有机TEDA浸渍剂也已被证明是一种可靠且环保的试剂，因此是从气流中去除有毒气体的传统ASC-碳中有害铬的安全替代品。
