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采用银氨溶液浸渍活性碳纤维的方法,制得载银量为14.07%的载银活性碳纤维吸附剂。利用管式炉对载银活性碳纤维筒状吸附体进行汞吸附性能试验。研究发现:气体汞浓度为5263.5μg/m3、H2O(g)体积分数为7%、吸附温度90℃、气体在吸附体的停留时间为0.1s条件下,筒式吸附体在前30min内汞吸附效率98%以上,吸附300min后汞吸附效率仍在20%以上。研究还表明,温度升高,汞吸附效率降低;停留时间延长,汞吸附效率增加;H2O(g)的存在有利于汞吸附,但H2O(g)含量过高又使汞吸附效率略有降低。扫描电镜分析发现,汞只吸附在含银活性点上,吸汞前形状不规则的银粒子与汞结合后变成形状较规则的银汞齐颗粒,且主要分布于活性碳纤维微晶的晶棱交界处。
The method of impregnating active carbon fiber with silver ammonia solution was used to obtain a silver-loaded activated carbon fiber adsorbent with a silver content of 14.07%. Mercury adsorption performance test of silver activated carbon fiber cylindrical adsorbent using tube furnace. The results showed that mercury was adsorbed by mercury in the first 30 min under the condition of gas concentration of 5263.5 μg / m3, volume fraction of H2O (g) of 7%, adsorption temperature of 90 ℃ and gas residence time of 0.1s Efficiency of more than 98%, mercury adsorption efficiency after 300min adsorption is still above 20%. The results also showed that the mercury adsorption efficiency decreased with increasing temperature, and the mercury adsorption efficiency increased with the prolongation of residence time. The presence of H 2 O (g) was favorable for mercury adsorption, while the H 2 O (g) content led to a slight decrease of mercury adsorption efficiency. Scanning electron microscopy analysis showed that mercury adsorbed only on the silver-containing active sites. Irregularly-shaped silver particles before mercury absorption were combined with mercury to become silver-mercury particles with regular shapes and were mainly distributed in the crystal edges of the activated carbon fiber crystallites Junction.