改性活性炭对甲胺恶臭气体吸附研究

Adsorption of an malodorous gas containing methylamine by modified activated carbon

甲胺作为一种具有代表性的胺类恶臭气体,是工业中常见的原料与中间体,广泛存在于污水处理过程中。其嗅阈值为0.021 mg/m^3,稳定且难以生化降解,会影响人体健康。同时,居民区人口密集,工业区与市政设施在部分地区距离居民区较近,因此甲胺是急需治理的大气污染物之一。以方便高效且应用性强的氧化方式对活性炭进行改性并应用于气态甲胺处理。当达到穿透点(出口质量浓度为5 mg/m^3,穿透率约2%)时,HNO 3改性活性炭最高穿透吸附量为517.30 mg/g,是原始活性炭的45.7倍。通过对比改性前后活性炭的表面特征,并用吸附动力学数据研究了甲胺的吸附特性,表明甲胺在HNO 3改性活性炭上的吸附是物理吸附和化学吸附的结合。当接近平衡时,吸附速率通过颗粒内扩散来控制。

Methylamine is a typical amine malodorous gas,which is often produced in the process of sewage treatment,and is widely used in industry as a common raw material and intermediate.The methylamine olfactory threshold is 0.021 mg/m^3.In addition,methylamine is stable and difficult to biodegrade,and can adversely affect many tissues and organs of the human body.At the same time,Chinese residents are densely populated.Industrial areas and municipal facilities are close to residential areas in some areas.Therefore,methylamine is one of the atmospheric pollutants,which is urgently needed to treat.In this paper,the activated carbon was modified in a convenient,efficient and adaptable way to treat methylamine.The highest penetration adsorption amount of HNO 3 modified activated carbon was 517.30 mg/g,45.7 times of that of initial activated carbon,when the breakthrough point(exit concentration was 5 mg/m^3,in other words,the breakthrough efficiency≈2%)arrived.The surface characteristics of activated carbon before and after modification and the kinetic characteristics of methylamine were studied,which indicated that the adsorption of methylamine on HNO 3 modified activated carbon was a combination of physical adsorption and chemical adsorption.The rate of adsorption was controlled by intraparticle diffusion approaching equilibrium.