Research On The Absorption Of Ammonia Gas By Silica Gel And Active Carbon

China is one of the most air-polluted countries in the world. It can be more polluted in the industrialize cities. How can we accurately master the quality conditions of the air that include living environment, workplace and the whole aerosphere? And how can we prevent and control the pollution effectively? This needs to carry on a long-term examination to the air. The collection of air samples is the first and most important step in environment examination, because it is directly related to the reliability of the results.Passive sampling method is a common method of sampling. It was adapted to the time-weighted average permissible concentration sampling and monitoring of personal exposure sampling, it also applied to the large-scale health survey and monitoring. This paper took the principle of adsorption and diffusion theory and Fick's law of diffusion as the basis and carried on foundational research on the passive sampling technique of the ammonia gas.This experiment evaluated the adsorption characteristics of a few common adsorbents. For taking into account the characteristics of ammonia pollution, purifying effect on ammonia pollution, technical feasibility, reasons of cost and so on, we selected silica gel and active carbon as the adsorbents of ammonia.To improve the adsorption properties of adsorbent, and increase the adsorption capacity, we soak the adsorbents into phosphoric acid to modify the adsorption properties of adsorbent. The best concentration of impregnating solution phosphate was selected through the different density of the phosphoric acid influenced on adsorbents.A static state and dynamic state experiment processes were built in this experiment. The environment of a certain concentration of ammonia can be simulated in these experiment processes. We can do adsorption experiment and find out the influence of temperature, humidity, wind speed, the concentration of ammonia and contact time. We can change temperature and humidity in static state experiment process; On the other hand, we can change wind speed, the concentration of ammonia and contact time in dynamic state experiment process. An experimental apparatus connected to the heating pipes and humidifiers can control temperature and humidity conditions.By changing the voltage of centrifugal fan we can regulate the speed of airflow. The change of the concentration of ammonia can be achieved by regulating cylinder pressure.The active carbon and silica gel adsorption value of the ammonia were determined in the experiment. The influence of temperature, humidity, wind speed, the concentration of ammonia, contact time parameters of the five conditions on the adsorption rate were discovered. After the experiment, we obtained the law that active carbon and silica gel adsorbed ammonia under different conditions.This topic achievement not only provided the reference valuable foundational data for the development work of ammonia passive sampling, but also provided theoretical foundation for time-weighted average permissible concentration sampling.