chapter  6
10 Pages

Volatile organic compounds: Mechanisms of filtration

ByJohn T. Fox

References .......................................................................................................................................72

6.1 VOC sorption fundamentals Volatile organic compounds (VOCs) are chemical constituents found in the gas phase-but with a change of pressure or temperature could become a liquid. Therefore, VOC behavior is similar to gases, but most VOCs can be defined as vapors.1 For example, when a pure organic liquid is in an enclosed system, some liquid will volatilize, exerting a pressure on the system. This volatized liquid is dependent on the vapor pressure. As such, when a compound exerts higher vapor pressure, the pure compound contains a higher affinity for the gas phase than a compound with a lower vapor pressure. As an example of this, medical facilities often use alcohols as sanitizing agents. The alcohol sanitizer is in the liquid form during application; however, the alcohol component will volatilize. Vapors, unlike gases, can often be transferred from the gas phase into the liquid phase or solid phase. The affinity to volatize is attributed to the vapor pressure of the organic compound. Removal of organic vapors can be achieved via sorption, including both absorption and adsorption.