abstract |
Novel acid-impregnated silica materials for use as environmental controls in air handling systems where highly efficient removal of ammonia and volatile amines from gaseous streams is required (e.g. clean rooms) are provided. Such silicas exhibit specific porosity and density measurements to provide a satisfactory support for an acid impregnant incorporated subsequent to initial solid silica particle production, in order to provide effective ammonia bonding sites. The combination of the silica support properties and the acid impregnant permits highly effective ammonia (or volatile amine) gas removal, resulting in excellent noxious gas removal efficiencies and capacities, particularly in comparison with prior media filtration products. Methods of using such acid-impregnated silica filter media and specific filter apparatuses are also encompassed within this invention. |