Removal of Waste Gases from Phenolic Resin Synthesis Using Cement and Fibers

• 1、China University of Mining and Technology Beijing

Abstract：During the synthesis of phenolic resin, two toxic gases, formaldehyde and ammonia, are simultaneously released. Conventional single treatment technologies struggle to achieve synergistic removal. In this study, modified polypropylene fibers were used as carriers to immobilize ammonia-oxidizing bacteria (AOA, AOB, COM) and formaldehyde-degrading bacteria (FA, FB). The removal efficiencies of ammonia and formaldehyde under different bacterial strains, carriers, and wet/dry conditions were systematically investigated. The long-term corrosion of carriers by bacteria was also evaluated. Furthermore, steel slag and slag loaded with AOB were tested for sustained formaldehyde removal.Ammonia removal experiments showed that AOB exhibited the best performance, completely removing 150ppm ammonia within 2 hours on the fabric carrier, significantly outperforming AOA and COM. Wet/dry comparison confirmed that bacterial activity was lost after drying at 60 C, with removal efficiency dropping below 20%, indicating that maintaining a wet state is critical for high efficiency. Corrosion tests revealed that AOA and COM caused severe damage to polypropylene fabric (strength retention of only 28%-32% after 20 cycles), while AOB caused only mild corrosion (retention 81%).For formaldehyde removal, FB alone outperformed FA. Mixing FA and FB increased the 4-hour removal efficiency from 55%-58% to 72%. Further addition of AOB raised it to 88.7%, with a rate constant approximately three times higher. Solid bacterial powder was almost ineffective.

Keywords： Ammonia-oxidizing bacteria Formaldehyde-degrading bacteria Modified polypropylene fiber Synergistic removal