TMA and H2S gas removals using metal loaded on rice husk activated carbon for indoor air purification

An excessive exposure to indoor toxic pollutant gases such as trimethylamine (TMA) and H2S is fatal to humans especially in the confined workspace. A porous carbon pollutant filter was developed using rice husk as a biomass waste. The different carbonization temperature highly affected on the surface area of ARH (activated rice husk carbon) and their performance of pollutant gas adsorption. With copper impregnation on the activated carbon (Cu/ARH), much better toxic gas adsorption was achieved in an enclosed chamber. The best performance was obtained with a Cu/ARH filter carbonized at 450 °C as it eliminated the 400 ppm of TMA in 30 min and H2S in 15 min. Isotherm and kinetic models were applied to understand the adsorption performance. The pseudo-second order kinetic model represented the best fit, followed by the intraparticle diffusion and Yoon-Nelson kinetic models. The H2S adsorbed Cu/ARH filter was successfully regenerated whereas a TMA adsorbed Cu/ARH filter was not successfully regenerated. The current study is expected to expand the utilization of biomass waste for the indoor air purification.