A holocellulose air filter with highly efficient formaldehyde adsorption prepared via low temperature pulping and...

Emissions of particulate matter (PM) originating from industrial and agricultural incineration had emerged as a significant public health concern. Furthermore, the considerable annual production of straw remains underutilized, particularly in China. In this study, we proposed a novel approach for holocellulose air filter production from corn stalks via low-temperature anthraquinone pulping, partial dissolving, and high-speed shear-induced regeneration. About 61.40-78.23 % of hemicellulose in corn stalks was retained in holocellulose, furthermore, the delignification rate was up to 81.63-92.51 % after low temperature (<100 °C) alkaline exactment. Subsequently, holocellulose air filters (RHF) were prepared through regeneration with high-speed shear induced (25,000 rpm) and freeze-drying. The final air filters contained approximately 8.56-12.4 % hemicellulose, exhibiting a substantial adsorption capacity for low molecules such as formaldehyde. The results revealed remarkably low PM_2.5 penetration ratio (0.12 %) and pressure drop (14.3 Pa) of the air filter, while exhibiting a remarkable formaldehyde adsorption capacity of 54.5 mg/g. Moreover, the characters of high crystallinity index and robust micro/nano-structure of regenerated cellulose were obtained. This study introduced an innovative and facile strategy for gaseous formaldehyde adsorption and introduced novel solutions for agricultural waste utilization.