Synthesis and application of quaternized biomass cellulose microspheres for high-efficiency removal of water...

The development of environmentally friendly, efficient and low-cost adsorbents for water purification is of great importance. In this study, cellulose microspheres (CM) with controllable size were prepared by a phase separation method and successfully modified with 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (CHPTAC) to obtain positively charged functionalized cellulose microspheres (QCM). The QCM can adsorb typical anionic pollutants (Cr(VI)) and cationic pollutants (RhB). The maximum adsorption capacity of QCM for Cr(VI) was 3.97 mg g^-1 (pH = 5, 45 °C), which conformed to the pseudo-secondary kinetics and Langmuir model, indicating that the process was a spontaneous heat-absorbing on a single molecular layer. The maximum adsorption capacity of RhB was 33.32 mg g^-1 (pH = 7, 15 °C), which conformed to the pseudo-primary kinetics and Langmuir model, and the adsorption process was a spontaneous exothermic monolayer. The adsorption mechanism demonstrated the key role of quaternary ammonium groups in enhancing the adsorption performance. In addition, QCM was renewable and retained more than 95% of adsorption efficiency after three cycles. The above results indicated that QCM had good adsorption performance and structural stability for the removal of heavy metals and dyes from wastewater.