Investigating the removal efficiency of methylene blue dye and the reusability of NaBO3 modified biomass ash geopolymer

Abstract A novel foaming agent, sodium perborate (NaBO 3 ), has been successfully integrated with biomass ash-based geopolymer (BAG). This yields a new material, NaBO 3 @BAG, representing a promising, cost-effective new approach for removing organic methylene blue (MB) dye. The NaBO 3 @BAG material exhibits superior absorption capabilities for MB dye compared to both hydrogen peroxide (H 2 O 2 ) modified BAG and the pure BAG. The 0.75 wt% NaBO 3 @BAG achieved the highest adsorption capacity for MB dye as 24.02 mg/g, outperforming 0.75 wt% H 2 O 2 @BAG (23.65 mg/g) and pure BAG (22.60 mg/g). Adding just 0.75 wt% NaBO 3 significantly increased mesopore structures, directly creating a greater active absorption area. The active surface area increased from 90.91 m 2 /g to 126.04 m 2 /g. While this is lower at 107.56 m 2 /g achieved with 0.75 wt% H 2 O 2 . The NaBO3@BAG material exhibited excellent stability and reusability, retaining over 81% efficiency after five absorption cycles.