Upcycling of biomass waste into value added materials. Catalysts and adsorbents for bisphenol A removal from wastewaters

Access to clean water is a pressing global challenge, demanding efficient purification methods. Simultaneously, there is growing interest in utilizing waste biomass, such as sawdust, from the forest industry. Currently, many of the materials used for water purification, like activated carbon, are expensive and sourced from fossil materials. This creates both environmental and economic burdens. The 2016 ban on organic waste in landfills has resulted in the incineration of large quantities of sawdust, a byproduct of sawmills. However, the future points toward higher-value applications of this biomass, such as producing water treatment materials and biofuels.

This dissertation explored the use of waste biomass in the creation of catalysts and adsorbents for water purification. The study used pine and spruce chips, pine and birch chips, and pine sawdust as starting materials. These were converted into both powdered and granular water treatment materials and tested in laboratory conditions for the removal of bisphenol A (BPA) from synthetic water samples through catalytic wet oxidation and adsorption processes.

The findings are promising: the biomass-based materials effectively removed BPA from synthetic water samples and show potential as future water purification solutions. Material performance can be enhanced by chemical treatments, such as nitric acid treatment or iron impregnation. Aluminum silicates could also be used as binders for carbon granule production. In experiments, the materials removed 60–100% of BPA and 30–70% of total organic carbon, while iron-modified adsorbents demonstrated a high BPA adsorption capacity of 41.5 mg/g. Notably, all materials showed stability and reusability over multiple tests, enhancing their practical applicability.

This research highlights the potential of waste biomass from industrial processes in promoting a circular economy. By demonstrating the viability of these biomass-derived materials in wastewater treatment, it paves the way for future studies, particularly in testing their effectiveness with real wastewater. Moreover, the materials might also have applications in other industries, such as in electrode production for the battery sector.