Influence of thermal neutralisation conditions on properties of the synthesized aluminium oxide adsorbent

Natural organic matter (NOM) is the primary fouling agent for ultrafiltration membranes, leading to reduced membrane lifespan, increased water treatment costs, and negative environmental impacts due to the disposal of numerous membranes. Heated aluminum oxide particles (HAOPs) have been proposed as a possible effective sorbent to prevent fouling by removing NOM in hybrid sorption/membrane processes. However, existing literature only reports synthesis conditions for HAOPs of 24 h at 110 °C and pH 7. This study aimed to investigate and determine the optimal synthesis parameters (duration, temperature, pH) for HAOPs in order to develop a sorbent with high NOM removal efficiency while reducing synthesis costs.

In this study, HAOPs were synthesized under varying conditions: synthesis durations from 2 to 24 h, temperatures from 70 °C to 110 °C, and pH values ranging from 6 to 9. The synthesized HAOPs were characterized using X-ray diffraction to assess crystallinity and phase composition, light microscopy and environmental scanning electron microscopy (ESEM) for morphological analysis, as well as dispersive X-ray analysis, particle size distribution measurements, specific surface area determination, and capillary suction time tests.