Removal of sugars from food and beverage wastewaters by amino-modified SBA-15

In the context of the removal of the biochemical oxygen demand (BOD5) from food and beverages production wastewaters, this paper reports the capabilities of SBA-15 modified with (3-aminopropyl)-triethoxysilane (S-APTES) and N-[3-(trimethoxysilyl)propyl]aniline (S-Aniline) in the removal of glucose, fructose and sucrose at very high concentrations (350,000 mg/L for glucose, 350,000 mg/L for fructose and 170,000 mg/L for sucrose), i.e. the sugars most widely used as sweeteners in food and beverage manufacturing. After the determination of the main physico-chemical characteristics, the study of the effect of pH on the removal capabilities of S-APTES and S-Aniline allowed to elucidate the main mechanisms involved. Based on the study of solid:liquid ratio, the optimal experimental conditions were defined to achieve a removal of BOD5 in simulated soft-drink wastewater as high as 80%. The results show that a lower adsorbent dosage is required in respect to current methodologies, representing an advantage especially for disposal procedures of the exhausted adsorbent. This work offers a proof of concept for the integration of amino-modified SBA-15 sorbents in industrial pre-treatment of wastewaters before discharging it in sewerage systems.