Phosphoric Acid Hydrolysis for Cellulose-to-Glucose Conversion in Paper Waste Sludge

Abstract

In this study, phosphoric acid was used as a hydrolytic agent to convert excess cellulose in the paper waste sludge (PWS) into a sugar solution. Then, the sugar solution was fermented with Acetobacter xylinum bacteria to synthesize bacterial cellulose (BC). The factors affecting the hydrolysis process were investigated through experiments to find the appropriate conditions. Experimental results show that, with a solid/liquid ratio of 1/20, a temperature of 130°C, a hydrolysis time of 2 hours, at an acid concentration of 7.5%, a solution with 5.21 ± will be obtained. 0.22 g/L sugar from An Binh PWS and at 8.5% acid concentration, 4.67±0.12 g/L sugar will be generated from Khoi Nguyen PWS. The hydrolyzed sugar solution is neutralized with NaOH solution, then diluted 3-5 times to lower the salt concentration, creating a suitable environment for the fermentation to produce BC. The implementation of this research is highly necessary as it allows for the utilization and conversion of residual cellulose in the PWS into a valuable resource, namely sugar solution, followed by its synthesis into BC. This process has successfully recovered the carbohydrate source (cellulose) present in PWS, creating a valuable product. Not only does this help prevent resource wastage, but it also mitigates the environmental pollution caused by paper sludge disposal from the paper mill.