Co-pyrolysis based activated Bio-char: Characterization and its utilization for secondary treated pulp and paper industry wastewater

In this study, the solid residue (bio-char) produced from co-pyrolysis of municipal sewage sludge (MSS)-sugarcane bagasse (SCB) was activated through a chemical activation method using phosphoric acid. The resulting activated bio-char was utilized for the removal of chemical oxygen demand (COD) and colour of pulp and paper industry wastewater obtained from conventional secondary treatment process to explore the recycling potential in the pulp and paper manufacturing process itself. In contrast to bio-char, activated bio-char showed higher surface area (50 times), total pore volume (10 times) and lower average diameter (5 times). Honeycomb shape in SEM image and existence of functional groups in FTIR spectra attributed to such a significant improvement. Results of adsorption experiments revealed that COD and colour was reduced by 84.61% and 98.03%, respectively at an optimized 3 pH with activated biochar doses of 0.14 g/L in 20 h. Moreover, Langmuir and Freundlich isotherm model was observed best suited to obtained equilibrium. Copyright (c) 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Chemical Engineering Conference 2021 (100 Glorious Years of Chemical Engineering & Technology).

Automated summary

In this study, the solid residue (bio-char) produced from co-pyrolysis of municipal sewage sludge (MSS)-sugarcane bagasse (SCB) was activated using phosphoric acid. The activated bio-char was then used for removing chemical oxygen demand (COD) and color from pulp and paper industry wastewater. The results showed that the activated bio-char had higher surface area, total pore volume, and lower average diameter compared to bio-char. Adsorption experiments demonstrated that the activated bio-char effectively reduced COD and color in the wastewater.