Scientific Reports (Feb 2022)

Kinetic and isotherm insights of Diclofenac removal by sludge derived hydrochar

  • Sadish Oumabady,
  • Paul Sebastian Selvaraj,
  • Kalaiselvi Periasamy,
  • Davamani Veeraswamy,
  • Paulian Thankanadathi Ramesh,
  • Thava Palanisami,
  • Sangeetha Piriya Ramasamy

DOI
https://doi.org/10.1038/s41598-022-05943-z
Journal volume & issue
Vol. 12, no. 1
pp. 1 – 13

Abstract

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Abstract Recently, hydrothermal carbonization emerges as the most viable option for the management of solid waste with high moisture content. Sludge derived hydrochar is used as an adsorbent for emerging contaminants or micro-pollutants in the domain of sustainability. Current study demonstrates the KOH activation of hydrochar produced from paper board mill sludge and evaluates its removal potential of a Non-steroidal anti-inflammatory drug, Diclofenac from aqueous solution. The activated hydrochars exhibited porous, spherical micro-structures with higher fraction of oxygenated functional groups paving way for the efficient adsorption of Diclofenac. The effect of initial Diclofenac concentration and contact time was ascertained using adsorption kinetics and isotherms. The adsorption kinetics exhibited second-order reaction for all adsorbents indicating higher coefficient of determination (R2 > 0.9). The Diclofenac adsorption on hydrochars followed Langmuir isotherm model with the post-activated hydrochar recording a highest adsorption capacity of 37.23 mg g−1 in 40 mg L−1 initial Diclofenac concentration at 15 h equilibrium time.