Removal of methylene blue dye using rice husk, cow dung and sludge biochar: Characterization, application, and kinetic studies

• Published in: Bioresource technology Vol. 306; p. 123202
• Main Authors: Ahmad, Anees, Khan, Nawaz, Giri, Balendu Shekher, Chowdhary, Pankaj, Chaturvedi, Preeti
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2020
• Subjects: adsorbents; Adsorption; Adsorption isotherms; Adsorption kinetics; Animals; Biochar; Cattle; Charcoal; cow manure; Female; Hydrogen-Ion Concentration; Kinetics; Methylene Blue; Oryza; Pyrolysis; rice hulls; Sewage; sludge; Solid waste management; sorption isotherms; Water Pollutants, Chemical; Pyrolysis; Adsorption isotherms; Adsorption kinetics; Biochar; Solid waste management; Methylene blue
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2020.123202

[Display omitted] •Lignocellulosic biomass was slow pyrolysed at 500 °C for the 3 h.•Cow Dung Biochar was the most effective adsorbent with ~99.0% of MB removal.•The pHz values were 7.8, 6.3 and 6.0 for the CDB, RHB, and SB, respectively.•R2 values of Pseudo first and second order were 0.925 and 0.994.•The R2 of Langmuir and Freundlich models were 0.996 and 0.927. The present studies aimed for the removal of Methylene blue (MB) dye using the rice husk biochar (RHB), cow dung biochar (CDB) and domestic sludge biochar (SB) synthesized through slow pyrolysis at 500 °C. The biochar was used for the adsorption of synthetic aqueous MB dye. The removal efficiencies of MB by CDB, RHB and SB in a batch experiment were 97.0–99.0; 71.0–99.0 and 73.0–98.9% at conditions, pH (2.0–11.0); Biochar dosage (0.5–6.0 g/100 mL) for 5 days. Adsorption isotherm of Langmuir constant (KL) were obtained 0.101, 0.583 and 0.128 for RHB, CDB and SB respectively. Further, adsorption kinetics of pseudo first order for RHB, CDB and SB were 0.068, 0.018, and 0.066 while it was 0.031, 0.023 and 0.273 for pseudo second order kinetics. Thus, CDB was more effective adsorbent for the dye removal. The pHz values were 7.8, 6.3 and 6.0 for the CDB, RHB, and SB, respectively.