The effect of various thermochemical methods on the production of biochar and removal of 2‐naphthol orange from wastewater

Abstract

BACKGROUNDThermochemical conversion methods are essential processes that are frequently used in the production of biochar and affect the properties of biochar. In this study, 2‐naphthol orange was removed from syntethic wastewater using biochar adsorbents produced from pelletized furniture sawdust by thermochemical techniques (torrefaction, pyrolysis, and gasification) at various durations (0.5–5 h) and temperatures (200–900°C).RESULTSThe adsorbent produced via torrefaction process at 200°C and in 1 hour exhibited the best removal performance. For furniture waste biochar (FWB), the optimum conditions for 2‐naphthol orange soption were found to be an initial concentration of 35 mg/L, a pH of 2.0, a contact duration of 2 hours, an agitation speed of 200 rpm, a temperature of 30°C, 1.0 g/L of biochar, and a biochar size of 50 mesh. The Langmuir isotherm and Pseudo‐second order models showed the highest coefficient of determination R2 (R2 = 0.9947 and 0.9978, respectively). The terms of qm (mg/g) and KL were found to be 230.45 and 0.28, respectively from Langmuir isotherm. Conversely, the terms of qe (mg/g) and k2 (g/mg.min) were found to be 29.27 and 0.00486, respectively from Pseudo‐second order model. According to the long‐stability experiment, the selected adsorbent of 200‐1 (biochar from torrefacation) remained more stable after 10 cycles of adsorption.CONCLUSIONIt was found that the torrefaction process provides significant advantages due to the removal efficiencies of 2‐naphthol orange dye and the fact that biochar production is easier and more economical at low temperature values.This article is protected by copyright. All rights reserved.