Removal of phenolics from aqueous pyrolysis condensate by activated biochar

Abstract

Aqueous pyrolysis condensate (APC) is rich in acetic acid and has been utilized as feedstock for anaerobic digestion to produce biogas. However, various phenolic compounds dissolved in the APC act as inhibitors, negatively affecting the anaerobic digestion. In this work, we have investigated the feasibility of employing pyrolytic biochar as an adsorbent for the selective removal of phenolics from APC. Biochars derived from the pyrolysis of soft wood, rice husks, and sewage sludge and their respective activated forms have been tested as potential adsorbents for the removal of pure phenol from water solutions. The experimental results showed that, among the adsorbents studied, activated soft wood (ASW) biochar has the highest adsorption efficiency and capacity for phenol removal from water. The kinetic and isotherm studies showed that the phenol adsorption data with ASW biochar may be well described by pseudo second‐order equation and Freundlich model. Batch experiments were carried out to investigate the effects of pH, adsorbent loading, contact time, and temperature on phenolics adsorption onto ASW from APC. At optimal adsorption conditions (pH of 6.0, contact time of 30 min, adsorbent loading of 9.61 0.25em0em0emgadsorbent·gTotal phenolics−1, and temperature of 25°C), an adsorption efficiency of 96.9% ± 1.8% and a capacity of 100.78 ± 2.7 mg · g−1 were achieved. Finally, the adsorption efficiency and capacity of ASW for phenolics removal from APC was successfully compared with those of commercial activated carbon, showing comparable results, which indicated the suitability of ASW as an environmentally friendly adsorbent.

A Comparative Study of Phenol Removal by Pisum‐sativum Peels Biochars Derived at Different Pyrolysis Temperatures: Isotherm, Kinetic and Thermodynamic Modelling

“…In the first step, fast removal of phenol by three biochars takes place (0–45 min), In the second step, moderate removal of phenol by three biochars takes place (45–90 min). In the third step, slow removal of phenol by three biochars takes place (90–150 min), which later on becomes constant and no phenol removal is observed [17,37] …”

“…In the third step, slow removal of phenol by three biochars takes place (90-150 min), which later on becomes constant and no phenol removal is observed. [17,37]…”

Value‐added products from waste: Slow pyrolysis of used polyethylene‐lined paper coffee cup waste

“…External standards were used to identify and quantify the peak areas. [ 23 ] To identify the compounds in the pyrolysis oil, gas‐chromatography‐mass spectrometry (GC–MS) was used. In the GC–MS system, the gas chromatograph is connected to a QP 2010 quadrupole mass spectrometer (Shimadzu, Kyoto, Japan) using a 30‐m long capillary column with a 0.25 mm diameter and 0.25 μm thickness.…”

Preface to the special issue honouring Professor Leo A. Behie

“…Dalai and coworkers [ 8 ] present a study on the influence of contact time, operating temperature, and amount of adsorbent on the sulphur adsorption capacity of a porous aluminosilicate geopolymer that was produced by alkali activation of metakaolin. Berruti and coworkers [ 9 ] examine the feasibility of pyrolytic biochar as an adsorbent for the selective removal of phenolics from aqueous pyrolysis condensate. Hawboldt and coworkers [ 10 ] investigate the production of biosurfactant by a native marine bacteria using waste carbon sources, with possible applications in treating off‐shore oil spills.…”