Exceptional Adsorption of Phenol and p-Nitrophenol from Water on Carbon Materials Prepared via Hydrothermal Carbonization of Corncob Residues

Abstract

Phenol and p-nitrophenol (PNP) are priority pollutants widely present in wastewater. Developing superior or low-cost sorbents for their removal would be of great benefit. Here, corncob residues (CCR) were converted to hydrochars via hydrothermal carbonization (HTC) and further upgraded to carbon materials by thermal activation in an N2 atmosphere. The influence of HTC conditions including the temperature, residence time, and CCR/water weight ratio on the material properties and their performance for removing phenol and PNP from water were investigated and compared with those that were obtained from pyrochar (directly pyrolyzed CCR). Hydrochars showed lower adsorption capacities for phenols than pyrochar. The initial hydrothermal treatment at 220 °C and 2 h resulted in an improved porosity and 4-to 5-fold higher adsorption capacities for phenol and PNP compared with the pyrochar. However, hydrochars prepared at 250 °C or with a prolonged residence time (4 and 6 h) could not be upgraded to high performance carbon materials by thermal activation. The adsorption isotherms of both phenols on the best performance material were well correlated by the Sips model.

Obtaining and characterization of a composite with polymer matrix and corn cob waste filler

“…Biomass resources are plentiful, renewable, and not competitive to human and animal consumption. Making value-added products from agricultural lignocellulosic biomass waste is attractive in terms of cost and pollution management, (Liu, Li, Gai, Yang, & Mao, 2016).…”

Adsorption and equilibrium studies of phenol and para-nitrophenol by magnetic activated carbon synthesised from cauliflower waste

“…Recent research has focused on the preparation of low-cost adsorbents to reduce the operating costs of adsorption. Recently several studies have been published on low cost adsorbents with high adsorption potential, such as natural zeolite [23], treated waste newspaper [24], canola residue [25], olive mill waste [26], and corn cob residue synthesized hydrochar [27]. Many researchers have proposed utilization of agricultural waste as a raw material for adsorption, as agricultural waste is reported to have high adsorption potential with low cost and high availability [28].…”

In-situ sampling of nitrophenols in industrial wastewaters using diffusive gradients in thin films based on lignocellulose-derived activated carbons

“…Low-cost adsorbents, especially low-cost activated carbon, which is produced from biomass precursors such as agricultural residues, exhibit excellent performance for the adsorption and removal of nitrophenols due to their high surface area, rich porous structure, and suitable chemical characteristics of the catalyst surface [25], [26], [27], [28]. In this study, low-cost lignocellulose hazelnut shell-derived activated carbons (HSACs) were prepared and characterized.…”