Adsorption-Based Removal of Gas-Phase Benzene Using Granular Activated Carbon (GAC) Produced from Date Palm Pits

Abstract

The Kingdom of Saudi Arabia is one of the leading countries in date fruit farming, and by-products from date palm trees can be used for several important applications, including pollution control. This study successfully employed date palm pit-based granular activated carbon (GAC) to adsorb gas-phase benzene under dynamic flow conditions. The percent carbon content (w/w) for raw date palm pits and produced GAC samples was found to be 47 and 82 %, respectively. Furthermore, the specific surface area (SSABET) of the produced GAC was 822 m2/g, and the t-Plot micropore area and t-Plot external surface area were 734.99 and 87.26 m2/g, respectively. The BJH graph for the pore size distribution also indicated a mesoporous structure. The use of date palm pit-based GAC for gas-phase benzene adsorption under dynamic continuous-flow conditions showed high efficiency with breakthrough points for different systems ranging from several hours to several days. The role of surface functional groups and their interactions with the benzene rings during the adsorption process were also explored, and surface oxygen-based groups may initiate an electron donor–acceptor mechanism with the benzene’s aromatic ring $${{\boldsymbol{\pi}}}$$ electrons. The findings confirmed that GAC produced from date palm pits can be successfully used for gas-phase benzene adsorption under various conditions. It is hoped that countries with large-scale date fruit farming, such as the Kingdom of Saudi Arabia, will be able to utilize this rich resource for environmental applications.