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 (SSA BET ) of the produced GAC was 822 m 2 /g, and the tPlot micropore area and t-Plot external surface area were 734.99 and 87.26 m 2 /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 π 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.

High-performance gas-phase adsorption of benzene and toluene on activated carbon: response surface optimization, reusability, equilibrium, kinetic, and competitive adsorption studies

“…Therefore, the adsorption time decreases with increasing VOC concentration and consequently no significant change in adsorption capacity is observed (Bansode et al 2003;Das et al 2004). Similar observations have been reported in the literature (Cal et al 1997;Chuang et al 2003;Huang et al 2006;Vohra 2015). These results which were obtained by examining the effects of independent variables indicate that the data in ANOVA results can be used safely.…”

“…However, there is no significant change in adsorption capacities with increasing initial concentration. This tendency can be explained by the fact that an increase in the concentrations of benzene and toluene naturally results in a certain extinction time, as the specific surface area available and the adsorption areas on the AC surface are constant (Vohra 2015). It is clear that the adsorption capacities do not change significantly after reaching the optimum adsorption time and initial concentration points.…”

Treatment of Gaseous Ammonia Emissions Using Date Palm Pits Based Granular Activated Carbon

“…The dynamic adsorption studies were completed using a bench scale experimental setup [47]. Figure 1a provides the layout of respective setup that was used for the gaseous ammonia dynamic adsorption experiments.…”

Gas Phase Toluene Adsorption Using Date Palm-Tree Branches Based Activated Carbon

“…This results from AC’s high specific surface area, which gives rise to excellent adsorption efficiency, as noted for numerous gas phase pollutants including benzene [ 23 ], toluene/ethylbenzene/xylene/styrene [ 24 ], ammonia, [ 25 , 26 , 27 , 28 , 29 ], amines [ 30 ], and landfill gas laden with BTEX compounds [ 3 ]. Recently, a great interest has also been shown in AC production from otherwise waste materials [ 31 ], including agricultural by-products such as palm shells [ 29 , 32 , 33 , 34 ], olive stones [ 35 ], and date fruit pits [ 23 , 28 ], which have also been successfully used to remove gaseous pollutants. In light of the above discussion, the present work investigated the efficiency of AC derived from date palm-tree branches (DPB) agricultural waste, for gaseous toluene (C 6 H 5 CH 3 ) treatment.…”

“…In comparison to some chemical activation methods such as employing zinc chloride [ 26 ], the phosphoric acid activation method is environmentally friendly. Additionally, phosphoric acid-based activation has been successfully used in earlier activated carbon production studies [ 23 , 28 , 40 ]. In this work, we evaluated the effect of several operational variables, including gas flow rate, and gas concentration on the ability of phosphoric acid activated DPB based AC to remove gaseous toluene under dynamic flow conditions.…”