Fluoride removal from aqueous solution onto activated carbon of Catha edulis through the adsorption treatment technology

Abstract

Background: Nowadays freshwater quality deterioration and quantity depletion are rapidly increasing across the globe. Especially fluoride polluted groundwater is causing a severe shortage of water supply and public health problem. Hence, this study was designed to investigate the performance of activated carbon produced from the Catha edulis stem for the removal of fluoride from aqueous solution. A C. edulis stem sample was collected from dumping sites of Addis Ababa City and its activation and carbonation processes were performed using H 2 SO 4 and a high temperature of 600 °C. The experimental study was designed to use a full factorial approach with a 3 3 which were the three factors with the three levels, namely pH (2, 7 and 9), contact times (60, 90 and 120 min) and adsorbent doses (0.5 g, 1.0 g and 1.5 g in 100 mL) at the initial fluoride concentration 30 mg/L which resulted in 81 experimental runs in triplicates. Results: The calculated maximum adsorption capacity of 18 mg/g was found under the Langmuir isotherm, whereas the Freundlich model (R 2 0.98) better fitted the experimental data, which indicated that the adsorption process was multilayer and cooperative. The maximum fluoride removal of 73% was observed at the optimum condition of adsorbent dose of 1.5 g in 100 mL contact time of 60 min and pH 2, whereas the predicted value of the fluoride removal of 69% was calculated under the same experimental condition. Fluoride removal was positive and strongly influenced by the adsorbent dose, whereas the adsorption pH was negatively and weakly impacted on removal. Conclusions: Generally, the performance of activated carbon for the removal of fluoride from aqueous solution is promising. The study also indicated that C. edulis activated carbon is a potential candidate for water treatment technology.

Adsorptive removal of malachite green dye from aqueous solution onto activated carbon of Catha edulis stem as a low cost bio-adsorbent

“…According to different scholar findings high fixed carbon, low moisture, low volatile matter and low ash content adsorbents are recommendable for adsorption activities (Fito et al, 2019;Mopoung et al, 2015;Pathania et al, 2017). Therefore the prepared activated carbon is efficient as it Shawn by various proximate analysis.…”

“…Sample preparation was conducted according to (Fito et al, 2019;Ghaedi et al, 2014;Ghaedi et al, 2012;Regti et al, 2017) with little modifications and presented on Fig. 1 in short summary.…”

“…The physicochemical properties of the adsorbent such as moisture content, ash content, volatile matter , and fixed carbon were determined according to (Bello et al, 2017;Fito et al, 2019;Temesgen et al, 2018) with slight modifications. The thermal drying method was applied for the proximate analysis of the adsorbent.…”

“…Each technique has its own advantages and drawbacks. The literature indicates that nowadays, those dye removal techniques and investigations are dominant through adsorption technology (Fito et al, 2019;Mezohegyi et al, 2012). The use of wasted martial as adsorbents has received especial interest from several researchers for different reasons such as high selectivity, low cost, availability, and efficiency [ (Giwa et al, 2013;Mezohegyi et al, 2012).According to different scholar findings the following martials were used for removal of dyes such as: agricultural wastes (Kadirvelu et al, 2003), magnetite loaded multi-wall carbon nanotube (Ai et al, 2011), treated avocado shells (Georgin et al, 2018), Brazilian pine-fruit shell (Royer et al, 2009) ,spent coffee [ (Safarik et al, 2012), montmorillonite clay (Almeida et al, 2009), Fe 3 O 4 nanoparticle [ (Ghaedi et al, 2015), activated carbon, graphene oxide, and carbon nanotubes (Li et al, 2013), Palm oil mill effluent waste (Gobi et al, 2011) , Bagasse Fly Ash [ (Gupta et al, 2000)] , tree fern (Ho et al, 2005) etc .…”

Adsorptive removal of malachite green dye from aqueous solution onto activated carbon of Catha edulis stem as a low cost bio-adsorbent

“…Each technique has its own advantages and drawbacks. The literature indicates that nowadays, those dye removal techniques and investigations are dominant through adsorption technology (Fito et al, 2019;Mezohegyi et al, 2012). The use of wasted martial as adsorbents has received especial interest from several researchers for different reasons such as high selectivity, low cost, availability, and efficiency [ (Giwa et al, 2013;Mezohegyi et al, 2012).According to different scholar findings the following martials were used for removal of dyes such as: agricultural wastes (Kadirvelu et al, 2003), magnetite loaded multi-wall carbon nanotube (Ai et al, 2011), treated avocado shells (Georgin et al, 2018), Brazilian pine-fruit shell (Royer et al, 2009) ,spent coffee [ (Safarik et al, 2012), montmorillonite clay (Almeida et al, 2009), Fe3O4nanoparticle [ (Ghaedi et al, 2015), activated carbon, graphene oxide, and carbon nanotubes (Li et al, 2013), Palm oil mill effluent waste (Gobi et al, 2011) , Bagasse Fly Ash [ (Gupta et al, 2000)] , tree fern (Ho et al, 2005) etc .…”