Defluoridation of Water Using Aluminum Hydroxide Activated Carbon Biosorbents

Abstract

This study was aimed to investigate the efficiency of locally available low-cost and eco-friendly activated agricultural biosorbents produced from corncob and sorghum husk for the removal of fluoride from aqueous solution using batch adsorption. The activated biosorbents were characterized using SEM, XRD and FTIR spectroscopy. Effects of particle size (0.063–1.0 mm), contact time (15–120 min), pH (2–12), dose (2–10 g), and initial concentration (0.5–5.0 mg/L) were investigated. The morphology analysis revealed that biosorbents showed the presence of a high binding capacity for fluoride adsorption. The maximum adsorption was attained; size of the adsorbent 0.063 mm, pH 7, contact time 60 min, and 6 g dose of the biosorbents. Moreover, the adsorption kinetics followed the pseudo-second-order model and the adsorption isotherms fitted well to the Langmuir model. Furthermore, a field study was conducted using real water sample collected from Semema, Tigray, Ethiopia, and maximum fluoride removal was observed to be 79.44% and 77.05% for the activated carbons of Corncob and Sorghum husk at optimum conditions. Therefore, this experimental finding indicated that activated carbon of Corncob and Sorghum husk can be used as efficient, cheap, and eco-friendly biosorbents for the removal of fluoride from drinking water at community level.

Biosorption of Fluoride from Water Using Aluminum Hydroxide Modified Activated Carbon from Composte Coffee Husk and Corn Cob

“…The comparison of the correlation coe cient values leads to the conclusion that the pseudo second order model provides the best expression for uoride adsorption on composite activated carbon. The adsorption kinetics of uoride removal by adsorption using corncob and sorghum husk activated carbon are consistent with this result (Gebremariam et al, 2022).…”

“…With a few small adjustments, the activated carbon modi cation process for coffee husk and corncob was carried out using the methodology of Gebremariam et al (2022). In summary, 500 mL of 0.6 M Al 2 (SO 4 ) 3 .16H 2 O solution was added to the conical ask.…”

“…Figure 6 shows that the activated biosorbent made of coffee husk and corncob increased in removal e ciency of uoride as the contact time increased, reaching saturation at 90 minutes. Functional groups and a large number of available active sites for the initial uoride adsorption may be the cause of the fast increase in adsorption up to 90 minutes (Gebremariam et al, 2022). To achieve the highest uoride removal effectiveness (88.1%) in this work, a lower initial uoride concentration (10 mg/L), a contact time of 90 minutes, and a dose of 3 g adsorbent with pH 3 were used.…”

“…In addition to being naturally occurring in igneous rocks, uorine can also be found in air dust from central sources, magmatic emissions, and industrial contamination (Eberly et al, 2020). Ethiopia is the country most affected by excessive uoride in drinking water (Gebremariam et al, 2022). For instance, research conducted by revealed that the uoride content of drinking water gathered from wells in Ethiopia's rift valley regions varied from 1.2 mg/L to 36.0 mg/L (Ambelu & Faris, 2014).…”

“…Numerous techniques are available for use, including reverse osmosis, ion exchange water, membrane separation, chemical treatment, electrolytic de uoridation, electrodialysis, membrane ltration, precipitation, nano ltration, coagulation, electrocoagulation, and chemical precipitation (Gebremariam et al, 2022). These methods' drawbacks include the production of hazardous sludge, the need for a labor-intensive treatment procedure, high costs, highenergy consumption, and chemical use (Rao, 2015).…”