An Experimental Study on Biosorption of Fluoride from Water Using LocallyObtained Moringa Oleifera Seeds

Moringa Oleifera is considered to be a natural bio-adsorbent. Unlike chemical coagulants, Moringa Oleifera seeds are environment friendly with various other advantages. The present study investigated the fluoride removal efficiency of Moringa Oleifera from water. Influence of adsorbent dose (1, 2, 4 g/L), contact time (20, 40 and 60 min) and initial fluoride concentration (2 and 5 mg/L) over removal efficiency were determined and optimized. It was found that increased adsorbent dose and contact time enhanced the removal efficiency which is in agreement with the previous studies. The highest removal of 88.1% was achieved when the adsorbent dose and contact time were optimized to 4 g/L and 60 minutes with an initial fluoride concentration of 2 mg/L. The results showed that Moringa Oleifera can be used as an environment friendly, cheap and effective bio-adsorbent for fluoride removal from aqueous solution. All the experimental facilities were provided by Bio-Fuel Lab, Energy & Environment Department, Quaid-e-Awam University of Engineering, Science and Technology, Nawabshah, Pakistan. The samples were analyzed at the Pakistan Council of Research in Water Resources (PCRWR), Tando Jam, Pakistan.

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Synthesis and characterization of aluminum-based adsorbent and application in fluoride removal from aqueous solution

Mediterranean Journal of Chemistry ◽

10.13171/mjc101020291172ja ◽

2020 ◽

Vol 10 (1) ◽

pp. 46-61 ◽

Cited By ~ 1

Author(s):

Jihane Assaoui ◽

Zineb Hatim ◽

Abdelmoula Kheribeche

Keyword(s):

Aqueous Solution ◽

Contact Time ◽

Fluoride Concentration ◽

Infrared Spectrometry ◽

Fluoride Removal ◽

Batch Adsorption ◽

X Ray ◽

Wide Range ◽

Adsorbent Dose

A novel adsorbent was obtained by a facile precipitation method and was used for fluoride removal from aqueous solution. Mineralogical and physicochemical characterization of the adsorbent was carried out by X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), Energy Dispersive X-Ray attached to Scanning Electron Microscopy (SEM-EDX), BET Specific Surface Area(SSAN2BET) analysis and Fourier-Transform Infrared Spectrometry (FTIR). The effect of various operational parameters such as contact time, initial fluoride concentration, (20-160 mg L-1) adsorbent dose (1-6 g L-1) and initial pH solution (3-11) was evaluated in batch procedures at room temperature (25±2°C). The results of the batch adsorption experiments proved that 24 h of contact time was sufficient for attaining equilibrium. The maximum wastewater defluoridation (84.91%) was obtained for 40 mg L-1 and 3 g L-1 of initial fluoride concentration and adsorbent dose, respectively. It appears that there was no significant effect on the F- removal over a wide range of pH 3-11. Kinetic studies revealed that fluoride adsorption fitted well to pseudo-second-order. The adsorption isotherm of fluoride sorption indicated that the maximum adsorption capacity was noted to be 43.29 mg g-1. Batch adsorption data was better described by Langmuir isotherm confirming monolayer adsorption with homogenous distribution of active sites and without interaction between adsorbed molecules. The obtained results indicated that the ion exchange is probably the main mechanism involved in the F- adsorption by the aluminium-based adsorbent.

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Removal of Fluoride from Drinking Water by Sorption Using Diatomite Modified with Aluminum Hydroxide

Journal of Analytical Methods in Chemistry ◽

10.1155/2019/4831926 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Tesfaye Akafu ◽

Achalu Chimdi ◽

Kefyalew Gomoro

Keyword(s):

Aluminum Hydroxide ◽

Contact Time ◽

Fluoride Concentration ◽

Freundlich Isotherm ◽

Intraparticle Diffusion ◽

Fluoride Removal ◽

Contaminated Water ◽

Optimum Conditions ◽

Intraparticle Diffusion Model ◽

Adsorbent Dose

Exposure to fluoride beyond the recommended level for longer duration causes both dental and skeletal fluorosis. Thus, the development of cost-effective, locally available, and environmentally benign adsorbents for fluoride removal from contaminated water sources is absolutely required. In the present study, diatomaceous earth (diatomite) locally available in Ethiopia, modified by treating it with an aluminum hydroxide solution, was used as an adsorbent for fluoride removal from aqueous solutions. Adsorption experiments were carried out by using batch contact method. The adsorbent was characterized using FT-IR spectroscopy. Effects of different parameters affecting efficiency of fluoride removal such as adsorbent dose, contact time, initial fluoride concentration, and pH were investigated and optimized. The optimum adsorbent dose, contact time, initial fluoride concentration, and pH values were 25 g/L, 180 min, 10 mg/L, and 6.7, respectively. The performance of the adsorbent was also tested under optimum conditions using groundwater samples taken from Hawassa and Ziway. Langmuir and Freundlich isotherm models were applied to describe the equilibrium data. Compared to Langmuir isotherm (R2 = 0.888), the Freundlich isotherm (R2 = 0.985) model was better fitted to describe the adsorption characteristics of fluoride on Al-diatomite. The Langmuir maximum adsorption capacity was 1.67 mg/g. The pseudosecond-order model was found to be more suitable than the pseudofirst-order to describe the adsorption kinetics. The low correlation coefficient value of R2 = 0.596 for the intraparticle diffusion model indicates that the intraparticle diffusion model does not apply to the present studied adsorption system. The maximum fluoride removal was observed to be 89.4% under the optimum conditions which indicated that aluminum hydroxide-modified diatomite can be used as efficient, cheap, and ecofriendly adsorbents for the removal of fluoride from contaminated water.

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REMOVAL OF FLUORIDE USING NEEM LEAVES BATCH REACTOR: KINETICS AND EQUILIBRIUM STUDIES

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2018.v11i3.14080 ◽

2018 ◽

Vol 11 (3) ◽

pp. 237

Author(s):

Tej Pratap Singh ◽

Majumder Cb

Keyword(s):

Removal Efficiency ◽

Batch Reactor ◽

Low Cost ◽

Fluoride Concentration ◽

Second Order ◽

Fluoride Removal ◽

Equilibrium Studies ◽

Neem Leaves ◽

Pseudo Second Order ◽

Adsorbent Dose

Objective: The aim of this paper is to study the fluoride removal efficiency of the neem leaves low-cost biosorbent for defluoridation of sewage wastewater.Methods: For finding the best operating condition for maximum removal of fluoride, batchwise experiments were performed at different contact times and keeping other parameters to be constant such as pH, initial fluoride concentration, and adsorbent dose. Various kinetic models such as intraparticle diffusion model, Bangham’s model, and Elovich model had been investigated for determining the suitable adsorption mechanism. The rate of adsorption of fluoride on neem leaves has been determined by pseudo-first-order and pseudo-second-order rate models.Results: The adsorption kinetics rate and mechanism was best described by the pseudo-second-order model and Bangham’s model, respectively. The optimum pH, initial concentration, adsorbent dose, and contact time were found to be 7, 20 mg/L, 10 g/L, and 40 min, respectively, for which there was maximum fluoride removal.Conclusion: The result obtained from the experiments show that the neem leaves have been proved to be a low-cost biosorbent for the defluoridation of the sewage wastewater and have high fluoride removal efficiency.

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Fluoride removal efficiency of Tulsi (Ocimum Sanctum) from water

Water Science & Technology Water Supply ◽

10.2166/ws.2021.257 ◽

2021 ◽

Author(s):

Kefelegn Bayu ◽

Abraham Geremew ◽

Wegene Deriba ◽

Yohannes Mulugeta ◽

Samuel Wagari ◽

...

Keyword(s):

Drinking Water ◽

Removal Efficiency ◽

Natural Water ◽

Water Samples ◽

Contact Time ◽

Ocimum Sanctum ◽

Fluoride Removal ◽

Initial Concentration ◽

Natural Water Samples ◽

Adsorbent Dose

Abstract Fluoride concentration in drinking water higher than recommended value imposes different health problems and there are advanced and chemical based defluoridation techniques even if they are not feasible for developing countries and have limitations. Due to this, defluoridation by using locally available plants is one of the most efficient and sustainable options. Therefore, the current study was intended to investigate fluoride removal efficiency of Tulsi (Ocimum Sanctum) from water that can be an alternative means to reduce the problem related to its high concentration. A laboratory based experimental study was implemented by using potentiometric determination in Haramaya University. The leaves of Tulsi were collected, washed with tap water, rinsed with distilled water, and then were dried at room temperature, crushed and sieved through 500-μm stain-less steel sieve. The experiments were conducted on artificially fluoridated water by anhydrous fluoride and natural water samples collected from deep well water sources from Adama and Harar town. Data was analyzed using Design of Expert (DOE) and Microsoft excel. Twenty-nine runs for aqueous solution were conducted at different factor combinations and the optimum combinations were applied for natural water samples. The study depicts that plant has an efficiency of removing 68.4% of fluoride from water. The best factor combinations to achieve this efficiency was 0.2 g/100 ml, 22.6 min, 5.7 and 6.6 mg/l, adsorbent dose, contact time, pH and initial concentration respectively. pH and initial concentration have a negative effect and adsorbent dose and contact time have a positive effect on removing fluoride from water. Hence, people living in fluorosis endemic areas can use the processed plant as a de-fluoridating agent to minimize adverse health effects. HIGHLIGHT This research articles paves way to further study to remove contaminants from water, wastewater, which can pose a substantial effect on public health. The study conducted to investigate removal mechanism of fluoride from drinking water with low cost locally available plant and the software technologies were applied to find the optimum conditions at which the adsorbent works best.

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A new adsorbent for fluoride removal: The utilization of sludge waste from electrocoagulation as adsorbent

Global NEST Journal ◽

10.30955/gnj.001472 ◽

2015 ◽

Vol 17 (1) ◽

pp. 186-197 ◽

Cited By ~ 8

Keyword(s):

Particle Size ◽

Contact Time ◽

Fluoride Concentration ◽

Freundlich Isotherm ◽

Solution Temperature ◽

Fluoride Removal ◽

Maximum Adsorption Capacity ◽

Batch Mode ◽

Adsorption Removal ◽

Adsorbent Dose

<div> This work investigated the potential of calcined electrocoagulation sludge (CES) within metals hydroxide generated during removal of boron using Al electrode for adsorption of fluoride from aqueous solution. The effects of contact time, pH of the solution (2-10), stirrer speed (50-450 rpm), initial concentration (5-100 mg l-1), adsorbent dose (1-4 mg l-1), solution temperature (293-333 K) and particle size (0.125-1000 µm) on fluoride removal were investigated. All the experiments were carried out by batch mode. It was found that the maximum adsorption takes place within 2 h at pH 6.0. The adsorption removal increased with increase in the adsorbent dose, but decreased with increase in fluoride concentration. It was found that the adsorption removal decreases with increase in temperature, which showed that the adsorption process was exothermic in nature. The decrease in particle size increased fluoride removal efficiency. The maximum adsorption capacity (qm) increased from 45.5 to 124.6 mg g-1 when the adsorbent dosage was adjusted to 1 instead of 4 g l-1. The Freundlich isotherm and Langmuir isotherm were used to fit the data of equilibrium experiments. The adsorption data fitted well into the linearly transformed Langmuir equation. The efficiency of CES to remove fluoride was found to be 99.99% at pH 6, contact time for 2 h, dose of 4 g l-1, when 25 mg l-1 of fluoride was present in 100 ml of water. Comparison with literature reported values of qm, it was found that CES was an attractive adsorbent. </div>

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Effect of Oxalic Acid on the Adsorption of Fluoride by Phosphate Rock from Aqueous Solution

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.610-613.390 ◽

2012 ◽

Vol 610-613 ◽

pp. 390-393

Author(s):

Yu Wang ◽

Xiao Qing Dong ◽

Bao Hua Zhou ◽

Zhi Bing Xu

Keyword(s):

Aqueous Solution ◽

Oxalic Acid ◽

Adsorption Capacity ◽

Contact Time ◽

Phosphate Rock ◽

Fluoride Concentration ◽

Maximum Adsorption Capacity ◽

Batch Experiments ◽

Fluoride Uptake ◽

Adsorbent Dose

The defluoridation capacity of phosphate rock in the presence of oxalic acid was investigated using batch experiments. Defluoridation capacity of phosphate rock was enhanced in the presence of oxalic acid, removing ﬂuoride from 22.46% up to 57.98% with 2.5 mmol/L oxalic acid. The contact time and pH for maximum ﬂuoride uptake were found 2 h and 5, respectively. Maximum adsorption capacity (0.36 mg/g) of ﬂuoride on phosphate rock was observed at 50 mg/L initial ﬂuoride concentration using 2 g adsorbent dose.

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Removal of Fluoride from Drinking Water Using Modified Immobilized Activated Alumina

Journal of Chemistry ◽

10.1155/2013/386476 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 25

Author(s):

Aneeza Rafique ◽

M. Ali Awan ◽

Ayesha Wasti ◽

Ishtiaq A. Qazi ◽

Muhammad Arshad

Keyword(s):

Drinking Water ◽

Removal Efficiency ◽

Activated Charcoal ◽

Contact Time ◽

Sol Gel ◽

Fluoride Concentration ◽

Fluoride Removal ◽

Batch Adsorption ◽

Activated Alumina ◽

Fluoride Adsorption

The study describes the removal of fluoride from drinking water using modified immobilized activated alumina (MIAA) prepared by sol-gel method. The modification was done by adding a specific amount of alum during the sol formation step. The fluoride removal efficiency of MIAA was 1.35 times higher as compared to normal immobilized activated alumina. A batch adsorption study was performed as a function of adsorbent dose, contact time, stirring rate, and initial fluoride concentration. More than 90% removal of fluoride was achieved within 60 minutes of contact time. The adsorption potential of MIAA was compared with activated charcoal which showed that the removal efficiency was about 10% more than the activated charcoal. Both the Langmuir and Freundlich adsorption isotherms fitted well for the fluoride adsorption on MIAA with the regression coefficientR2of 0.99 and 0.98, respectively. MIAA can both be regenerated thermally and chemically. Adsorption experiments using MIAA were employed on real drinking water samples from a fluoride affected area. The study showed that modified immobilized activated alumina is an effective adsorbent for fluoride removal.

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Effects of operational parameters on defluoridation efficiency using electrocoagulation process

Water Practice & Technology ◽

10.2166/wpt.2011.015 ◽

2011 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

M. Behbahani ◽

M.R. Alavi Moghaddam ◽

M. Arami

Keyword(s):

Reaction Time ◽

Anode Material ◽

Removal Efficiency ◽

Fluoride Concentration ◽

Fluoride Removal ◽

Operational Parameters ◽

Applied Current ◽

Initial Ph ◽

Electrocoagulation Process ◽

Electrode Connection

The aim of this study is to examine the effect of operational parameters on fluoride removal using electrocoagulation method. For this purpose, various operational parameters including initial pH, initial fluoride concentration, applied current, reaction time, electrode connection mode, anode material, electrolyte salt, electrolyte concentration, number of electrodes and interelectrode distance were investigated. The highest defluoridation efficiency achieved at initial pH 6. In the case of initial fluoride concentration, maximum removal efficiency (98.5%) obtained at concentration of 25mg/l. The increase of applied current and reaction time improved defluoridation efficiency up to 99%. The difference of fluoride removal efficiencies between monopolar and bipolar series and monopolar parallel were significant, especially at reaction time of 5 min. When aluminum used as anode material, higher removal efficiency (98.5%) achieved compared to that of iron anode (67.7%). The best electrolyte salt was NaCl with the maximum defluoridation efficiency of 98.5% compared to KNO3 and Na2SO4. The increase of NaCl had no effect on defluoridation efficiency. Number of electrodes had little effect on the amounts of Al3+ ions released in the solution and as a result defluoridation efficiency. Almost the same fluoride removal efficiency obtained for different interelectrode distances.

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Characterisation of smectite-rich clay soil: Implication for groundwater defluoridation

South African Journal of Science ◽

10.17159/sajs.2016/20150442 ◽

2016 ◽

Vol Volume 112 (Number 11/12) ◽

Cited By ~ 4

Author(s):

Rabelani Mudzielwana ◽

Mugera W. Gitari ◽

Titus A.M. Msagati ◽

◽

...

Keyword(s):

South Africa ◽

Rural Areas ◽

Contact Time ◽

Clay Soil ◽

Dental Fluorosis ◽

Fluoride Concentration ◽

Limpopo Province ◽

World Health ◽

Fluoride Removal ◽

X Ray

Abstract Groundwater is a widely used and affordable source of drinking water in most of the rural areas of South Africa. Several studies have indicated that groundwater in some boreholes in South Africa has a fluoride concentration above the level recommended by the World Health Organization (1.5 mg/L). Fluoride concentrations above the permissible limit (>1.5 mg/L) lead to dental fluorosis, with even higher concentrations leading to skeletal fluorosis. In the present work, we evaluate the application of smectite-rich clay soil from Mukondeni (Limpopo Province, South Africa) in defluoridation of groundwater. The clay soil was characterised by mineralogy using X-ray diffraction, by elemental composition using X-ray fluorescence and by morphology using scanning electron microscopy. Surface area and pore volume was determined by the Brunauer–Emmett–Teller surface analysis method. Cation exchange capacity and pHpzc of the soil were also evaluated using standard laboratory methods. Batch experiments were conducted to evaluate and optimise various operational parameters such as contact time, adsorbent dose, pH and initial adsorbate concentration. It was observed that 0.8 g/100 mL of smectite-rich clay soil removed up to 92% of fluoride from the initial concentration of 3 mg/L at a pH of 2 with a contact time of 30 min. The experimental data fitted well to a Langmuir adsorption isotherm and followed pseudo second order reaction kinetics. Smectite-rich clay soil showed 52% fluoride removal from field groundwater with an initial fluoride concentration of 5.4 mg/L at an initial pH of 2 and 44% removal at a natural pH of 7.8. Therefore smectite-rich clay soil from Mukondeni has potential for application in defluoridation of groundwater. Chemical modification is recommended to improve the defluoridation capacity.

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