Removal of Fluoride from Drinking Water by Gel Composite of Metal Ion and Humic Acid Adsorbent

2013 ◽  
Vol 726-731 ◽  
pp. 695-699
Author(s):  
Li Hong ◽  
Si Xiang Wang ◽  
Yong Liu ◽  
Yue Chun Zhang
Keyword(s):  
Drinking Water ◽  
Humic Acid ◽  
Contact Time ◽  
Metal Ion ◽  
Fluoride Removal ◽  
Batch Adsorption ◽  
Solution Ph ◽  
Adsorption Method ◽  
Sem Images ◽  
Fluoride Adsorption

Humic acid adsorbent modified with metal ions was prepared by gel polymerization and named gel composite of metal ion and humic acid, which abbreviated GCMH to uptake fluoride from drinking water. The samples were measured by X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images. Fluoride adsorption onto the synthesized samples was investigated by batch adsorption method. In previous works, detailed studies were carried out to investigate the effect of contact time, adsorbent dose, initial solution pH, temperatures and co-existing anions. The maximum fluoride removal was obtained at pH7. Presence of HCO3− adversely affected the adsorption of fluoride. The optimum absorption conditions were at the dose of 10g/L, temperature of water of 55°Cand contact time of 6hs.

scholarly journals Removal of Fluoride from Drinking Water Using Modified Immobilized Activated Alumina

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
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.

scholarly journals Enhanced fluoride removal from drinking water in wide pH range using La/Fe/Al oxides loaded rice straw biochar

2021 ◽  
Author(s):  
Nan Zhou ◽  
Xiangxin Guo ◽  
Changqing Ye ◽  
Ling Yan ◽  
Weishi Gu ◽  
...  
Keyword(s):  
Drinking Water ◽  
Rice Straw ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Batch Adsorption ◽  
Solution Ph ◽  
Adsorption Sites ◽  
Wide Ph Range ◽  
Rice Straw Biochar ◽  
Ph Range

Abstract A novel and highly efficient adsorbent was prepared by loading La/Fe/Al oxides onto rice straw biochar (RSBC) and was tested for the ability to remove fluoride from drinking water. Characterized by SEM, XRD, Zetapotential and FTIR, it was found that the ternary metal oxides were successfully loaded on the surface of biochar in amorphous form, resulting in the formation of hydroxyl active adsorption sites and positive charges, which played a synergistic role in fluoride removal. Through batch adsorption tests, key factors including contact time, initial fluoride concentration, initial pH and co-existing anions effects were investigated. Results showed that the tri-metallic modified biochar (La/Fe/Al-RSBC) had excellent fluoride removal performance with an adsorption capacity of 111.11 mg/g. Solution pH had little impacts on the removal of fluoride, the adsorbent retained excellent fluoride removal capacity in a wide pH range of 3.0–11.0. The co-existing anions had almost no effect on the fluoride removal by La/Fe/Al-RSBC. In addition, La/Fe/Al-RSBC could be regenerated and reused. Electrostatic adsorption and ion exchange were responsible for this adsorption behavior. These findings suggested the broad application prospect of a prepared biochar adsorbent based on rare earth and aluminum impregnation for the fluoride removal from drinking water.

scholarly journals Release of toxic methylene blue from water by mesoporous silicalite-1: characterization, kinetics and isotherm studies

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Sabarish Radoor ◽  
Jasila Karayil ◽  
Aswathy Jayakumar ◽  
Jyotishkumar Parameswaranpillai ◽  
Suchart Siengchin
Keyword(s):  
Electron Microscopy ◽  
Contact Time ◽  
Dye Removal ◽  
Batch Adsorption ◽  
Aqueous Environment ◽  
Order Kinetic ◽  
Adsorption Method ◽  
X Ray ◽  
Ft Ir ◽  
Adsorption Desorption

AbstractIn the present work, we have developed a mesoporous silicalite-1 using CMC as a template for the removal of MB from aqueous solution. The synthesized silicalite-1 were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Energy-dispersive X-ray spectroscopy (EDAX) and N2 adsorption–desorption isotherm (BET). XRD and FT-IR analysis confirmed the formation of crystallinity and development of MFI structure in the mesoporous silicalite-1. The adsorption of MB dye on mesoporous silicalite-1 was conducted by batch adsorption method. The effect of various parameters such as adsorbent dosage, initial dye concentration, contact time and temperature on the dye uptake ability of silicalite-1 was investigated. The operating parameters for the maximum adsorption are silicalite-1 dosage (0.1 wt%), contact time (240 min), initial dye concentration (10 ppm) and temperature (30 ℃). The MB dye removal onto mesoporous silicalite-1 followed pseudo-second-order kinetic and Freundlich isotherm. The silicalite-1 exhibits 86% removal efficiency even after six adsorption–desorption cycle. Therefore, the developed mesoporous silicalite-1 is an effective eco-friendly adsorbent for MB dye removal from aqueous environment.

scholarly journals Batch Sorption Experiments: Langmuir and Freundlich Isotherm Studies for the Adsorption of Textile Metal Ions onto Teff Straw (Eragrostis tef) Agricultural Waste

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mulu Berhe Desta
Keyword(s):  
Heavy Metals ◽  
Metal Ions ◽  
Contact Time ◽  
Metal Ion ◽  
Low Cost ◽  
Agricultural Waste ◽  
Equilibrium Concentration ◽  
Eragrostis Tef ◽  
Batch Adsorption ◽  
Textile Effluents

Adsorption of heavy metals (Cr, Cd, Pb, Ni, and Cu) onto Activated Teff Straw (ATS) has been studied using batch-adsorption techniques. This study was carried out to examine the adsorption capacity of the low-cost adsorbent ATS for the removal of heavy metals from textile effluents. The influence of contact time, pH, Temperature, and adsorbent dose on the adsorption process was also studied. Results revealed that adsorption rate initially increased rapidly, and the optimal removal efficiency was reached within about 1 hour. Further increase in contact time did not show significant change in equilibrium concentration; that is, the adsorption phase reached equilibrium. The adsorption isotherms could be fitted well by the Langmuir model. The value in the present investigation was less than one, indicating that the adsorption of the metal ion onto ATS is favorable. After treatment with ATS the levels of heavy metals were observed to decrease by 88% (Ni), 82.9% (Cd), 81.5% (Cu), 74.5% (Cr), and 68.9% (Pb). Results indicate that the freely abundant, locally available, low-cost adsorbent, Teff straw can be treated as economically viable for the removal of metal ions from textile effluents.

scholarly journals Sustainable Conversion of Agriculture and Food Waste into Activated Carbons Devoted to Fluoride Removal from Drinking Water in Senegal

2015 ◽  
Vol 8 (1) ◽  
pp. 8 ◽  
Author(s):  
Mohamad M. Diémé ◽  
Maxime Hervy ◽  
Saïdou N. Diop ◽  
Claire Gérente ◽  
Audrey Villot ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Activated Carbons ◽  
Public Health Problem ◽  
Calcium Content ◽  
Fluoride Removal ◽  
Carbonaceous Materials ◽  
Water Steam ◽  
Surface Areas ◽  
Fluoride Adsorption

<p>The objective of this study was to investigate the production of activated carbons (AC) from cashew shells, and millet stalks and their efficiency in fluoride retention. These agricultural residues are collected from Senegal. It is known that some regions of Sénégal, commonly called the groundnut basin, are affected by a public health problem caused by an excess of fluoride in drinking water used by these populations. The activated carbons were produced by a combined pyrolysis and activation with water steam; no other chemical compounds were added. Then, activated carbonaceous materials obtained from cashew shells and millet stalks were called CS-H<sub>2</sub>O and MS-H<sub>2</sub>O respectively. CS-H<sub>2</sub>O and MS-H<sub>2</sub>O show very good adsorbent features, and present carbon content ranges between 71 % and 86 %. The BET surface areas are 942 m² g<sup>-1</sup> and 1234 m².g<sup>-1</sup> for CS-H<sub>2</sub>O and MS-H<sub>2</sub>O respectively. A third activated carbon produced from food wastes and coagulation-flocculation sludge (FW/CFS-H<sub>2</sub>O) was produced in the same conditions. Carbon and calcium content of FW/CFS-H<sub>2</sub>O are 32.6 and 39.3 % respectively. The kinetics sorption were performed with all these activated carbons, then the pseudo-first equation was used to describe the kinetics sorption. Fluoride adsorption isotherms were performed with synthetic and natural water with the best activated carbon from kinetics sorption, Langmuir and Freundlich models were used to describe the experimental data. The results showed that carbonaceous materials obtained from CS-H<sub>2</sub>O and MS-H<sub>2</sub>O were weakly efficient for fluoride removal. With FW/CFS-H<sub>2</sub>O, the adsorption capacity is 28.48 mg.g<sup>-1 </sup>with r² = 0.99 with synthetic water.</p>

Utilization of Powdered Cassava Stem as an Alternative Bioadsorbent for Lead (Pb2+) Removal from Aqueous Solution

2021 ◽  
Vol 1033 ◽  
pp. 82-86
Author(s):  
Tintin Mutiara ◽  
Andira Budi Trimartina ◽  
Rafika Erniza Putri ◽  
Achmad Chafidz
Keyword(s):  
Heavy Metals ◽  
Industrial Waste ◽  
Contact Time ◽  
Metal Ion ◽  
Adsorption Process ◽  
Cellulose Content ◽  
Optimum Conditions ◽  
Adsorption Method ◽  
Cassava Stem ◽  
Mesh Sieve

Industrial waste containing heavy metals can pollute the aquatic environment. One method that can be done to manage heavy waste is the adsorption method that uses adsorbent from cassava stem powder. This research was conducted to utilize cassava stem powder waste for the adsorption of Pb2 + metal ions. Cassava stem powder was mashed until it passed 100 mesh sieve. Cassava stems have a cellulose content of 70-80%, lignin 15-20%, ADF 15-20% and cellulose can be used as an absorber of heavy metals. The adsorption process is carried out with variations in pH, time and concentration under optimum conditions. In this adsorption involves the functional groups contained therein so that the interaction between the adsorbent with the metal ion Pb2 +. Based on the research, the optimum conditions were obtained at pH 6, 180 minutes contact time and 50 ppm concentration. This test is carried out using Atomic Absorption Spectroscopy (AAS).

Effect of ageing on surface charge characteristics and adsorption behaviour of cadmium and arsenate in two contrasting soils amended with biochar

Soil Research ◽  
2014 ◽  
Vol 52 (2) ◽  
pp. 155 ◽  
Author(s):  
Chamali Laksala Nagodavithane ◽  
Balwant Singh ◽  
Yunying Fang
Keyword(s):  
Surface Charge ◽  
Contaminated Soils ◽  
Negative Charge ◽  
Exchange Capacity ◽  
Batch Adsorption ◽  
Adsorption Behaviour ◽  
Solution Ph ◽  
Adsorption Method ◽  
Adsorption Processes ◽  
Anionic Species

Biochar has been recognised as an effective amendment for the remediation of contaminated soils; however, there is limited knowledge on the effects of biochar ageing in soil on its adsorption behaviour for cationic and anionic species. Biochars are considered to develop negative charge from oxidation with ageing, which may create additional interaction mechanisms for adsorption processes. In the present study, surface charge characteristics and cadmium (Cd) and arsenate (AsO43–) adsorption behaviour of aged biochar were investigated in two soils with variable charge, an Oxisol and an Inceptisol, by comparing (i) unamended soils, and soils amended with (ii) fresh biochar (450°C) and (iii) biochar (450°C) aged for 12 months, applied at a rate of 2% w/w. Surface charge characteristics were assessed using the ‘index’ ion adsorption method, with a LiCl electrolyte. Batch adsorption studies were conducted using fresh and aged soil–biochar mixtures. In contrast to previous studies, the results provided no evidence of an increase in cation exchange capacity as a consequence of biochar ageing. There was an increase in Cd adsorption in the presence of aged biochar in both soil types compared with unamended soils and soils amended with fresh biochar. Results also indicated an increase in AsO43– adsorption in the Inceptisol amended with aged biochar, whereas a decrease in AsO43– adsorption was observed in the Oxisol amended with aged biochar. Overall, the study has highlighted that adsorption behaviour of aged biochar varies depending on the ion it interacts with, soil properties and solution pH.

scholarly journals Adsorption of Pollutants from Aqueous Solutions Using Activated and Non-Activated Oak Shells: Parametric and Fractional Factorial Design Study. Part I. Removal of Copper

2003 ◽  
Vol 21 (2) ◽  
pp. 177-188 ◽  
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Nagham Al-Hamed
Keyword(s):  
Aqueous Solutions ◽  
Factorial Design ◽  
Contact Time ◽  
Fractional Factorial Design ◽  
Ion Uptake ◽  
Fractional Factorial ◽  
Ion Concentration ◽  
Batch Adsorption ◽  
Solution Ph ◽  
Operating Variables

Non-activated and chemically activated oak shells were evaluated for their ability to remove Cu2+ ions from aqueous solutions. Batch adsorption experiments were conducted to investigate the effect of contact time, sorbent concentration, Cu2+ ion concentration and the pH of the solution on the sorption process. The Cu2+ ion uptake by oak shells increased with decreasing sorbent concentration or with an increase in Cu2+ ion concentration or solution pH. The fractional factorial design technique was applied in order to determine the average Cu2+ ion uptake, the contribution of each operating variable to the value of the uptake and the interaction among the operating variables when the sorbent type, sorbent concentration, Cu2+ ion concentration, pH, contact time and salt were all varied from one level to another. Application of this technique showed that the sorbent concentration had the largest influence on the value of the Cu2+ ion uptake followed by Cu2+ ion concentration and sorbent type. Interaction among the different operating variables played an important role in the adsorption process.

scholarly journals Paraquat dichloride adsorption from aqueous solution using Carbonized Bambara Groundnut (Vigna subterranean) Shells

2020 ◽  
Vol 12 (1) ◽  
pp. 167-177
Author(s):  
Ayuba Abdullahi Muhammad ◽  
Nyijime Thomas Aondofa
Keyword(s):  
Aqueous Solution ◽  
Water Treatment ◽  
Contact Time ◽  
Adsorption Process ◽  
Bambara Groundnut ◽  
Experimental Result ◽  
Isotherm Model ◽  
Batch Adsorption ◽  
Solution Ph ◽  
Adsorbent Dosage

Carbonized Bambara GroundNut Shell (CBGNS) was used as adsorbent for the adsorption of paraquat dichloride (PQ) from aqueous solution. The prepared adsorbent was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy methods. Several parameters that might affect the adsorption process including pH, contact time, adsorbent dosage, temperature and initial concentration were investigated and optimized using batch adsorption technique. Results of the study revealed that maximum removal efficiency (98%) was achieved using 0.05g adsorbent dosage, solution pH of 5 and 60 min of contact time. The equilibrium experimental result revealed that Langmuir model best described the adsorption process with R2 value of 0.956.The heat of adsorption process was estimated from Temkin Isotherm model to be 19.99J/mol and the mean free energy was estimated from Duninin-Radushkevich (DRK) isotherm model to be 0.289KJ/mol indicating chemisorptions process. The kinetic and thermodynamic studies revealed that the adsorption processes followed pseudo-second-order kinetics with R2 value of 0.999 and the value of ∆G (- 27.74 kJ mol-1), ∆H (13.145 kJ mol-1) indicate the spontaneous and endothermic nature of PQ adsorption on CBGNS. The results suggested that CBGNS had the potential to become a promising material for PQ contaminated water treatment. Keywords: Adsorption, Paraquat dichloride, Carbonized Bambara Ground nut shell, Water treatment.

scholarly journals Response surface methodology for optimization of Cd(II) adsorption from wastewaters by fabricated tartaric acid-maize tassel magnetic hybrid sorbent

2019 ◽  
Vol 9 (4) ◽  
pp. 3996-4005 ◽  
Keyword(s):  
Tartaric Acid ◽  
Contact Time ◽  
Adsorption Process ◽  
Desirability Function ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Solution Ph ◽  
Biomass Waste ◽  
Hybrid Sorbent ◽  
Maize Tassel

Maize tassels (MT), an agro-based biomass waste was carbonised followed by thermo-chemical modification using tartaric acid. The functionalized activated carbon was further modified to yield a magnetic hybrid composite adsorbent. The adsorbent was characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The adsorbent was evaluated for its efficiency to remove Cd(II) ions from aqueous solutions through batch adsorption studies following a Central Composite Design. Effects of solution pH, contact time, adsorbent dosage, initial metal concentration and temperature on Cd(II) adsorption were investigated. Optimization of the adsorption process was done using desirability function on the Design Expert V11 software. The desirability function showed that the optimum parameters were pH 5.29, contact time (67.50 min), dosage (0.575 g) and initial concentration (152.50 mg/L). The adsorption process was analysed using kinetic and isotherm models. The kinetics of the adsorption process followed the pseudo-second-order model (lowest sum of square error (SSE) values and correlation coefficients (R2) > 0.999) in addition to the intraparticle diffusion model. The isotherm data were consistent with the Langmuir isotherm as evidenced by the highest correlation coefficient (R2= 0.998). The thermodynamic parameters showed that the process was endothermic and spontaneous in nature. The adsorption capacity of the adsorbent was found to be 188.68 mg/g at 20 ⁰C which is higher than that of the previously reported magnetic maize tassel hybrid (52.05 mg/g). The adsorbent showed good removal efficiency on real effluent samples.

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