Performance and Mechanism for Fluoride Removal in Groundwater with Calcium Modified Biochar from Peanut Shell

2020 ◽  
Vol 12 (4) ◽  
pp. 492-501 ◽  
Author(s):  
Rui-Ling Zhang ◽  
Jing Xu ◽  
Lei Gao ◽  
Zhe Wang ◽  
Bo Wang ◽  
...  
Keyword(s):  
Calcium Chloride ◽  
Functional Groups ◽  
Removal Efficiency ◽  
Low Cost ◽  
Calcium Content ◽  
Fluoride Removal ◽  
Peanut Shell ◽  
Modified Biochar ◽  
Pseudo Second Order ◽  
Safe Technique

Fluoride in groundwater poses a great risk to humans. Biochar is an effective and environmental-friendly adsorbent for fluoride removal. The objectives of this study were to develop a calcium modified biochar derived from peanut shell and to study its mechanism in the adsorptive removal of fluoride. For these purposes, biochar was prepared using three different techniques. No. 1 biochar was prepared by direct carbonization, No. 2 biochar was modifiied with 30% calcium chloride solution before carbonization, and No. 3 biochar was modified with 30% calcium chloride following carbonization. The No. 2 biochar clearly showed the highest percentage fluoride removal (92.1%) and the fluoride removal efficiency improved by 30%–60% compared with other techniques. The adsorption isotherms and kinetics of the biochar modified with calcium were best described by the Langmuir and pseudo-second-order model, respectively. Based on the calcium content from the energy spectrum, calcium was well loaded onto the biochar. Calcium detached experiments indicated the loaded calcium was the main method for fluoride removal of No. 2 biochar, the adsorption mechanism was clearly demonstrated through the changes of morphology and group during adsorption. Fourier transform infrared spectroscopic (FTIR) analyses indicated the highest fluoride removal efficiency of No. 2 biochar was due to cleavage and structural change in many functional groups. But only C–H was involved in No. 3 biochar fluoride removal process. The good performance of No. 2 biochar for de-fluoridation was due to the calcium stably loaded onto the biochar and many of the changed functional groups there. Biochar modified with calcium before carbonization is an efficient, low-cost, safe technique for de-fluoridation.

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

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.

scholarly journals Efficient Removal of Cd (II) From Aqueous Solution By Chitosan Modified Kiwi Branch Biochar

2021 ◽  
Author(s):  
Yuehui Tan ◽  
Xirui Wan ◽  
Xue Ni ◽  
Le Wang ◽  
Ting Zhou ◽  
...  
Keyword(s):  
Functional Groups ◽  
Low Cost ◽  
Maximum Adsorption Capacity ◽  
Surface Functional Groups ◽  
Order Model ◽  
Efficient Removal ◽  
Adsorption Ability ◽  
Modified Biochar ◽  
Pseudo Second Order ◽  
Interaction Surface

Abstract A novel chitosan-modified kiwi branch biochar (CHKB) was successfully fabricated as cut-price modified biochar to remove Cd (II) from wastewater. Characterization experiments with SEM-EDS, FTIR and XPS suggested that CHKB had more cations and surface functional groups compared with the original kiwi biochar (KB). The adsorption experiment results of Cd (II) on CHKB showed that the adsorption isotherms can be described best by the Langmuir model and that the pseudo-second-order model fits the Cd (II) adsorption kinetics well, indicating that the process was monolayer and controlled by chemisorption. CHKB exhibited the Langmuir maximum adsorption capacity of Cd (II) (126.58 mg g-1), however, that of KB is only 4.26 mg g-1. The adsorption ability of CHKB was improved by the increase of the surface area and abundant surface functional groups (-OH, -NH, C=O and so on). And the cation exchange, electrostatic interaction, surface complexation and precipitation were main mechanisms in the sorption of Cd (II) on CHKB. In addition, CHKB can be regenerated and reused for Cd (II) sorption by the eluent of EDTA-2Na. Excellent adsorption performance, low-cost, and environmental-friendly made CHKB become the fantastic adsorbent to remove Cd (II) in wastewater.

scholarly journals Eggshell Powder as an Adsorbent for Removal of Fluoride from Aqueous Solution: Equilibrium, Kinetic and Thermodynamic Studies

2012 ◽  
Vol 9 (3) ◽  
pp. 1457-1480 ◽  
Author(s):  
R. Bhaumik ◽  
N. K. Mondal ◽  
B. Das ◽  
P. Roy ◽  
K. C. Pal ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Fluoride Removal ◽  
Contaminated Water ◽  
Fluoride Adsorption ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Kinetic And Thermodynamic Studies ◽  
Maximum Removal

A new medium, eggshell powder has been developed for fluoride removal from aqueous solution. Fluoride adsorption was studied in a batch system where adsorption was found to be pH dependent with maximum removal efficiency at 6.0. The experimental data was more satisfactorily fitted with Langmuir isotherm model. The kinetics and the factor controlling adsorption process fully accepted by pseudo-second-order model were also discussed. Eawas found to be 45.98 kJmol-1by using Arrhenius equation, indicating chemisorption nature of fluoride onto eggshell powder. Thermodynamic study showed spontaneous nature and feasibility of the adsorption process with negative enthalpy (∆H0) value also supported the exothermic nature. Batch experiments were performed to study the applicability of the adsorbent by using fluoride contaminated water collected from affected areas. These results indicate that eggshell powder can be used as an effective, low-cost adsorbent to remove fluoride from aqueous solution as well as groundwater.

scholarly journals Risk Evaluation of Pyrolyzed Biochar from Multiple Wastes

2019 ◽  
Vol 2019 ◽  
pp. 1-28 ◽  
Author(s):  
Shem M. Ndirangu ◽  
Yanyan Liu ◽  
Kai Xu ◽  
Shaoxian Song
Keyword(s):  
Functional Groups ◽  
Risk Evaluation ◽  
Low Cost ◽  
Risk Index ◽  
Potential Ecological Risk ◽  
Pyrolysis Process ◽  
Air Oxidation ◽  
Net Benefit ◽  
Modified Biochar ◽  
Contaminated Food

This paper aims at demonstrating the significance of biochar risk evaluation and reviewing risk evaluation from the aspects of pyrolysis process, feedstock, and sources of hazards in biochar and their potential effects and the methods used in risk evaluation. Feedstock properties and the resultant biochar produced at different pyrolysis process influence their chemical, physical, and structural properties, which are vital in understanding the functionality of biochar. Biochar use has been linked to some risks in soil application such as biochar being toxic, facilitating GHGs emission, suppression of the effectiveness of pesticides, and effects on soil microbes. These potential risks originate from feedstock, contaminated feedstock, and pyrolysis conditions that favor the creation of characteristics and functional groups of this nature. These toxic compounds formed pose a threat to human health through the food chain. Determination of toxicity levels is a first step in the risk management of toxic biochar. Various sorption methods of biochar utilized low-cost adsorbents, engineered surface functional groups, and nZVI modified biochars. The mechanisms of organic compound removal was through sorption, enhanced sorption, modified biochar, postpyrolysis thermal air oxidation and that of PFRs degradation was through activation, photoactive functional groups, magnetization, and hydrothermal synthesis. Emissions of GHGs in soils amended with biochar emanated through physical and biotic mediated mechanisms. BCNs have a significance in reducing the health quotient indices for PTEs risk contamination by suppressing cancer risk arising from consumption of contaminated food. The degree of environmental risk assessment of HM pollution in biomass and biochars has been determined by using potential ecological risk index and RAC while organic contaminant degradation by EPFRs was considered when assessing the environmental roles of biochar in regulating the fate of contaminants removal. The magnitude of technologies’ net benefit must be considered in relation to the associated risks.

scholarly journals Comparative Study of Biochar Modified with Different Functional Groups for Efficient Removal of Pb(II) and Ni(II)

2021 ◽  
Author(s):  
Chengchen Liu ◽  
Jiaxin Lin ◽  
Haojia Chen ◽  
Wanjun Wang ◽  
Yan Yang
Keyword(s):  
Adsorption Capacity ◽  
Functional Groups ◽  
Ethylenediaminetetraacetic Acid ◽  
X Ray Diffraction ◽  
Modified Biochar ◽  
Hierarchical Porous ◽  
Phosphorus Containing ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order ◽  
Ft Ir

Abstract The potential application of biochar in water treatment is attracting interest due to its sustainability and low production cost. In the present study, H3PO4-modified biochar (H-PBC), ethylenediaminetetraacetic acid-modified biochar (E-PBC), and NaOH-modified biochar (O-PBC) were prepared for Ni(II) and Pb(II) adsorption in an aqueous solution. Scanning electron microscopy (SEM), X-ray diffraction analysis, Brunauer–Emmett–Teller analysis, and Fourier transform infrared (FT-IR) spectroscopy were employed to characterize the as-obtained samples, and their capacities for Ni(II) and Pb(II) adsorption were determined. SEM showed that H-PBC retained the hierarchical porous structure of pristine biochar, and projections were observed on its surface. FT-IR showed that H-PBC possessed abundant oxygen-containing and phosphorus-containing functional groups on the surface. H-PBC, E-PBC, and O-PBC all exhibited excellent performance at Ni(II) and Pb(II) adsorption with qmax values of 64.94 mg/g, 47.17 mg/g, and 60.24 mg/g, and 243.90 mg/g, 156.25 mg/g, and 192.31 mg/g, respectively, which were significantly higher than the adsorption capacity (19.80 mg/g and 38.31 mg/g) of pristine biochar. Pseudo-second order models suggested that the adsorption process was controlled by chemical adsorption. Regeneration analysis showed that H-PBC had superior reusability characteristics. H-PBC had a greater adsorption capacity than other adsorbents due to its large specific surface area, and abundant oxygen-containing and phosphorus-containing functional groups. The results obtained in this study suggest that H-PBC is a promising adsorbent for the removal of heavy metals from aqueous solutions.

scholarly journals Characterization of ultraviolet-modified biochar from different feedstocks for enhanced removal of hexavalent chromium from water

2019 ◽  
Vol 79 (9) ◽  
pp. 1705-1716 ◽  
Author(s):  
Zhongya Peng ◽  
Xiaomei Liu ◽  
Hongkun Chen ◽  
Qinglong Liu ◽  
Jingchun Tang
Keyword(s):  
Functional Groups ◽  
Hexavalent Chromium ◽  
Uv Irradiation ◽  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Low Cost ◽  
Surface Areas ◽  
Modified Biochar ◽  
Sorption Ability ◽  
Novel Material

Abstract Biochars produced from different feedstocks via pyrolytic carbonization and ultraviolet (UV) modification were used as alternative adsorbents for aqueous hexavalent chromium (Cr(VI)) remediation. Structural and morphological analysis showed that UV irradiation increased the surface area of biochar and added a large amount of oxygen-containing functional groups on the biochar's surface, resulting in about 2–5 times increase of Cr(VI) removing capacity (14.39–20.04 mg/g) compared to that of unmodified biochars (3.60–8.43 mg/g). The sorption ability among different feedstocks after modification was as follows: corn stack > sawdust > wheat straw. The adsorption kinetics and adsorption isotherm data agreed well with the pseudo-second-order model and Freundlich model, respectively. Experimental and modeling results suggested that the oxygen-containing functional groups and surface areas of biochars were notably increased after UV irradiation, which was mainly governed by surface complexation. X-ray photoelectron spectroscopy analysis showed that reduction occurred during Cr(VI) adsorption. In addition, UV irradiation significantly increased the concentration of dissolved organic matter (DOM) in biochars. The collected outcomes showed that UV-modified biochar was a good material for the removal of hexavalent chromium from aqueous medium. The excellent adsorption capacity, environmental-friendly and low cost properties made the novel material an auspicious candidate for environmental remediation.

scholarly journals Eggshell-Derived Nanohydroxyapatite Adsorbent for Defluoridation of Drinking Water from Bofo of Ethiopia

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Kifle Workeneh ◽  
Enyew Amare Zereffa ◽  
Toshome Abdo Segne ◽  
Rajalakshmanan Eswaramoorthy
Keyword(s):  
Removal Efficiency ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Batch Adsorption ◽  
Alternative Source ◽  
Fluoride Adsorption ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Eggshell Waste

Fluoride has become a notable toxicological environmental hazard worldwide because it is often found in groundwater. In the present study, hydroxyapatite adsorbent was synthesized from eggshell waste to remove fluoride from aqueous solution. XRD, FT-IR, and TGA techniques were used to characterize the prepared adsorbent. Batch adsorption studies were performed to examine the adsorption capacity of hydroxyapatite such as the effect of the initial pH of the solution, contact time, adsorbent dose, and initial fluoride concentration. The fluoride ion-selective electrode was used to determine the fluoride removal efficiency. 98.8% of fluoride was removed at pH 3.0, but at pH ~7.0, 85% of fluoride was removed; it shows that the fluoride adsorption is pH dependent. The adsorption isotherm studies (Langmuir and Freundlich models) and the experimental results for the removal of fluoride showed that the Langmuir model was more favorable and the reaction followed pseudo-second-order kinetics. In real water samples, the prepared hydroxyapatite derived from eggshell exhibited 81% removal efficiency. Our results indicate that eggshell waste-derived hydroxyapatite may be an alternative source for defluoridation in developing countries.

Ultrasound and microwave-assisted preparation of Fe-activated carbon as an effective low-cost adsorbent for dyes wastewater treatment

RSC Advances ◽  
2016 ◽  
Vol 6 (82) ◽  
pp. 78936-78946 ◽  
Author(s):  
Song Cheng ◽  
Libo Zhang ◽  
Hongying Xia ◽  
Jinhui Peng ◽  
Jianhua Shu ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Langmuir Isotherm ◽  
Low Cost ◽  
Order Model ◽  
Microwave Assisted ◽  
Pseudo Second Order ◽  
Mb Adsorption

A and B are Langmuir isotherm and pseudo-second-order model. We conclude that MB adsorption capacity of Fe-activated carbon is bigger than raw activated carbon, indicating that Fe-activated carbon has better MB removal efficiency.

scholarly journals Application of new biosorbent based on chemicaly modified Lagenaria vulgaris shell for the removal of copper(II) from aqueous solutions: Effects of operational parameters

2013 ◽  
Vol 67 (4) ◽  
pp. 559-567 ◽  
Author(s):  
Milos Kostic ◽  
Miljana Radovic ◽  
Jelena Mitrovic ◽  
Danijela Bojic ◽  
Dragan Milenkovic ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Low Cost ◽  
Batch Process ◽  
Maximum Adsorption Capacity ◽  
Operational Parameters ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Process Mode ◽  
Lagenaria Vulgaris

In present study a low cost biosorbent derived from Lagenaria vulgaris plant by xanthation, was tested for its ability to remove copper from aqueous solution. The effect of contact time, initial pH, initial concentration of copper(II) ions and adsorbent dosage on the removal efficiency were studied in a batch process mode. The optimal pH for investigated metal was 5. A dosage of 4 g dm-3 of xanthated Lagenaria vulgaris biosorbent (xLVB) was found to be effective for maximum uptake of copper(II). The kinetic of sorption of metal was fast, reaching at equilibrium in 50 min. The kinetic data were found to follow closely the pseudo-second-order model. The adsorption equilibrium was described well by the Langmuir isotherm model with maximum adsorption capacity of 23.18 mg g-1 copper(II) ions on xLVB. The presence of sulfur groups on xLVB were identified by FTIR spectroscopic study. Copper removal efficiency was achieved at 81.35% from copper plating industry wastevater.

scholarly journals Application of Novel Clay Composite Adsorbent for Fluoride Removal

2019 ◽  
Vol 16 (2) ◽  
pp. 164-173 ◽  
Author(s):  
Lechisa Daba Gidi ◽  
Enyew Zereffa Amare ◽  
H C Ananda Murthy ◽  
Buzuayehu Abebe
Keyword(s):  
Removal Efficiency ◽  
Volume Ratio ◽  
Cost Effective ◽  
Xrd Analysis ◽  
Fluoride Removal ◽  
Clay Material ◽  
Composite Adsorbent ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Ir Analysis

A novel cost-effective, eco-friendly clay composite adsorbent was developed towards fluoride remediation. Clay, Grog, Bone char, and Sawdust were dry mixed within volume ratios of (5:1:1:1), (4:2:2:1), and (3:3:3:1), respectively. The powders were mixed again with distilled water, pressed with disc shape; sun dried for three days and fired for one hour in the muffle furnace at 400oC, 500oC, and 600oC. The cooled discs were ground and sieved to obtain nine different composite powdered with particle size less than 1.18 mm. The developed composite adsorbent was characterized using advanced techniques: XRD, SEM, and FT-IR. The adsorption studies showed that among the developed adsorbents, composite with the volume ratio of (3:3:3:1) and optimized at firing temperature of 400°C exhibited maximum adsorption capacities of 91.6% fluoride removal efficiency. The XRD analysis revealed mixed phases in the composite, and the presence of OH¯ functional groups was indicated by FT-IR analysis. The experimental results indicated that the Langmuir model was found to fit better for the removal of fluoride ion and followed the pseudo-second-order rate equation. The composite clay material exhibited excellent removal efficiency for the real water samples analyzed.

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