scholarly journals Phragmites australis (Reed) as an Efficient, Eco-Friendly Adsorbent for Brackish Water Pre-Treatment in Reverse Osmosis: A Kinetic Study

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 6016
Author(s):  
Abeer El Shahawy ◽  
Inas A. Ahmed ◽  
Rabab Wagdy ◽  
Ahmed H. Ragab ◽  
Nasser H. Shalaby

A cost-effective adsorbent was prepared by carbonization of pre-treated Phragmites australis reed at 500 °C. Phragmites australis was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) surface analyses. XRD of the as-prepared adsorbent exhibited a partially crystalline structure with a specific surface area of 211.6 m2/g and an average pore diameter of 4.2 nm. The biosorption potential of novel biosorbent Phragmites australis reed was investigated with a batch scale and continuous flow study. The study was conducted at different constraints to obtain optimum pH conditions, adsorbent dose, contact time, agitation speed, and initial TDS concentration. In order to analyze the properties of the procedure and determine the amount of sodium removal, Langmuir, Freundlich, and Dubinin–Radushkevich isotherms were tested. The optimal values of contact time, pH, and adsorbent dose were found to be 150 min, 4, and 10 g/L, respectively, with an agitation speed of 300 rpm at room temperature (27 °C). The three tested isotherms show that the adsorption of Na+ onto the prepared adsorbent is a hybrid process from physi- and chemisorption. For industrial application, the adsorbent was tested using the adsorbent column technique. Pseudo-first-order, pseudo-second-order, and diffusion models were connected, and it was discovered that the information fit best to the pseudo-second-arrange active model. According to the intraparticle diffusion model, the mechanism goes through four stages before reaching equilibrium. The periodicity test shows that the adsorption ability of Phragmites australis can be recovered by washing with 0.1 M HCl.

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Tesfaye Akafu ◽  
Achalu Chimdi ◽  
Kefyalew Gomoro

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.


2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Rajeshkannan Rajan ◽  
Manivasagan Rajasimman ◽  
Rajamohan Natarajan

In this study, the use of wheat bran as a possible adsorbent has been successfully demonstrated in the removal of Acid blue9 (AB9) from aqueous solution. The effect of different parameters such as temperature, adsorbent dose, contact time, adsorbent size and agitation speed were investigated. The optimum conditions obtained from response surface methodology are: temperature-38.1°C, adsorbent dose (3.1g/L), contact time (206 min), adsorbent size 0.1mm (150mesh), and agitation speed (222rpm). The effect of pH and initial substrate concentration were studied. The pseudo-first order and pseudo-second order kinetics were tested. The sorption equilibrium, expressed by the Langmuir and Freundlich equations, indicated that the process was in compliance with Freundlich isotherm.


2017 ◽  
Vol 14 (1) ◽  
pp. 148-156
Author(s):  
Baghdad Science Journal

Lead remediation was achieved using simple cost, effective and eco-friendly way from industrial wastewater. Phragmitesaustralis (P.a) (Iraqi plant), was used as anovel biomaterial to remove lead ions from synthesized waste water. Different parameters which affected on adsorption processes were investigated like adsorbent dose, pH, contact time, and adsorbent particle size, to reach the optimized conditions (maximum adsorption). The adsorption of Pb (?) on (P.a) involved fast and slow process as a mechanism steps according to obey two theoretical adsorption isotherms; Langmuir and Freundlich. The thermos dynamic adsorption parameters were evaluated also. The (?H) obtained positive value that meanes adsorption of lead ions was an endothermic processwhile (?G)values were negative which means that adsorption of lead ions was a spontaneous process and the decrease in (?G) with temperature increasing revealed that lead ions adsorption on (P.a) became favorable with temperature increasing


2016 ◽  
Vol 18 (3) ◽  
pp. 546-558 ◽  

<div> <p>In the present study, adsorption potential of potassium permanganate (Hypermangan) modified zeolite was investigated for the removal of nitrate from synthetic wastewater. Effects of the most significant parameters (pH, adsorbent dose, nitrate concentration and contact time) were initially evaluated based on the percentage of nitrate removed from the water solutions. Over 90 % removal of 150 mg L<sup>-1</sup> nitrate was achieved at an optimum pH of 5, adsorbent dose of 2g L<sup>-1</sup> after a 60 min contact time. The chemical and morphological characterizations of Hypermangan modified zeolite (HMZ) were carried out by using scanning electron microscopy (SEM), fourier transform infrared (FT-IR), x-ray diffraction (XRD) and x-ray fluorescence (XRF) analysis methods. Kinetic evaluation indicated that the nitrate adsorption onto HMZ followed the pseudo-first-order model. The equilibrium data assessment illustrated the removal of nitrate by HMZ follows a Langmuir model which attains the maximum adsorption capacity 6.7 mg g<sup>-1</sup>.The mean free energy of adsorption was 0.15 kJ mol<sup>-1</sup>, which indicates the adsorption of nitrate onto HMZ, occurs through a physical mechanism.</p> </div> <p>&nbsp;</p>


Author(s):  
Desalegn Abdissa ◽  
Temesgen Abeto ◽  
Yigezu Mekonnen ◽  
Dejene Beyene

Tannery wastewater is the most challenging due to the complex toxic pollutants it releases into the environment. Similarly, coffee husk from coffee processing operations pollutes the environment. The use of coffee husk to remove hexavalent chromium (VI) and Zink (II)from tannery wastewater solves pollution problems due to untreated tannery wastewater and coffee husk. A batch adsorption process was conducted to determine chromium (VI) and Zink (II)adsorptive capacity of waste coffee husk to treat tannery wastewater. The effects of adsorbent dose (0.2-2.4 g/L), contact time (20- 60 min), agitation speed (50-250 rpm), and pH value (2-8) on the adsorptive capacity of coffee husk on the removal of hexavalent chromium (VI) & zinc (II) from tannery wastewater were studied. Using 2.4 g/L adsorbent dose, 250 rpm agitation speed, 60 min contact time, and pH value of 2, a maximum Cr(VI) removal capacity of coffee husk was 83%. The maximum Zn(II) removal capacity of coffee husk was found to be 79% at an adsorbent dose of 2.4 g/L, 60 min contact time, pH 7, and agitation speed of 250 rpm. Therefore, it can be concluded that coffee husk achieved significant removal of hexavalent chromium (VI) and zinc (II) from tannery wastewater.


2020 ◽  
Vol 10 (1) ◽  
pp. 46-61 ◽  
Author(s):  
Jihane Assaoui ◽  
Zineb Hatim ◽  
Abdelmoula Kheribeche

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.


2020 ◽  
Vol 10 (11) ◽  
Author(s):  
Yohanis Birhanu ◽  
Seyoum Leta ◽  
Getachew Adam

AbstractNowadays, Cr-loaded wastewater released from industrial activities pose an increasing risk to human health and the environment. Adsorption processes have been widely used for the removal of chromium from the waste stream. In this regard, natural adsorbents are the most preferable and cost-effective methods. In this study, the efficiency of Odaracha adsorbent as a novel green technology in the removal of chromium from synthetic wastewater is analyzed. Batch adsorption experiments were conducted to evaluate the effect of contact time, pH, adsorbent dose, and initial concentration of adsorbate on Cr removal. The surface morphology of Odaracha adsorbent was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray powder diffraction. Experimental results showed that Odaracha adsorbent could perform effectively in a wide range of experimental conditions. However, in optimum experimental conditions, such as 180-min contact time, pH 3, and 15 g/L of adsorbent dose Odaracha adsorbent removes 94.68% of Cr from an aqueous solution having 110 mg/L of Cr concentration.


2019 ◽  
Vol 9 (12) ◽  
pp. 2415 ◽  
Author(s):  
Mohamed Abatal ◽  
Atl V. Córdova Quiroz ◽  
María T. Olguín ◽  
América R. Vázquez-Olmos ◽  
Joel Vargas ◽  
...  

The removal of Pb(II) from aqueous solutions by acid-modified clinoptilolite-rich tuff was investigated in this work. Clinoptilolite-rich tuff samples were treated using H2SO4 at different concentrations. Prior to and following acid treatment, the samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FTIR). The pH of the point of zero charge (pHPZC) was also determined as part of this characterization. Batch studies were studied to investigate Pb(II) removal as a function of contact time, initial Pb(II) concentration, adsorbent dosage, and solution pH. The results of the XRD and SEM techniques showed that clinoptilolite is the main mineral of the non- and acid-treated natural zeolite samples. However, EDS analysis indicated that the Si/Al ratio increases as the exchangeable ions decrease with increasing acid concentrations. The optimum conditions for Pb(II) removal for samples with 4.37 ≤ Si/Al ≤ 7.9 were found to be as follows: Contact time of 60–360 min, pH: 6–8, and adsorbent dose of 6 mg g−1; whereas for acid-modified clinoptilolite-rich tuffs with 9.01 ≤ Si/Al ≤ 9.52, these conditions were as follows: Contact time of 1440 min, pH: 8–10, and adsorbent dose of 10 mg g−1. The experimental data were analyzed by kinetic and isotherms models. The results showed that the sorption of Pb(II) on samples with Si/Al ratios of 4.37, 5.31, and 7.91 were in agreement with the pseudo-second order and Langmuir isotherm with qm = 48.54, 37.04, and 14.99 mg g−1, respectively, while the kinetic data and isotherm for samples with 9.01 ≤ Si/Al ≤ 9.52 were found to fit the pseudo-first order and Freundlich model.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Van Hao Nguyen ◽  
Huu Tap Van ◽  
Van Quang Nguyen ◽  
Xuan Van Dam ◽  
L. P. Hoang ◽  
...  

In this study, Fe3O4 nanoparticle-loaded biochar derived from the pomelo peel (FO-PPB) was synthesized and applied as an affordable material for the adsorption of Reactive Red 21 (RR21) in an aqueous solution. The characteristics of FO-PPB were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), Raman spectra, Fourier transform infrared spectra (FTIR), and Brunauer–Emmett–Teller (BET) surface area. The adsorption process of FO-PPB with RR21 was evaluated through batch experiments to examine various parameters including solution pH, contact time, adsorbent dose, initial RR21 concentration, and solution temperature. Results show that FO-PPB produced by the impregnation ratio between iron (Fe) and pomelo peel biochar (PPB) of 5 : 1 (w/w) had the best adsorption performance. The adsorption capacities of PPB and FO-PPB at optimum experimental conditions (solution pH 3, contact time of 60 min, solution temperature of 40°C, initial RR21 concentration of 300 mg/L, and adsorbent dose of 2 g/L) were 18.59 and 26.25 mg/g, respectively. The adsorption isotherms of RR21 on PPB and FO5-PPB were described well by Langmuir and Sips models with high R2 values of 0.9826 and 0.9854 for FO5-PPB and 0.9701 and 0.9903 for PPB, respectively. The obtained data also well matched the pseudo-first-order and pseudo-second-order models with R2 values ≥ 0.96. Chemisorption through sharing or electronic exchange was determined as the main adsorption mechanism.


2020 ◽  
Vol 38 (11A) ◽  
pp. 1602-1617
Author(s):  
Anaam A. Sabri ◽  
Yaser A. Hashim

In the present work, agricultural waste, Iraqi rice husk (A’anbar type) was developed with thermal and chemical treatments for using as an adsorbent to remove phosphate anion from aqueous solution and the thermal treatment at 500 Co was the best. Batch experiments were conducted to obtain the maximum removal of phosphate via changing the parameters of process, such as contact time, pH, adsorbent dose, initial solute concentration, and the existence of competitive anions upon the removal of phosphate and were investigated. The adsorbent characterization was performed employing Fourier transform infrared (FTIR), X-ray fluorescence (XRF), scanning electron microscope (SEM), the BET surface area and pore volume, and X-ray diffraction spectrophotometric analysis (XRD). The maximum removal of phosphate was achieved respectively as (96 %), of contact time 140 min., pH 2.0, adsorbent dose 20 g/L, and initial concentration 30 mg/L at room temperature. The effects of competing ions of CO3-2, NO-3 and SO4-2 anions were studied. The experimental data manifested the best fit for the Langmuir isotherm model (R2 = 0.99) and pseudo-second order kinetic model (R2 = 0.99). Rice husk ash was found efficient for the phosphate removal from the wastewater.


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