scholarly journals Selenium in wastewater can be adsorbed by modified natural zeolite and reused in vegetable growth

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110198
Author(s):  
Xiao Zhang ◽  
Xinyuan Li ◽  
Zihao Jin ◽  
Sadam Hussain Tumrani ◽  
Xiaodong Ji
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Soil Improvement ◽  
Pollutant Removal ◽  
Maximum Adsorption Capacity ◽  
Selenium Content ◽  
Water Release ◽  
Soil Release ◽  
Release Ratio ◽  
Water Pollutant

Modified natural zeolites (MNZ) are widely used in pollutant removal, but how to address these MNZ that have adsorbed pollutants must be considered. Selenium is an essential trace element for metabolism and is also a water pollutant. Selenium is adsorbed in the water by MNZ in this study first. Then the Brassica chinensis L. was planted in the soil which contains the MNZ loaded with selenium (MNZ-Se) to explore selenium uptake. MNZ-Se release tests in water and soil were also considered. The results showed the following: (1) The maximum adsorption capacity of MNZ for selenium is 46.90 mg/g. (2) Water release experiments of MNZ-Se showed that regardless of how the pH of the aqueous solution changes, the trend of the release of selenium from MNZ-Se in aqueous solution is not affected and first decreases before stabilizing. (3) Soil release experiments of MNZ-Se showed that the selenium content in the soil increased and reached the concentration in the standard of selenium-rich soil. Addition amount and soil pH value will affect the release ratio. The release ratio of MNZ-Se in the water was higher than that in the soil. (4) With an increase in the soil MNZ-Se content, the selenium content in the soil and B. c increases. Above all, MZN can be a good medium for water pollutant removal and soil improvement.

scholarly journals Adsorption of hexavalent chromium by polyacrylonitrile-based porous carbon from aqueous solution

2018 ◽  
Vol 5 (1) ◽  
pp. 171662 ◽  
Author(s):  
Bin Feng ◽  
Wenzhong Shen ◽  
Liyi Shi ◽  
Shijie Qu
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Porous Carbon ◽  
Photoelectron Spectroscopy ◽  
Ph Value ◽  
Functional Materials ◽  
High Specific Surface Area ◽  
Maximum Adsorption Capacity ◽  
Elementary Analysis ◽  
Initial Adsorption

Owing to the unique microporous structure and high specific surface area, porous carbon could act as a good carrier for functional materials. In this paper, polyacrylonitrile (PAN)-based porous carbon materials (PPC-0.6-600, PPC-0.8-600, PPC-0.6-800 and PPC-0.8-800) were prepared by heating KOH at 600°C and 800 o C for the removal of Cr(VI) from aqueous solution. The adsorbent was characterized by the techniques of Fourier transform infrared spectroscopy (FT-IR), elementary analysis, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and N 2 adsorption techniques. The results showed that the adsorption capacity increased with decreasing pH value of the initial solution. The adsorption capacity of Cr(VI) on PPC-0.8-800 was much greater than that on other materials, and maximum adsorption capacity were calculated to be 374.90 mg g −1 . Moreover, PPC-0.8-800 had superior recyclability for the removal of Cr(VI) from wastewater, about 82% of its initial adsorption capacity was retained even after five cycles. The result of kinetic simulation showed that the adsorption of Cr(VI) on the PAN-based porous carbon could be described by pseudo-second-order kinetics. The adsorption process was the ionic interaction between protonated amine groups of PPC and HCrO 4 - ions.

Facile synthesis of chitosan nanoparticle-modified MnO2 nanoflakes for ultrafast adsorption of Pb(II) from aqueous solution

2016 ◽  
Vol 17 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Tianli Han ◽  
Xiaoman Zhang ◽  
Xiangqian Fu ◽  
Jinyun Liu
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Facile Synthesis ◽  
Adsorption Sites ◽  
Chitosan Nanoparticle ◽  
Pseudo Second Order ◽  
Potential Strategy

Chitosan nanoparticle (CS NP)-modified MnO2 nanoflakes were presented as a novel adsorbent for fast adsorption of Pb(II) from aqueous solution. Loading dense CS NPs onto mono-dispersive flower-like MnO2 nanostructures reduces the overlap of CS during adsorption, and thus improves the contact of functional adsorption sites on the surface of MnO2 nanoflakes with heavy metal ions. The results show that the removal efficiency of the nanoadsorbents reaches up to 93% in 3 min for Pb(II). In addition, the maximum adsorption capacity, effects of adsorbent dosage and pH value, and the reusability were investigated. The kinetic process and adsorption isotherm fit well with the pseudo-second-order model and Langmuir model, respectively. These findings provide a potential strategy to address the overlap issue of some common nanoadsorbents.

scholarly journals Comparative study on the synthesis of magnetic ferrite adsorbent for the removal of Cd(II) from wastewater

2018 ◽  
Vol 36 (7-8) ◽  
pp. 1456-1469 ◽  
Author(s):  
Fang Liu ◽  
Kanggen Zhou ◽  
Quanzhou Chen ◽  
Aihe Wang ◽  
Wei Chen
Keyword(s):  
Aqueous Solution ◽  
Wastewater Treatment ◽  
Adsorption Capacity ◽  
Settling Velocity ◽  
Ph Value ◽  
Cost Effective ◽  
Precipitation Method ◽  
Maximum Adsorption Capacity ◽  
Effects Of Ph ◽  
Magnetic Ferrites

The magnetic ferrites were synthesized at ambient temperature through the precipitation method in aqueous solution at varying pH values and were used as novel adsorbents for heavy metal-containing wastewater treatment. The magnetic ferrites were applied for the removal of Cd(II) ion from wastewater. The synthesized magnetic ferrites were characterized by settling velocity, X-ray diffraction, scanning electron microscopy, laser particles size analyzer, and vibrating sample magnetometer. The effects of pH value and contact time on the adsorption process were investigated. The magnetic ferrites had a saturation magnetization value of 82.30 emu/g and a settling velocity of 2%, indicating easy separation from aqueous solution under magnetic field. The adsorption of Cd(II) onto the magnetic ferrites followed the pseudo-second-order kinetics and the Langmuir isotherm model. The most suitable pH condition for the synthesis of magnetic ferrite with optimal Cd(II) adsorption capacity was 9.0, and a maximum adsorption capacity of 160.91 mg/g for Cd(II) ions can be achieved. Based on the cost analysis, the magnetic ferrite was a cost-effective adsorbent for Cd-containing wastewater treatment.

scholarly journals Study on Adsorption of Nickel and Methylene Blue in Aqueous Solution by Magnetic Carboxylate-Rich Carbon

2021 ◽  
Vol 37 (2) ◽  
Author(s):  
Doan Van Dat ◽  
Nguyen Hoai Thuong ◽  
Tran Thi Kieu Ngan ◽  
Le Thi Thanh Nhi ◽  
Dao My Uyen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
High Adsorption ◽  
Endothermic Process ◽  
High Adsorption Capacity

In this study, magnetic carboxylate-rich carbon material (Fe3O4@CRC) was synthesized via a low-temperature carbonization method and applied as an adsorbent for adsorption of Ni(II) ions and methylene blue (MB) in aqueous solution. The synthesized Fe3O4@CRC was characterized by various techniques (XRD, FTIR, FE-SEM, TEM, EDX, VSM, and BET). The adsorption kinetics, isotherms, thermodynamics, and the effects of key adsorption factors, including the pH value, initial adsorbate concentration, contact time, adsorbent dose and temperature were investigated in detail. The results showed that Fe3O4@CRC exhibited a high adsorption capacity for MB and Ni(II) with the maximum adsorption capacity of 187.26 mg/g and 106.75 mg/g, respectively. The adsorption of MB and Ni(II) on Fe3O4@CRC was a spontaneous and endothermic process, and was best described with the first-order kinetic model, Freundlich (for MB) and Langmuir (for Ni(II)) isotherm models. In addition, Fe3O4@CRC could maintain a high adsorption capacity after many consecutive cycles. Therefore, the Fe3O4@CRC material can be used as a highly efficient adsorbent for the removal of heavy metals and dyes from wastewater due to the advantages of high adsorption performance, easy separation, and good reusability.  

Removing Cd(II) from Aqueous Solution by Inverse Opal Hybrid SiO2

NANO ◽  
2020 ◽  
Vol 15 (04) ◽  
pp. 2050047
Author(s):  
Yanhong Wang ◽  
Xiuli Wang ◽  
Cuihong Wu ◽  
Xiaomei Wang ◽  
Xu Zhang
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Pore Wall ◽  
Ionic Concentration ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Inverse Opal ◽  
Solution Ph ◽  
Adsorption Desorption

A hybrid adsorbent with inverse opal (IO) structure was prepared for removing Cd(II) from aqueous solution. The functional polymeric chains were grafted from the pore wall of IO silica to prepare the porous hybrid material by surface-initiated atom-transfer radical polymerization. Furthermore, the amidation reaction was carried out to obtain diethylenetriamine-modified hybrid adsorbent (IO SiO2-g-PAA-DETA). Batch adsorption of removing Cd(II) onto IO SiO2-g-PAA-DETA was studied as the effect of solution pH, adsorbent doses, contact time, ionic concentration, and temperature. When the grafted amount was 73%, the maximum adsorption capacity was obtained. The optimum adsorbent dose and pH value for adsorbing Cd(II) were found to be 5[Formula: see text]g/L and 0.5[Formula: see text]g/L, respectively. The adsorption capacity was almost unaffected by Na[Formula: see text] at low concentrations. The adsorption data was depicted by the corresponding models and the results displayed that adsorbing Cd(II) on IO SiO2-g-PAA-DETA followed the Freundlich and pseudo-first-order model. In addition, after six adsorption–desorption cycles, IO adsorbent could remain above 80% of the first adsorption ability while it was washed using 0.025[Formula: see text]M EDTA.

Removal of Strontium Ions from Aqueous Solution by Adsorption onto Sodium Trititanate Whisker

2011 ◽  
Vol 391-392 ◽  
pp. 1173-1178 ◽  
Author(s):  
Zu Lei Zhang ◽  
Lei Li
Keyword(s):  
Aqueous Solution ◽  
Solid Phase Extraction ◽  
Contact Time ◽  
Ph Value ◽  
Solid Phase ◽  
Maximum Adsorption Capacity ◽  
Phase Extraction ◽  
Flame Atomic Absorption ◽  
Relative Standard ◽  
Strontium Ions

Utilization of solid-phase extraction (SPE) to remove aqueous strontium ions by adsorption onto activated sodium trititanate whisker (STW) was investigated in this work under the conditions of various pH value, STW amount, shaken time and contact time by flame atomic absorption spectrometry (FAAS). The optimum conditions obtained were: pH value = 5.0, STW amount = 0.2 g, shaken time = 5 min and contact time of 3 h on the remove of 2 mg·L-1strontium(II). The adsorption of Sr(II) on activated STW follows pseudo-second order kinetics and the maximum adsorption capacity Q being 8.37 mg·g-1at 25°C. Finally, the detection limit (3σ) of 0.030 μg·mL-1with the relative standard deviation (RSD) for 1.0 μg·mL-1Sr(II) of 0.93 % (n=10) were obtained. Results showed that activated STW was a solid-phase extraction sorbent of efficient, low-cost, convenient adsorption of Sr(II) from aqueous solution and could be reused for five times with about 8.0%-9.0% regeneration loss.

The Effective Removal of Congo Red Dye from Aqueous Solution Using Fly Ash/CeO2 Composite Material

2014 ◽  
Vol 535 ◽  
pp. 671-674 ◽  
Author(s):  
Lei Ding ◽  
Bei Gang Li ◽  
Jing Mi
Keyword(s):  
Aqueous Solution ◽  
Fly Ash ◽  
Congo Red ◽  
Ph Value ◽  
Removal Rate ◽  
Langmuir Model ◽  
Raw Material ◽  
Precipitation Method ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity

Fly ash/CeO2 composite adsorbent (FA/CeO2) was prepared by HCl treatment and precipitation method using a low-cost waste fly ash (FA) as the raw material and used for the removal of Congo Red (CR) from aqueous solution. Effects of important parameters such as contact time, initial dye concentration, pH value and temperature were explored. Adsorption equilibrium and isotherms were investigated. The adsorption of CR onto FA/CeO2 is a fast process and to achieve a basic balance in 30 minutes. The removal of CR is strongly pH-dependent. FA/CeO2 is an effective adsorbent for the CR removal with removal rate of 98.8% when initial CR concentration is 1000 mg/L. The experimental isotherm data were analyzed using Langmuir and Freundlich isotherm models. The results revealed that the adsorption behavior of CR on FA/CeO2 fitted well with the Langmuir model at different temperatures. The maximum adsorption capacity obtained by Langmuir model is 232.56 mg/g which is nearly consistent with the actual adsorption value of 230.01 mg/g at 298K. The Adsorption amount decreases with increasing temperature, but the variation of the amplitude is very small.

Synthesis of Lignin-Base Bead Adsorbent and its Application in Removing Pb (II) from Aqueous Solution

2011 ◽  
Vol 391-392 ◽  
pp. 773-777 ◽  
Author(s):  
Ya Ling Huang ◽  
Ru Lin Fu ◽  
Zhen Kun Huang ◽  
Xian Su Cheng
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Maximum Adsorption Capacity ◽  
Condensation Polymerization ◽  
High Concentration ◽  
Modified Lignin ◽  
Scanning Electron ◽  
Better Than

A spherical amine modified lignin-base adsorbent had been prepared (L-BAA) by condensation polymerization of lignin with epoxy chloropropane and diamines. The modified products were characterized by FTIR spectra and scanning electron microscopy. Few researches on adsorbing Pb (II) of high concentration from aqueous had been reported. The spherical lignin-base adsorbent was used to adsorb Pb (II) of high concentration from aqueous solution. The effect of shaking time, pH value and temperature on adsorption had been investigated in the study. It was indicated that the adsorption was dependent on pH and temperature of Pb (II) aqueous solution. The maximum adsorption capacity was 151.0 mg/g at follow condition: pH value was 4.00 and temperature was 35°C. The adsorption capacity was better than other reported adsorbents.

Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column

2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Particle Size ◽  
Adsorption Capacity ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Fungal Biomass ◽  
Solution Flow Rate ◽  
Maximum Adsorption Capacity ◽  
Solution Flow

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

Removal of Toxic Dyestuffs from Aqueous Solution by Amphoteric Bioadsorbent

2020 ◽  
Vol 16 ◽  
Author(s):  
Reda M. El-Shishtawy ◽  
Abdullah M. Asiri ◽  
Nahed S. E. Ahmed
Keyword(s):  
Aqueous Solution ◽  
Ion Exchange ◽  
Dye Removal ◽  
Exchange Process ◽  
Cationic Dyes ◽  
Carboxyl Groups ◽  
Maximum Adsorption Capacity ◽  
Equilibrium Isotherm ◽  
Ion Exchange Process ◽  
Dyes And Pigments

Background: Color effluents generated from the production industry of dyes and pigments and their use in different applications such as textile, paper, leather tanning, and food industries, are high in color and contaminants that damage the aquatic life. It is estimated that about 105 of various commercial dyes and pigments amounted to 7×105 tons are produced annually worldwide. Ultimately, about 10–15% is wasted into the effluents of the textile industry. Chitin is abundant in nature, and it is a linear biopolymer containing acetamido and hydroxyl groups amenable to render it atmospheric by introducing amino and carboxyl groups, hence able to remove different classes of toxic organic dyes from colored effluents. Methods: Chitin was chemically modified to render it amphoteric via the introduction of carboxyl and amino groups. The amphoteric chitin has been fully characterized by FTIR, TGA-DTG, elemental analysis, SEM, and point of zero charge. Adsorption optimization for both anionic and cationic dyes was made by batch adsorption method, and the conditions obtained were used for studying the kinetics and thermodynamics of adsorption. Results: The results of dye removal proved that the adsorbent was proven effective in removing both anionic and cationic dyes (Acid Red 1 and methylene blue (MB)), at their respective optimum pHs (2 for acid and 8 for cationic dye). The equilibrium isotherm at room temperature fitted the Freundlich model for MB, and the maximum adsorption capacity was 98.2 mg/g using 50 mg/l of MB, whereas the equilibrium isotherm fitted the Freundlich and Langmuir model for AR1 and the maximum adsorption capacity was 128.2 mg/g. Kinetic results indicate that the adsorption is a two-step diffusion process for both dyes as indicated by the values of the initial adsorption factor (Ri) and follows the pseudo-second-order kinetics. Also, thermodynamic calculations suggest that the adsorption of AR1 on the amphoteric chitin is an endothermic process from 294 to 303 K. The result indicated that the mechanism of adsorption is chemisorption via an ion-exchange process. Also, recycling of the adsorbent was easy, and its reuse for dye removal was effective. Conclusion: New amphoteric chitin has been successfully synthesized and characterized. This resin material, which contains amino and carboxyl groups, is novel as such chemical modification of chitin hasn’t been reported. The amphoteric chitin has proven effective in decolorizing aqueous solution from anionic and cationic dyes. The adsorption behavior of amphoteric chitin is believed to follow chemical adsorption with an ion-exchange process. The recycling process for few cycles indicated that the loaded adsorbent could be regenerated by simple treatment and retested for removing anionic and cationic dyes without any loss in the adsorbability. Therefore, the study introduces a new and easy approach for the development of amphoteric adsorbent for application in the removal of different dyes from aqueous solutions.

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