La2O3-modified MCM-41 for efficient phosphate removal synthesized using natural diatomite as precursor

2019 ◽  
Vol 79 (10) ◽  
pp. 1878-1886 ◽  
Author(s):  
Xiaoning Jia ◽  
Xiaojuan He ◽  
Kaixuan Han ◽  
Yuhong Ba ◽  
Xia Zhao ◽  
...  
Keyword(s):  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Treated Wastewater ◽  
Molar Ratio ◽  
Phosphate Adsorption ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Isothermal Model ◽  
Enhanced Adsorption ◽  
Ph Range

Abstract In this study, an ordered mesoporous silica modified with lanthanum oxide was synthesized using diatomite as silica source and applied for adsorption of phosphate from aqueous solution. By taking cost-effectiveness for practical application into consideration, the adsorbent with a theoretical La/SiO2 molar ratio of 0.2 (La0.2M41) possessed a promising performance. In the batch adsorption tests, the adsorbents with La2O3 loading possessed markedly enhanced adsorption capacities. Phosphate uptake by La0.2M41 was pH-dependent with the highest sorption capacities observed over a pH range of 3.0–6.0. Coexistent anions displayed an adverse effect on phosphate adsorption following the order of CO32−  > F−  > NO3− > Cl− > SO42−. In the kinetic study, phosphate adsorption onto La0.2M41 followed the pseudo-second-order equation better than the pseudo-first-order, suggesting chemisorption. The Langmuir isothermal model well described the adsorption isotherm data, showing a maximum adsorption capacity for phosphate of up to 263.16 mg/g at 298 K. In a real treated wastewater effluent with phosphate concentration of 2.5 mg P/L, La0.2M41 efficiently reduced the phosphate concentration to 28 µg P/L.

scholarly journals CRUSHED CONCRETE AS ADSORPTIVE MATERIAL FOR REMOVAL OF PHOSPHATE IONS FROM AQUEOUS SOLUTIONS

2020 ◽  
Vol 5 (2) ◽  
pp. 58-64
Author(s):  
Arega Genetie Abetu ◽  
Adisu Befekadu Kebede
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Isotherms ◽  
Low Income ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Low Income Countries ◽  
Phosphate Adsorption ◽  
Adsorptive Capacity ◽  
Batch Adsorption ◽  
Crushed Concrete

The contamination of surface and groundwater with phosphate originating from industrial, agricultural and household wastewater remains a serious environmental issue in low-income countries. Currently, demolished concrete is mainly recycled as aggregate for reconstruction and conventional wastewater treatment systems for removing phosphate are expensive and complex. In this study, we were aiming at testing crushed concrete as an efficient adsorbent for the removal of phosphate from aqueous solutions, obtained from the demolition of construction site. It can reduce pollution and landfill disposal by converting construction waste into valuable products and an alternative solution for phosphate removal. Batch adsorption experiments were conducted using phosphate solutions to examine the adsorption kinetic as well as equilibrium conditions. Results show that the phosphate adsorption of all absorbents follows the adsorption isotherms with a varying phosphate concentration from 3 mg/L to 18 mg/L, and the adsorption isotherms data are fitted well by Langmuir equation as compared with the Freundlich isotherm. The maximum phosphate adsorption (97.67 %) was obtained at a contact time of 120 min, an initial phosphate concentration of 10 mg/L, and a solution pH of 4. The pseudo second-order equation describes the experimental data has good agreement, with a correlation value of R2 = 0.99. The results obtained indicate that the environmentally available crushed concrete have a good adsorptive capacity for phosphate and shall be considered in future studies as test materials for phosphate removal from water in technical-scale experiment.

scholarly journals Adsorptive Removal of Phosphate from Aqueous Solutions Using Low-Cost Volcanic Rocks: Kinetics and Equilibrium Approaches

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1312
Author(s):  
Dereje Tadesse Mekonnen ◽  
Esayas Alemayehu ◽  
Bernd Lennartz
Keyword(s):  
Aqueous Solutions ◽  
Low Income ◽  
Low Cost ◽  
Volcanic Rocks ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Adsorptive Capacity ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Adsorptive Removal

The contamination of surface and groundwater with phosphate originating from industrial and household wastewater remains a serious environmental issue in low-income countries. Herein, phosphate removal from aqueous solutions was studied using low-cost volcanic rocks such as pumice (VPum) and scoria (VSco), obtained from the Ethiopian Great Rift Valley. Batch adsorption experiments were conducted using phosphate solutions with concentrations of 0.5 to 25 mg·L−1 to examine the adsorption kinetic as well as equilibrium conditions. The experimental adsorption data were tested by employing various equilibrium adsorption models, and the Freundlich and Dubinin-Radushkevich (D-R) isotherms best depicted the observations. The maximum phosphate adsorption capacities of VPum and VSco were calculated and found to be 294 mg·kg−1 and 169 mg·kg−1, respectively. A pseudo-second-order kinetic model best described the experimental data with a coefficient of correlation of R2 > 0.99 for both VPum and VSco; however, VPum showed a slightly better selectivity for phosphate removal than VSco. The presence of competitive anions markedly reduced the removal efficiency of phosphate from the aqueous solution. The adsorptive removal of phosphate was affected by competitive anions in the order: HCO3− >F− > SO4−2 > NO3− > Cl− for VPum and HCO3− > F− > Cl− > SO4−2 > NO3− for VSco. The results indicate that the readily available volcanic rocks have a good adsorptive capacity for phosphate and shall be considered in future studies as test materials for phosphate removal from water in technical-scale experiments.

Optimization of Crystallization of Magnesium Ammonium Phosphate: Initial Phosphate Concentration, PH and Reactants Molar Ratio

2013 ◽  
Vol 295-298 ◽  
pp. 1289-1292 ◽  
Author(s):  
Kai Huang ◽  
Li Ping Qiu ◽  
Jin Feng Meng ◽  
Dong Wang
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Ammonium Phosphate ◽  
Xrd Analysis ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Molar Ratio ◽  
Septic Tank ◽  
Magnesium Ammonium Phosphate ◽  
Magnesium Ammonium

By- products are widespread in the crystallization of magnesium ammonia phosphate (MAP) as the differences in reactive conditions which effects the forms and habits of crystals. The study focused on the supernatant from septic tank in order to achieve in-situ treatment. Based on the effluent, the optimization research of initial phosphate concentration and pH was investigated by using single factor analysis. The crystal products with different reaction condition were also characteristiced through the XRD analysis. The experimental results showed that the optimum reactants molar ratio of n(NH4+):n(Mg2+):n(PO43-) were 90:25:1, 4:1.6:1 and 3:1.4:1 when pH value was 9.5 with initial phosphate concentration 8mg/L, 50mg/L and 100mg/L, respectively. It was also observed that the phosphate removal rate increased with increasing the initial phosphate concentration or pH value. As the aging time increased, the removal rate was in parabolic curve with 30 minute at the highest point. The XRD analysis revealed that the best MAP crystal could be produced with initial phosphate concentration 50mg/L and pH 9.0.

scholarly journals Effective and selective removal of phosphate from water by the Co(II)-based adsorbent

2019 ◽  
Vol 1 (1) ◽  
pp. 134-144 ◽  
Author(s):  
Keke Han ◽  
Deng You ◽  
Penghui Shao ◽  
Liming Yang ◽  
Hui Shi ◽  
...  
Keyword(s):  
Water Management ◽  
Valence Electron ◽  
Langmuir Model ◽  
Phosphate Removal ◽  
Coordination Mechanism ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Batch Experiments ◽  
Phosphate Ions ◽  
Competing Ions

Abstract In this study, a novel Co(II)-based adsorbent Co-H2L is developed for the removal of phosphate. The batch experiments demonstrate that the Co-H2L possesses preferable ability of phosphate capture from water in mildly acidic to neutral pHs, with a maximum adsorption capacity of 194.44 mg P g−1. Adsorption isotherms for phosphate agree with the Langmuir model, suggesting a monolayer process. The mechanism for phosphate adsorption onto Co-H2L mainly followed the coordination mechanism, and the Co valence electron orbitals play the key role in the phosphate adsorption. In addition, the Co-H2L adsorbent can selectively remove phosphate ions in the presence of the competing ions (Cl−, NO3−, and SO42−) at higher concentrations. Our results therefore indicate that the Co(II)-based adsorbent is expected to find extensive applications in phosphate removal for water management.

Reduction of highly concentrated phosphate from aqueous solution using pectin-nanoscale zerovalent iron (PNZVI)

2016 ◽  
Vol 73 (11) ◽  
pp. 2689-2696 ◽  
Author(s):  
Hongyu Wang ◽  
Zhuocheng Zou ◽  
Xuelian Xiao ◽  
Dan Chen ◽  
Kai Yang
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Photoelectron Spectroscopy ◽  
Phosphate Removal ◽  
Zerovalent Iron ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Surface Areas ◽  
Nanoscale Zerovalent Iron ◽  
The Fourier Transform

Pectin-nanoscale zerovalent iron (PNZVI) has been studied as an effective phosphate adsorption material to remove highly concentrated phosphate from aqueous solution. Batch phosphate removal and equilibrium experiments were conducted in order to evaluate the effects of environmental factors such as pH, coexisting anions and ionic strengths on phosphate removal by PNZVI. The scanning electron microscope images of nanoscale zerovalent iron (NZVI) and PNZVI demonstrated that PNZVI exhibited larger specific surface areas than NZVI so that PNZVI had higher phosphate removal efficiency than NZVI. Equilibrium experiments showed that phosphate adsorption by PNZVI was well fitted with the Freundlich and Langmuir models. In addition, the maximum adsorption capacity reached 277.38 mgP/gPNZVI. The ionic strengths and common anions showed no significant effects on the process of phosphate adsorption by PNZVI. The phosphate removal efficiency increased to a peak value with pH increased from 2.0 to 5.0, then decreased with pH further increased from 5.0 to 10.0. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses of PNZVI and P-loaded PNZVI indicated that adsorption, rather than redox reaction, was the dominant mechanism for the removal of phosphate by PNZVI.

One-Pot Synthesis of Mesoporous MCM-41 with Different Functionalization Levels and their Adsorption Abilities to Phosphate

2012 ◽  
Vol 476-478 ◽  
pp. 1969-1973 ◽  
Author(s):  
Wei Ya Huang ◽  
Jun Yang ◽  
Yuan Ming Zhang
Keyword(s):  
Removal Rate ◽  
Langmuir Model ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Experiment Data ◽  
Sorption Equilibrium ◽  
One Pot ◽  
Adsorption Capacities ◽  
Mcm 41

Ethylenediamine (EDA) functionalized mesoporous MCM-41 particles displaying various functionalization levels have been prepared by one-pot method. The prepared samples were treated with Fe(III) to form cationic complexes inside MCM-41 pores (MCM-41-NN-Fe-x%, x=10, 20 and 30) for trapping phosphate from water. The prepared adsorbents were characterized by XRD, BET, TGA and elemental analysis, and their phosphate adsorption performances were studied. The results showed that the phosphate removal rate of all the prepared adsorbents were higher than 95% at the initial phosphate concentration of 2 ppm. Additionally, the Langmuir model was used to simulate the sorption equilibrium, and the results indicated that the experiment data agreed well with the Langmuir model. The maximum adsorption capacities calculated from the Langmuir model increased with the increase of diamino loadings in adsorbents, and the maximum adsorption capacities of MCM-41-NN-Fe-30% was 52.5 mg/g.

scholarly journals Cr(VI) Adsorption from Aqueous Solution by UiO-66 Modified Corncob

2021 ◽  
Vol 13 (23) ◽  
pp. 12962
Author(s):  
Hongzhong Xie ◽  
Yanlei Wan ◽  
Hao Chen ◽  
Guangcheng Xiong ◽  
Lingqing Wang ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Adsorption Capacity ◽  
Polluted Water ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Mechanism Analysis ◽  
Solution Ph ◽  
Isothermal Adsorption ◽  
Promising Application ◽  
Ph Range

To adsorb hexavalent chromium (Cr(VI)) in polluted water, this paper prepared a UiO-66 (Zr6O4(OH)4(BDC)12) modified granular corncob composite adsorbent by hydrothermal method with in situ loading of UiO-66 on pretreated corncob particles. The physicochemical properties of the synthesized samples were characterized. Batch adsorption experiments were conducted to investigate the adsorption process of aqueous Cr(VI) under various conditions (different ionic strength, pH and co-existing anions). The results showed that UiO-66 was successfully loaded on the modified corncob particles. The isothermal adsorption data of Cr(VI) adsorption by the UiO-66 modified corncob fit well with the Langmuir model with the maximum adsorption capacity of Cr(VI) on UiO-66@Corn+ being 90.04 mg/g. UiO-66 loading could increase Cr(VI) adsorption capacity of Corn+. The kinetic study showed that the equilibrium time for Cr(VI) adsorption on UiO-66 modified corncob was about 180 min and the kinetic data followed the pseudo-secondary kinetic model. The Cr(VI) adsorption capacity on UiO-66@Corn+ decreased with the increasing solution pH, and the optimum pH range was 4–6. The ionic strength has little effect on the Cr(VI) adsorption capacity, but the coexistence of CO32−, SO42− and PO43− in the solution could significantly decrease the equilibrium adsorption capacity of Cr(VI). The adsorption mechanism analysis showed that Cr(VI) was adsorbed on the surface of adsorbents through electrostatic attraction and was reduced further to the less toxic Cr(III) by the electron donor on the surface of adsorbent. The electrostatic interaction was the main force affecting the adsorption of Cr(VI) by UiO-66. UiO-66@Corn+ had an excellent removal efficiency of Cr(VI) and excellent reusability. UiO-66@Corn+ could effectively remove Cr(VI) from water and have a promising application.

scholarly journals Kinetic and Thermodynamic Studies on the Phosphate Adsorption Removal by Dolomite Mineral

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaoli Yuan ◽  
Wentang Xia ◽  
Juan An ◽  
Jianguo Yin ◽  
Xuejiao Zhou ◽  
...  
Keyword(s):  
Adsorption Kinetics ◽  
Removal Rate ◽  
Second Order ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Thermodynamic Studies ◽  
Pseudo Second Order ◽  
Second Order Model

The efficiency of dolomite to remove phosphate from aqueous solutions was investigated. The experimental results showed that the removal of phosphate by dolomite was rapid (the removal rate over 95% in 60 min) when the initial phosphate concentration is at the range of 10–50 mg/L. Several kinetic models including intraparticle diffusion model, pseudo-first-order model, Elovich model, and pseudo-second-order model were employed to evaluate the kinetics data of phosphate adsorption onto dolomite and pseudo-second-order model was recommended to describe the adsorption kinetics characteristics. Further analysis of the adsorption kinetics indicated that the phosphate removal process was mainly controlled by chemical bonding or chemisorption. Moreover, both Freundlich and Langmuir adsorption isotherms were used to evaluate the experimental data. The results indicated that Langmuir isotherm was more suitable to describe the adsorption characteristics of dolomite. Maximum adsorption capacity of phosphate by dolomite was found to be 4.76 mg phosphorous/g dolomite. Thermodynamic studies showed that phosphate adsorption was exothermic. The study implies that dolomite is an excellent low cost material for phosphate removal in wastewater treatment process.

Magnetically separable ZrO2@SiO2@Fe3O4 for selective phosphate removal from wastewater

2019 ◽  
Vol 26 (2) ◽  
pp. 88-96
Author(s):  
Baile Wu ◽  
Xiaoyan Li ◽  
Irene Man Chi Lo
Keyword(s):  
Magnetic Separation ◽  
Adsorption Kinetics ◽  
Separation Efficiency ◽  
Renewable Resource ◽  
Phosphate Removal ◽  
Water Bodies ◽  
Molar Ratio ◽  
Phosphate Adsorption ◽  
Confined Water ◽  
Design Effectiveness

Phosphorus (P), which is a non-renewable resource, has been extensively used in agricultural and industrial fields. However, the release of P into surface water through agricultural runoffs and wastewater can cause enrichment of P and eutrophication in confined water bodies. Hence, a novel technology that can remove phosphate (major species of P in water) from water bodies for eutrophication prevention and recover phosphate for minimising the loss of P resource is desired. Adsorption is a preferable approach for phosphate removal due to its simplicity of design, effectiveness even at low P concentrations, and potential for recovery. The use of zirconium-based adsorbents for phosphate removal from wastewater has received increasing attention. However, challenges remain to recover zirconium-based adsorbents. In this study, zirconium oxide-based superparamagnetic adsorbents (i.e. ZrO2@SiO2@Fe3O4) were developed for phosphate removal from wastewater. Magnetic separation efficiency, phosphate adsorption kinetics and isotherm, effects of coexisting anions and organic matters, and reusability are reported. The developed ZrO2@SiO2@Fe3O4 has an excellent magnetic separation efficiency of > 98%, fast adsorption kinetics, high adsorption capacity at low phosphate concentrations, and strong selectivity for phosphate even at a competitive anion (i.e. Cl-, NO3-, SO42- and HCO3-) to phosphate molar ratio of 100:1 and humic acid (HA) concentration of 100 mg C/L. Adsorption-desorption cyclic experiments demonstrated the good reusability of the ZrO2@SiO2@Fe3O4.

The Removal of Phosphate by Coal Gangue from Wastewater

2012 ◽  
Vol 209-211 ◽  
pp. 2005-2008 ◽  
Author(s):  
Fang Juan Zhang ◽  
Hua Yong Zhang ◽  
Lu Yi Zhang
Keyword(s):  
Waste Water ◽  
Adsorption Process ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Coal Gangue ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

The feasibility of coal gangue as an adsorbent for phosphate removal from wastewater was investigated. The results showed that the equilibrium data were well fit to Langmuir isotherm model and the maximum adsorption capacity calculated was 2.49 mg/g at 25°C. The adsorption process followed pseudo-second order model. And the practical waste water experiment indecated that the phosphate concentration of real sewage decreased from 0.625mg/L to 0.121mg/L. These results suggested that coal gangue can be used as an adsorbent to removal phosphate from wastewater.

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