scholarly journals Synthesis of Fe/Mg-Biochar Nanocomposites for Phosphate Removal

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 816 ◽  
Author(s):  
Xuefeng Tao ◽  
Tao Huang ◽  
Bo Lv
Keyword(s):  
Adsorption Capacity ◽  
Cost Effective ◽  
Phosphate Removal ◽  
Point Of Zero Charge ◽  
Molar Ratio ◽  
Walnut Shell ◽  
Phosphate Adsorption ◽  
Isothermal Adsorption ◽  
Freundlich Model ◽  
Magnetic Biochar

Magnetic biochar derived from agricultural biomass has been recognized as a cost-effective biochar sorbent for phosphate removal. This study evaluated the use of novel Fe/Mg-biochar nanocomposites (WBC1x), prepared by impregnating ground walnut shell in a solution with a different molar ratio of Fe2+ to Mg2+, then pyrolyzing slowly, at a temperature of 600 °C, to remove phosphate. The results showed that MgO and Fe3O4 were loaded onto the biochar successfully through the impregnation-pyrolysis method and the composites were able to be separated easily by magnetic field. Meanwhile, a higher surface area and point of zero charge on WBC1x were observed compared to the non-magnetic biochar (WBC). Moreover, the isothermal adsorption and kinetics data further suggested the that phosphate adsorption onto WBC1x resulted from chemisorption. Additionally, the maximum phosphate adsorption capacity of WBC1x was 6.9 mg.g−1, obtained though the Langmuir–Freundlich model, which was threefold higher than WBC, where MgO addition could enhance the adsorption capacity of WBC1x markedly by improving the surface charge.

scholarly journals Study of phosphate removal from aqueous solution by zinc oxide

2015 ◽  
Vol 13 (3) ◽  
pp. 704-713 ◽  
Author(s):  
Zhen Luo ◽  
Suiyi Zhu ◽  
Zhongmou Liu ◽  
Jiancong Liu ◽  
Mingxin Huo ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Zinc Oxide ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Chloride Ions ◽  
Phosphate Removal ◽  
Point Of Zero Charge ◽  
Phosphate Adsorption ◽  
Solution Ph ◽  
Base Interaction

Zinc oxide (ZnO) was synthesized and used to investigate the mechanism of phosphate removal from aqueous solution. ZnO particles were characterized by X-ray diffraction, scanning electron microscope and Fourier transform infrared spectroscopy before and after adsorption. Batch experiments were carried out to investigate the kinetics, isotherms, effects of initial pH and co-existing anions. The adsorption process was rapid and equilibrium was almost reached within 150 min. The adsorption kinetics were described well by a pseudo-second-order equation, and the maximum phosphate adsorption capacity was 163.4 mg/g at 298 K and pH ∼6.2 ± 0.1. Thermodynamic analysis indicated the phosphate adsorption onto ZnO was endothermic and spontaneous. The point of zero charge of ZnO was around 8.4 according to the pH-drift method. Phosphate adsorption capacity reduced with the increasing initial solution pH values. The ligand exchange and Lewis acid-base interaction dominated the adsorption process in the lower and the higher pH range, respectively. Nitrate, sulfate and chloride ions had a negligible effect on phosphate removal, while carbonate displayed significant inhibition behavior.

scholarly journals Kinetic analysis of sucrose activated carbon for nutrient removal in water

2020 ◽  
Vol 3 (1) ◽  
pp. 208-220
Author(s):  
Sara Jamaliniya ◽  
O. D. Basu ◽  
Saumya Suresh ◽  
Eustina Musvoto ◽  
Alexis Mackintosh
Keyword(s):  
Activated Carbon ◽  
Kinetic Analysis ◽  
Adsorption Capacity ◽  
Nitrate Removal ◽  
Freundlich Isotherm ◽  
Langmuir Model ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Isotherm Models ◽  
Nitrate Adsorption

Abstract A renewable, green activated carbon made from sucrose (sugar) was compared with traditional bituminous coal-based granular activated carbon (GAC). Single and multi-component competitive adsorption of nitrate and phosphate from water was investigated. Langmuir and Freundlich isotherm models were fitted to data obtained from the nitrate and phosphate adsorption experiments. Nitrate adsorption fits closely to either Freundlich or Langmuir model for sucrose activated carbon (SAC) and GAC with a Langmuir adsorption capacity of 7.98 and 6.38 mg/g, respectively. However, phosphate adsorption on SAC and GAC demonstrated a selective fit with the Langmuir model with an adsorption capacity of 1.71 and 2.07 mg/g, respectively. Kinetic analysis demonstrated that adsorption of nitrate and phosphate follow pseudo-second-order kinetics with rate constant values of 0.061 and 0.063 g/(mg h), respectively. Competitive studies between nitrate and phosphate were demonstrated in preferential nitrate removal with GAC and preferential phosphate removal with SAC. Furthermore, nitrate and phosphate removals decreased from 75% removal to 35% removal when subject to multi-component solutions, which highlights the need for adsorption analysis in complex systems. Overall, SAC proved to be competitive with GAC in the removal of inorganic contaminants and may represent a green alternative to coal-based activated carbon.

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.

Adsorptive removal of phosphate from aqueous solutions using lead–zinc tailings

2013 ◽  
Vol 67 (5) ◽  
pp. 983-988 ◽  
Author(s):  
Shuncai Wang ◽  
Rongzhuo Yuan ◽  
Xueyong Yu ◽  
Chaojie Mao
Keyword(s):  
Laboratory Experiments ◽  
Low Cost ◽  
Ph Effect ◽  
Cost Effective ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Isotherm Models ◽  
Effective Removal ◽  
Elovich Equation ◽  
Lead Zinc

This study explored the feasibility of utilizing lead–zinc tailings for phosphate removal in laboratory experiments. The adsorption isotherm, kinetics and pH effect were examined in batch experiments. The Freundlich and Langmuir isotherm models were used for data fitting. The adsorption kinetics can be best described by the simple Elovich equation. The phosphate adsorption tends to decrease with the increase of pH, from 0.37 mg P/g at pH 2.05 to 0.12 mg P/g at pH 7.01, and tends to increase from 0.12 mg P/g at pH 7.01 to 0.64 mg P/g at pH 12.52. The actual phosphate removal on the tailings could be a consequence of adsorption and precipitation reactions with Fe, Al and Ca. Due to their low cost, this type of tailings has the potential to be utilized for cost-effective removal of phosphate from wastewater.

scholarly journals Single and Competitive Adsorption Behaviors of Cu2+, Pb2+ and Zn2+ on the Biochar and Magnetic Biochar of Pomelo Peel in Aqueous Solution

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 868
Author(s):  
Qianlan Wu ◽  
Shuzhen Dong ◽  
Lijun Wang ◽  
Xiaoyun Li
Keyword(s):  
Adsorption Capacity ◽  
Competitive Adsorption ◽  
Separation Efficiency ◽  
Engineering Application ◽  
Cost Effective ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Magnetic Biochar ◽  
Pomelo Peel ◽  
Ternary Metal

As an environment-friendly material, biochar has been used to remove heavy metals from wastewater, and the development of cost-effective biochar has been an emerging trend. However, limited studies consider the competitive adsorption of co-existing metals and the separation efficiency of absorbent and solution after adsorption. In this study, pomelo peel was used to prepare biochar (BC) and magnetic biochar (MBC) at different temperatures. Then, the physicochemical properties of the biochars were characterized and the adsorption characteristics of Cu2+, Pb2+, and Zn2+ on the biochars in single, binary, and ternary metal systems were investigated. The results showed that both pyrolysis temperature and magnetization could affect the adsorption capacity of biochar. The adsorption kinetic and thermodynamic processes could be well described by the pseudo-second-order kinetic model and Langmuir model. The adsorption isotherm types of Pb2+ and Zn2+ changed in the binary metal condition. The competitive adsorption order of three heavy metal ions in ternary metal adsorption was Pb2+ > Cu2+ > Zn2+. The MBC of 500 °C showed a good adsorption capacity to Pb2+ in the co-existing environment, and the maximum adsorption capacity was 48.74 mmol g−1. This study also provided technical support for the utilization of pomelo peel and the engineering application of biochar.

scholarly journals Preparation and Characterization of Physicochemical Properties of Spruce Cone Biochars Activated by CO2

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3859
Author(s):  
Katarzyna Jedynak ◽  
Barbara Charmas
Keyword(s):  
Adsorption Capacity ◽  
Nitrogen Adsorption ◽  
Cost Effective ◽  
Point Of Zero Charge ◽  
Physical Activation ◽  
Energy Dispersion Spectroscopy ◽  
Surface Areas ◽  
Activated Biochar ◽  
Developed Surface ◽  
Nh3 Adsorption

In this study the pyrolysis of Norway spruce cones, a lignocellulosic biomass was made. The biochar product was obtained by means of the physical activation method. CO2 was used as the activating gas. The surface properties of biochars were characterized by the nitrogen adsorption/desorption isotherms, scanning electron microscopy (SEM/EDS), X-ray fluorescence energy dispersion spectroscopy (ED-XRF), thermal analysis (TGA/DTA), infrared spectroscopy (ATR FT-IR), Raman spectroscopy and the Boehm’s titration method as well as the point of zero charge (pHpzc). The adsorption capacity and the possibility of ammonia desorption (TPD) were also examined. It has been shown that spruce cones can be successfully used as a cheap precursor of well-developed surface biochars, characterized by a large pore volume and good sorption properties. All obtained activated biochars exhibit a largely microporous structure and an acidic character surface. The investigated activated materials have the specific surface areas from 112 to 1181 m2 g−1. The maximum NH3 adsorption capacity of the activated biochar was determined to be 5.18 mg g−1 (88.22 mmol g−1) at 0 °C. These results indicate the applicability of spruce cones as a cheap precursor for the sustainable production of the cost-effective and environmentally friendly biochar adsorbent.

scholarly journals CHARACTERIZATION AND ADSORPTION CAPACITY OF AMINE-SIO2 MATERIAL FOR NITRATE AND PHOSPHATE REMOVAL

2019 ◽  
Vol 57 (4) ◽  
pp. 492
Author(s):  
Phan Phuoc Toan ◽  
Nguyen Trung Thanh ◽  
Nguyen Nhat Huy ◽  
Le Ngoc Hang ◽  
Le Tri Thich
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Stable Performance ◽  
Regeneration Times ◽  
Sem Analyses

Amine-SiO2 material was synthesized and applied as a novel adsorbent for nitrate and phosphate removal from aqueous solution. The characterization of Amine-SiO2 were done by using TGA, FTIR, BET, and SEM analyses. Results showed that Amine-SiO2 had higher nitrate and phosphate adsorption capacity of 1.14 and 4.16 times, respectively, than commercial anion exchange resin (Akualite A420). In addition, Amine-SiO2 also had good durability with stable performance after at least 10 regeneration times, indicating that this material is very promising for commercialization in the future as an adsorbent for water treatment.

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.

scholarly journals Enhanced Phosphate Removal from Water by Honeycomb-Like Microporous Lanthanum-Chitosan Magnetic Spheres

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1659 ◽  
Author(s):  
Rong Cheng ◽  
Liang-Jie Shen ◽  
Ying-Ying Zhang ◽  
Dan-Yang Dai ◽  
Xiang Zheng ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Active Sites ◽  
Lanthanum Oxide ◽  
Ph Value ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Magnetic Spheres ◽  
Hierarchical Porous

The removal of phosphate in water is crucial and effective for control of eutrophication, and adsorption is one of the most effective treatment processes. In this study, microporous lanthanum-chitosan magnetic spheres were successfully synthetized and used for the removal of phosphate in water. The characterization results show that the dispersion of lanthanum oxide is improved because of the porous properties of the magnetic spheres. Moreover, the contact area and active sites between lanthanum oxide and phosphate were increased due to the presence of many honeycomb channels inside the magnetic spheres. In addition, the maximum adsorption capacity of the Langmuir model was 27.78 mg P·g−1; and the adsorption kinetics were in good agreement with the pseudo-second-order kinetic equation and intra-particle diffusion model. From the results of thermodynamic analysis, the phosphate adsorption process of lanthanum-chitosan magnetic spheres was spontaneous and exothermic in nature. In conditional tests, the optimal ratio of lanthanum/chitosan was 1.0 mmol/g. The adsorption capacity of as-prepared materials increased with the augmentation of the dosage of the adsorbent and the decline of pH value. The co-existing anions, Cl− and NO3− had little effect on adsorption capacity to phosphate, while CO32− exhibited an obviously negative influence on the adsorption capacity of this adsorbent. In general, owing to their unique hierarchical porous structures, high-adsorption capacity and low cost, lanthanum-chitosan magnetic spheres are potentially applicable in eutrophic water treatment.

scholarly journals Phosphate sequestration and recovery from eutrophication water by in situ magnesium phosphate formation

2020 ◽  
Vol 20 (6) ◽  
pp. 2226-2236
Author(s):  
Fazhi Xie ◽  
Kang Song ◽  
Shixiong Geng ◽  
Lu Li
Keyword(s):  
Adsorption Capacity ◽  
Phosphate Removal ◽  
Magnesium Phosphate ◽  
Phosphate Adsorption ◽  
Phosphorus Concentration ◽  
Eutrophic Lakes ◽  
Phosphorus Adsorption ◽  
X Ray ◽  
Xps Characterization

Abstract Phosphate removal from eutrophic lakes has caused wide concern in the world, while an effective process is still lacking. A novel synthetic magnesium carbonate with spherical flower-like structure (MCSF) was prepared. Its performance for phosphorus adsorption from a eutrophic lake by in situ magnesium phosphate formation was tested and characterized. The effect of initial phosphorus concentration, adsorption time, adsorption dose, temperature, ionic strength and pH on phosphorus adsorption by MCSF was investigated. Results showed that higher initial phosphorus concentration and longer adsorbing time could improve the adsorption capacity. The maximum sorption capacity was 143.27 mg/g under initial pH value 7.0. The phosphate adsorption process was fitted with the Langmuir isotherm model and pseudo-second-order model. Thermodynamic parameter values revealed that the sorption process at 298–318 K was spontaneous and endothermic. The X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) characterization of MCSF revealed that electrostatic attraction and chemical conversion were the major contributors for phosphate adsorption. MCSF releases magnesium ions from its surface and rapidly combines with phosphate to form insoluble magnesium phosphate precipitate. The prepared MCSF has the potential to be used for the restoration of eutrophic lakes by removing phosphate with higher adsorption capacity.

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