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 Efficient and Selective Adsorption of Gold Ions from Wastewater with Polyaniline Modified by Trimethyl Phosphate: Adsorption Mechanism and Application

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 652 ◽  
Author(s):  
Wang ◽  
Zhao ◽  
Wang ◽  
Zhang ◽  
Zhang
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Process ◽  
Selective Adsorption ◽  
Interaction Mechanism ◽  
Single Layer ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Trimethyl Phosphate ◽  
Selective Recovery

The selective recovery of gold from wastewater is necessary because it is widely used in various fields. In this study, a new polymeric adsorbent (TP-AFC) was prepared by modifying polyaniline with trimethyl phosphate for the selective recovery of gold from wastewater. Bath experiments were carried out to explore the adsorption capacity and mechanism. The optimum pH of adsorption is 4. The adsorption equilibrium is reached at 840 min. The maximum adsorption capacity is 881 mg/g and the adsorption was a spontaneous endothermic process. The adsorption process fitted well with pseudo second-order kinetic and the Langmuir-models. The single-layer chemisorption governed the adsorption process. In addition, the application in wastewater indicated that the interfering ions had no effect on the adsorption of gold ions. TP-AFC has good selectivity. The interaction mechanism was mainly ion exchange and complexation. In general, TP-AFC was successfully prepared and has an excellent future in practical application.

scholarly journals Adsorptive removal of phosphate by a Fe–Mn–La tri-metal composite sorbent: Adsorption capacity, influence factors, and mechanism

2020 ◽  
Vol 38 (7-8) ◽  
pp. 254-270
Author(s):  
Yuanrong Zhu ◽  
Xianming Yue ◽  
Fazhi Xie
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Phosphate Removal ◽  
Maximum Adsorption Capacity ◽  
Hydroxyl Groups ◽  
Metal Composite ◽  
Order Kinetic ◽  
Composite Sorbent ◽  
Composite Adsorbent

Reducing input of phosphorus is the key step for control of eutrophication and algal blooming in freshwater lakes. Adsorption technology is a cost-effective technology for phosphate removal in water for the purpose. Thus, in this study, a novel Fe–Mn–La tri-metal composite sorbent was developed, and then evaluated for phosphate removal. The results showed that the maximum adsorption capacity could be approached to 61.80 mg g−1 at 25°C under pH of 6.03. Adsorption of phosphate by Fe–Mn–La tri-metal composite adsorbent fitted better by pseudo-second-order kinetic equation and Langmuir model, which suggested that the adsorption process was surface chemical reactions and mainly in a monolayer coverage manner. The thermodynamic study indicated that the adsorption reaction was an endothermic process. The phosphate removal gradually decreased with the increasing of pH from 3.02 to 11.00. The sequence of coexisting anions competing with phosphates was that CO32− > Cl− > SO42− > NO3−. Dissolved organic matter, fulvic acid as a representative, would also decrease adsorption capacities of phosphate by Fe–Mn–La tri-metal composite adsorbents. Adsorption capacity would be decreased with increasing addition of adsorbents, while removal efficiency would be increased in this process. The Fe–Mn–La tri-metal composite adsorbent showed a good reusability when applied to removal of dissolved phosphate from aqueous solutions. The Fourier transform infrared spectrometer and X-ray photoelectron spectroscopy analyses indicated that some hydroxyl groups (–OH) on the surface of adsorbent were replaced by the adsorbed PO43−, HPO42−, or H2PO4−. Aggregative results showed that the novel Fe–Mn–La tri-mental composite sorbent is a very promising adsorbent for the removal of phosphate from aqueous solutions.

Synthesis and Characterization of Zeolite X Obtained from Coal Gangue for Adsorption of Cu2+

2021 ◽  
Vol 13 (8) ◽  
pp. 1512-1520
Author(s):  
MiaoSen Zhang ◽  
SiYang Wang ◽  
Zheng Hu ◽  
RunZe Zhang ◽  
XiaoLi Wang
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Kinetics ◽  
Ph Value ◽  
Copper Ions ◽  
Removal Rate ◽  
Coal Gangue ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Zeolite X ◽  
Initial Ph

China is a big coal producing country, there are a lot of coal gangue piled up. The zeolite X was synthesized by alkali melting and hydrothermal method based on the coal gangue from Chifeng city, Inner Mongolia. The obtained zeolite X sample is characterized by X-ray diffraction, SEM, EDS spectrum and IR which showed the X zeolite is an octahedral structure with complete crystal shape and uniform grain size. The results of BET showed the specific surface area of zeolite X is 354.8 m2/g and the minimum pore size is 3.8 nm which indicated that the zeolite X belongs to mesoporous materials. The adsorption conditions of the zeolite X adsorbent on copper ions were optimized. A solution containing Cu2+ ions with an initial concentration of 300 mg/L was added to the zeolite X with a dosage of 0.1 g and the initial pH value of the solution was adjusted to 6. Then the solution was oscillated for 120 min at 225 r/min. The maximum adsorption capacity and removal rate were 148.6 mg/g and 99.1%, respectively. The adsorption mechanism was discussed by adsorption kinetics and thermodynamics. The quasi-second order kinetic equation can be well used to describe the adsorption kinetics of zeolite X to Cu2+ (R2 = 0.9994) and Langmuir can well describe the adsorption behavior of zeolite X to Cu2+ (R2 = 0.9995) which showed the adsorption is a monolayer of chemical adsorption. The adsorption capacity of zeolite X to Cu2+ is about 4.0 times that of coal gangue, indicating that the zeolite X has good adsorption capacity.

scholarly journals Synthesis of Nanocellulose Aerogels and Cu-BTC/Nanocellulose Aerogel Composites for Adsorption of Organic Dyes and Heavy Metal Ions

2021 ◽  
Author(s):  
Nuhaa Shaheed ◽  
Shahrzad Javanshir ◽  
Mohammad G. Dekamin ◽  
Mohammad Reza Naimi-Jamal
Keyword(s):  
Adsorption Capacity ◽  
Inductively Coupled Plasma ◽  
Organic Dyes ◽  
Precursor Solution ◽  
Optical Emission ◽  
Nanofibrillated Cellulose ◽  
Emission Spectrometry ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Hierarchical Porous

Abstract MOFs compounds have great adsorption potential and catalysis applications. However, the powdery morphology limits its applications. To overcome this problem, they can be trapped in a flexible aerogel matrix to form hierarchical porous structures. In this work, Cu-BTC/CNC (crystalline nanocellulose) and Cu-BTC/NFC (nanofibrillated cellulose) aerogel composites were synthesized using a direct mixing method by the addition of Cu-BTC powder to the liquid precursor solution followed by gelation and freeze-drying. Also, pure CNC and NFC aerogels were synthesized using cellulose isolated from peanut shells. All structure and morphology were scrutinized by Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD). The adsorption ability of pure CNC and Cu-BTC/NFC for Congo Red (CR) and Mn7 + was studied and determined by the UV-Vis spectrophotometry and inductively-coupled plasma optical emission spectrometry (ICP-OES). The results revealed that Cu-BTC/NFC has excellent adsorption capacity for CR. The adsorption process is well described by the pseudo-second-order kinetic model and Langmuir isotherm, with a maximum adsorption capacity of 39 mg/g for CR. Both CNC and Cu-BTC/NFC act as a solid monolithic reducer and remove MnO4- from aqueous solution by reducing them to manganese dioxide, without releasing any side product.

Adsorption Characteristic of U(VI) on Fe-Immobilized Bentonite

2013 ◽  
Vol 639-640 ◽  
pp. 1300-1306
Author(s):  
Zhen Ping Tang ◽  
Hui Ling ◽  
Shui Bo Xie ◽  
S.Y. Li ◽  
J.S. Wang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Mechanism ◽  
Ph Value ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
Adsorption Characteristic ◽  
Order Kinetic Equation

Fe-immobilized bentonite, prepared with bentonite and FeCl3 was used for the adsorption of uranium(VI) in this study, solution pH, ion strength, contact time and temperature were investigated, structural characterization of Fe-immobilized bentonite was assayed by X-ray Diffraction and Fourier Transform Infrared Spectroscopy. Results indicated that the adsorption capacity were strongly affected by the solution pH and ion strength, the adsorption efficiency was 91.8% when pH value was 6 and ion strength was 0.01 mol•L-1, higher or lower pH did not favor the U(VI) adsorption. The adsorption mechanism was discussed by the views of reactive kinetics and thermodynamics along with Scanning Electron Microscope. The adsorption kinetics process was fitted well with the second-order kinetic equation, when the initial U(VI) concentration was less than 38.08mg/L, Langmuir equations could describe the adsorption isotherm of U(VI) well with the maximum adsorption capacity of 169.5mg/g at 303K

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.  

Adsorption of Phosphate onto Slag from Aqueous Solution

2012 ◽  
Vol 550-553 ◽  
pp. 2255-2258
Author(s):  
Bing Bing Liu ◽  
Hua Yong Zhang ◽  
Lu Yi Zhang
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Langmuir Model ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
High Adsorption ◽  
Pseudo Second Order

Phosphate adsorption from aqueous solution using slag was investigated as the function of pH, contact time and adsorbent dosage. The results showed that the optimum value of pH was 2. Both Langmuir isotherm and Freundlich isotherm model were fit to describe the phosphate adsorption, and the maximum adsorption capacity from Langmuir model calculated was 9.09 mg/L. The adsorption process on slag followed pseudo second-order kinetic. Due to the relatively high adsorption capacity, the slag has the potential for application to removal phosphate from wastewater.

scholarly journals Chitosan Fiber as Green Material for Removing Cr(VI) and Cu(II) Contaminants:Adsorption Properties,Kinetics and Machanism

2021 ◽  
Author(s):  
shujie Zhang ◽  
Yating Zhang ◽  
Lisong Fu ◽  
Mengke Jing
Keyword(s):  
Adsorption Capacity ◽  
Ph Value ◽  
Copper Ions ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Chemical Adsorption ◽  
Adsorption Effect ◽  
Green Material ◽  
Chromium Ions ◽  
Chitosan Fiber

Abstract Chitosan (CS) fiber is used as a new green material to remove Cu(II) and Cr(VI) in wastewater.Varying factors, including pH value, dosage of CS, reaction time and original Cr (VI) contents and Cu(II) were studied to investigate the Cr (VI) and Cu(II) removal efficiency.The adsorption of two metal ions by chitosan fiber conforms to the second-order kinetic equation, and can be fitted with Langmuir isotherms. The adsorption process is a spontaneous thermal reaction with both physical adsorption and chemical adsorption, and copper ions reach adsorption equilibrium. It takes longer than chromium ions, but the adsorption effect of copper ions is better. The maximum actual adsorption capacity of copper ions is 539.6 mg/g, and the maximum adsorption capacity of chromium ions is 75 mg/g. SEM, FTIR and XRD were used to characterize the physicochemical properties of CS fiber. The result shows that the complex process of the Cr (VI) and Cu(II) removal involves physical and chemical adsorption, CS fiber have exerted significant role in Cr (VI) and Cu(II) removal.

scholarly journals Granular ferric hydroxide adsorbent for phosphate removal: demonstration preparation and field study

2015 ◽  
Vol 72 (12) ◽  
pp. 2179-2186 ◽  
Author(s):  
Bei Zhao ◽  
Yu Zhang ◽  
Xiaomin Dou ◽  
Hongying Yuan ◽  
Min Yang
Keyword(s):  
Adsorption Capacity ◽  
Active Sites ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Ferric Hydroxide ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Poly Vinyl Alcohol ◽  
Secondary Effluents ◽  
High Phosphate

Ferric hydroxide (FHO), which has high phosphate adsorption capacity, was prepared by precipitation at industrial scale and then fabricated via the drum granulation method with cross-linked poly(vinyl alcohol) as the binder. The optimum binder/FHO powder ratio was 0.6 for producing a granular adsorbent with a high phosphate adsorption capacity and stability. The Langmuir maximum adsorption capacities of powder and granular FHOs were 74.07 mg g−1 and 56.18 mg g−1 at pH 7.0 ± 0.2, respectively, which were higher than those of other reported phosphate adsorbents under neutral or acidic conditions. Phosphate-loaded granular FHO could be regenerated by NaOH solution. Columns containing the granular FHO were used for phosphate removal from ozonated secondary effluents of a municipal wastewater treatment plant at space velocity (SV) of 2 and 5 h−1. During more than 2 months’ operation, the average removal percentage of PO43– was more than 90% and the turbidity and concentration of CODMn in the effluents were lower than in the influents. In addition, energy dispersive X-ray results suggested that active sites inside the granular FHO were available for phosphate removal. The results demonstrated that granular FHO can be applied as an assist technology for phosphate removal from secondary effluents.

scholarly journals Bentonite surface modification and characterization for high selective phosphate adsorption from aqueous media and its application for wastewater treatments

2016 ◽  
Vol 7 (2) ◽  
pp. 175-186 ◽  
Author(s):  
S. Yaghoobi-Rahni ◽  
B. Rezaei ◽  
N. Mirghaffari
Keyword(s):  
Adsorption Capacity ◽  
Aqueous Media ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Modified Bentonite ◽  
X Ray ◽  
Langmuir Isotherm Model ◽  
Better Than

Raw and modified bentonite has been used to develop effective sorbents to remove phosphate from aqueous solution. Acid thermoactivation, Rewoquate, Irasoft, calcium, Fe and Al were employed to treat the bentonite. Results show that samples adsorption capacity for phosphate is in the order of, unmodified bentonite = acid thermoactivation < Rewoquate < calcium ≅ Irasoft < Fe < Al ≅ Fe-Al. The phosphate adsorption with Fe-Al-bentonite (FAB) modification was more than 99% and the phosphate removal reached the peak value in the initial 30 min. The phosphate adsorption of FAB was pH independent in the range of 2–10. The common coexisting ions in wastewater have no effect on the phosphate adsorption. The phosphate adsorption results were very well fitted in the Freundlich and Langmuir isotherm model and the maximum adsorption capacity was 8.33 mg P/g at pH 6.5 for 1 hour, which was better than similar modified bentonite with low time and Fe-Al consumption. FAB was characterized by scanning electron microscopy, X-ray diffraction, X-ray fluorescence and Fourier transform infrared. Therefore, the results confirm that FAB is a selective phosphate sorbent and environmentally friendly for its potential application for phosphate removal from wastewater.

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