scholarly journals Adsorption performances and electrochemical characteristics of methyl blue onto magnesium-zinc ferrites

2021 ◽  
Author(s):  
Shuping Xu ◽  
Dandan Liu ◽  
Aihua Liu ◽  
Fu Sun ◽  
Shengying Pan ◽  
...  
Keyword(s):  
Calcination Temperature ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Methyl Blue ◽  
Maximum Adsorption Capacity ◽  
Electrochemical Characteristics ◽  
Cycle Times ◽  
Grain Sizes ◽  
Pseudo Second Order ◽  
Controllable Preparation

Abstract A novel and facile rapid combustion approach was developed for the controllable preparation of small size and easy recovery magnesium-zinc ferrites for methyl blue (MB) removal in dye solution. The effects of prepared criteria of x value, calcination temperature, and the amount of ethanol on the average grain sizes and magnetic property were reviewed. The characterization results displayed that Mg0.5Zn0.5Fe2O4 nanoparticles met the expectations of the experiment at the calcination temperature of 400℃ with absolute ethanol volume of 20 mL, and they were selected to remove MB. The adsorption process belonged to chemical adsorption on the basis of the pseudo-second-order model. The electrochemical characteristics of MB onto the prepared nanoparticles were analyzed by cyclic voltammetry (CV). The influences of pH and cycle times on the removal efficiency were investigated. When the pH went beyond 3, the removal efficiency of MB onto the magnetic Mg0.5Zn0.5Fe2O4 nanoparticles maintained above 99%，the maximum adsorption capacity was 318.18 mg/g. After seven cycles, the relative removal rate of MB remained 96% of the first one.

Removal of acetaminophen (ACT) from aqueous solution by using nanosilica adsorbent: experimental study, kinetic and isotherm modeling

2020 ◽  
Vol 49 (1) ◽  
pp. 55-62
Author(s):  
Akbar Eslami ◽  
Zahra Goodarzvand Chegini ◽  
Maryam Khashij ◽  
Mohammad Mehralian ◽  
Marjan Hashemi
Keyword(s):  
Removal Rate ◽  
Synthesis Method ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Content Type ◽  
Bet Analysis ◽  
Pseudo Second Order

Purpose A nanosilica adsorbent was prepared and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and BET. Design/methodology/approach The optimum conditions for the highest adsorption performance were determined by kinetic modeling. The adsorbent was used for the adsorption of acetaminophen (ACT), and the parameters affecting the adsorption were discussed like pH, initial concentration, contact time and adsorbent dosage. The adsorbent have been characterized by SEM, XRD and BET analysis. The kinetic models including pseudo-first-order and pseudo-second-order with Langmuir and Freundlich isotherm models were applied to investigate the kinetic and isotherms parameters. Findings The adsorption of ACT increased to around 95% with the increase of nanosilica concentration to 30 g/L. Moreover, the adsorption process of ACT follows the pseudo-second-order kinetics and the Langmuir isotherm with the maximum adsorption capacity of 609 mg/g. Practical implications This study provided a simple and effective way to prepare of nanoadsorbents. This way was conductive to protect environmental and subsequent application for removal of emerging pollutants from aqueous solutions. Originality/value The novelty of the study is synthesizing the morphological and structural properties of nanosilica-based adsorbent (specific surface area, pore volume and size, shape and capability) and improving its removal rate through optimizing the synthesis method; and studying the capability of synthesis of nanosilica-based adsorbent for removal of ACT as a main emerging pharmaceutical water contaminant.

The Treatment of Acid Copper-Containing Wastewater by Eggshell-Flyash System

2011 ◽  
Vol 183-185 ◽  
pp. 967-970
Author(s):  
Tao Liu
Keyword(s):  
Heavy Metal ◽  
Calcination Temperature ◽  
Removal Efficiency ◽  
Treatment Effect ◽  
Ph Value ◽  
Removal Rate ◽  
Good Treatment ◽  
Egg Shells ◽  
Egg Shell ◽  
Application Prospects

Removal efficiency of heavy metal Cu from acid wastewater using egg shell as adsorbent was investigated. The influence of calcination temperature and dosage of egg shell, as well as pH value on the removal efficiency were discussed to obtain the optimum removal condition. The results show that the removal rate of lead would achieve the best result of 99.56% when we use the egg shells calcined at 400°C,2h, and the content of egg shells is 30g/L, pH=3.0.Using eggshells to treat acid chrome-containing wastewater is simple and easy to be operated, which has application prospects for the process and good treatment effect.

scholarly journals Porous Multifunctional Phenylcarbamoylated-β-Cyclodextrin Polymers for Rapid Removal of Organic Pollutants

2021 ◽  
Author(s):  
He Wang ◽  
Congzhi Liu ◽  
Xiaofei Ma ◽  
Yong Wang
Keyword(s):  
Organic Contaminants ◽  
Adsorption Process ◽  
Removal Rate ◽  
Pollutant Removal ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Monolayer Adsorption ◽  
Pseudo Second Order ◽  
Rapid Removal ◽  
Cyclodextrin Polymers

Abstract In this work, a series of porous multifunctional cyclodextrin (CD) polymers were fabricated using tetrafluoroterephthalonitrile (TFTPN) as the rigid crosslinker for the condensation of different functional phenylcarbamoylated-β-cyclodextrin derivatives to afford three preliminary polymerized adsorption materials such as poly nitrophenylcarbamoylated-β-cyclodextrin (NO2-CDP), poly trifluoromethylphenylcarbamoylated-β-cyclodextrin (F-CDP), poly chlorophenylcarbamoylated-β-cyclodextrin polymers (Cl-CDP) and a mix β- cyclodextrin polymer (X-CDP) prepared via a secondary crosslinking procedure of the above three materials. The X-CDP preparation process connects the `pre-formed nanoparticles and increases the presence of linkers inside the particles. At the same time, X-CDP exhibited porous structure with various functional groups such as nitro, chlorine, fluorine and hydroxyl. Those special characteristics render this material with good adsorption ability towards various pollutants in water, including tetracycline, ibuprofen, dichlorophenol, norfloxacin, bisphenol A, naphthol. Especially the maximum adsorption capacity for tetracycline at equilibrium reached 230.15 mg·g− 1, which is competitive with the adsorption capacities of other polysaccharides adsorbents. X-CDP removed organic contaminants much more quickly than other adsorbents, reaching almost ~ 95% of its equilibrium in only 30 s. The main adsorption process of the pollutants by X-CDP fitted the pseudo-second-order kinetic and Langmuir isotherm well, indicating that the adsorption process is monolayer adsorption. Moreover, X-CDP possessed the good reusability where the pollutant removal rate was only reduced 8.3% after five cycles.

scholarly journals Effects of Process Parameters on Material Removal in Vibration-Assisted Polishing of Micro-Optic Mold

Micromachines ◽  
2018 ◽  
Vol 9 (7) ◽  
pp. 349 ◽  
Author(s):  
Jiang Guo ◽  
Hirofumi Suzuki
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Removal Efficiency ◽  
Process Parameters ◽  
Material Removal ◽  
Removal Rate ◽  
Grain Sizes ◽  
Tool Influence Function ◽  
Polishing Pressure ◽  
Lower Material

Process parameter conditions such as vibrating motion, abrasives, pressure and tool wear play an important role in vibration-assisted polishing of micro-optic molds as they strongly affect material removal efficiency and stability. This paper presents an analytical and experimental investigation on the effects of process parameters, aimed at clarifying interrelations between material removal and process parameters which affect polishing quantitatively. The material removal rate (MRR) and surface roughness which represent the polishing characteristics were examined under different vibrating motions, grain sizes of abrasives and polishing pressure. The effects of pressure and tool wear conditions on tool influence function were analyzed. The results showed that 2D vibrating motion generated better surface roughness with higher material removal efficiency while a smaller grain size of abrasives created better surface roughness but lower material removal efficiency. MRR gradually decreases with the increase of polishing pressure when it exceeds 345 kPa, and it was greatly affected by the wear of polisher when wear diameter on the polisher’s head exceeds 300 μm.

Characteristics of Cu2+ Adsorption by Modified Rice Straw

2013 ◽  
Vol 726-731 ◽  
pp. 2622-2628
Author(s):  
Ming Da Liu ◽  
Lei Guo ◽  
Jun Yang ◽  
Yao Jing Wang
Keyword(s):  
Rice Straw ◽  
Ph Value ◽  
Removal Rate ◽  
Maximum Adsorption Capacity ◽  
Static State ◽  
Metal Biosorption ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Sorption Time

In this paper, modified rice straw was investigated for its Cu2+removal ability from aqueous solution. The effects of environmental factors on metal biosorption were studied under static state, including initial concentration of metal ions, sorption time, initial pH value and adsordent dosage. In addition, the relevant equilibrium, kinetics were discussed. The results showed that the rice straw which was modified by NaOH had been improved greatly in its Cu2+removal ability. The rice straw had good effects on adsorption of low concentration of Cu2+solution. The adsorption data fit Langmuir isotherm model well, the maximum adsorption capacity for Cu2+reached 8.48 mg·g-1. The adsorption of Cu2+on the modified rice straw was a very rapid process, the kinetics fit a pseudo-second-order equation well. The pH value had prominent effect on the removal rate of Cu2+, adsorption efficient could reach over 92% when pH value was between 5 and 6.5. With increasing adsordent dosage, the removal rate of Cu2+increased.

scholarly journals Application of new biosorbent based on chemicaly modified Lagenaria vulgaris shell for the removal of copper(II) from aqueous solutions: Effects of operational parameters

2013 ◽  
Vol 67 (4) ◽  
pp. 559-567 ◽  
Author(s):  
Milos Kostic ◽  
Miljana Radovic ◽  
Jelena Mitrovic ◽  
Danijela Bojic ◽  
Dragan Milenkovic ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Low Cost ◽  
Batch Process ◽  
Maximum Adsorption Capacity ◽  
Operational Parameters ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Process Mode ◽  
Lagenaria Vulgaris

In present study a low cost biosorbent derived from Lagenaria vulgaris plant by xanthation, was tested for its ability to remove copper from aqueous solution. The effect of contact time, initial pH, initial concentration of copper(II) ions and adsorbent dosage on the removal efficiency were studied in a batch process mode. The optimal pH for investigated metal was 5. A dosage of 4 g dm-3 of xanthated Lagenaria vulgaris biosorbent (xLVB) was found to be effective for maximum uptake of copper(II). The kinetic of sorption of metal was fast, reaching at equilibrium in 50 min. The kinetic data were found to follow closely the pseudo-second-order model. The adsorption equilibrium was described well by the Langmuir isotherm model with maximum adsorption capacity of 23.18 mg g-1 copper(II) ions on xLVB. The presence of sulfur groups on xLVB were identified by FTIR spectroscopic study. Copper removal efficiency was achieved at 81.35% from copper plating industry wastevater.

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.

scholarly journals A Study on the Removal of Copper (II) from Aqueous Solution Using Lime Sand Bricks

2019 ◽  
Vol 9 (4) ◽  
pp. 670 ◽  
Author(s):  
Xiaoran Zhang ◽  
Shimin Guo ◽  
Junfeng Liu ◽  
Ziyang Zhang ◽  
Kaihong Song ◽  
...  
Keyword(s):  
Residence Time ◽  
Removal Rate ◽  
Low Cost ◽  
Column Experiment ◽  
Residual Fraction ◽  
Maximum Adsorption Capacity ◽  
Copper Adsorption ◽  
Exchangeable Fraction ◽  
Pseudo Second Order ◽  
Stormwater Infiltration

Heavy metals such as Cu(II), if ubiquitous in the runoff, can have adverse effects on the environment and human health. Lime sand bricks, as low-cost adsorbents to be potentially applied in stormwater infiltration facilities, were systematically investigated for Cu(II) removal from water using batch and column experiments. In the batch experiment, the adsorption of Cu(II) to bricks reach an equilibrium within 7 h and the kinetic data fits well with the pseudo-second-order model. The sorption isotherm can be described by both the Freundlich and Langmuir model and the maximum adsorption capacity of the bricks is 7 ± 1 mg/g. In the column experiment, the best removal efficiency for Cu(II) was observed at a filler thickness of 20 cm, service time of 12 min with a Cu(II) concentration of 0.5 mg/L. The Cu(II) removal rate increases with the increasing bed depth and residence time. The inlet concentration and residence time had significant effects on the Cu(II) removal analyzed by the Box–Behnken design (BBD). The Adams-Bohart model was in good agreement with the experimental data in representing the breakthrough curve. Copper fractions in the bricks descend in the order of organic matter fraction > Fe-Mn oxides fraction > carbonates fraction > residual fraction > exchangeable fraction, indicating that the lime sand bricks after copper adsorption reduce the long-term ecotoxicity and bioavailability to the environment.

scholarly journals Preparation of Polyaniline/Emulsion Microsphere Composite for Efficient Adsorption of Organic Dyes

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 167 ◽  
Author(s):  
Yuanli Liu ◽  
Liushuo Song ◽  
Linlin Du ◽  
Peng Gao ◽  
Nuo Liang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
In Situ Polymerization ◽  
Organic Dyes ◽  
Removal Rate ◽  
Three Dimensional ◽  
Maximum Adsorption Capacity ◽  
Adsorption Selectivity ◽  
Polymeric Microspheres ◽  
Pseudo Second Order ◽  
Adsorption Desorption

Surface-functionalized polymeric microspheres have wide applications in various areas. Herein, monodisperse poly(styrene–methyl methacrylate–acrylic acid) (PSMA) microspheres were prepared via emulsion polymerization. Polyaniline (PANI) was then coated on the PSMA surface via in situ polymerization, and a three-dimensional (3D) structured reticulate PANI/PSMA composite was, thus, obtained. The adsorption performance of the composite for organic dyes under different circumstances and the adsorption mechanism were studied. The obtained PANI/PSMA composite exhibited a high adsorption rate and adsorption capacity, as well as good adsorption selectivity toward methyl orange (MO). The adsorption process followed pseudo-second-order kinetics and the Langmuir isotherm. The maximum adsorption capacity for MO was 147.93 mg/g. After five cycles of adsorption–desorption, the removal rate remained higher than 90%, which indicated that the adsorbent has great recyclability. The adsorbent materials presented herein would be highly valuable for the removal of organic dyes from wastewater.

scholarly journals Pectin/Activated Carbon-Based Porous Microsphere for Pb2+ Adsorption: Characterization and Adsorption Behaviour

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2453
Author(s):  
Ri-si Wang ◽  
Ya Li ◽  
Xi-xiang Shuai ◽  
Rui-hong Liang ◽  
Jun Chen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Profile Analysis ◽  
Removal Rate ◽  
Physical Adsorption ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
Texture Profile ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Adsorption Desorption

The development of effective heavy metal adsorbents has always been the goal of environmentalists. Pectin/activated carbon microspheres (P/ACs) were prepared through simple gelation without chemical crosslinking and utilized for adsorption of Pb2+. Scanning electron microscopy (SEM) revealed that the addition of activated carbon increased the porosity of the microsphere. Texture profile analysis showed good mechanical strength of P/ACs compared with original pectin microspheres. Kinetic studies found that the adsorption process followed a pseudo-second-order model, and the adsorption rate was controlled by film diffusion. Adsorption isotherms were described well by a Langmuir isotherm model, and the maximum adsorption capacity was estimated to be 279.33 mg/g. The P/ACs with the highest activated carbon (P/AC2:3) maintained a removal rate over 95.5% after 10 adsorption/desorption cycles. SEM-energy-dispersive X-ray spectrum and XPS analysis suggested a potential mechanism of adsorption are ion exchange between Pb2+ and Ca2+, electronic adsorption, formation of complexes, and physical adsorption of P/ACs. All the above results indicated the P/ACs may be a good candidate for the adsorption of Pb2+.

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