Coagulation-adsorption of reactive orange from aqueous solution by freshly formed magnesium hydroxide: mixing time and mechanistic study

2017 ◽  
Vol 75 (8) ◽  
pp. 1776-1783 ◽  
Author(s):  
Jianhai Zhao ◽  
Huanhuan Shi ◽  
Meile Liu ◽  
Jingfang Lu ◽  
Wenpu Li
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Magnesium Hydroxide ◽  
Mixing Time ◽  
Particle Dispersion ◽  
Mechanistic Study ◽  
X Ray Diffraction ◽  
Adsorption Mechanisms ◽  
Ft Ir ◽  
Reactive Orange

The utilization of magnesium hydroxide was successfully carried out to remove reactive orange by coagulation-adsorption from aqueous solution. The coagulation-adsorption mechanisms and magnesium hydroxide-reactive orange floc property were analyzed through zeta potential, scanning electron microscope (SEM), X-ray diffraction and Fourier transform infrared spectroscopy (FT-IR). Flocculation Index was then discussed with controlled experiments using intelligent Particle Dispersion Analyzer (iPDA) and optimum rapid mixing time of 90 s was obtained for pH 12. The results of this study indicate that charge neutralization and adsorption are proposed to be the main coagulation mechanisms. The FT-IR spectra and SEM showed that reactive orange was adsorbed on the magnesium hydroxide surface during coagulation and adsorption. Freshly generated magnesium hydroxide can effectively remove reactive orange and the removal efficiency can reach 96.7% and 46.3% for coagulation and adsorption, respectively. Adsorption process accounts for 48% of the whole coagulation experiment. The removal efficiency decreased significantly with increasing magnesium hydroxide formation time.

scholarly journals Synthesis Fe3O4/Talc nanocomposite by coprecipition-ultrasonication method and advances in hexavalent chromium removal from aqueous solution

2020 ◽  
Vol 38 (9-10) ◽  
pp. 483-501
Author(s):  
Nguyen Thi Huong ◽  
Nguyen Ngoc Son ◽  
Vo Hoang Phuong ◽  
Cong Tien Dung ◽  
Pham Thi Mai Huong ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Batch Experiments ◽  
X Ray Diffraction ◽  
Order Model ◽  
X Ray ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Langmuir And Freundlich Equations

The Fe3O4/Talc nanocomposite was synthesized by the coprecipitation-ultrasonication method. The reaction was carried out under a inert gas environment. The nanoparticles were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry techniques (VSM), the surface area of the nanoparticles was determined to be 77.92 m2/g by Brunauer-Emmett-Teller method (BET). The kinetic data showed that the adsorption process fitted with the pseudo-second order model. Batch experiments were carried out to determine the adsorption kinetics and mechanisms of Cr(VI) by Fe3O4/Talc nanocomposite. The adsorption process was found to be highly pH-dependent, which made the material selectively adsorb these metals from aqueous solution. The isotherms of adsorption were also studied using Langmuir and Freundlich equations in linear forms. It is found that the Langmuir equation showed better linear correlation with the experimental data than the Freundlich. The thermodynamics of Cr(VI) adsorption onto the Fe3O4/Talc nanocomposite indicated that the adsorption was exothermic. The reusability study has proven that Fe3O4/Talc nanocomposite can be employed as a low-cost and easy to separate.

scholarly journals Optimization and Application of Bioflocculant Passivated Copper Nanoparticles in the Wastewater Treatment

2019 ◽  
Vol 16 (12) ◽  
pp. 2185 ◽  
Author(s):  
Nkosinathi Goodman Dlamini ◽  
Albertus Kotze Basson ◽  
Viswanadha Srirama Rajasekhar Pullabhotla
Keyword(s):  
Electron Microscope ◽  
Removal Efficiency ◽  
Copper Nanoparticles ◽  
Antimicrobial Properties ◽  
Domestic Wastewater ◽  
X Ray Diffraction ◽  
Great Opportunity ◽  
Transmission Electron ◽  
Flocculation Activity ◽  
Ft Ir

Nanotechnology offers a great opportunity for efficient removal of pollutants and pathogenic microorganisms in water. Copper nanoparticles were synthesized using a polysaccharide bioflocculant and its flocculation, removal efficiency, and antimicrobial properties were evaluated. The synthesized nanoparticles were characterized using thermogravimetry, UV-Visible spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction, scanning electron microscope (SEM), and transmission electron microscope (TEM). The highest flocculation activity (FA) was achieved with the lowest concentration of copper nanoparticles (0.2 mg/mL) with 96% (FA) and the least flocculation activity was 80% at 1 mg/mL. The copper nanoparticles (CuNPs) work well without the addition of the cation as the flocculation activity was 96% and worked best at weak acidic, neutral, and alkaline pH with the optimal FA of 96% at pH 7. Furthermore, the nanoparticles were found to be thermostable with 91% FA at 100 °C. The synthesized copper nanoparticles are also high in removal efficiency of staining dyes, such as safranin (92%), carbol fuchsine (94%), malachite green (97%), and methylene blue (85%). The high removal efficiency of nutrients such as phosphate and total nitrogen in both domestic wastewater and Mzingazi river water was observed. In comparison to ciprofloxacin, CuNPs revealed some remarkable properties as they are able to kill both the Gram-positive and Gram-negative microorganisms.

Magnesium hydroxide coagulation performance and floc properties in treating high pH reactive orange wastewater

2015 ◽  
Vol 71 (9) ◽  
pp. 1310-1316 ◽  
Author(s):  
Meile Liu ◽  
Jingfang Lu ◽  
Lei Wei ◽  
Kang Wang ◽  
Jianhai Zhao
Keyword(s):  
Magnesium Hydroxide ◽  
Ph Value ◽  
Particle Dispersion ◽  
Magnesium Ion ◽  
Feeding Mode ◽  
High Ph ◽  
Coagulation Performance ◽  
Initial Ph ◽  
Floc Properties ◽  
Reactive Orange

Application of magnesium hydroxide as a coagulant for treating high pH reactive orange wastewater was studied. The coagulation performance and magnesium hydroxide-reactive orange floc properties were investigated under different dosages, feeding modes and pH values. Flocculation index (FI) was then discussed with controlled experiments using an intelligent particle dispersion analyzer and optimum coagulant dose of 150 mg/L (magnesium ion) was obtained for pH value 12. The results showed that the optimum magnesium ion dose tended to decrease with the increase of initial pH value. One time addition feeding mode led to relatively large FI value and higher removal efficiency compared with other addition modes. All of the flocs under investigation showed a limited capacity for re-growth when they had been previously broken. Based on the changes of zeta potential and floc properties, charge neutralization and precipitate enmeshment were proposed to be the main coagulation mechanisms.

Adsorptive Removal of Ni(II) Ions from Aqueous Solution by Polyacrylic Acid/Attapulgite Composite Hydrogels

2017 ◽  
Vol 727 ◽  
pp. 859-865 ◽  
Author(s):  
Yi Wei Zheng ◽  
Wen Wen Tao ◽  
Gui Fang Zhang ◽  
Chao Lv ◽  
Yi Ping Zhao ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Capacity ◽  
Polyacrylic Acid ◽  
Swelling Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorptive Removal ◽  
Composite Hydrogels ◽  
Ph Values ◽  
Ft Ir

Polyacrylic acid/attapulgite (PAA/ATP) composite hydrogels used for removal of heavy metal ions from aqueous solution was synthesized via radical polymerization with acrylic acid (AA) and attapulgite (ATP) modified by hydrochloric acid as adsorbent. Chemical composition of the modified ATP was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) and the morphology of the PAA/ATP hydrogels was characterized by scanning electron microscope (SEM), respectively. The swelling ratio, pH-sensitivity and adsorption performance of Ni (II) ions of the composite hydrogels were studied. The results showed the swelling ratio of the PAA/ATP composite hydrogels was higher than that of PAA hydrogels and the composite hydrogels displayed sensitivity to pH values with a sharp increase of swelling ratio when the pH values increased from 4 to 6. Comparing with PAA hydrogels, the composite hydrogels obtained a larger adsorption capacity of Ni (II) ions, the average adsorption capacity could reach 72.8 mg/g and adsorption ratio could reach 84%.

Effect of Magnetic Field on the Electropolymerization and Corrosion Properties of Polyaniline (PANI) Film

2012 ◽  
Vol 472-475 ◽  
pp. 198-205 ◽  
Author(s):  
Chao Fang Dong ◽  
Yang Yang ◽  
Hong Luo ◽  
Kui Xiao ◽  
Xiao Gang Li
Keyword(s):  
Magnetic Field ◽  
Aqueous Solution ◽  
304 Stainless Steel ◽  
Pani Film ◽  
Stainless Steel Electrode ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
Steel Electrode ◽  
X Ray ◽  
Ft Ir

The polyaniline have been prepared in the absence and presence of magnetic field by the technique of cyclic voltammetry (CV) on 304-stainless steel electrode in H2SO4 aqueous solution of aniline (Ani). The influence of magnetic field on electropolymerization of PANI was investigated by electrochemical properties, FT-IR spectra, X-ray diffraction (XRD) and microstructure. The results indicate that the effect of magnetic field on the polyaniline is positive.

scholarly journals A Facilely Synthesized Tourmaline-Biochar Composite For Enhanced Removal of Cr (VI) From Aqueous Solution

2021 ◽  
Author(s):  
Qi Lu ◽  
Siyi Huang ◽  
Xiaorui Ma
Keyword(s):  
Aqueous Solution ◽  
Pyrolysis Temperature ◽  
Adsorption Property ◽  
Energy Dispersive Spectrometer ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Adsorption Mechanisms ◽  
Monolayer Adsorption ◽  
Initial Ph ◽  
Pseudo Second Order

Abstract A tourmaline-biochar composite (TMBC) was facilely synthesized to effectively remove Cr (Ⅵ) from aqueous solution. The effects of different ratio (TM: BC) and pyrolysis temperature on TMBC adsorption performance were compared for optimal condition of TMBC preparation. The TMBC samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) and scanning electron microscope-energy dispersive spectrometer (SEM-EDS). The kinetics and thermodynamics were analyzed to investigate the sorption mechanism for removal of Cr (VI). The results showed that the proper pyrolysis temperature was 650℃, and the ratio of TM and BC was 1:3. SEM results showed that there are many pores in the biochar structure, which is helpful for tourmaline dispersion. The adsorption kinetics was fitted well by the pseudo-second-order model, indicating the sorption is related to chemical absorption. Freundlich adsorption isotherms suggested monolayer adsorption between Cr (Ⅵ) and TMBC, and the maximum adsorption capacity of TMBC for Cr (Ⅵ) was 53.10 mg/g at initial pH 4.0, which is more than twice higher than pristine TM (17.85 mg/g). Such adsorption mechanisms included water automatically polarized, ion exchange and electrode adsorption, among which the automatic polarization of water caused by tourmaline was the unique adsorption property of TMBC. So TMBC composite can be used as an economic adsorbent in the remediation of heavy metal pollution in water.

scholarly journals Fabrication of magnetic lignin-based adsorbent for removal of methyl orange dye from aqueous solution

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5436-5449
Author(s):  
Chao Cao ◽  
Lupeng Shao ◽  
Lucian A. Lucia ◽  
Yu Liu
Keyword(s):  
Aqueous Solution ◽  
Methyl Orange ◽  
Influence Factors ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Adsorption Mechanisms ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Methyl Orange Dye ◽  
Adsorption Desorption

Magnetic lignin-based adsorbent (MLA) was successfully fabricated to remove methyl orange dye from aqueous solution. The synthesized MLA was characterized by means of Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), N2 adsorption-desorption, scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM). In the process of adsorption, influence factors and recycling performance were considered, and the adsorption mechanisms such as isotherm and kinetics were investigated. The result showed that the equilibrium data was consisted with the Langmuir model with a maximum adsorption capacity of 85.0 mg/g. The adsorption kinetics followed a pseudo-second-order model. Based the adsorption performance, MLA showed good recyclability. Therefore, these results demonstrate that MLA could offer a great potential as an efficient and reusable adsorbent in the wastewater treatments.

Functionalized magnetic Fe3O4 nanoparticles for removal of heavy metal ions from aqueous solutions

e-Polymers ◽  
2016 ◽  
Vol 16 (4) ◽  
pp. 313-322 ◽  
Author(s):  
Dun Chen ◽  
Tunsagnl Awut ◽  
Bin Liu ◽  
Yali Ma ◽  
Tao Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heavy Metal ◽  
Metal Ions ◽  
Removal Efficiency ◽  
Heavy Metal Ions ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Magnetic Adsorbents ◽  
Ft Ir ◽  
Magnetic Fe3o4 Nanoparticles

AbstractFe3O4 nanoparticles (MNP) were coated with 3-aminopropyltriethoxy-silane (APTES), resulting in anchoring of primary amine groups on the surface of the particles, then four kinds of novel magnetic adsorbents (Fe3O4@SiO2-NH-HCGs) were formed by grafting of different heterocyclic groups (HCG) on amino groups via substitution reaction. These Fe3O4@SiO2-NH-HCGs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and energy disperse spectroscopy (EDS). The results confirmed the formation of Fe3O4@SiO2-NH-HCGs nanoparticles and the Fe3O4 core possessed superparamagnetism. Batch experiments were performed to evaluate adsorption conditions of Cu2+, Hg2+, Pb2+ and Cd2+. Under normal temperature and neutral condition, just 20 min, the removal efficiency of any Fe3O4@SiO2-NH-HCGs is more than 96%. In addition, these Fe3O4@SiO2-NH-HCGs have good stability and reusability. Their removal efficiency has no obvious decrease after being used seven times. After the experiments were finished, Fe3O4@SiO2-NH-HCGs were conveniently separated via an external magnetic field due to superparamagnetism. These results indicate that these Fe3O4@SiO2-NH-HCGs are potentially attractive materials for the removal of heavy metal ions from industrial wastewater.

scholarly journals Effects of Mixing Conditions on Floc Properties in Magnesium Hydroxide Continuous Coagulation Process

2019 ◽  
Author(s):  
Yanmei Ding ◽  
Jianhai Zhao ◽  
Lei Wei ◽  
Wenpu Li ◽  
Yongzhi Chi
Keyword(s):  
Zeta Potential ◽  
Removal Efficiency ◽  
Magnesium Hydroxide ◽  
Retention Time ◽  
Mixing Conditions ◽  
Floc Size ◽  
Mixing Speed ◽  
Coagulation Process ◽  
Floc Properties ◽  
Reactive Orange

Magnesium hydroxide continuous coagulation process was used for treating simulated reactive orange wastewater in this study. Effects of mixing conditions and retention time on the coagulation performance and floc properties of magnesium hydroxide were based on the floc size distribution (FSD), zeta potential and floc morphology analysis. Floc formation and growth in different reactors were also discussed.The results showed that increasing rapid mixing speed led to a decrease in the final floc size. Floc formation process was mainly carried out in rapid mixer, rapid mixing speed of 300rpm was chosen according to zeta potential and removal efficiency. Reducing retention time caused relatively small floc size in all reactors. When influent flow is 30 L/h (retention time of 2min in rapid mixer), the average floc size reached 8.06μm in rapid mixer, through breakage and re-growth, the floc size remained stable in flocculation basin. After growth, the final floc size reached to 11.21μm in sedimentation tank. The removal efficiency of reactive orange is 89% in magnesium hydroxide coagulation process.

scholarly journals Preparation of aluminum-ferric-magnesium polysilicate and its application on oily sludge

2015 ◽  
Vol 80 (12) ◽  
pp. 1553-1565 ◽  
Author(s):  
Si Li ◽  
Shuang Yang ◽  
Pan Yi ◽  
Jin-Hui Zhang
Keyword(s):  
Removal Efficiency ◽  
Ph Value ◽  
Xrd Analysis ◽  
Oily Sludge ◽  
X Ray Diffraction ◽  
Chemical Structures ◽  
Coagulation Performance ◽  
Ft Ir ◽  
Oily Water ◽  
The Fourier Transform

Aluminum-ferric-magnesium polysilicate (PAFMS) was prepared by introducing aluminum, ferric and magnesium metal ions into Polymer silica acid solution. PAFMS was applied in the treatment of oily wastewater from treatment of oily sludge in this paper, and the coagulation performance was valued by the removal efficiency of turbidity and colority. The structure and morphology of PAFMS were characterized by the Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD) and Scanning Electronic Microscopy (SEM). The results indicated that mole ratios 6:4:15 of Al:Fe:Mg is beneficial to forming of Al-O-Si, Fe-O-Si and Mg-Si-O. Fe played main inhibition role among the three metals. XRD analysis showed that the addition of Al, Fe and Mg into Polysilicon acid did not produce a simple mixture, but resulted in the formation of new chemical structures. The intensity of peaks was influenced by the mole ratios of metals. SEM spectra presented that PAFMS appeared to be a spatial structure consisting of many irregular protuberant parts. The removal efficiency of turbidity and colority in oily water from the treatment of oily sludge was better when the mole ratio of (Al+Fe+Mg):Si was 0.5 and if the mole ratios of Al:Fe:Mg are kept at 6:4:15. Moreover, when the dosage of PAFMS was 1.4-1.8 % and the pH value in range of 8-9, the efficiency of turbidity and colority removal are up to 97.3 and 96.8%, respectively.

Sign in / Sign up

Export Citation Format

Share Document