Production of ferrihydrite and schwertmannite using a microjet mixer device

Reichelt, Lydia; Bertau, Martin

doi:10.1016/j.cherd.2015.04.008

Cited by 7 publications

(9 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, characteristic “hedgehog” aggregates can be observed in the SCH B sample (Fe 2+ oxidation), but the main forms in which schwertmannite occurs are rounded, isomeric aggregates of about 2 μm in size ( Figure 3 C,D), resembling ferrihydrite clusters but differing in surface character, indicating that they consist of very fine, elongated crystallites. Very similar morphological features were observed for synthetic schwertmannite in the literature [ 27 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. Finally, the SEM images show the size of the sorbent particles produced.…”

Section: Resultssupporting

confidence: 83%

Comparison of Cr(VI) Adsorption Using Synthetic Schwertmannite Obtained by Fe3+ Hydrolysis and Fe2+ Oxidation: Kinetics, Isotherms and Adsorption Mechanism

Ulatowska¹,

Stala²,

Polowczyk³

2021

IJMS

View full text Add to dashboard Cite

Good sorption properties and simple synthesis route make schwertmannite an increasingly popular adsorbent. In this work, the adsorption properties of synthetic schwertmannite towards Cr(VI) were investigated. This study aimed to compare the properties and sorption performance of adsorbents obtained by two methods: Fe3+ hydrolysis (SCHA) and Fe2+ oxidation (SCHB). To characterise the sorbents before and after Cr(VI) adsorption, specific surface area, particle size distribution, density, and zeta potential were determined. Additionally, optical micrographs, SEM, and FTIR analyses were performed. Adsorption experiments were performed in varying process conditions: pH, adsorbent dosage, contact time, and initial concentration. Adsorption isotherms were fitted by Freundlich, Langmuir, and Temkin models. Pseudo-first-order, pseudo-second-order, intraparticle diffusion, and liquid film diffusion models were used to fit the kinetics data. Linear regression was used to estimate the parameters of isotherm and kinetic models. The maximum adsorption capacity resulting from the fitted Langmuir isotherm is 42.97 and 17.54 mg·g−1 for SCHA and SCHB. Results show that the adsorption kinetics follows the pseudo-second-order kinetic model. Both iron-based adsorbents are suitable for removing Cr(VI) ions from aqueous solutions. Characterisation of the adsorbents after adsorption suggests that Cr(VI) adsorption can be mainly attributed to ion exchange with SO42− groups.

show abstract

Section: Resultssupporting

confidence: 83%

Comparison of Cr(VI) Adsorption Using Synthetic Schwertmannite Obtained by Fe3+ Hydrolysis and Fe2+ Oxidation: Kinetics, Isotherms and Adsorption Mechanism

Ulatowska¹,

Stala²,

Polowczyk³

2021

IJMS

View full text Add to dashboard Cite

show abstract

“…As Table 3 shows, only a few reports have directly described the pore structure of Sch as mainly having a "bimodal distribution" 51 with micropores (nearly microscale) and mesopores (mesoscale). 37,52 There is very little mention of macro-pores. The pore size distributions (PSDs) for the micro and mesopores are similar due to the interspaces among the nanoscale villi and the aggregated Sch particles, respectively.…”

Section: Characteristicsmentioning

confidence: 99%

Schwertmannite: occurrence, properties, synthesis and application in environmental remediation

Zhang

Bi²,

Li³

et al. 2018

RSC Adv.

View full text Add to dashboard Cite

show abstract

“…Former studies had shown that chemical as well as physical properties of ferric oxides were strongly effected by precipitation conditions and subsequent treatment [25,26] . These variations were studied for a potential impact on catalytic activity in sulphur dioxide oxidation.…”

Section: Resultsmentioning

confidence: 99%

“…From our former study concerning precipitation of ferric sulphate with ammonia solution it was known that 2‐line‐ferrihydrite and schwertmannite were formed as a function of pH during precipitation [25] . Samples of both materials were annealed at 300, 500 and 900 °C for 8 h in a subsequent study [26] .…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, this study deals with the application of sulphated ferric oxides for sulphur dioxide oxidation, which is a continuation of former investigations concerning reproducible production of sulphated ferric oxides using a microjet mixer [25] and research on the influence of precipitation parameters [25] as well as calcination temperature [26] on chemical and structural properties. However, for better classification of observed effects and dependencies as well as identification of influencing parameters, various commercially available ferric oxide micro‐ and nanoparticles (pigments, ferric oxide nanoparticles and microparticles synthesized for research application) were examined, too.…”

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Oxidation of Sulphur Dioxide using Micro‐ and Nanoparticles of various Iron Oxides

Reichelt

Hippmann

Brichkin

et al. 2021

Zeitschrift anorg allge chemie

Self Cite

View full text Add to dashboard Cite

Sulphuric acid is the chemical with highest production rates in the world. At present, it is mainly synthesized using vanadium pentoxide as catalyst, which determines the applied production process particularly in terms of gas pre‐treatment and heat management. For processes, which cannot be run with vanadium pentoxide, alternative catalysts are required to make different SO2 qualities accessible to sulphuric acid production. Ferric oxides are a very promising alternative, since they combine higher thermal with improved chemical stability. Within this study, various ferric oxides were examined with regard to conversion rates and structural changes during application. Effects of crystal structure, particle size as well as thermal treatment and the influence of precipitation conditions were studied. Although conversion rates are very promising, it has become apparent, though, that these materials cannot compete with vanadium pentoxide in terms of conversion rate as well as long‐time stability, yet. Nevertheless, from the results of this study, it is clear that high potential lies in focused catalyst optimisation.

show abstract

Production of ferrihydrite and schwertmannite using a microjet mixer device

Cited by 7 publications

References 42 publications

Comparison of Cr(VI) Adsorption Using Synthetic Schwertmannite Obtained by Fe3+ Hydrolysis and Fe2+ Oxidation: Kinetics, Isotherms and Adsorption Mechanism

Comparison of Cr(VI) Adsorption Using Synthetic Schwertmannite Obtained by Fe3+ Hydrolysis and Fe2+ Oxidation: Kinetics, Isotherms and Adsorption Mechanism

Schwertmannite: occurrence, properties, synthesis and application in environmental remediation

Oxidation of Sulphur Dioxide using Micro‐ and Nanoparticles of various Iron Oxides

Contact Info

Product

Resources

About