scholarly journals Immobilization of aPleurotus ostreatusLaccase Mixture on Perlite and Its Application to Dye Decolourisation

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Cinzia Pezzella ◽  
Maria Elena Russo ◽  
Antonio Marzocchella ◽  
Piero Salatino ◽  
Giovanni Sannia
Keyword(s):  
Porous Silica ◽  
Dye Adsorption ◽  
Fine Tuning ◽  
Conversion Degree ◽  
Related Enzyme ◽  
Dye Decolourisation ◽  
Recycle Reactor ◽  
Reactor Space ◽  
Scale Reactor ◽  
Catalytic Performances

In the present study, a crude laccase preparation fromPleurotus ostreatuswas successfully immobilized on perlite, a cheap porous silica material, and tested for Remazol Brilliant Blue R (RBBR) decolourisation in a fluidized bed recycle reactor. Results showed that RBBR decolourisation is mainly due to enzyme action despite the occurrence of dye adsorption-related enzyme inhibition. Fine tuning of immobilization conditions allowed balancing the immobilization yield and the resulting rate of decolourisation, with the adsorption capacity of the solid biocatalyst. In the continuous lab scale reactor, a maximum conversion degree of 56.1% was achieved at reactor space-time of 4.2 h. Stability and catalytic parameters of the immobilized laccases were also assessed in comparison with the soluble counterparts, revealing an increase in stability, despite a reduction of the catalytic performances. Both effects are most likely ascribable to the occurrence of multipoint attachment phenomena.

scholarly journals Porous Silica-Based Organic-Inorganic Hybrid Catalysts: A Review

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 79
Author(s):  
Andrea Erigoni ◽  
Urbano Diaz
Keyword(s):  
Active Sites ◽  
Sol Gel ◽  
Porous Silica ◽  
Silyl Derivative ◽  
Inorganic Hybrid ◽  
Inorganic Solids ◽  
Hybrid Catalysts ◽  
Different Types ◽  
General Scope ◽  
Catalytic Performances

Hybrid organic-inorganic catalysts have been extensively investigated by several research groups in the last decades, as they allow combining the structural robust-ness of inorganic solids with the versatility of organic chemistry. Within the field of hybrid catalysts, synthetic strategies based on silica are among the most exploitable, due to the convenience of sol-gel chemistry, to the array of silyl-derivative precursors that can be synthesized and to the number of post-synthetic functionalization strategies available, amongst others. This review proposes to highlight these advantages, firstly describing the most common synthetic tools and the chemistry behind sol-gel syntheses of hybrid catalysts, then presenting exemplificative studies involving mono- and multi-functional silica-based hybrid catalysts featuring different types of active sites (acid, base, redox). Materials obtained through different approaches are described and their properties, as well as their catalytic performances, are compared. The general scope of this review is to gather useful information for those approaching the synthesis of organic-inorganic hybrid materials, while providing an overview on the state-of-the art in the synthesis of such materials and highlighting their capacities.

scholarly journals Solution Blow Spun Silica Nanofibers: Influence of Polymeric Additives on the Physical Properties and Dye Adsorption Capacity

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3135
Author(s):  
Rosiane Maria da Costa Farias ◽  
Lucas Leite Severo ◽  
Artur P. Klamczynski ◽  
Eliton Souto de Medeiros ◽  
Lisiane Navarro de Lima Santana ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Porous Silica ◽  
Dye Adsorption ◽  
Silica Particles ◽  
Simple Method ◽  
Polymeric Additives ◽  
High Fraction ◽  
Silica Nanofibers ◽  
Pore Properties

The physical properties of porous silica nanofibers are an important factor that impacts their performance in various applications. In this study, porous silica nanofibers were produced via solution blow spinning (SBS) from a silica precursor/polymer solution. Two polyvinylpyrrolidone (PVP, Mw = 360,000 and 1,300,000) were chosen as spinning aids in order to create different pore properties. The effect of their physical properties on the adsorption of methylene blue (MB) in an aqueous solution was explored. After forming, the nanofibers were calcined to remove the organic phase and create pores. The calcined nanofibers had a large amount of micro and mesopores without the use of additional surfactants. The molecular weight of the PVP impacted the growth of silica particles and consequently the pore size. High Mw PVP inhibited the growth of silica particles, resulting in a large volume of micropores. On the other hand, silica nanofibers with a high fraction of mesopores were obtained using the lower Mw PVP. These results demonstrate a simple method of producing blow spun silica nanofibers with defined variations of pore sizes by varying only the molecular weight of the PVP. In the adsorption process, the accessible mesopores improved the adsorption performance of large MB molecules.

scholarly journals Fine-Tuning Dye Adsorption Capacity of UiO-66 by Mixed-Ligand Approach

2021 ◽  
Author(s):  
Chompoonoot Nanthamathee ◽  
Chantamalinee Chantarangkul ◽  
Chanida Jakkrawhad ◽  
Apirak Payaka ◽  
Pongsathorn Dechatiwongse
Keyword(s):  
Adsorption Capacity ◽  
Metal Organic Framework ◽  
Indigo Carmine ◽  
Dye Adsorption ◽  
Mixed Ligand ◽  
Fine Tuning ◽  
Synthetic Approach ◽  
Freundlich Isotherms ◽  
Ligand Adsorption ◽  
Decreasing Ph

Abstract Mixed ligand synthetic approach offers an alternative to engineer a specific character in metal-organic framework (MOFs) materials. Herein, we synthesized and characterized a well-known prototype zirconium based-MOF, so called UiO-66 and its mixed ligand derivatives UiO-66-xATA, where x is mole fraction (0.5, 0.75 and 1.0) and ATA is 2-animoterephthalate. The aim of the study is to observe whether the dye adsorption capacity can be tuned/enhanced by the ATA ligand substitution into the framework. We found that, at room temperature, UiO-66-0.75ATA shows the highest adsorption capacity toward various dye solution including methylene blue (MB), indigo carmine (IC) and congo red (CR). The optimum adsorption conditions in all four materials were found to be in a common trend where their adsorption capacities can be increased with decreasing pH and adsorbent dose, increasing of IC concentration, contact time and temperature. Pseudo-second order kinetics model fits best with their adsorption data, where UiO-66-ATA has the fastest rate of adsorption. Langmuir and Freundlich isotherms were found to best describe adsorption behaviour in ATA-containing UiO-66 and UiO-66 respectively, where adsorption processes were found to be physisorption. Confirming by thermodynamic studies, the adsorption in all four materials occurred spontaneously, driven by entropy. Computational studies showed ligand to metal charge transfer where the distribution of electron densities was varied with the amount of functionalized ligand. Adsorption mechanism is proposed as a synergistic interplay between electrostatic interaction and hydrogen bonding. The findings in this work broaden potential strategy to fine-tune the dye adsorption capacity in MOF materials.

Tuning porous silica nanofibers by colloid electrospinning for dye adsorption

2014 ◽  
Vol 313 ◽  
pp. 389-395 ◽  
Author(s):  
Chaojie Wu ◽  
Wei Yuan ◽  
Salem S. Al-Deyab ◽  
Ke-Qin Zhang
Keyword(s):  
Porous Silica ◽  
Dye Adsorption ◽  
Silica Nanofibers

Fine-Tuning Futures

ASHA Leader ◽  
2017 ◽  
Vol 22 (6) ◽  
Author(s):  
Christi Miller
Keyword(s):  
Fine Tuning

Food Safety Security: A new Concept for Enhancing Food Safety Measures

2012 ◽  
Vol 82 (3) ◽  
pp. 216-222 ◽  
Author(s):  
Venkatesh Iyengar ◽  
Ibrahim Elmadfa
Keyword(s):  
Food Safety ◽  
Hazard Analysis ◽  
Warning System ◽  
Shared Responsibility ◽  
Fine Tuning ◽  
Strategic Action ◽  
Surveillance Network ◽  
Measurement Systems ◽  
Critical Control Points ◽  
The Impact

The food safety security (FSS) concept is perceived as an early warning system for minimizing food safety (FS) breaches, and it functions in conjunction with existing FS measures. Essentially, the function of FS and FSS measures can be visualized in two parts: (i) the FS preventive measures as actions taken at the stem level, and (ii) the FSS interventions as actions taken at the root level, to enhance the impact of the implemented safety steps. In practice, along with FS, FSS also draws its support from (i) legislative directives and regulatory measures for enforcing verifiable, timely, and effective compliance; (ii) measurement systems in place for sustained quality assurance; and (iii) shared responsibility to ensure cohesion among all the stakeholders namely, policy makers, regulators, food producers, processors and distributors, and consumers. However, the functional framework of FSS differs from that of FS by way of: (i) retooling the vulnerable segments of the preventive features of existing FS measures; (ii) fine-tuning response systems to efficiently preempt the FS breaches; (iii) building a long-term nutrient and toxicant surveillance network based on validated measurement systems functioning in real time; (iv) focusing on crisp, clear, and correct communication that resonates among all the stakeholders; and (v) developing inter-disciplinary human resources to meet ever-increasing FS challenges. Important determinants of FSS include: (i) strengthening international dialogue for refining regulatory reforms and addressing emerging risks; (ii) developing innovative and strategic action points for intervention {in addition to Hazard Analysis and Critical Control Points (HACCP) procedures]; and (iii) introducing additional science-based tools such as metrology-based measurement systems.

Cationic dye adsorption in sugar cane juice

1959 ◽  
Vol 9 (9) ◽  
pp. 482-486
Author(s):  
M. C. Bennett ◽  
D. A. Haydon
Keyword(s):  
Sugar Cane ◽  
Dye Adsorption ◽  
Cationic Dye ◽  
Cane Juice ◽  
Sugar Cane Juice

Preparation of nanocomposite hydrogels with nanoclay: characterization, swelling properties and dye adsorption behavior

2020 ◽  
Vol 65 (2) ◽  
pp. 119-133
Author(s):  
Nesrimne SEDIIKI ◽  
◽  
Djamel ALIOUCHE ◽  
Imene BOUDHENE ◽  
◽  
...  
Keyword(s):  
Dye Adsorption ◽  
Adsorption Behavior ◽  
Swelling Properties ◽  
Nanocomposite Hydrogels
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