scholarly journals Lignin-Derived Compounds as Efficient Laccase Mediators for Decolorization of Different Types of Recalcitrant Dyes

2005 ◽  
Vol 71 (4) ◽  
pp. 1775-1784 ◽  
Author(s):  
Susana Camarero ◽  
David Ibarra ◽  
María Jesús Martínez ◽  
Ángel T. Martínez

ABSTRACT Ten phenols were selected as natural laccase mediators after screening 44 different compounds with a recalcitrant dye (Reactive Black 5) as a substrate. Their performances were evaluated at different mediator/dye ratios and incubation times (up to 6 h) by the use of Pycnoporus cinnabarinus and Trametes villosa laccases and were compared with those of eight known synthetic mediators (including -NOH- compounds). Among the six types of dyes assayed, only Reactive Blue 38 (phthalocyanine) was resistant to laccase-mediator treatment under the conditions used. Acid Blue 74 (indigoid dye), Reactive Blue 19 (anthraquinoid dye), and Aniline Blue (triarylmethane-type dye) were partially decolorized by the laccases alone, although decolorization was much more efficient and rapid with mediators, whereas Reactive Black 5 (diazo dye) and Azure B (heterocyclic dye) could be decolorized only in the presence of mediators. The efficiency of each natural mediator depended on the type of dye to be treated but, with the only exception being Azure B (<50% decolorization), nearly complete decolorization (80 to 100%) was attained in all cases. Similar rates were attained with the best synthetic mediators, but the reactions were significantly slower. Phenolic aldehydes, ketones, acids, and esters related to the three lignin units were among the best mediators, including p-coumaric acid, vanillin, acetovanillone, methyl vanillate, and above all, syringaldehyde and acetosyringone. The last two compounds are especially promising as ecofriendly (and potentially cheap) mediators for industrial applications since they provided the highest decolorization rates in only 5 to 30 min, depending on the type of dye to be treated.

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1729
Author(s):  
Patrizio Raffa

The study of interactions between polyelectrolytes (PE) and surfactants is of great interest for both fundamental and applied research. These mixtures can represent, for example, models of self-assembly and molecular organization in biological systems, but they are also relevant in industrial applications. Amphiphilic block polyelectrolytes represent an interesting class of PE, but their interactions with surfactants have not been extensively explored so far, most studies being restricted to non-associating PE. In this work, interactions between an anionic amphiphilic triblock polyelectrolyte and different types of surfactants bearing respectively negative, positive and no charge, are investigated via surface tension and solution rheology measurements for the first time. It is evidenced that the surfactants have different effects on viscosity and surface tension, depending on their charge type. Micellization of the surfactant is affected by the presence of the polymer in all cases; shear viscosity of polymer solutions decreases in presence of the same charge or nonionic surfactants, while the opposite charge surfactant causes precipitation. This study highlights the importance of the charge type, and the role of the associating hydrophobic block in the PE structure, on the solution behavior of the mixtures. Moreover, a possible interaction model is proposed, based on the obtained data.


2018 ◽  
Vol 877 ◽  
pp. 294-298 ◽  
Author(s):  
Kundan Patel ◽  
Jay Patel ◽  
Piyush Gohil ◽  
Vijaykumar Chaudhary

Composite materials play a vital role in many industrial applications. Researchers are working on fabrication of new composite materials worldwide to enhance the applicability of these materials. The present study aimed to investigate the effect of Nano clay loading as filler on the mechanical properties of the bamboo fiber yarn reinforced polyester composite. Five different types of composite specimen were prepared with Nano clay loadings of 0 to 4 % weight fraction using hand lay-up technique. It was observed that the composite sheet with 1 wt % nano clay content exhibited the optimized tensile and flexural strength. However the mechanical properties tend to decrease with addition of nano clay content from 2 to 4 wt %. In spite of that the values of mechanical properties with 2 and 3 wt % nano clay content is higher than 0 wt % nano clay content.


Author(s):  
Ahmed E. Al Prol Khalid M. El Moselhy ◽  
Magdi Abdel Azzem kamel Adel Amer ◽  
Mahmoud Abdel Moneim

Minerals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 482 ◽  
Author(s):  
Przemyslaw Kowalczuk ◽  
Hassan Bouzahzah ◽  
Rolf Kleiv ◽  
Kurt Aasly

Simultaneous leaching of seafloor massive sulfides (SMS) from Loki’s Castle on the Arctic Mid-Ocean Ridge (AMOR) and polymetallic nodules (PN) from Clarion Clipperton Zone (CCZ) of the Central Pacific Ocean was studied. Leaching tests were conducted using sulfuric acid and sodium chloride, at a temperature of 80 °C for 48 h under reflux. The effect of PN-to-SMS ratio was examined. It was shown that simultaneous leaching of two different types of marine resources was possible resulting in high dissolution rates of metals. The proposed process has many advantages as it does not require pyrometallurgical pretreatment, and yields solid products (i.e., silica, barite, elemental sulfur, albite, microcline, muscovite), which might be utilized for various industrial applications.


2001 ◽  
Vol 57 (5-6) ◽  
pp. 725-730 ◽  
Author(s):  
A. Lomascolo ◽  
D. Navarro ◽  
M. Delattre ◽  
M. Asther ◽  
L. Lesage-Meessen ◽  
...  

2012 ◽  
Vol 627 ◽  
pp. 394-398 ◽  
Author(s):  
Hamid Reza Rashidi ◽  
Nik Meriam Sulaiman ◽  
Nur Awanis Hashim ◽  
Che Rosmani Che Hassan

One of the most important manufacturing industries in Malaysia is textile and specifically batik making. Many local batik factories discharge their wastewater, which contains wax, resin, silicate and dyes, without treatment, directly to nature. A possible treatment system involving membrane filtration has been tested to remove the dyes. However the presence of wax the wastewater requires a pretreatment stage to remove the undesired wax. In this study the performance of baffle tank pretreatment (own designed and fabricated) was evaluated for 4 different types of synthetic batik wastewater, which contain wax, resin, sodium silicate and 4 different fibers reactive dyes namely, Remazol Turquoise Blue G133 (Blue 21), Remazol Red 194 and Remazol Yellow 14 and Reactive black 5. The removal efficiency (%), pH and COD of each sample were evaluated and recorded. Wax removal efficiency in all samples was more than 88%. The COD and pH of all samples decreased after 60 minutes pretreatment cycle.


Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6056
Author(s):  
Gaoliang Liao ◽  
Zhizhou Li ◽  
Feng Zhang ◽  
Lijun Liu ◽  
Jiaqiang E

Heat exchangers play an important role in power, the chemical industry, petroleum, food and many other industrial productions, while compact heat exchangers are more favored in industrial applications due to their high thermal efficiency and small size. This paper summarizes the research status of different types of compact heat exchangers, especially the research results of heat transfer and pressure drop of printed circuit heat exchangers, so that researchers can have an overall understanding of the development of compact heat exchangers and get the required information quickly. In addition, this paper summarizes and analyzes several main working fluids selected in compact heat exchangers, and puts forward some discussions and suggestions on the selection of working fluids. Finally, according to the existing published literature, the performance evaluation indexes of compact heat exchangers are summarized and compared, which is convenient for developers and researchers to better grasp the design direction.


Author(s):  
Mohammad Al Ktash ◽  
Otto Hauler ◽  
Edwin Ostertag ◽  
Marc Brecht

Different types of raw cotton were investigated by a commercial ultraviolet-visible/near infrared (UV-Vis/NIR) spectrometer (210–2200 nm) as well as on a home-built setup for NIR hyperspectral imaging (NIR-HSI) in the range 1100–2200 nm. UV-Vis/NIR reflection spectroscopy reveals the dominant role proteins, hydrocarbons and hydroxyl groups play in the structure of cotton. NIR-HSI shows a similar result. Experimentally obtained data in combination with principal component analysis (PCA) provides a general differentiation of different cotton types. For UV-Vis/NIR spectroscopy, the first two principal components (PC) represent 82 % and 78 % of the total data variance for the UV-Vis and NIR regions, respectively. Whereas, for NIR-HSI, due to the large amount of data acquired, two methodologies for data processing were applied in low and high lateral resolution. In the first method, the average of the spectra from one sample was calculated and in the second method the spectra of each pixel were used. Both methods are able to explain ≥90 % of total variance by the first two PCs. The results show that it is possible to distinguish between different cotton types based on a few selected wavelength ranges. The combination of HSI and multivariate data analysis has a strong potential in industrial applications due to its short acquisition time and low-cost development. This study opens a novel possibility for a further development of this technique towards real large-scale processes.


Author(s):  
Nicolo` Bachschmid ◽  
Paolo Pennacchi ◽  
Ezio Tanzi

This paper presents the experimental validation of a model based transverse crack identification method suitable for industrial machines, described in part 1. The method is validated by experimental results obtained on two test rigs, which were expressly designed for investigating the dynamical behavior of cracked horizontal rotors. On the first test rig, only one crack type is considered, while on the second one three different types of crack have been analyzed: the first is a slot, therefore not actually a crack since it has not the typical breathing behavior, the second a small crack (14% of the diameter) and the third a deep crack (47% of the diameter). The excellent accuracy obtained in identifying position and depth of different cracks proves the effectiveness and reliability of the proposed method. Moreover, the implementation of identification method operates on a PC and takes short time to run, therefore is suitable for industrial applications.


Author(s):  
Maya Scott-Richardson ◽  
Marilyn O’Hara Ruiz ◽  
Rebecca Smith

Arsenic is an abundant, highly toxic element that is a global health concern due to damage from acute and chronic exposure and the potential for high local concentrations in heavily populated areas. In Florida, arsenic has been used heavily in agricultural, commercial, and industrial applications for decades. While studies have identified and quantified the contributions of arsenic to the state, there are fewer studies that have attempted to index to identify spatial distribution patterns. The aim of this study was to develop representative indices that would identify and estimate the distribution of arsenic from historic and present usage for the state of Florida at the county-level. Eight variables are summarized and categorized into two different types of arsenic indices that represent the arsenic distribution from natural occurrence and anthropogenic practices in Florida. The anthropogenic index had distributions scores that ranged from 0.20 to 1.60 with a mean of 0.61 (SD = 0.34). The natural index had distribution scores that ranged from 1.00 to 3.00 and a mean of 1.47 (SD = 0.43). Our finding noticed comparability between high arsenic distributions mainly occur in counties located in the northwestern and southwestern regions in both the anthropogenic and natural indices with diverse arsenic sources contributions.


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