scholarly journals Synthesis and characterization of calcium carbonate whisker from yellow phosphorus slag

2020 ◽  
Vol 18 (1) ◽  
pp. 347-356
Author(s):  
Qiuju Chen ◽  
Wenjin Ding ◽  
Tongjiang Peng ◽  
Hongjuan Sun

AbstractIn this study, a procedure for producing calcium carbonate whisker through yellow phosphorus slag carbonation without adding any crystal control agents was proposed. The influence of process parameters on the crystal phase and morphology of the product was discussed. The content of aragonite in the product was more than 90% under optimal conditions. The whiteness of the product was 97.6%. The diameter of a single particle was about 1.5–3 μm, and the length of a single particle was about 8–40 μm. Various polymorphs and morphologies of CaCO3 could be formed by adjusting the production conditions. The by-products produced during the whole preparation process could also be reused. The whole preparation process of fibrous aragonite from yellow phosphorus slag without using any chemical additives was also proposed. These indicated that the production strategy had a good application prospect.

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1299
Author(s):  
Pablo Doménech ◽  
Aleta Duque ◽  
Isabel Higueras ◽  
José Luis Fernández ◽  
Paloma Manzanares

Olive trees constitute one of the largest agroindustries in the Mediterranean area, and their cultivation generates a diverse pool of biomass by-products such as olive tree pruning (OTP), olive leaves (OL), olive stone (OS), and extracted olive pomace (EOP). These lignocellulosic materials have varying compositions and potential utilization strategies within a biorefinery context. The aim of this work was to carry out an integral analysis of the aqueous extractives fraction of these biomasses. Several analytical methods were applied in order to fully characterize this fraction to varying extents: a mass closure of >80% was reached for EOP, >76% for OTP, >65% for OS, and >52% for OL. Among the compounds detected, xylooligosaccharides, mannitol, 3,4-dihydroxyphenylglycol, and hydroxytyrosol were noted as potential enhancers of the valorization of said by-products. The extraction of these compounds is expected to be more favorable for OTP, OL, and EOP, given their high extractives content, and is compatible with other utilization strategies such as the bioconversion of the lignocellulosic fraction into biofuels and bioproducts.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1301
Author(s):  
Zully J. Suárez Montenegro ◽  
Gerardo Álvarez-Rivera ◽  
Jose A. Mendiola ◽  
Elena Ibáñez ◽  
Alejandro Cifuentes

This work reports the use of GC-QTOF-MS to obtain a deep characterization of terpenoid compounds recovered from olive leaves, which is one of the largest by-products generated by the olive oil industry. This work includes an innovative supercritical CO2 fractionation process based on the online coupling of supercritical fluid extraction (SFE) and dynamic adsorption/desorption for the selective enrichment of terpenoids in the different olive leaves extracts. The selectivity of different commercial adsorbents such as silica gel, zeolite, and aluminum oxide was evaluated toward the different terpene families present in olive leaves. Operating at 30 MPa and 60 °C, an adsorbent-assisted fractionation was carried out every 20 min for a total time of 120 min. For the first time, GC-QTOF-MS allowed the identification of 40 terpenoids in olive leaves. The GC-QTOF-MS results indicate that silica gel is a suitable adsorbent to partially retain polyunsaturated C10 and C15 terpenes. In addition, aluminum oxide increases C20 recoveries, whereas crystalline zeolites favor C30 terpenes recoveries. The different healthy properties that have been described for terpenoids makes the current SFE-GC-QTOF-MS process especially interesting and suitable for their revalorization.


2021 ◽  
Vol 36 (3) ◽  
pp. 374-380
Author(s):  
Linnü Lü ◽  
Yisa Wang ◽  
Yongjia He ◽  
Fazhou Wang ◽  
Shuguang Hu

2021 ◽  
Vol 11 (13) ◽  
pp. 5924
Author(s):  
Elisa Levi ◽  
Simona Sgarbi ◽  
Edoardo Alessio Piana

From a circular economy perspective, the acoustic characterization of steelwork by-products is a topic worth investigating, especially because little or no literature can be found on this subject. The possibility to reuse and add value to a large amount of this kind of waste material can lead to significant economic and environmental benefits. Once properly analyzed and optimized, these by-products can become a valuable alternative to conventional materials for noise control applications. The main acoustic properties of these materials can be investigated by means of a four-microphone impedance tube. Through an inverse technique, it is then possible to derive some non-acoustic properties of interest, useful to physically characterize the structure of the materials. The inverse method adopted in this paper is founded on the Johnson–Champoux–Allard model and uses a standard minimization procedure based on the difference between the sound absorption coefficients obtained experimentally and predicted by the Johnson–Champoux–Allard model. The results obtained are consistent with other literature data for similar materials. The knowledge of the physical parameters retrieved applying this technique (porosity, airflow resistivity, tortuosity, viscous and thermal characteristic length) is fundamental for the acoustic optimization of the porous materials in the case of future applications.


2005 ◽  
Vol 39 (6) ◽  
pp. 1409-1419 ◽  
Author(s):  
Chul-Un Ro ◽  
HeeJin Hwang ◽  
HyeKyeong Kim ◽  
Youngsin Chun ◽  
René Van Grieken

2011 ◽  
Vol 102 (1-2) ◽  
pp. 49-56 ◽  
Author(s):  
Elmar Gelhausen ◽  
Klaus-Peter Hinz ◽  
Andres Schmidt ◽  
Bernhard Spengler

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