scholarly journals Simultaneous Detoxification of Aflatoxin B1, Zearalenone and Deoxynivalenol by Modified Montmorillonites

Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 315
Author(s):  
Jiaqi Mao ◽  
Ying Zhou ◽  
Guanglie Lv ◽  
Renxian Zhou

Raw Ca-based montmorillonite (MMT) was treated by H2SO4, calcination and organic compounds (hexadecyltrimethyl ammonium bromide (HTAB), cetylpyridinium chloride (CPC) and chitosan (CTS)), respectively. The modified montmorillonites were characterized by different methods and their adsorption performances for three mycotoxins (Aflatoxin B1 (AFB1), zearalenone (ZEA) and deoxynivalenol (DON)) were evaluated at pH = 2.8 and 8.0, respectively. The results indicate that surfactants (CPC and HTAB) intercalation is the most efficient modification, which obviously improves the adsorption performance of montmorillonite for mycotoxins, with adsorption efficiency of above 90% for AFB1 and ZEA whether under acid or alkaline conditions, due to the increase in basal spacing and the improvement of hydrophobicity. Moreover, the adsorption efficiencies of AFB1 and ZEA over CPC-modified montmorillonite (CPC-AMMT-3) coexisting with vitamin B6 or lysine are still at a high level (all above 94%). All modified montmorillonites, however, have low adsorption efficiency for DON, with somewhat spherical molecular geometry.

Author(s):  
Masashi Nakayama ◽  
Haruo Sato ◽  
Yutaka Sugita ◽  
Seiji Ito ◽  
Masashi Minamide ◽  
...  

In Japan, any high level radioactive waste (HLW) repository is to be constructed at over 300 m depth below surface. Tunnel support is used for safety during the construction and operation, and shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement and various admixtures. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. Japan Atomic Energy Agency (JAEA) has developed a low alkaline cement, named as HFSC (Highly Fly-ash Contained Silicafume Cement), containing over 60 wt% of silica-fume (SF) and fly-ash (FA). HFSC was used experimentally as the shotcrete material in construction of part of the 140m deep gallery in the Horonobe Underground Research Laboratory (URL). The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40 wt% OPC (Ordinary Portland Cement), 20 wt% SF, and 40 wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC. The total length of tunnel using HFSC shotcrete is about 73 m and about 500 m3 of HFSC was used. The workability of HFSC shotcrete was confirmed in this experimental construction.


2015 ◽  
Vol 7 (3) ◽  
pp. 372-381
Author(s):  
Comfort O. AFOLAYAN ◽  
Michael Olugemi AWODIRAN

The genetic differentiation of Archachatina marginata populations from three different zones of Nigeria was studied with a view to delimiting them into sub-species. One hundred and nineteen (119) snail specimens were collected, comprising of forty (40) specimens from Yenagoa (Mangrove forest) and from Kabba (Guinea Savanna) and thirty nine (39) specimens were from Ile-Ife (Rainforest). Eight parameters of the shell specimens of A. marginata which included height of shell, width of shell, aperture height, aperture width, spire length, spire width, penultimate whorl length and first whorl length were subjected to Principal Component Analysis (PCA) and Canonical Variates Analysis (CVA) to delimit the populations into sub-species. DNA of the various populations was extracted from the foot muscle using CTAB (Cetyl Trimethyl Ammonium Bromide) method, which was subjected to RAPD analysis. The RAPD studies employed five (5) oligonucleotide primers (OPB – 17, OPH – 12, OPH – 17, OPI – 06 and OPU – 14) to amplify DNA from 27 samples of A. marginata selected. All five primers produced different band patterns, and the number of fragments amplified per primer varied. Among them, OPB- 17 gave DNA profiles with more numerous bands than the others primers. Both PCA and CVA produced overlapped clusters of A. marginata specimens from the three vegetation zones. The height of shell was observed to be the most variable feature and preferably the most suitable parameter for population grouping. Analysis of the proportions of polymorphic loci and band sharing based on similarity indices for A. marginata samples indicated a relatively high level of genetic variation in the populations from the three areas.


2013 ◽  
Vol 68 (11) ◽  
pp. 2473-2478 ◽  
Author(s):  
Wenhao An ◽  
Hua Xiao ◽  
Man Yu ◽  
Xiaoyang Chen ◽  
Yuxin Xu ◽  
...  

Because of the wide use of antibiotics in the livestock industry, trace tetracycline antibiotics are frequently detected in swine wastewater and water bodies near pig farms. Based on natural zeolite, modified zeolite was synthesized by treatment with nitric acid. As one kind of typical tetracyclines, oxytetracycline (OTC) was chosen as the target adsorbate. Removal of trace OTC by modified zeolite and the effects of several main water matrices on OTC adsorption were studied in detail. OTC removal efficiency by acid-modified zeolite was about 90%, compared to less than 20% by natural zeolite. In general, in acidic conditions the removal efficiency of OTC by modified zeolite was about 90%, which was much higher than 20–35% in alkaline conditions. An increase in ionic strength from 0.01 to 1.0 M led to a decrease in adsorption efficiency from 90 to 27%. The presence of 10.0 mg L−1 dissolved humic acid accelerated sorption of OTC on modified zeolite, while 100.0 mg L−1 humic acid resulted in the opposite effect. An increase in temperature contributed to enhancing the adsorption efficiency.


2017 ◽  
Vol 898 ◽  
pp. 1649-1654 ◽  
Author(s):  
Min Chen ◽  
Run Hua Fan ◽  
Zi Dong Zhang ◽  
Yan Sheng Yin ◽  
Li Hua Dong

The uniform hexagonal barium ferrite powders were synthesized by co-precipitation method using metal chloride. The effects of the amount of hexadecyltrimethyl ammonium bromide (CTAB), the water bath and calcination temperature on the phase formation, microstructure and density of barium ferrites were systematically investigated. The results showed that the formation of uniform hexagonal barium ferrite powders was significantly influenced by the amount of CTAB and the water bath could lead to the larger grain size and density. The SEM demonstrated that the BaFe12O19 powders had plate-like shape with crystallite sizes varing from 150 to 200 nm. When the amount of CTAB was 0.2g/100ml and the calcination temperature was 850 °C, the barium ferrite powders were uniform which indicated that the amount of surfactant and calcination temperature were very optimum.


2020 ◽  
Vol 10 (17) ◽  
pp. 6107
Author(s):  
Zhiguo Sun ◽  
Menglu Wang ◽  
Jiaming Fan ◽  
Yue Zhou ◽  
Li Zhang

This study explored the regenerated performance of activated carbon (AC) as SO2 adsorbent. The optimal conditions of SO2 removal were determined by experiment, and then the adsorption efficiency of AC was studied by a method of thermal regeneration. The characteristics of regenerated AC were analyzed by Brunauer-Emmett-Teller (BET) and Scanning Electron Microscopy (SEM) methods. The test results showed that the most suitable adsorption conditions were using 4 g of activated carbon, 1.65 L/min gas flue rate, and 5% O2. During the ten regenerations, the desulfurization efficiency and sulfur capacity of AC still maintained a high level. The characterization results showed that the increase of material surface area and pore volume were 101 m2 g−1, and 0.13 cm3 g−1, respectively, after the cycles.


2013 ◽  
Vol 67 (3) ◽  
pp. 527-534 ◽  
Author(s):  
Bin Yan ◽  
Ping Wang ◽  
Wenchao Liao ◽  
Qian Ye ◽  
Meilan Xu ◽  
...  

The responses of microbial community to pH and salt shock during phenols degradation under high salt conditions were revealed by two DNA fingerprint methods, i.e. ribosomal intergenic spacer analysis (RISA) and amplified functional DNA restriction analysis (AFDRA), together with 16S rDNA clone library analysis. It was shown that the phenols removal rate was improved with increasing NaCl concentration from 0 to 50 mg/L, and could remain at a high level even in the presence of 100 mg/L NaCl. The degradation efficiency remained stable under neutral conditions (pH 7.0–9.0), but decreased sharply under acidic (below pH 5.0) or more alkaline conditions (above pH 10.0). The community structure was dramatically changed during salt fluctuations, with Halomonas sp. and Marinobacter sp. as the predominant salt-tolerant species. Meanwhile, Marinobacter sp. and Alcaligenes faecalis sp. were the major species which might play the key role for stabilizing the treatment systems under different pH conditions. Moreover, the changes of phenol hydroxylase genes were analyzed by AFDRA, which showed that these functional genes were substantially different under any shock conditions.


2008 ◽  
Vol 66 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Aleksandra Daković ◽  
Srđan Matijašević ◽  
George E. Rottinghaus ◽  
David R. Ledoux ◽  
Paula Butkeraitis ◽  
...  

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