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Ali Sdiri Teruo Higashi Rochdi Chaabouni Fakher Jamoussi 《Water, air, and soil pollution》2012,223(3):1191-1204
A batch sorption method was used to study the removal of few toxic metals onto the Late Cretaceous clays of Aleg formation
(Coniacian–Lower Campanian system), Tunisia, in single, binary and multi-component systems. The collected clay samples were
used as adsorbents for the removal of Pb(II), Cd(II), Cu(II) and Zn(II) from aqueous solutions. Results show that the natural
clay samples were mainly composed of silica, alumina, iron and magnesium oxides. N2-adsorption measurements indicated mesoporous materials with modest specific surface area of <71 m2/g. Carbonate minerals were the most influencing parameters for heavy metal removal by natural clays in both single and multi-element
systems. The affinity sequence was Pb(II)>Cu(II)>Zn(II)>Cd(II) due to the variable physical properties of the studied metals.
The maximum adsorption capacity reached 131.58 mg/g in single systems, but decreased to <50.10 mg/g in mixed systems. In single,
binary and muti-element systems, the studied clay samples removed substantial amounts of heavy metals, showing better effectiveness
than the relevant previous studies. These results suggest that the studied clay samples of the Late Cretaceous clays from
Tunisia can be effectively used as natural adsorbents for the removal of toxic heavy metals in aqueous systems. 相似文献
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New degreening treatments to improve the quality of citrus fruit combining different periods with and without ethylene exposure 总被引:1,自引:0,他引:1
Sawsen Sdiri Pilar NavarroAdela Monterde Jameleddine BenabdaAlejandra Salvador 《Postharvest Biology and Technology》2012,63(1):25-32
In the Mediterranean area, early-season citrus fruit reach acceptable internal maturity standards for marketing, while the fruit are still green. A degreening treatment is widely used as a postharvest practice to improve the external color. Nevertheless, the application of ethylene during this treatment can be associated with calyx senescence. The aim of this study was to evaluate new degreening treatments in order to reduce this disorder. ‘Clemenules’ mandarins and ‘Navelina’ oranges, harvested at different external colors, were submitted to different degreening treatments, combining periods with and without ethylene exposure. In both cultivars, the periods without ethylene exposure during degreening reduced the incidence of calyx disorders. To obtain a typical ‘Clemenules’ variety color with the lowest incidence of calyx alteration, the optimum degreening treatment was based on 72 h with ethylene and 48 h without ethylene when fruit were harvested with a color index of between −9 and −3. On the other hand, a treatment of 24 h with ethylene plus 48 h without ethylene is recommended for fruit with an external color index higher than −2. For ‘Navelina’ oranges, highly sensitive to calyx senescence during degreening, a treatment consisting of 24 h with ethylene plus 48 h without ethylene is recommended, which involves harvesting the fruit with a color index of over 0. 相似文献
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Oumar Ibrahima Farhat Chibani Sawsen A. Oran Mohamed Boussaid Yannis Karamanos Aly Raies 《Genetic Resources and Crop Evolution》2005,52(8):1087-1097
Allozyme variation was assessed in a collection of pearl millet cultivars derived from three different regions of traditional
cultivation of this cereal in Tunisia and West African countries. Using starch gel electrophoresis, 11 loci corresponding
to seven enzyme staining systems were identified. Important within-cultivar genetic diversity was detected. Genetic diversity
within Tunisian cultivars was similar and was more pronounced than for West African ones. This result could be explained by
the low level of the human selection characterizing the Tunisian cultivars. Most of the total genetic diversity is maintained
within subregions suggesting little genetic differentiation. Cluster analysis did not reveal separate clusters for the various
subregion cultivars. However the cluster analysis should help in the selection of interesting genotypes for future breeding
programs. 相似文献
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Myriam Lamine Fatma Zohra Rahali Ghaith Hamdaoui Sawsen Selmi Ahmed Mliki Mahmoud Gargouri 《Euphytica》2017,213(2):44
Variation in metabolite composition and content is often observed in citrus, however, it is poorly understood to what extent this variation has a genetic basis. C. aurantium genotypes originating from Tunisia were evaluated to detect genomic (SSR markers) and chemotypic polymorphisms and to discover possible associations between them. A total of fifteen highly polymorphic SSR markers were selected to screen the genetic variability of the most widespread sour orange genotypes. Targeted secondary metabolite profiling analysis generated twenty-one compounds differentially accumulated in the leaves of sour orange genotypes. PCA analysis revealed that genomic and chemotypic data generated similar pattern of clustering, highlighting the intra-specific variability in C. aurantium species. Both data were integrated, leading to the identification of associated SSR alleles with secondary metabolites. Based on results, a relatively high correlation (r = 0.381; p < 0.0001) between chemotypic patterns and genetic markers was identified. Associations between traits of interest for phenolic compounds and genetic markers were tested using statistical methods including three linear model approaches. These results consolidate the presence of a chemical fingerprint that may be suitable for assessing identity and quality of a particular genotype which will be very useful for citrus breeding programs. 相似文献
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