کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2025580 | 1070003 | 2009 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Lignite pre-treatment and its effect on bio-stimulative properties of respective lignite humic acids
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
دانش خاک شناسی
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چکیده انگلیسی
Humic acids originating from South-Moravian lignite were subjected to a comparative study with the aim to assess the alteration of their physico-chemical properties after various lignite pre-treatments. Physical modification was achieved with two organic acids, such as acetic acid and citric acid and chemical modification by nitric acid and hydrogene peroxide in various concentrations. Elemental analysis, solid-state NMR, GC-MS analysis of polyols and size exclusion chromatography were carried out for chemical-physical characterization of obtained humic acids. Their biological effect, in form of potassium and ammonium humates, was tested on maize (Zea mays) seedlings. In these tests, potassium humates achieved far better overall results than ammonium humates. Results were inter-correlated in order to appraise the influence of humic acids physical and chemical properties on biological activity. Surprisingly, fractions with the lowest molecular size (0-35Â kDa) showed no correlation with bioactivity results (Pearson coefficient from 0.05 to â0.4). On the contrary, middle-sized fractions (35-175Â kDa) showed highly significant positive correlation (Pearson coefficient up to 0.92) and the highest molecular-size-fractions (275-350Â kDa) showed negative correlation (Pearson coefficient up to â0.75). These findings were identical for both potassium and ammonium humates. No connection was found between bioactivity of humates and polyols content which was remarkably high; it reached 150Â mg per g of humic acids in the most extreme case of 5% hydrogene peroxide pre-treatment. In the final analysis, the preparation mode bore pivotal responsibility for the control of humic acids biological effect and showed the best results for potassium humates obtained from lignite pre-treated by acetic acid and by 2% hydrogen peroxide.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Soil Biology and Biochemistry - Volume 41, Issue 9, September 2009, Pages 1894-1901
Journal: Soil Biology and Biochemistry - Volume 41, Issue 9, September 2009, Pages 1894-1901
نویسندگان
Zoja VlÄková, Laurent Grasset, Barbora AntoÅ¡ová, Miloslav PekaÅ, JiÅà KuÄerÃk,