The Stabilization Of Organic Carbon In Organo-mineral Complex In Chemical Oxidant

Changes in soil organic carbon pool is an important factor in the greenhouse effect and climate change. Organo-mineral complex is an important contribution to the storage for organic matter in soil organic carbon pool. The different kind of organic and inorganic minerals formed organo-mineral complexes by complex interaction between them. According to previous studies and the combination of the nature of the soil in Yunnan, in this paper, using peat around Dianchi extraction organic matter and four kinds of representative aromatic, aliphatic, molecular size of model compounds tannic acid, gallic acid, sodium oleate, sodium fumarate prepare complexes. Choice of two iron oxide minerals, namely nano iron oxide, microns iron oxide, and a clay mineral kaolin as preparation of complexes. Use solid-liquid adsorption for prepare organo -mineral complexes. Use 6wt% pH=8 NaOCl solution as an oxidant for the complex and a variety of organic and mineral oxidation experiments. After oxidative degradation experiments, the use of elemental analyzers, Fourier transform infrared spectroscopy and determination of ash measure samples before and after oxidation. By calculating the ratio of different samples of the residual carbon, study the protective effect of complex for organic matter.The experimental results show:(1) Elemental analysis showed four model compounds and humic acid polar descending order of sodium fumarate>gallic acid≈tannic acid> humic acid> sodium oleate, aromatic descending order of tannic acid> gallic acid≈humic acid. After adsorption of organic matter, shows lower polar and aromatic increasing trend, indicating that non-polar organic functional groups and aromatic components adsorbed on the surface of complexes.(2) In the complex and organic matter oxidation experiments, the stability of the complex components can be separated in the 8d. Loss of organic matter is completely over-oxidants, the remaining carbon ratio of 0%. After the complex oxidation experiments, the remaining proportion of carbon composites as high as 20%, including sodium oleate-nano iron oxide complexes up to 80%. This shows that complexes are oxidized leaving stability of organic matter, which confirms the protective effect of the mineral to organic matter. (3) Comparison of different minerals to form complexes, can be found in the role of nano iron oxide protect organic matter is higher than micro iron oxide, kaolin minimum. The comparison of the results of the different nature of the compound to form a complex, complex stability by sodium oleate and sodium fumarate formed higher than other organic matter. This shows that the protective effect of nano iron oxide stronger, and better resistance to oxidation of fat chain, and the ligand exchange between the role of minerals and organic matter, as well as their own polar organic matter are closely related. (4) Elemental analysis after oxidation composite display, the polarity of the sample is increased as compared to prior to oxidation, shows oxidant for non-polar functional groups have oxidation. After oxidizing complexes, aromatic substances reduced compared to before oxidation, indicating that the structure of the oxidant for aromatic complexes have oxidation. This may be as a result of such macromolecules sodium oleate aliphatic difficult to be oxidized. (5) In the IR spectra before and after oxidation of humic acid, organic matter content of aromatic substances in a certain degree of decline, because the oxidation and decomposition, generating the functional groups of the aromatic ring and aliphatic substances. When humic acid adsorbed on minerals, complexes with the corresponding aromatic functional groups and hydroxyl functional groups or containing C-O bond. After oxidation, the functional groups of aromatic reduction, increased mineral absorption, and therefore can be reduced by oxidation of aromatic functional group.Oxidation stability of organo-mineral complexes main difference between the two depends on the nature of mineral and organic matter and the interaction between them. Organic non-polar and aromatic, The role of ligand exchange between organic matter and minerals, electrostatic adsorption, and the particle size of organo-mineral complexes are all factors that the antioxidant capacity of organo-mineral complexes has contributed. The resistance mechanisms which need further study.