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Volatile alkyl sulfides include dimethyl sulfide (DMS), dimethyl disulfide (DMDS) and methyl mercaptan (MT), are constructed wetland over a major source of odor. At the same time these sulfides on global warming, acid rain and other natural phenomena have important implications. Constructed wetlands as the mainland wetlands important part, because an efficient, low running costs, simple operation, and other advantages by many countries as a unique, new sewage treatment technology widely used. Currently, wetland studies are focused on the design and wetland sewage treatment capacity, etc., over land alkyl wetlands as an important producer of sulfur is often overlooked, and thus there are few studies focus on its internal alkyl sulfide formation mechanism and an alkylthio intermediate degradation products and the link between In this thesis, a pilot constructed wetland as an object, in-depth study wetlands alkylthio generation, transformation and degradation processes, the main contents are as follows: 1. An artificial wetland mud as a substrate, simulated wetland environment, research common organic matter degradation intermediates alcohols, aldehydes, acids and ketones for the production and release of DMS DMS methyl donor influence and new exploration. Two wetland in sulfate, nitrate, etc. on the DMS, DMDS, MT formation and transformation between the impact and cause analysis. 3 Use the Fenton reaction principle looking for a quick, efficient and environmentally friendly method of degradation of DMS. By studying the main results obtained are as follows: 1. To explore the constructed wetland in dimethyl sulfide DMS sources, the paper simulation of artificial wetlands, wetland by assuming methyl or aldehyde group containing dissolved organic matter to produce DMS methyl donor research DMS generating mechanism. The results showed that: DMS artificial wetlands under the action of microorganisms through methylation of sulfide produced by microbial degradation simultaneously. Ethanol, acetic acid, acetone and aldehydes were able to inhibit the methane-producing bacteria to increase the consumption of the DMS DMS production. In the inhibition of methanogenic activity environment, ethanol, acetic acid, acetone, etc. on the DMS produced no significant effects, the first 48 h, 72 h DMS are generated with the corresponding concentrations close to the control group, indicating that they are not the methyl donor body; aldehydes significant impact on the DMS (p lt; 0.001), and between the two there is a high linear correlation (R2 = 0.937-0.984), formaldehyde added 40 mmol / L so that DMS concentrations up 153.05μg / L, the most significant impact. Methyl-containing organic compounds by means of sodium sulfide in water and the reaction was found: add formaldehyde reaction flask with 5.32μg / L produced a DMS, the yield is much smaller than the substrate in the mud, and other organic sulfide can not be produce alkyl sulfur. This results show that indeed the DMS of formaldehyde methyl donor, and sulfide synthesis DMS biological pathways can also be by chemical means, is the primary mechanism biological pathways. the pH value of the DMS more significant impact, DMS larger concentration under acidic conditions, basic conditions of DMS was significantly reduced to disappear. (2) the presence of nitrate and DMS DMDS favor the generation of nitrite can promote the generation of MT and DMS, sulfate-reducing bacteria can be reduced to generate a DMS provided sulfide sulfur donor, thereby promoting the generation of DMS. Metal ions only produce copper ions can promote the DMS, other metal ions had no significant effect, alkyl sulfide production nanomaterials on whether an effect with its own nature and size are closely related to iron oxide nanomaterials can significantly affect production and release of DMS, and the carbon nanotube can not. 3 degradation in Fenton, Fe2 concentration less than 1mg / L, H2O2 concentration was less than 5mg / L will enable the degradation efficiency DMS 100%, pH of this oxidation reaction is small. If using only H2O2, the concentration required to achieve 1000 mg / L, when the temperature is 60 ℃ to close completely degraded. Degradation products to Fe3 and SO42-, etc., derived from the power curve of this reaction activation energy Ea = 39.18kJ/mol, by calculating the Fe2, H2O2 indices (m, n) has a value of m = 0.4998, n = 0.2284, m gt; n, the description for this reaction is more dependent on the concentration of Fe2, that this Fenton reaction Fe2 degradation than H2O2 play a greater role.
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