RONG Hui (1983-), male, Ph. D., Associate Professor. E-mail: huirongtcu@126.com
Sulfur oxidation characteristics of sulfur oxidizing bacteria under different substrates and the mechanical properties and microstructure of mortar samples were investigated. The growth concentrations of sulfur oxidizing bacteria are different under different substrates, i.e., the corresponding growth concentration decreases from high to low in an order of Na2S2O3, Na2SO3 and Na2S. The natural oxidation and biological oxidation both occur in the transformation of SO42- by the sulfur oxidizing bacteria under different substrates. S2O32- can be transformed to SO32- through SseA enzyme and then to SO42- through Soe enzyme. The swelling gypsum content of mortar sample under Na2S2O3 substrate is lower than that under Na2SO3 substrate. This is because SO42- concentration of natural oxidation of Na2SO3 is greater than that of the biological oxidation, thus leading to a higher reaction rate and a stronger corrosion effect. The compressive strength and mass change rate of the mortar samples under Na2S2O3 substrate are 10.4% and 1.04%, respectively. The change rate of compressive strength and mass of the mortar samples under Na2SO3 substrate are -12.9% and 1.44%, respectively. Combined with the mineral composition analysis results, it is indicated that the gypsum content of the samples under Na2S2O3 substrate is lower than that of the samples under Na2SO3 substrate, while the mortar samples are eventually deteriorated, due to the expansive force of a large amount of gypsum after 75 d and 45 d.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |