自养反硝化脱氮耦合沼气同步脱硫效能研究

污水深度脱氮问题日益突出,在实现污水深度脱氮的过程中尽可能降低运行成本更是符合目前我国的发展目标,因此,开发经济绿色的污水脱氮技术对可持续发展具有重大意义.本试验提出自养反硝化脱氮耦合沼气同步脱硫工艺,具有成本低,资源利用率高等优势.以沼气中的硫化氢作为电子供体,实现了污水中同步脱氮及沼气脱硫净化的耦合,并探究了上升流速、硫氮比对该工艺运行效能的影响.实验结果显示,以硫化氢代替硫化物作为电子供体参与反硝化,对工艺脱氮效能无明显影响,在低硝酸盐负荷条件下运行时,污水脱氮效能不受气体上升流速及硫氮比的影响,均能达到100%.而本工艺的脱硫效能受上升流速影响较小,受硫氮比影响较大.在不同上升流速下,硫化氢去除率均为100%.在硫氮比为5∶8时,硫化氢100%转化为硫酸盐;硫氮比为5∶5时,硫化氢去除率为99.1%,单质硫产率约为30%;硫氮比为5∶2,回流比为1∶1时,硫化氢去除率最高可达91%,单质硫产率为77%.本试验可为后续自养反硝脱氮同步沼气脱硫工艺参数优化及应用的拓展提供理论依据和参考.

The study on efficiency of autotrophic denitrification coupling biogas desulfurization simultaneously

It is becoming important to reduce the operation cost as much as possible in the process of deep denitrification of sewage. So, developing the economical and green denitrification technology is of great significance for sustainable development. This study was proposed to couple the autotrophic denitrification and biogas desulfurization simultaneously, which has the advantages of low cost and high resource utilization. The test used the hydrogen sulfide in biogas as electronic donors and nitrate in wastewater as electron acceptors to realize simultaneous wastewater denitrification and biogas desulfurization. At the same time, the influence of flow rate and S/N ratio on the operation efficiency was investigated. The results show that replacing sulfide with hydrogen sulfide as electron donor in denitrification has no significant impact to the denitrification efficiency. Nitrogen removal efficiency of sewage was not affected by gas upwelling velocity and S/N ratio, and both reached 100% under the low nitrate loading conditions. However, the desulfurization efficiency was affected by upwelling velocity but much more affected by S/N ratio. The hydrogen sulfide removal efficiency could reach 100% although changing the upwelling velocity. When the S/N ratio was 5:8, the convertion of the hydrogen sulfide to sulfate was 100%, and 99.1% under S/N ratio of 5:5. It is about 30% of the yield of the elemental sulfur. When the S/N ratio was 5:2 and the reflux ratio was 1:1, the removal rate of hydrogen sulfide could reach 91% and the yield of elemental sulfur was 77%. This study could provide the theoretical basis for the parameters optimization of biogas desulfurization with autotrophic denitrification.