5种植物材料的水解释碳性能及反硝化效率

碳源在硝酸盐去除过程中起电子供体的作用,是生物反硝化反应的关键物质之一。为解决污水处理脱氮时碳源不足抑制反硝化反应造成脱氮效率低的问题,本研究选取风车草、甘蔗渣、芦竹、美人蕉和稻草秆5种植物材料作为反硝化碳源,探讨不同植物材料的水解释碳能力和释放规律;并进一步以其水解液作为外加碳源,探讨其对反硝化脱氮效率的影响。研究结果表明,植物材料水解释碳过程符合二级动力学反应规律,不同植物材料的释碳能力具有显著性差异,以甘蔗渣在固液比1∶80时COD释放当量最大,为45.45 mg/L;添加植物水解液可显著提高反硝化脱氮效率,以芦竹水解液脱氮效果最好,达到71.9%。此外,碳氮比是影响脱氮效率的重要因素之一,以碳氮比为9时反硝化脱氮效果最佳。

Carbon releasing characteristics and denitrification effects of five plant materials

Organic carbon is used as an electron donor in the process of nitrate reduction, which is essential for biological denitrification. To solve the problem of low-efficiency nitrogen removal due to a shortage of organic carbon, we selected Arundo donax, Canna indica, Cyperus alternifolius, rice straw, and bagasse as potential carbon sources for denitrification, and explored the carbon-releasing ability of these different plant materials and its release rule by hydrolysis way. We also investigated the nitrogen removal efficiency of additional carbon resources by adding hydrolyzates of the aforementioned five plant materials. The results showed that the release process of the various carbon sources follows a second dynamics equation. The carbon-releasing abilities of the different plant materials were shown to be significantly different (p < 0.01). We found that the chemical oxygen demand was highest with a solid:liquid carbon ratio of 1:80, and the highest was 45.45 mg/L with bagasse.Compared with the control group that lacked an additional carbon source, all the experimental groups had a significantly improved nitrogen removal efficiency (p < 0.05). Among the various carbon sources, nitrogen removal efficiency was highest (total nitrogen, 71.9%) when using a hydrolyzate of Arundo donax. We conclude that, for denitrification, Arundo donax hydrolyzate is the best choice as a carbon source, and that a carbon:nitrogen ratio of 9 is optimal.