研究报告
丁怡,宋新山,严登华.补充碳源提取液对人工湿地脱氮作用的影响[J].环境科学学报,2012,32(7):1646-1652
补充碳源提取液对人工湿地脱氮作用的影响
- Effect of adding carbon source extracts on nitrogen removal in constructed wetland
- 基金项目：国家自然科学基金(No.51079028);国家重点基础研究发展(973)计划(No.2010CB951102-4);上海市自然科学基金(No.10ZR1400300)
- 作者
- 单位
- 丁怡
- 东华大学环境科学与工程学院,上海 201620
- 宋新山
- 东华大学环境科学与工程学院,上海 201620
- 严登华
- 中国水利水电科学研究院,北京 100044
- 摘要：为了提高人工湿地的脱氮效率,在不同条件下分别对美人蕉、香蒲及稻杆进行稀硫酸水解,以获得相应碳源提取液.正交实验表明,稀硫酸浓度的提高和水解时间的增加都会导致碳源释碳能力的提高,稻杆在5%稀硫酸溶液中水解30 min以上,释碳能力最高.通过观察,前2 d是系统脱氮反应高峰时段.对以NH4+-N和NO3--N为氮源的脱氮过程,随C/N比升高,NO3--N和TN去除率增长明显;而NH4+-N受溶解氧制约,去除有限;随C/N比升高,碳源对系统溶解氧的竞争会进一步抑制硝化反应的彻底进行.而对以NO3--N为氮源的反硝化过程,补充碳源对TN和NO3--N的去除有明显作用;TN去除率由54%提高到95%,NO3--N去除率由48%提高到96%;中间产物NO2--N的积累与NO3--N去除率有关;当NO3--N去除率较高时,NO2--N无积累.此外,基质反硝化强度也随C/N比升高呈上升趋势,湿地填料细沙层的反硝化强度略高于碎石层.
- Abstract：To enhance the nitrogen removal efficiency in constructed wetland, Canna indica Typha latifolia and straw were hydrolyzed by dilute sulphuric acid under different conditions to get relevant carbon source extracts. Orthogonal test indicated that the increase of dilute acid concentration and time of the hydrolysis led to the increase of COD concentration. Straw hydrolyzed in 5% dilute sulphuric acid over 30 minutes had the highest COD concentration. The removal rate of nitrogen was high in the initial two days of the experiment. The removals of NH4+-N and TN obviously increased as the C/N ratio increased, while NH4+-N was controlled by DO and its removal was limited. Carbon source further restrained nitrification by competition for DO. Adding carbon source significantly enhanced the removal of TN and NO3--N, with the removal of TN increased from 54% to 95% and the removal of NO3--N increased from 48% to 96%.The accumulation of intermediate product, NO2--N, was dependent on the removal rate of NO3--N. When the removal of NO3--N was relatively high, no accumulation of NO2--N was found. Furthermore, denitrification in matrix showed an increasing tendency as the C/N ratio increased and denitrification in the fine sand layer was relatively higher than that in the rubble layer.
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