选定因素下湿地基质释放氮的正交试验研究

Orthogonal Experiment Study on Nitrogen Release from Substrate of Wetland under Selected Factors

通过正交试验考察了成熟湿地基质在选定的影响因素及水平下的氮释放量。结果表明,25℃下氨氮的平均释放量是15℃下的2.9倍,亚硝态氮及硝态氮的释放量在两温度下无显著差异;35℃下氨氮的平均释放量是15℃下的5.6倍,亚硝态氮和硝态氮的释放量较15℃时有明显增加。由于湿地基质中COD的释放,在试验设定的进水COD浓度水平(≤40 mg/L)下,COD含量难以对氮的释放产生显著影响。湿地基质对pH有较强的缓冲能力,试验设定的进水pH基本不会影响氮的释放。

Under the selected factors and levels,nitrogen release quantity from the mature substrate of wetland was investigated by orthogonal experiments.The results show that the average release quantity of ammonia nitrogen at 25 ℃ is 2.9 times of that at 15 ℃,but the release quantity of nitrite and nitrate nitrogen at the two temperatures has no evident difference.The average release quantity of ammonia nitrogen at 35 ℃ is 5.6 times of that at 15 ℃,and the release quantity of nitrite and nitrate nitrogen is also higher than that at 15 ℃.Due to COD release from the substrate of wetland,under the condition of influent COD concentration levels selected in the experiment（≤40 mg/L）,the COD concentration is difficult to affect the nitrogen release evidently.The substrate of wetland has sufficient buffer capacity to pH,and the pH of influent selected in the experiment can not influence the nitrogen release remarkably.