摘要
本研究通过对江西千烟洲香溪流域的氮输出进行长期监测,并对该流域内的底泥进行基于正交试验的氮释放规律模拟研究,评估干湿季节交替下底泥氮释放对流域氮输出的贡献.结果表明：1流域底泥在静态下TN释放速率最大值为36mg·（m2·d）-1,且随着时间的延续释放速率不断变小;2对底泥氮释放影响的主次顺序为：温度〉扰动〉p H,如将扰动视为误差项,温度和p H对底泥氮释放的影响均为极显著;3 TN释放速率与温度成正比例关系,随着温度升高,释放速率增大;酸性和碱性条件均能促进底泥氮释放,且酸性条件的促进作用更强;4流域底泥TN和有效氮含量变化范围分别为：414.7-899.6 mg·kg-1和17.5-58.9 mg·kg-1,有效氮占TN的质量分数为3%-10%;5流域在旱季TN输出浓度范围为0.58-2.40 mg·L-1,在雨季TN输出浓度范围为1.73-4.87 mg·L-1;流域底泥的氮释放通量约为106.34 kg·a-1,流域氮输出总量为864.15 kg·a-1,底泥的氮释放对流域水体氮输出的贡献率约为12.31%,底泥氮释放对流域水体富营养化的贡献应引起重视.
In this study,N export from Xiangxi River Basin in Qianyanzhou station was measured by long-term monitoring,and simulation study on N release law from the sediment in watershed was carried out based on orthogonal experiment,and at last the contributions of N release from sediment to N transport from watershed under dry and rainy season alternation were estimated. The results showed that the maximum of TN release rate was 36 mg·（ m2·d）- 1in stable status,which decreased with increasing time; the impact of the three controlling factors on the N release followed the order of temperature disturbance p H,and the effect of temperature and p H on N release from the sediment was significant when disturbance was considered as the error term; TN release rate increased with increase of temperature,and acidic and alkaline conditions could also promote N release from sediment,wherein the effect of acidic conditions on N release was stronger; the changes of TN and available N content in sediment were 414. 7-899. 6mg·kg- 1and 17. 5- 58. 9 mg·kg- 1,so the percentage of available N only accounted for 3%-10% of TN; the TN transport concentrations were 0. 58-2. 40 mg·L- 1and 1. 73-4. 87 mg·L- 1in dry and wet seasons,respectively,the N release flux from sediment was about 106. 34 kg·a- 1,the total N transport from watershed was 864. 15 kg·a- 1,and the contribution rate of N release from sediment to N transport from watershed was about 12. 31%,so we should pay much attention to the contribution of N release from sediment to water eutrophication.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2016年第2期534-541,共8页
Environmental Science
基金
国家自然科学基金重大项目(31570465
31290223)
中国科学院“青年创新促进会”项目
关键词
流域
氮输出
底泥
氮释放
干湿交替
watershed
N export
sediment
N release
wet and dry alternation
