巢湖滨岸水塘洼地沉积物反硝化速率及对外源碳氮的响应 |
摘要点击 2532 全文点击 959 投稿时间:2019-10-18 修订日期:2019-11-06 |
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中文关键词 水塘洼地 反硝化速率 外源碳氮 限制性因素 巢湖 |
英文关键词 ponds and bottomland denitrification rates exogenous carbon and nitrogen influencing factors Lake Chaohu |
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中文摘要 |
2018年10月至2019年8月,在巢湖西半湖北侧滨岸筛选3个典型水塘洼地,采集表层沉积物及上覆水样,开展外源碳氮浓度梯度培养实验,解析底质反硝化速率对碳氮的限制性,并识别主要环境影响因素.结果表明:①洼地蒲草、水塘芦苇、水塘蒲草等3种植物丛沉积物对照样的反硝化速率[mg·(kg·h)-1]分别为2.15~10.87(均值为6.47)、2.08~10.65(均值为6.97)、2.06~10.88(均值为6.76),彼此间差异性不显著;②总体上,外源氮(硝态氮)的添加可以明显提高沉积物的反硝化速率,表明硝态氮为反硝化过程的限制性因素;③外源碳(葡萄糖)的添加导致植物丛沉积物反硝化速率明显下降,表明有机碳对沉积物反硝化产生了抑制作用;④外源碳氮同时添加明显提高了沉积物反硝化速率,除10月洼地蒲草丛和6月水塘蒲草丛低碳氮浓度沉积物反硝化速率相对较高以外,其它情形均表现为高碳氮浓度沉积物反硝化速率更高. |
英文摘要 |
From October 2018 to August 2019, three typical ponds and bottomland were selected in the Chaohu lakeshore zone, where surface sediments and overlying water samples were collected simultaneously. A set of incubation experiments, along with exogenous carbon and nitrogen concentration gradients, were conducted to analyze sediment denitrification rates and its response to carbon and nitrogen limitation. Moreover, the main influencing factors for the sediment denitrification process were identified using correlation analysis method. The results showed that ① the denitrification rates of three plant plexus sediments were 2.15-10.87, 2.08-10.65, and 2.06-10.88 mg·(kg·h)-1, with averages of 6.47, 6.97, and 6.76 mg·(kg·h)-1, respectively. Overall, there was no significant difference between them. ② In general, exogenous nitrogen addition could significantly increase denitrification rates of the three plant sediments, indicating that nitrate was the limiting factor for the sediment denitrification process. ③ Exogenous carbon addition resulted in a significant decrease in the denitrification rates of three plant plexus sediments, indicating that organic carbon inhibited the denitrification process. ④ Exogenous carbon and nitrogen added simultaneously displayed a dramatic effect on the increase of sediment denitrification rates. Except for the bottomland Pucao in October and pond Pucao in June, all other cases showed higher denitrification rates for high carbon and nitrogen concentration. |
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