摘要
研究沉水植物腐解过程中的氮素释放规律及其对上覆水的冲击影响,可以为沉水植物的科学管理提供技术支撑。为了研究季相交替时期不同密度金鱼藻(Ceratophyllum demersum L)腐解过程的氮素释放及其对上覆水中溶解氧、总氮、氨氮、硝酸盐氮和亚硝酸盐含量的影响,作者通过实验室模拟的方法,在烧杯中进行金鱼藻的浸泡试验,以不同密度梯度的金鱼藻浸泡作对比,不放金鱼藻的烧杯做空白对照,测定水体中的各氮素含量以及水体相关的物理指标。结果表明,随时间的增加,实验组的上覆水总氮含量急剧上升,且上覆水总氮含量随着浸泡密度的升高而增高;同时,上覆水溶解氧含量在36 h后均迅速降低至0.04 mg/L左右。实验组中硝酸盐氮和亚硝酸盐氮含量,均在8 h时达到峰值(分别为0.35、0.075 mg/L左右)后分别迅速下降至0.1、0.01 mg/L水平以下。各组上覆水氨氮和总氮含量则在4 h时就达到峰值(氨氮分别为3.83、8.78、13.40 mg/L,总氮分别为11.08、23.87、36.78 mg/L),氨氮随后持续降低至1.0 mg/L,总氮持续降低至1.5 mg/L,至实验结束时达到最小值。金鱼藻腐解的氮素释放量与其生物量密度呈现正相关关系,且金鱼藻腐解会使其上覆水的总氮和氨氮含量在4 h内达到最大,而硝酸盐氮和亚硝酸盐氮含量则在8 h达到最大值。因此,金鱼藻种植密度适宜控制在鲜重10 g/L以内,且季相交替时,应及时收割金鱼藻残体。
The aim of this study was to study the release of nitrogen and impact on overlying water during the decomposition of submerged plants, and to provide technical support for the scientific management of submerged plants. Nitrogen release during decomposition of hornwort(Ceratophyllum demersum L.) at different densities during seasonal alternation and its effects on dissolved oxygen, total nitrogen, ammonia, nitrate nitrogen and nitrite content in overlying water was investigated. The experiment of hornwort immersion was carried out in beaker by laboratory simulation. A beaker without hornwort was used as a blank control to determine the nitrogen content in the water and the physical indicators related to the water. Results showed that with the increase of immersing time, the total nitrogen content in overlying water of all experimental groups immersed with hornwort increased sharply, and the total nitrogen content in overlying water increased with the increase of immersing density. The dissolved oxygen content in the overlying water of all treatments decreased rapidly to about 0.04 mg/L after 36 hours. Nitrate and nitrite contents in the experimental group reached their peak values at 8 hours, with the contents about 0.35 mg/L and 0.075 mg/L, respectively. After that, they dropped rapidly to below 0.1 mg/L and 0.01 mg/L levels respectively. The ammonia and total nitrogen content in the overlying water of each treatment group reached the peak at 4 hours, with ammonia as 3.83 mg/L, 8.78 mg/L and 13.40 mg/L, total nitrogen as 11.08 mg/L, 23.87 mg/L and 36.78 mg/L respectively. The ammonia continued to decrease to 1.0 mg/L, and the total nitrogen continued to decrease to 1.5 mg/L, at the end of the experiment it came to the minimum. The release of nitrogen from decomposition of hornwort was positively correlated with its biomass density, and the decomposition of hornwort could maximize the total nitrogen and ammonia content in the overlying water within 4 hours, while the nitrate and nitrite content reached the maximum within 8 hours. Therefore, the planting density of hornwort should be controlled under 10 g/L. Moreover, the residue of hornwort should be harvested quickly when seasons alternate.
作者
武闯
张劲
聂梓源
张静
张明志
WU Chuang;ZHANG Jin;NIE Ziyuan;ZHANG Jing;ZHANG Mingzhi(Faculty of Resources and Environment,Hubei University,Wuhan 430062,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2019年第8期13-19,共7页
Environmental Science & Technology
基金
湖北省科技惠民计划(2017ACB642)
湖北大学基金(400-164003000001)
关键词
金鱼藻
自然腐解
氮素响应
密度
hornwort
decomposition naturally
nitrogen corresponding
density
