水流扰动强度对高原山地农村沟渠底泥氮释放的影响  

Effect of Flow Disturbance Intensity on Nitrogen Release from Bottom Muddy of Plateau Rural Ditches

作　　者：郑淑君 王铁运 刘云根[1,2] 杜鹏睿 王妍 贾玉洁[1] 文明发 ZHENG Shu-jun;WANG Tie-yun;LIU Yun-gen;DU Peng-rui;WANG Yan;JIA Yu-jie;WEN Ming-fa(College of Ecology and Environment,Southwest Forestry University,Kunming 650224,China;Yunnan Key Laboratory of Ecological Environment Evolution and Pollution Control in Mountainous Rural Areas,Kunming 650224,China;Yunnan Deyuan Lüchuang Environmental Protection Technology Co.Ltd.,Kunming 650041,China)

机构地区：[1]西南林业大学生态与环境学院,云南昆明650224 [2]云南省山地农村生态环境演变与污染治理重点实验室,云南昆明650224 [3]云南省德源绿创环保科技有限公司,云南昆明650041

出　　处：《生态与农村环境学报》2022年第8期1076-1083,共8页Journal of Ecology and Rural Environment

基　　金：国家自然科学基金(41761098,31760245)。

摘　　要：为揭示水动力扰动对高原山地农村沟渠内源氮营养盐释放的影响,通过室内模拟试验研究不同水流扰动强度(0、5、15、30、60 L·h^(-1))对底泥氮释放的影响。结果表明:(1)水动力扰动初期可引起底泥氮元素向上覆水释放,5 L·h^(-1)扰动下水体中NH_(4)^(+)-N浓度达到最高值,60 L·h^(-1)扰动下水体TN浓度达到最高值,在连续扰动30 d后,静置水体氮浓度高于扰动水体;(2)随扰动强度的增加,底泥TN含量也增加,但总体低于背景值,呈现出0<5<30<15<60 L·h^(-1)的规律;(3)底泥各形态可转化态氮(TTN)含量由大到小依次表现为强氧化剂可提取态氮(SOEF-N)、强碱可提取态氮(WAEF-N)、离子交换态氮(IEF-N)和弱酸可提取态氮(SAEF-N);释放程度从易到难依次为IEF-N、WAEF-N、SAEF-N、SOEF-N;各形态氮的最小值均出现在静置时,说明扰动更有利于底泥对水体氮营养盐的吸收,减轻其沿途对周围环境造成潜在的危害。To investigate the effect of hydrodynamic disturbance on endogenous nitrogen(N)release in plateau mountainous rural ditches,N concentrations in overlying water under various flow disturbance intensities(0,5,15,30,60 L·h^(-1))were analyzed by a simulation experiment.The results show that:(1)Sediment N can be released into overlying water by the initial hydrodynamic disturbance and reaches the highest values of NH_(4)^(+)-N and TN at 5 and 60 L·h^(-1) flow disturbance intensity,respectively.After 30 days,N concentration in the undisturbed water was higher than that in the disturbed water;(2)Sediment TN contents increased with the increasing of disturbance intensity,which however were lower than the background values,showing 0<5<30<15<60 L·h^(-1);(3)The contents of different forms of transformable nitrogen(TTN)were in the order of strong oxidant extractable-N(SOEF-N)>strong alkali extractable-N(WAEF-N)>ion exchange-N(IEF-N)>weak acid extractable-N(SAEF-N),with releasing tendentiousness of IEF-N>WAEF-N>SAEF-N>SOEF-N.All N fractions of the sediment were at the lowest values under undisturbed treatment,indicating that the disturbance of flow benefits the N settlement in sediments,thus decreasing the risk of N to the surrounding environment.

关 键 词：农村沟渠 底泥 氮释放 扰动 

分 类 号：X171[环境科学与工程—环境科学]