枯水期环渤海16条河流N_2O释放通量研究  

Emission Flux of N_2O in 16 Rivers Flowing into Bohai Sea during Dry Season

作　　者：蔡林颖[1,2] 杨丽标[2] 刘树庆[1] 雷坤[2] 

机构地区：[1]河北农业大学资源与环境科学学院,河北保定071000 [2]中国环境科学研究院河流与海岸带环境创新基地,北京100012

出　　处：《环境科学与技术》2014年第12期89-95,共7页Environmental Science & Technology

基　　金：国家自然科学基金(41203080)

摘　　要：研究了枯水期环渤海16条河流N2O溶存浓度及释放通量,分析了河流N2O与氮浓度的响应关系,讨论了河流的N2O释放系数。结果表明,枯水期16条河流TN浓度介于5.53~37.49 mg/L,均超过Ⅴ类水标准。河流N2O处于过饱和状态,其溶存浓度及饱和度变化范围分别为0.02~40.10μmol/L和203%~390 245%。N2O溶存浓度与NH4＋、TN显著正相关,表明河流氮负荷增加会极大促进N2O的产生和释放。研究采用5种常用通量模型对N2O释放通量进行了估算。结果表明,不同模型间通量结果差异很大。BO04方法估算通量最大（均值217.27μg N2O-N/（m2·h））,分别是LM86模型结果的5.5倍、W92a的2.3倍、W92b的2.9倍及RC01方法的1.7倍。W92b通量均值与5种方法的通量均值较为接近。研究对16条河流N2O排放系数的计算结果表明,其整体变化范围介于0.002 9~0.008 0,均值为0.005 8,高于IPCC的建议值0.002 5。因此,文章建议加强河流N2O实测与估算通量的对比研究,以减少在缺乏实测通量时由于模型选择不当造成的通量误差。Being one of the main global green-house gases,N2 O was investigated during dry season,concerning its dissolved concentration and emission flux in 16 rivers that flow into the Bohai Sea. Emphasis was laid on analyzing the relationship between concentrations of N and N2 O and estimating N2 O emission factor of these rivers. Results of the study showed that concentration of TN in all the rivers related ranged from 5.53 to 37.49 mg/L,exceeding the limit of the water quality standard（Class V）in China;dissolved N2 O concentration ranged from 0.02 to 40.10 μmol/L and the percent saturation ranged from 203% to 390 245%,indicating those rivers were super-saturated with N2O;and dissolved N2 O was positively correlated with NH4＋,TN,which meant N2 O release would be significantly accelerated by N load increased in the rivers. In addition,emission fluxes of N2 O were estimated by five models,which suggested that N2 O emission fluxes estimated by these models highly differed. In conclusion,N2 O emission factor of these rivers calculated ranged 0.002 9 ~0.008 0,on an average of 0.0058,which was higher than 0.002 5suggested by IPCC. Finally,it was suggested that further efforts are needed in the comparison study on N2 O flux in terms of measurement and estimation methodology thus the errors of N2 O flux caused by applying single model could be minimized.

关 键 词：河流 氧化亚氮 释放通量 排放系数 

分 类 号：X522[环境科学与工程—环境工程]