自动化顶空平衡-气相色谱法测定京杭运河中溶解甲烷  

Determination of dissolved methane in the Beijing-Hangzhou Grand Canal using automated head space-GC system

作　　者：温军 臧昆鹏 潘凤梅 申小龙 魏康轩 兰文港 胡智伟 陈啸鸣 陈炳江 李珊 鲁嫣冉 陈丽涵 郭朋 方双喜 林溢 陈圆圆 刘硕[1,2] 徐宏辉 WEN Jun;ZANG Kun-peng;PAN Feng-mei;SHEN Xiao-long;WEI Kang-xuan;LAN Wen-gang;HU Zhi-wei;CHEN Xiao-ming;CHEN Bing-jiang;LI Shan;LU Yan-ran;CHEN Li-han;GUO Peng;FANG Shuang-xi;LIN Yi;CHEN Yuan-yuan;LIU Shuo;XU Hong-hui(College of Environment Sciences,Zhejiang University of Technology,Hangzhou 310014,China;Zhejiang Carbon Neutral Innovation Institute,Zhejiang University of technology,Hangzhou 310014,China;Zhejiang Meteorological Science Institute,Hangzhou 310008,China)

机构地区：[1]浙江工业大学环境学院,浙江杭州310014 [2]浙江工业大学浙江碳中和创新研究院,浙江杭州310014 [3]浙江省气象科学研究所,浙江杭州310008

出　　处：《中国环境科学》2024年第3期1507-1514,共8页China Environmental Science

基　　金：国家重点研发计划项目(2020YFA0607501);浙江省自然科学基金联合基金资助项目(LZJMZ23D050002,LZJMZ24D050011);浙江省基础公益研究计划项目(LGF22D050004)。

摘　　要：将顶空平衡法和气相色谱仪相结合,通过自主设计和优化测试实现了技术升级,建立了可自动化进样并同步测定水中溶解CH_(4)和CO_(2)浓度的新型气相色谱系统及方法.结果表明,本系统线性范围宽且运行稳定,自动化程度更高,运行成本更低.该系统对CH_(4)的测定精密度优于0.16%,准确度优于0.02%,满足水中溶解CH_(4)浓度监测需求.基于本方法,于2022年8月对京杭大运河杭州段水体中溶解CH_(4)开展了试观测研究.结果显示:夏季京杭大运河杭州段水体中溶解CH_(4)浓度平均值为(642.4±423.3)nmol/L,饱和度平均值为(22310±14701)%,水-气界面CH_(4)扩散通量平均值为(548.57±603.70)μmol/(m^(2)·d),是大气CH_(4)的净源.根据该河段的面积,可估算观测期内CH_(4)的日均排放量约为1710mol,相当于大约38.31m^(3)天然气或约82.94kg碳.A new head-space gas chromatography system equipped with a flame ionization detector and method was self-assembled and established,which could automatically and simultaneously measure concentrations of dissolved methane and carbon dioxide in water samples,with wider linear range and low operating cost.Precision and accuracy of this system for CH_(4)were better than 0.16%and 0.02%,respectively,which met the measurement requirements.In August 2022,dissolved CH_(4)concentration and related parameters were observed in the Beijing-Hangzhou Grand Canal in Hangzhou City.Results showed that mean dissolved CH_(4)concentration was(642.4±423.3)nmol/L,mean saturation was(22310±14701)%and mean air-water CH_(4)flux was(548.57±603.70)μmol/(m^(2)⋅d)during field survey,indicated the observed area was a net source of atmospheric CH_(4).In addition,it was reasonable to estimate that the mean daily release rate of CH_(4)from the Canal was approximate 1710mol,which was equivalent to 38.31m^(3)of natural gas or 82.94kg of carbon.

关 键 词：顶空平衡 气相色谱 京杭大运河 甲烷 通量 

分 类 号：X511[环境科学与工程—环境工程]