矿山酸水影响下岩溶地表河二氧化碳分压及扩散通量变化  

Changes in Partial Pressure and Diffusion Flux of Carbon Dioxide in Karst Surface Rivers under the Influence of Acid Mine Drainage

作　　者：周诗宇 曹星星[1,2] 吴攀 李凯[1,2] 李林蔚 ZHOU Shiyu;CAO Xingxing;WU Pan;LI Kai;LI Linwei(School of Resource and Environmental Engineering,Guizhou University,Guiyang 550025,China;Key Laboratory of Karst Geological Resources and Environment,Ministry of Education,Guizhou University,Guiyang 550025,China)

机构地区：[1]贵州大学资源与环境工程学院,贵阳550025 [2]贵州大学喀斯特地质资源与环境教育部重点实验室,贵阳550025

出　　处：《地球与环境》2023年第2期196-208,共13页Earth and Environment

基　　金：国家自然科学基金项目(42163003);国家重点研发计划(2019YFC1805300);国家自然科学基金委员会-贵州省人民政府喀斯特科学研究中心项目(U1612442);贵州大学人才引进项目(贵大人基合字﹝2019﹞24号);贵州省人才基地项目(RCJD2018-21)。

摘　　要：为揭示矿山酸水影响下岩溶地表河流水-气界面CO_(2)分压(pCO_(2))时空分布特征,本文选择受矿山酸水影响的贵州麻江格当寨河为研究对象,分平水期、枯水期和丰水期对该河流进行了样品采集,通过对水样水化学指标的测定,揭示其表层水体pCO_(2)的时空变化及影响因素,并利用模型法估算了水-气界面CO_(2)扩散通量。研究结果表明:全河段整体表现为大气CO_(2)的排放源,平水期、枯水期、丰水期未受矿山酸水影响前河流pCO_(2)分别为57~122 Pa、79~98 Pa、146~189 Pa,在受矿山酸水影响后河流pCO_(2)分别为99~4034 Pa、81~701 Pa、146~2117 Pa,整体上受矿山酸水影响河段的pCO_(2)高于未受矿山酸水影响河段。与此同时,在受到矿山酸水影响下,河流pCO_(2)呈现随着流向先增加再降低的趋势。CO_(2)扩散通量空间变化趋势与pCO_(2)相似,受到矿山酸水影响后的河流前端CO_(2)扩散通量是未受影响时的5.2~203.1倍,其中在平水期变化最显著,且该通量值高于文献报道的未受矿山酸水影响的岩溶地表河流,表明矿山酸水可增强岩溶地表河流中CO_(2)的释放。In order to reveal the spatial and temporal distribution characteristics of CO_(2)partial pressure(pCO_(2))at the water-air interface of karst surface rivers under the influence of acid mine drainage,the Gedangzhai River in Majang,Guizhou province,which is affected by acid mines dranage,is selected as the research sites in this study.Samples were collected in wet season,dry season,and normal water season.The spatial and temporal variation of pCO_(2)in water and the influencing factors were measured,and the CO_(2)diffusion flux at the water-air interface was analyzed by the model method.The results showed that the whole river was manifested as a source of atmospheric CO_(2)emission.The pCO_(2)of the rivers was 57-122 Pa,79-98 Pa and 146-189 Pa during the normal,dry,and wet season before the influence of acid mine drainage,respectively.Under the influence of mine acid water,the river pCO_(2)is 99-4034 Pa,81-701 Pa and 146-2117 Pa,respectively.As a whole,the pCO_(2)in the acid mine drainage-affected reaches was higher than that in the non-acid mine drainage-affected reaches.At the same time,under the influence of acid mine drainage,river pCO_(2)showed a trend of increasing and then decreasing with the direction of river flow.The spatial variation trend of CO_(2)diffusion flux was similar to that of pCO_(2).The rivers front end of the riverside CO_(2)diffusion flux after being affected by the mineral acid and water was 5.2-203.1 times when it was not affected,and the variation was most significant in the normal period.Additionally,the flux was higher than that of the karst surface river without the influence of acid mine drainage reported in the literature.The results showed that acid mine drainage can enhance the emission of CO_(2)in karst surface rivers.

关 键 词：岩溶地表河 矿山酸水 水体二氧化碳分压 水-气界面 二氧化碳通量 

分 类 号：X143[环境科学与工程—环境科学]