Huttunen J T, Lappalainen K M, Saarijärvi E, Väsänen T, Martikainen P J
Department of Environmental Sciences, University of Kuopio, Finland.
Sci Total Environ. 2001 Feb 5;266(1-3):153-8. doi: 10.1016/s0048-9697(00)00749-x.
A novel sediment bubble gas sampler and a subsurface bubble gas collector were designed to measure the ebullition of gases from profundal sediments of aquatic ecosystems. The sediment gas sampler was constructed to collect bubble gas samples directly from the uppermost sediment layers for gas composition analysis. The floating subsurface gas collector, designed to trap the bubbles released naturally from sediments, permitted the measurement of both the volume and the composition of the bubble gas. Due to its low cost, light weight and rapid sampling capability, the gas collector is ideal for studies requiring many replicate collectors. These devices were used for measurement of the ebullition of methane (CH4) and carbon dioxide (CO2) during an open water period from hypereutrophic Lake Postilampi, situated within the midboreal zone in Finland. The bubble gas obtained from the sediment with the sediment gas sampler had higher concentrations of CH4 and CO2 than the bubbles trapped in the gas collectors. This indicated that the bubble gas composition changed, either naturally during the migration of the bubbles from the sediment through the water column to the gas collectors, and/or during their storage in the collectors prior to sampling. The mean CH4 ebullition from Lake Postilampi was estimated to be in the range from 36 to 46 mg m(-2 d(-1), based on the bubble gas CH4 concentrations measured from the gas collectors and sediment, respectively. The bubbles contained only 0.02-0.57% of CO2 and thus, the ebullition had no significance in the release of CO2 from the lake.
设计了一种新型沉积物气泡气体采样器和一种次表层气泡气体收集器，用于测量水生生态系统深层沉积物中的气体冒泡情况。沉积物气体采样器的构造是直接从最上层沉积物中收集气泡气体样本，用于气体成分分析。漂浮的次表层气体收集器旨在捕获从沉积物中自然释放的气泡，可对气泡气体的体积和成分进行测量。由于其成本低、重量轻且采样速度快，该气体收集器非常适合需要多个重复收集器的研究。这些设备用于测量位于芬兰中北部地区的富营养化湖泊波斯蒂兰皮湖在开放水域期间甲烷（CH4）和二氧化碳（CO2）的冒泡情况。用沉积物气体采样器从沉积物中获得的气泡气体中CH4和CO2的浓度高于气体收集器中捕获的气泡。这表明气泡气体成分发生了变化，要么是在气泡从沉积物穿过水柱迁移到气体收集器的过程中自然变化，和/或在采样前它们存储在收集器中的过程中发生了变化。根据分别从气体收集器和沉积物中测得的气泡气体CH4浓度，估计波斯蒂兰皮湖的平均CH4冒泡量在36至46毫克·平方米−2·天−1范围内。气泡中仅含有0.02 - 0.57%的CO2，因此，冒泡对该湖CO2的释放没有显著影响。
