气候变化领域集成服务门户(CCPortal): Impact of physical processes on oxygen loss and production of hydrogen sulphide and methane in a tropical freshwater reservoir

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DOI	10.1007/s11356-021-13472-x
	Impact of physical processes on oxygen loss and production of hydrogen sulphide and methane in a tropical freshwater reservoir
	Shenoy D.M.; Kurian S.; Shirodkar G.; Uskaikar H.; Gauns M.; Naqvi S.W.A.
发表日期	2021
ISSN	9441344
英文摘要	Carbon neutrality of tropical reservoirs is a big concern in recent years as some estimates project high methane emission from these reservoirs. While there are studies available on the impact of physical processes (stratification and mixing) on the biogeochemistry of tropical reservoirs, not much information is available on the inter-annual variability in the low-oxygen conditions and production/accumulation of hydrogen sulphide (H2S) and methane (CH4) during summer. This paper presents time series data based on monthly in situ observations from a tropical reservoir (Tillari, Maharashtra) situated in the Western Ghats in India. Sampling was carried out for temperature, dissolved oxygen (DO), H2S, and CH4 at a fixed location from March 2010 until June 2014. The reservoir experiences stable stratification during summer (March to June) with complete loss of oxygen and production of H2S (max. ~ 9 μM) and CH4 (max. ~ 185 μM) in the profundal zone. During the summer stratification, the hypolimnion acted as a pool of CH4 with integrated values ranging between 3502 and 41,632 mg m−2. However, the intensity and duration of anoxia varied during different years, influencing H2S and CH4 production. Mixing in the reservoir was observed between July and September in association with the monsoonal runoff, which increased the DO concentrations in the sub-surface layers. Besides, complete mixing was observed between December and February due to winter convection. This, however, was found to play an important role, as weaker mixing in the preceding year was associated with severe oxygen loss in the profundal zone during the following summer with a production of H2S and CH4. In contrast, more robust mixing during winter led to moderate low-oxygen conditions with less production of these gases in the subsequent summer. Based on our observations and considering a large number of reservoirs in the tropics, we hypothesise that with the present trends of global warming and less cold winters, low-oxygen conditions in the profundal zone may become more severe in the future with positive feedback on H2S and CH4 production during summer. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	Dissolved oxygen; Hydrogen sulphide; Methane; Mixing; Stratification; Tropical reservoirs
来源期刊	Environmental Science and Pollution Research
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/177160
作者单位	Chemical Oceanography Division, CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India; Council of Scientific & Industrial Research, 2, Rafi Marg, New Delhi, 110001, India
推荐引用方式 GB/T 7714	Shenoy D.M.,Kurian S.,Shirodkar G.,et al. Impact of physical processes on oxygen loss and production of hydrogen sulphide and methane in a tropical freshwater reservoir[J],2021.
APA	Shenoy D.M.,Kurian S.,Shirodkar G.,Uskaikar H.,Gauns M.,&Naqvi S.W.A..(2021).Impact of physical processes on oxygen loss and production of hydrogen sulphide and methane in a tropical freshwater reservoir.Environmental Science and Pollution Research.
MLA	Shenoy D.M.,et al."Impact of physical processes on oxygen loss and production of hydrogen sulphide and methane in a tropical freshwater reservoir".Environmental Science and Pollution Research (2021).