地表自然过程排汞研究进展及展望

Earth surface natural mercury emission:Research progress and perspective

地表自然过程排汞包括了自然源排汞过程和先前排放的汞沉降到地表后的再排放过程。已有证据显示,地表自然过程向大气的排汞量可能远大于人为活动直接向大气的排汞量。准确确定自然过程汞的释放通量,不仅对正确评价目前减少人为活动向大气排汞对全球环境汞污染的影响程度具有重要的意义,而且可为全球大气汞的减排政策的制定提供重要科学理论依据。本综述通过对国内外地表自然排放源相关文献的调研分析发现:由于缺少可靠的观测技术、对地表与大气间汞交换过程和机理的准确认识及大气汞沉降对地表自然排汞过程影响的认识还不清楚,因此目前还难以准确估算地表自然过程向大气的排汞量。近年来,随着技术手段的进步,已具备了开展地表自然排汞及先前排汞沉降后的再释放过程、机理和通量研究的可行性。地表自然过程排汞的研究将是汞的生物地球化学循环演化研究领域的前沿之一。

Earth surface natural mercury（Hg） emission includes the Hg emission from natural sources and the re-emission from previously deposited Hg.It was demonstrated that the total amount of natural Hg emission from earth surface could be far larger than that of the direct emission from human activities.It is of great importance to quantify the natural Hg emission,not only for the evaluation of the effects of reducing anthropogenic Hg emission on the global environment,but also for providing guidance on the policy-making in global Hg-reduction strategy.Due to the lack of reliable methodologies in quantifying the Hg emission from natural sources,we still don＇t have a clear understanding about the processes and mechanisms of Hg exchange between earth surface and atmosphere as well as the effects of atmospheric Hg deposition on the processes of earth surface natural Hg emission,and thereby,we are hard to accurately quantify the Hg emission from natural sources.However,with the development of new technologies,we have the feasibility to study the processes,mechanisms,and fluxes of Hg emission from natural sources.To quantify the Hg emission from natural sources would be one of the research frontiers about the biogeochemical cycling of Hg in the environment.