Bertagni Matteo B, Porporato Amilcare
The High Meadows Environmental Institute, Princeton University, Princeton, NJ 08544, USA.
The High Meadows Environmental Institute, Princeton University, Princeton, NJ 08544, USA; Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544, USA.
Sci Total Environ. 2022 Sep 10;838(Pt 4):156524. doi: 10.1016/j.scitotenv.2022.156524. Epub 2022 Jun 13.
Enhanced weathering (EW) is a promising negative-emission technology that artificially accelerates the dissolution of natural minerals, promotes biomass growth, and alleviates the acidification of soils and natural waters. EW aims to increase the alkalinity of natural waters (alkalinization) to promote a transfer of CO from the atmosphere to the water. Here we provide a quantification of the alkalinization carbon-capture efficiency (ACE) as a function of the water chemistry. ACE can be used for any alkaline mineral in various natural waters. We show that ACE strongly depends on the water pH, with a sharp transition from minimum to maximum in a narrow interval of pH values. We also quantify ACE in three compartments of the land-to-ocean aquatic continuum: the world topsoils, the lakes of an acid-sensitive area, and the global surface ocean. The results reveal that the efficiency of terrestrial EW varies markedly, from 0 to 100 %, with a significant trade-off in acidic conditions between carbon-capture efficiency and enhanced chemical dissolution. The efficiency is more stable in the ocean, with a typical value of around 80 % and a latitudinal pattern driven by differences in seawater temperature and salinity. Our results point to the importance of an integrated hydrological and biogeochemical theory to assess the fate of the weathering products across the aquatic continuum from land to ocean.
强化风化（EW）是一项很有前景的负排放技术，它能人为加速天然矿物的溶解，促进生物量增长，并缓解土壤和天然水体的酸化。EW旨在提高天然水体的碱度（碱化），以促进大气中的碳向水体转移。在此，我们给出了碱化碳捕获效率（ACE）作为水化学函数的量化结果。ACE可用于各种天然水体中的任何碱性矿物。我们表明，ACE强烈依赖于水体pH值，在狭窄的pH值区间内会从最小值急剧转变为最大值。我们还对陆地到海洋的水生连续体的三个部分中的ACE进行了量化：全球表层土壤、一个对酸敏感地区的湖泊以及全球表层海洋。结果表明，陆地EW的效率变化显著，从0到100%，在酸性条件下碳捕获效率与增强的化学溶解之间存在显著权衡。海洋中的效率更为稳定，典型值约为80%，并且存在由海水温度和盐度差异驱动的纬向模式。我们的结果表明，综合水文和生物地球化学理论对于评估风化产物从陆地到海洋的水生连续体中的归宿至关重要。
