天津师范大学肖敏团队研究了天津城市河流中主要离子和溶解无机碳的动态。相关论文于2025年3月27日发表在《地球化学学报》上。

不同岩性的分布和人类活动影响着河流系统的水化学和碳生物地球化学。2021年，基于时空采样方案，研究组对中国天津市城市河流中的主要离子化学和溶解无机碳（DIC）进行了检测。主要离子的浓度表现出显著的空间变化，表明上游为农业投入，下游为城市污染。河流中DIC的同位素组成（δ¹³C）范围为-12.39‰至-0.45‰，表明由于停留时间长，某些水域的水和大气之间存在部分平衡，其中δ¹³C通常为0‰。

δ¹³C值较负的水域表明，生物CO₂是大多数河流DIC的主要因素。在雨季，它的消耗量略高于旱季，这反映了夏季有机物的强烈降解。季节变化可能反映了河流代谢过程的变化以及水文状况的改变，突出了淡水在地球科学、生态和环境方面的影响。人类活动的基本方面，包括农业、城市发展和大坝建设，对水化学和DIC的动态有重大影响。该研究强调，岩性和水文的变化显著影响了河流系统中水化学和碳地球化学的时空变化。

附：英文原文

Title: The dynamic of major ions and dissolved inorganic carbon in urban rivers in Tianjin, North China

Author: Xiao, Min, Li, Lili, Yi, Yuanbi, Zhang, Wenxi, Yue, Fujun

Issue&Volume: 2025-03-27

Abstract: The distribution of diverse lithology and human activities impacts the water chemistry and carbon biogeochemistry of river systems. Major ion chemistry and dissolved inorganic carbon (DIC) in the urban rivers at Tianjin City, China, were examined based on a temporal and spatial sampling scheme in 2021. The concentrations of major ions exhibited significant spatial variations, showing agricultural input in the upstream and urban pollution in the downstream. The isotopic composition (δ13C) of DIC in the rivers ranges from 12.39‰ to 0.45‰, indicating partial equilibrium between the water and the atmosphere in some waters due to long residence time, where δ13C is typically 0‰. The waters with more negative δ13C values showed that biological CO2 was a major contributor to DIC in most rivers. It experienced slightly more depletion during the wet season than in the dry season, reflecting strong degradation of organic matter in summer. The seasonal variations likely reflected changes in metabolic processes in the river in addition to alterations in the hydrological regime, highlighting the implications of freshwater given geoscientific, ecological, and environmental aspects. Essential aspects of human activities, including agriculture, urban development, and dam construction, significantly influence the dynamics of water chemistry and DIC. The study highlighted that variations in lithology and hydrology significantly affect the spatial and temporal changes in water chemistry and carbon geochemistry within river systems.

DOI: 10.1007/s11631-025-00768-9

Source: https://link.springer.com/article/10.1007/s11631-025-00768-9