The hydrosphere, including water on the surface of the planet, underground, and in the air, provides organisms and their living environments with stable flows of matter and energy. As one of the major carriers of organic carbon in the hydrosphere, humic substances link abiotic and biotic processes in aquatic ecosystems and play a critical role in global carbon cycling. Humic substances are operationally defined and are believed to be supramolecular associations of relatively small molecules. Humic substances have complex chemical compositions (e.g., fulvic acids, humic acid, humin, and peptides) and functional groups (e.g., carboxyls, phenols, and hydroxyls). As a result, they have diverse environmental biogeochemical behaviors and effects, including interactions with other matter (e.g., nutrients, xenobiotics, pheromones, and electron acceptors/donors), facilitation of the release of toxics from underground minerals, acidification of water, attenuation of solar radiation, control of food webs and even regulation of global matter cycling.
The aim of this Research Topic is to bring together a series of high-quality articles that outline recent advances in the environmental biogeochemical behaviors and effects of humic substances in the hydrosphere. Papers will include issues that focus on field investigations, laboratory experiments, and model simulations that reveal the physio-chemical characteristics, interaction mechanisms, and environ-biogeochemical roles and impacts of humic substances. Special attention will be paid to multidisciplinary research (e.g., environmental chemistry, atmospheric chemistry, hydrogeology, geochemistry, toxicology, biology, and ecology) and combining insight from different methodologies (e.g., isotope, ultra-resolution mass spectrometry, network analysis, machine learning, and quantitative structure-activity relationships), which can substantially improve our systematic understanding of humic substances, protect dystrophic aquatic ecosystems, facilitate remediation of contaminated environments and support carbon-neutral technology.
This Research Topic is intended to provide cutting-edge knowledge about humic substances in the hydrosphere. Themes of interest include, but are not limited to, the following:
1. Chemical composition, structure, and paleo- and contemporary environmental implications of humic substances in surface water, groundwater, and atmospheric water.
2. Adsorption/desorption, aggregation/dissolution, photochemical reaction, binding behaviors, organic-mineral interaction, diagenetic transformations of humic substances in various waters.
3. The acidification, attenuation of solar radiation, climatic and hydrologic control, ecological regulation, and geochemical determinants of humic substances in various waters.
4. The ecological roles and effects of humic substances and their internal and external influencing factors in aquatic ecosystems (e.g. humic lakes and other dystrophic ecosystems).
5. The roles of humic substances in carbon budgets, carbon cycling, and carbon sequestration.
The hydrosphere, including water on the surface of the planet, underground, and in the air, provides organisms and their living environments with stable flows of matter and energy. As one of the major carriers of organic carbon in the hydrosphere, humic substances link abiotic and biotic processes in aquatic ecosystems and play a critical role in global carbon cycling. Humic substances are operationally defined and are believed to be supramolecular associations of relatively small molecules. Humic substances have complex chemical compositions (e.g., fulvic acids, humic acid, humin, and peptides) and functional groups (e.g., carboxyls, phenols, and hydroxyls). As a result, they have diverse environmental biogeochemical behaviors and effects, including interactions with other matter (e.g., nutrients, xenobiotics, pheromones, and electron acceptors/donors), facilitation of the release of toxics from underground minerals, acidification of water, attenuation of solar radiation, control of food webs and even regulation of global matter cycling.
The aim of this Research Topic is to bring together a series of high-quality articles that outline recent advances in the environmental biogeochemical behaviors and effects of humic substances in the hydrosphere. Papers will include issues that focus on field investigations, laboratory experiments, and model simulations that reveal the physio-chemical characteristics, interaction mechanisms, and environ-biogeochemical roles and impacts of humic substances. Special attention will be paid to multidisciplinary research (e.g., environmental chemistry, atmospheric chemistry, hydrogeology, geochemistry, toxicology, biology, and ecology) and combining insight from different methodologies (e.g., isotope, ultra-resolution mass spectrometry, network analysis, machine learning, and quantitative structure-activity relationships), which can substantially improve our systematic understanding of humic substances, protect dystrophic aquatic ecosystems, facilitate remediation of contaminated environments and support carbon-neutral technology.
This Research Topic is intended to provide cutting-edge knowledge about humic substances in the hydrosphere. Themes of interest include, but are not limited to, the following:
1. Chemical composition, structure, and paleo- and contemporary environmental implications of humic substances in surface water, groundwater, and atmospheric water.
2. Adsorption/desorption, aggregation/dissolution, photochemical reaction, binding behaviors, organic-mineral interaction, diagenetic transformations of humic substances in various waters.
3. The acidification, attenuation of solar radiation, climatic and hydrologic control, ecological regulation, and geochemical determinants of humic substances in various waters.
4. The ecological roles and effects of humic substances and their internal and external influencing factors in aquatic ecosystems (e.g. humic lakes and other dystrophic ecosystems).
5. The roles of humic substances in carbon budgets, carbon cycling, and carbon sequestration.
