Related Experiment Video
Updated: Jul 12, 2026
06:42
Measuring Phosphorus Release in Laboratory Microcosms for Water Quality Assessment
Published on: July 22, 2019
Summary
Three key processes govern global surface water chemistry: atmospheric precipitation, rock weathering, and evaporation-crystallization. Analytical data from diverse water bodies reveal these dominant factors influencing water composition worldwide.
Area of Science:
- Geochemistry
- Environmental Science
- Hydrology
Background:
- Surface water chemistry is influenced by complex interactions between atmospheric, geological, and hydrological processes.
- Understanding these controls is crucial for managing water resources and interpreting Earth's chemical cycles.
Purpose of the Study:
- To identify and define the primary mechanisms controlling global surface water chemistry.
- To provide a framework for understanding variations in the chemical composition of rain, rivers, lakes, and oceans.
Main Methods:
- Analysis of extensive chemical data from a wide range of global surface water samples.
- Statistical and comparative analysis to identify dominant chemical control processes.
Main Results:
- Identified atmospheric precipitation as a significant input controlling surface water chemistry.
- Determined rock dominance (weathering) as a major source of dissolved ions in surface waters.
- Established the evaporation-crystallization process as a key factor influencing the chemistry of more evolved waters.
Conclusions:
- Global surface water chemistry is primarily controlled by three major processes: atmospheric precipitation, rock weathering, and evaporation-crystallization.
- These mechanisms provide a fundamental understanding of water composition across diverse aquatic environments.
- The findings offer a basis for further research into specific regional water chemistry variations.
Related Concept Videos
01:00The Water Cycle
The Earth’s hydrosphere includes all of the areas where the storage and movement of water occurs. Since water is the basis of all living processes, the cycling of water is extremely important to ecosystem dynamics.
01:30Microbial Wastewater Treatment
Microbial communities in aquatic ecosystems play a key role in the natural breakdown of contaminants introduced through domestic and industrial effluents. Acting as biological catalysts, these microbes change and mineralize a wide range of organic and inorganic pollutants under different redox conditions.In oxygen-rich surface waters, aerobic heterotrophs lead organic matter breakdown, using oxygen as the terminal electron acceptor to efficiently oxidize substrates to carbon dioxide and water.
04:01Factors Affecting Solubility
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Chȃtelier’s principle. Consider the dissolution of silver iodide:
01:26Regulation of Water Output
The human body predominantly expels water through the urinary system. On average, an individual generates around 1.5 liters of urine each day. This amount can fluctuate based on how well a person is hydrated, but a critical minimum quantity of urine must be produced to ensure the body's proper functioning. Daily, the kidneys remove 600 to 1200 milliosmoles of dissolved substances, effectively excreting excess minerals and water-soluble toxins such as creatinine, urea, and uric acid from the...
02:30Water: A Bronsted-Lowry Acid and Base
The reaction between a Brønsted-Lowry acid and water is called acid ionization. For example, when hydrogen fluoride dissolves in water and ionizes, protons are transferred from hydrogen fluoride molecules to water molecules, yielding hydronium ions and fluoride ions:
01:24Microbes and Other Elemental Cycles
Microbial activity plays a pivotal role in the biogeochemical cycling of iron and manganese, especially at the redox gradients characteristic of stratified aquatic environments. These cycles are driven by microbial transformations between oxidized and reduced forms of the metals, allowing organisms to exploit them for metabolic energy and structural purposes.Iron Cycling Across Redox GradientsIn neutral, oxygen-rich surface waters, iron is predominantly found in its oxidized, insoluble ferric...