How pressure affects oxygen?4 answersPressure affects oxygen in various ways. High oxygen pressure improves the discharge performance of potassium-oxygen batteries and prevents parasitic reactions induced by oxygen depletion within the cathode. Hydrostatic pressure intensifies the process of diffusion coalescence in the oxygen subsystem of ReBa2Cu3O7−x single crystals. Pressure can also be used to increase the storage capacity of pressure vessels for storing oxygen by enriching oxygen within an oxygen sorbent. In pressurized water electrolysis, increasing pressure strengthens the generation of O-2(-) and enhances the oxygen reduction reaction (ORR) dynamics. Additionally, pressure affects the magnetism in solid oxygen, as observed through spectroscopic techniques, with pressure increasing the splitting of the exciton-magnon doublet and the total band intensity.
How temperature affects the dissolved oxygen in water?4 answersTemperature has a significant impact on the dissolved oxygen (DO) levels in water. The studies show that there is a negative correlation between temperature and DO concentration, with an increase in temperature leading to a decrease in DO levels. The rate of solution of oxygen in water also increases linearly with increasing temperatures. Additionally, rising river water temperatures (RWTs) due to climate change can decrease DO saturation capacity, leading to a decrease in DO levels in surface waters. The temperature-dependent hydrodynamics under ice in lakes can also affect under-ice oxygen conditions, with changes in deep water temperature leading to changes in DO concentrations. Overall, these findings highlight the importance of considering temperature when assessing and predicting DO levels in water.
How does freshwater systems absorb oxygen?5 answersFreshwater systems absorb oxygen through various processes. Photosynthesis by phytoplankton is the main source of dissolved oxygen in freshwater. Oxygen partially enters water from the atmosphere and is also released by plant organisms through photosynthesis. The mixing of water layers caused by wind, flow, precipitation, and temperature changes also aids in the penetration of oxygen from the atmosphere. Additionally, oxygen can be absorbed through diffusion from the atmosphere to the water, moving towards equilibrium. In cases of oxygen depletion, reservoir managers may monitor and introduce aerators to ensure adequate dissolved oxygen circulation. Micro-nanobubbles loaded with oxygen have also been explored as a cost-effective method for oxygen delivery in large natural water systems. Overall, the absorption of oxygen in freshwater systems is influenced by biological processes, atmospheric exchange, and physical mixing.
What are the factors that affect the concentration of dissolved oxygen in water?3 answersThe factors that affect the concentration of dissolved oxygen in water include the partial pressures and solubilities of gases, temperature, salinity, wind-driven or other turbulence in the water, and the pressure of oxygen in the water. Other factors that can influence dissolved oxygen concentration are pH, oxidation-reduction potential (ORP), electron density, and magnetic effects. Additionally, effluent biochemical oxygen demand, effluent flow rate, river flow rate, river temperature, and effluent dissolved oxygen can impact minimum dissolved oxygen concentrations in streams. Temperature and salinity also have a significant negative correlation with dissolved oxygen concentration. Furthermore, parameters such as phosphor, nitrate, phosphate, dissolved nitrogen, water alkalinity, water temperature, dissolved chlorophyll, electrical conductivity, precipitation rate, wind velocity, and environmental temperature can be used as correlated factors to predict dissolved oxygen concentration.
Can El niño have an impact on water oxigenation?5 answersEl Niño can have an impact on water oxygenation. Studies have shown that El Niño affects the oxygen content in lakes and reservoirs, indicating a link between climate processes and water quality. In a Mediterranean reservoir, the oxygen content was found to be influenced by interannual climate variability, including El Niño Southern Oscillation. The inflow and oxygen content of the reservoir showed consistent signatures of El Niño. Additionally, a decreasing streamflow trend associated with El Niño reduced the oxygen content of the reservoir. These findings suggest that El Niño can affect water oxygenation in reservoirs, highlighting the importance of considering climate change impacts on water quality and streamflow in water resource management.
What is the estimated amount of oxygen produced by phytoplanktons?2 answersPhytoplankton produce approximately half of the oxygen consumed by humans on Earth, which amounts to 49,400 trillion cubic feet (1.4 quadrillion liters) of oxygen per year. However, the Census of Marine Life reports that phytoplankton have been decreasing by about 1 percent annually since 1900, potentially due to rising temperatures. As a result, ocean oxygen production is now estimated to be one-third of historical levels. By 2050, when the world's population is projected to reach nine billion, phytoplankton levels are expected to be only 22 percent of historical averages.