Sparging Oxygen Ions Into the Ocean: Geochemistry at its Best

 73 grams of Oxygen Ions could draw down as much as 1Kg of CO₂ and is going to be tested.

Deeper sparging (bubbling) is better for the more acidic mid depth waters below the thermocline, thereby reducing the risk of precipitating magnesium Hydrate above pH of 8.25¹, and Calcium Hydroxide above 8.4. Because the logarithmic range of 7-8 is 1/10th of 8-9, the relative remediation is also higher, the water is colder and will hold more oxygen, and any gas not dissolving there will have a longer residence time in water for best absorption and remedial impact on the average overall pH.

Ideal pH and a cooler temperature has caused the ocean to absorb 1/3 of the industrial revolution’s CO2², but as it drops, the net dissolved oxygen has lowered and is more alarming when coupled with CO₂ combustion ³ caused atmospheric oxygen depletion as a loss to CO₂.

FIGURE 2.2 Inorganic carbon and pH vary as a function of depth and latitude. (a) Vertical profiles typical of the mid-North Pacific showing variations of several seawater chemical parameters with depth. Adapted from Morel and Hering (1993) with calculations using constants from Dickson et al. (2007) and Lueker et al. (2000). (b) Typical distribution of pH with depth along a North-South transect for the Pacific Ocean. (Byrne et al., 2010a). ²

On a 1” oxygen sparging line, delivering to a 50-60’ depth of water gives about 26 pounds of resistance to the 2100 psi pressure of the oxygen tanks. (.036lb/inch H₂O x 12” x 60ft).

Influencing Seawater pH Slots

Seawater CO2 in the three slots has increasing alkalinity as it moves to the right, and as a formed carbonate ion it will trigger the two left side slots to become accommodating to more CO2, so leveraging with Oxide is shown in line 2.

1. CO₂ + H₂O ↔ (1,4) H₂CO₃ ↔ H⁺ + (2,5)HCO₃^– ↔ 2 H⁺ + (3,6)CO₃^2–

2. O^2- + H₂O ↔ 2OH ↔ 4 H⁺ + 2CO₃^2-

2CO₃^2- is the most alkaline species, and leaves room for the other two slots to absorb CO2 as the less alkaline ions. Thesis: One O^2- ion triggers room for up to 5 accommodation slots for CO₂ in the buffer (arbitrary slot number in brackets) and some additional Oxygen in the form of OH- will serve as a helpful oxidant.

The sparging pH target has a limit as mentioned of 8.25, but when this much CO₂ can be absorbed into the water, this technique could be extremely helpful. This would also take an oxygen demand load and remediate it as the auto-ionization of the OH of the seawater (a separate natural mechanism) would be strengthened by the presence of this added oxygen.

About 89 percent of the carbon dioxide dissolved in seawater takes the form of bicarbonate ion, about 10 percent as carbonate ion, and 1 percent as dissolved gas ⁴. Placing carbonate ions via this method thus could be helpful for ocean life affected by acidity as well as for CO₂ mitigation. Using oxygen ions avoids the sodium (cation) loading problems with sodium hydroxide and other hydroxides, and there is little difference over concern for control of the dosage (solid powder vs gas) because it must be restricted to a target pH of 8.25 to avoid precipitation of minerals.

The effective stoichancy of oxygen ions to absorbed CO₂ would range from 1:5 to 1:6 assuming that the continual uptake of CO₂ by plant life and continual CO₂ vapor pressure are actively moving CO₂ and make some of the stochastic ratios for those overlap on the buffer system. This can be tested in the lab.

Sea Life Conditions

Because the pH adjustment is limited t within the precipitation maximum, membranes of animals are not at much risk^{5 ,} in fact slight alkalinity and negative ions (as even a small increase in ecosystem voltage) may be helpful, as well because that pH rests close to the mineralogically ideal ocean pH. Again, deeper waters can be alkalized more aggressively but would require mechanical assistance to access the deeper water or piping for sub surface sparging. Diffusion would occur and the net absorption of CO₂ would be achieved regardless. Viva Cundliffe PhD abd

 

 

1. A. R. Haas, The Effect Of The Addition Of Alkali To Sea Water Upon The Hydrogen Ion Concentration. Laboratory Of Plant Physiology, Harvard University, Cambridge. July 18, 1916
2. National Research Council. 2010. Ocean Acidification: A National Strategy to Meet the Challenges of a Changing Ocean. Washington, DC: The National Academies Press. Doi: 10.17226/12904
3. Ralph Keeling, Scripps O2 Program; http://scrippso2.ucsd.edu/
4. Scientific American, “Rising Acidity in the Ocean: The Other CO2 Problem”, retrieved April 1, 2018, https://www.scientificamerican.com/article/rising-acidity-in-the-ocean/.
5. Idlir Liko, Jonathan T. S. Hopper, Timothy M. Allison, Justin L. P. Benesch, Carol V. Robinson, “Negative Ions Enhance Survival of Membrane Protein Complexes”,J. Am. Soc. Mass Spectrom. (2016) 27:1099Y1104