Globes, the pink paper (it is printed on pink paper, seriously), writes that
the Ministry of National Infrastructures plans to build a string of desalination facilities along the coast with a combined capacity of 750 million cubic meters a year. The facilities will discharge 3,000 tons of iron a year into the sea. Although seawater naturally includes iron, the Ministry of Environmental Protection is worried that the discharge of so much iron is liable to damage the marine environment, especially plants and fish.The membrane separation process produces ion free water and a stream of concentrated seawater, including iron cations. The process just sends back to the sea what it took from it minus some of the H2O. Now they want to avoid contaminating the sea with concentrated seawater. I think I know who is behind this idea and he is not intrinsically a bad person. His problem, I think, is that the water is red and highly visible, and it may call the attention of the blood-thirsty environmental movement, always on the look of a suitable victim. What better than an Environmental Ministry high official?
During the reverse osmosis desalination process, the facility removes iron from the seawater before it its pushed through the desalination membranes that produce fresh water. Ministry of Environmental Protection officials from the Coastal and Marine Division told "Globes" that they were unaware that the Ashkelon facility discharges this iron into the sea, in the form of "red water", and that they were taken by surprise when they learned about it.
The ministry officials claim that VID was also taken by surprise by the amount of iron discharge. The Ministry of Environmental Protection is worried that the construction of other desalination facilities using reverse osmosis technology will result in a huge discharge of iron and that there is no research on the effect on the marine environment.
The Ministry of Environmental Protection intends to ask the Ministry of Finance to ensure that future tenders for desalination facilities will require the operator to substantially reduce iron discharges.
The pic shows the Amazonas delta. The river flows through red laterite and carries lots of iron into the sea. Millions of tons. All tropical rivers are red.
8 comments:
Where I grew up, there was at one time (in the early 19th century, before the discovery of larger iron and more economic ore deposits elsewhere) an industry mining "bog iron" which was iron oxide that naturally precipitated in the local swamps from the iron rich streams. Would it be possible (and economical) to artificially precipitate the iron oxide from the RO process and kill two birds with one stone - on the one hand a source of iron ore and on the other no unsightly red discharge?
Yes, iron can be chemically precipitated, but it is not cost effective. The solution, in this case, is dilution. The problem is regulation.
Could they just build a pipe several miles out to sea and have the water dumped away from the coast where it is not visible? When I went on a vacation to California several years ago there was a large drainage pipe leading away from the coast from a local sewage treatment plant. I don't know if the city still used the pipe, as it seemed to be at least 50 years old.
You are right, a sea outfall with a diffuser would effectively solve the "problem". But why to make it easy when the "polluter" can be legally prosecuted, judicially tortured and forced to invest millions to solve a non-existent problem? Moreover, the issue may be developing (I hope not) into a public issue that can be exploited to manufacture another "victory" for the Greens.
I am not familiar with the way a diffuser works, so I have a question about the water that comes out of a diffuser. Is the content of iron in 1m3 of this post treated water nearly the same as in 1m3 of seawater. Are there any studies about this problem?
A sea outfall diffuser is a very simple artifact whose only funtion is to spread out the wastewater in the mass of seawater. Generally is a 10 inch diameter pipe with holes every meter or so, mounted perpendicularly to the sea outfall. Then the water, instead of exiting from a central pipe, exits through hundreds of smaller holes. We have a 150 meter wide diffuser 800 meters from the shore in the coast of Herzlia, and works very well. Of course we have a strong northern current in the Eastern Mediterranean, caused by the Nile pouring into the sea.
Regarding the iron content of the desalination permeate, it is not the concentration but its visibility. It is a problem, I presume, specific to Israel. As of yet.
J. I came accross a novel catalyst which enhances easy Fe precipitation. I wouldn't mind checking the economics. Do you have specific concentrations?
Relex: Please contqact the principals, or the Israeli Ministry of Environment's Marine Dept.
Post a Comment