Phosphate and fertility

When I was a child my family frequently took trips though the Tennessee country side on the way to visit relatives. We often drove by tobacco plots. On such occasions, my mother would talk to us about the effects of tobacco on soil fertility. Mother said that tobacco robbed the soil of trace minerals and the trace minerals it needed to sustain plant life. My mother also talked about soil erosion, and told us all sorts of other neat things she learned in her college botany classes in the 1930's. Unfortunately the other energy writers on the Internet appear to have had mothers who ignored discussion soil conservation issues on family trips.

One of those trace minerals that mother talked about is phosphate, and ironically my father worked for a brief time as a chemist for a phosphate mine near Bartow, Florida in the 1940's. Phosphate is a disappearing resource, and as the song goes, "we've got trouble right here in River City".

As the SNB phosphate recovery web site tells us:

The demand for phosphate is increasing. Global stocks are finite. According to experts all the phosphate in the world will have been used within the foreseeable future. The majority of estimates are a maximum of 100 years, and the consequences will be enormous, especially for food production. A shortage of phosphate will result in large-scale famine and political turmoil. What makes the problem serious is that there are no alternatives for phosphate.

SNB adds:

Our bodies need phosphor and extract it from our food. Plants also need phosphor to live. Under normal circumstances plants extract phosphor from the soil, but intensive farming is rapidly exhausting this phosphate. This is why phosphate is added to the soil in the form of artificial fertiliser in order to compensate for the shortage and maintain our food production. In the Netherlands and the majority of countries in Europe we have done this to such a great degree that the soil currently contains more than sufficient phosphate. Nevertheless, this quantity will also become depleted if we do not continue to supplement it. In other parts of the world, such as Africa, artificial fertiliser is far less readily available and the soil is poorer. The end of the stocks is on the horizon. The problem is even more acute due to the fact that demand for phosphate is increasing. This is because of the growing world population, increasing consumption of meat and the cultivation of energy crops.

Besides the fact that we extract phosphate from our food, we also use phosphate in the pharmaceuticals sector and industrial and household cleaning. However, consumption for the purpose of food production is by far the most important. Approximately 80% of all phosphate is used for this purpose.

The SNB account continues:

Australian research conducted by Dana Cordell shows that approximately 14.9 million tons of phosphate ore is mined worldwide. Of this, 3.5 million tons of phosphate finds its way into our food. Eventually, three million tons of phosphates are released through human waste. If we recover this 3 million tons of phosphate we will have covered 20% of our worldwide phosphate requirement. The Netherlands uses relatively little artificial fertiliser because we produce a relatively large quantity of animal manure. This means that the percentage in the Netherlands is even 50%.

Approximately 11.4 million tons is lost worldwide. This is due to over-fertilisation. If too much phosphate is released onto the soil a large amount is lost due to erosion and precipitation. It is also essential that a solution is also developed for this. However, in this web site we concentrate on the recovery of phosphate from waste water. Phosphates can be recovered at several points in the waste chain:

There you have the whole story. We need phosphate. Not a lot, but life requires phosphate. There is not a whole lot of it compared to the human appetite for it. We are using it up. If we don't do something different, it will be gone. We live in a way that makes phosphate a necessity. We cannot live without it. The phosphate supply is an issue that is not quite as urgent as CO2/AGW but serious enough to draw the attention of this post and others as well. We need to start thinking and talking about solutions. Solving the phosphate problem is not an option.

Phosphate and phosphate tailings

This is a picture of raw materials for a Liquid Fluoride Thorium Reactors. It is also the picture of a significant radiation hazard. 

Phosphate mining tailings contain large amounts of recoverable fluoride, and significant amounts of recoverable uranium and thorium. Phosphate or can be so radioactive that it poses a radiation hazard to milling workers. Not all uranium and thorium is extracted in the phosphate milling process, and phosphate fertiliser contain significant amounts of uranium and thorium along with radioactive decay products. Ground water can become polluted by uranium and thorium from phosphate fertiliser, and phosphate tailings. Even more startling organic food growers are allowed to treat their fields with the raw, unprocessed phosphate tailings once every six years, without any prior extraction of uranium, thorium or radioactive daughter products. Not only can uranium and thorium enter ground water through phosphate fertiliser, but some authorities believe that Polonium 210 a daughter product present in phosphate fertiliser can become concentrated in plants like tobacco, and can be a significant source of tobacco related cancer.

Polonium 210 os extremely toxic and is believed to have been the poison used in the 2006 London murder of Alexander Litvinenko, a Russian dissident.

Phosphate tailings are considered so radioactive that they are not allowed to be used for wall-board filler or for road bed construction in the US and Canada.

The extraction of Uranium and Thorium from Phosphate ore and old phosphate mine tailings would make a large contribution to the elimination of significant radiation problems, as well as the elimination of toxic pollution of ground water.

A hat tip to Owen T.