Phosphorus, found naturally in all plants, is essential for plant growth, but its use as a fertilizer creates widespread pollution in developed countries because much of it is wasted. Phosphorus is the main cause of water pollution, as runoff from the use of fertilizers in the fields produces excess nutrients that disrupt the natural balance of rivers and lakes, leading to algal blooms that harm fish and plants. Most of the phosphorus used to make fertilizers is mined from rocks, instead of being recycled from sources such as sewage. Only about 15% of phosphorus in wastewater is currently recovered worldwide, but the rising cost of fertilizers means that it is now much cheaper to do so. Bryan Spears, a professor at the UK Center for Ecology and Hydrology (UKCEH) and lead author of the most detailed report on the phosphorus problem to date, said: “Phosphorus could push us to the brink of a food security crisis. It is a finite resource and is overused in developed countries, while developing countries do not have enough. It is a major cause of pollution as it disturbs the ecological balance [in waterways]. “Phosphorus pollution also threatens drinking water supplies.” He said phosphorus reserves were rising sharply in price, which would threaten food security if governments did not act to reduce phosphorus wastage in our agricultural systems and encourage its recycling from wastewater and other sources. The report, compiled by 40 international experts, led by UKCEH and the University of Edinburgh, shows that much more could be done, at low cost, to recover phosphorus. Prices have jumped from about $ 240 (2 192) a tonne to more than $ 900 a tonne for some phosphorus-containing rocks, as the war in Ukraine has disrupted fertilizer production. Phosphorus stone comes from only a few countries, mainly from Morocco. Most fertilizers use a mixture of phosphorus, nitrogen and potassium (NPK) and Ukraine and Russia are both major suppliers of fertilizers. High fertilizer prices have left farmers with large losses, unable to plant crops or face lower yields. As a result, food prices for consumers, which have already been affected by supply problems and the negative effects of high energy prices, are rising further. CEH scientists said farmers could also save money and reduce phosphorus wastage by using fertilizer more efficiently, as most of the phosphorus in fertilizers is now wasted in the runoff. This can be as simple as targeting the crop fertilizer and injecting it into the soil and avoiding using it just before the expected heavy rain. The report, which represents the most detailed examination of the global phosphorus problem to date, sets a 50:50:50 target for a 50% reduction in global phosphorus pollution due to a 50% increase in phosphorus recycling by 2050. To achieve this, scientists are urging governments to improve wastewater treatment to remove and reuse phosphorus from wastewater. to help farmers use more targeted fertilizer techniques; to encourage the conversion of more animal fertilizers into fertilizer as an alternative to chemical fertilizers; and for people to eat less meat, which would reduce the amount of phosphorus the cultivation of animal feed. A spokesman for the UK Department for the Environment, Food and Rural Affairs said the government was acting: “Phosphorus pollution in our rivers has been reduced by 67% in the last two decades. “We have proposed setting long-term goals in our environmental law to further reduce phosphorus pollution from agriculture by 40% and wastewater by 80% by 2037.” CEH scientists estimate that the capital investment required in the UK to recover phosphorus from wastewater is around 6 1.6 billion, which would easily be offset by the benefits of reusing the recovered mineral as fertilizer. A small but important use of phosphorus is in beverages such as Coca-Cola, in which it is used as a preservative. Removing it could cause changes in taste, but an alternative would be to supply phosphorus from recycling – which would make consumers effectively drink a by-product of urine. Will Brownlie, a freshwater scientist from the University of Edinburgh who co-authored the report, said: “I wish Coca-Cola could develop an alternative, using recycled phosphorus – to remove pollution from rivers and our lakes and turn it into a drink. . » Coca-Cola did not respond to a request for comment from the Guardian.
