Phosphates became famous due to their reputation for being pollutants. That is true? Is it fair to place all the blame for the environmental “chaos” we are experiencing today on a simple compound?
Let's go to the beginning, when cleaning product factories decided to add phosphates in production, more precisely sodium tripolyphosphate (STPP). This phosphate was once one of the main ingredients in detergents, it works by making water less heavy. Once dirt such as grease, for example, has already come off the clothes, the STPP is responsible for keeping them suspended in the water, so that they can be removed later.
The efficient cleaning action of detergents quickly spread, which made this product a sales success. With the growing demand came a dire accusation from environmentalists: phosphate would be a potential pollutant. From the 80's onwards, the percentage of STPP in detergents has been decreasing until reaching the zero mark. From then on, products that had the words “no phosphate” on the label had greater acceptance by the consumer public.
Now we need to understand the reason for such a threat from phosphates. From the moment STPP enters the sewers, it is associated with the phosphates present in industrial effluents and continues until being discharged into rivers. Thus begins, then, an ecological imbalance.
Phosphate availability governs the growth rate of many organisms, such as seaweed. Phosphates can cause an overpopulation of surface algae, which lowers the dissolved oxygen content of the water. The lack of oxygen has direct consequences for aquatic fauna, one of which could be the death of hundreds of fish.
By Líria Alves
Graduated in Chemistry
Brazil School Team
Environmental Chemistry - Chemistry - Brazil School
Source: Brazil School - https://brasilescola.uol.com.br/quimica/fosfatos-poluentes-ou-nao.htm