Wastewater treatment plants are undoubtedly a great achievement. After all, they have made a significant contribution to improving the quality of natural waters. A study published in the journal “Water Research” shows, however, that substances still manage to enter the water cycle that have an impact on the composition of the organisms living in it.
Effluents from wastewater treatment plants have a dual effect: Some species disappear, while others benefit. Especially certain insect orders, such as stonefly and caddisfly larvae, are decimated. Certain worms and crustaceans, by contrast, can increase in number. A team from Goethe University Frankfurt led by Daniel Enns and Dr. Jonas Jourdan has corroborated this in a comprehensive study, which has now been published in the journal “Water Research”. They examined 170 wastewater treatment plants in Hesse in relation to species composition.
Wastewater treatment plants are an indispensable part of our modern infrastructure; they have made a significant contribution to improving the quality of our surface waters. However, their ability to completely remove what are known as micropollutants from wastewater is mostly limited. These substances include, for example, active ingredients from pharmaceuticals and personal care products, pesticides and other synthetic substances enter waterbodies via the treated wastewater, placing an additional burden on rivers and streams. This exacerbates the challenges faced by already vulnerable insect communities and aquatic fauna. Previous studies – which have primarily focused on single wastewater treatment plants – have already shown that invertebrate communities downstream of such effluents are generally dominated by pollution-tolerant taxa.
Read more at: Goethe University Frankfurt
Treated wastewater is discharged into a nearby stream. In this way, numerous trace substances enter our waters. (Photo Credit: Jonas Jourdan)