Wastewater use in agriculture can result in the contamination of soil, crops and water sources. There is an inherent risk of contamination having harmful effects on exposed soil organisms. Even when soil acts as an efficient living filter to remove, deactivate and transform the pollutants contained in wastewater, there are some pollutants that it cannot fully eliminate. Moreover, sludge from wastewater may contain synthetic substances such as microplastics, microfibers and heavy metals, and when used as compost, it may negatively impact the effectiveness of soil as a treatment system by poisoning the degrading microorganisms, destroying the physical structure of the soil or damaging the natural cycles occurring within the soil (Durán–Álvarez 2014).
From collection: Sanitation and Wastewater Atlas of Africa - Ecosystems