Nanoecotoxicity of Selective Adsorbents for the Removal of Nutrients from Sewage Treatment Effluents in the Perspective of Reuse as Fertilizer

Abstract

The growing global population demands more food and agricultural production needs to be intensified; therefore, the use of nutrients and fertilizers is increasing, but their efficiency is very low. In this context, agricultural production through sustainable agriculture must be guaranteed to guarantee food security and reduce the impact on the environment due to the indiscriminate use of fertilizers, which generate adverse effects on aquatic and terrestrial ecosystems. A possible solution to this problem could be using modified nanoclays to deliver nutrients (P and N mainly) in a slower or more controlled manner. If the nutrients are obtained by absorption from sewage, a residue will be transformed into input for reuse as fertilizer, allowing the reduction of the use of chemical fertilizers. The FAPESP project at UFABC with which this project will collaborate evaluates the use of Montmorillonite (MnT) clays modified with Fe called TechPhos®, for applications in bioremediation, N and P recovery and with potential use for soil improvement. Also, the proponent has collaborated with the Graphene laboratory at UFABC, and demonstrated that graphene has slight or no toxicity in microalgae and plant germination, in concentrations close to and above 100 mg/L, with toxicity being lower than that of other materials. related to graphene.This project will address the study of: i) the nanotoxicity of montmorillonite (MN) clays enriched with Fe (TechPhos®), in three important biological models in human nutrition: a plant of horticultural interest (Lactuca sativa, lettuce), and as model crops , Triticum aestivum (wheat) and Oryza sativa (rice); ii) the possible synergy between modified clays and graphene in the absorption of nutrients (N and P) from sewage effluents; iii) the possible synergy between modified clays and Chlorella vulgaris in the absorption of nutrients (N and P) from sewage effluents. iv) the potential of nanoclays as biostimulants for the growth of a species of agricultural relevance, wheat or rice, will also be evaluated. Furthermore, the project's objective is to stimulate multidisciplinary collaboration in frontier areas such as nanoecotoxicology and biotechnology, combining contributions from biology, chemistry, and physics, for environmental bioremediation, within the circular economy framework. (AU)