Production of Selective Adsorbents for the Removal of Nutrients from Sewage Treatment Effluents with the Perspective of Reuse as Biofertilizer

Abstract

This project is inserted in a strategic area at the national and global levels, concerning the generation of scientific and technological knowledge, in addition to the focus on training qualified personnel, involving environmental, social, and economic sustainability, with strong adherence to the Sustainable Development Goals (SDG), number 2, zero hunger and sustainable agriculture and number 6, clean water and sanitation. The general objective is to establish the optimal conditions for removing the nutrients phosphorus (P) and nitrogen (N) from sludge from sewage treatment plants. Regarding phosphorus, we have a shortage of phosphate rocks, compromising agricultural practices and aggravating the issue of food security. At the same time, nitrogen in the form of nitrate is the most common contaminant in aquifers, both in Brazil and abroad. In both cases, we have a great threat to water resources, which are eutrophicated by the discharge of untreated sewage, or treated until the secondary stage, in which only the organic matter is removed, but not the nutrients. Their removal using materials specially prepared for this purpose can contribute strongly to water security and food production if the adsorbent materials are incorporated into agricultural soils after use. The biggest challenge is to provide an alternative for the tertiary treatment of effluents and soil fertilization. This is especially strategic in a country like Brazil, which has one of the largest agricultural areas in the world and an economy heavily based on agribusiness, both in terms of food production and biofuels. Combined with using adsorbents prepared from abundant and low-cost sources, we should promote greater economic viability for sewage treatment, individually, combined, or in successive stages, making nutrients available for reuse. The assumptions for preparing the adsorbents are related to the group's previous experience with clays, coals, and the production of adsorbents and supports for heterogeneous catalysts, especially products patented by the proponent. (AU)