Abstract
Sludges from water treatment plants - WTPs - have characteristics that make their disposal a challenge. The composition variability, the low content of organic matter and, mainly, the high content of aluminum salts considerably limit its direct application in agricultural soils. This strategy is a solution already studied for sludge from sewage treatment plants (STPs), which have a higher organic matter content. However, its mineral structure could, in principle, be the basis for the production of pellets that would act as soil conditioners or as adjuvants for controlled release fertilizer systems, an alternative that would enable the high-volume consumption of the residue. Thus, simple and alternative technological routes that immobilize aluminum salts in non-soluble structures could, together with formulation technologies, enable conditions for the agricultural use of this residue. Therefore, it is proposed to develop, from WTPs sludges representative of SABESP's production, a wet mechanochemical route for the production of zeolitic concentrates from reactions with KOH, and that can be formulated as extruded fertilizer granules using plasticized starch with urea and thus composing a slow-release NK fertilizer. To avoid subsequent precipitation effects of phosphate (P) immobilization, essential fertilizer applied concurrently with NK. Standardized laboratory, greenhouse and field tests will be carried out to evaluate the agronomic efficiency of the fertilizers. Thus, it is expected that the integration of different strategies will provide greater agronomic efficiency and competitiveness in the reuse of these residues. (AU)
| Articles published in Agência FAPESP Newsletter about the research grant: |
| More itemsLess items |
| TITULO |
| Articles published in other media outlets ( ): |
| More itemsLess items |
| VEICULO: TITULO (DATA) |
| VEICULO: TITULO (DATA) |