Explorando o potencial agrícola do lodo de esgoto: uma revisão critica

Abstract

This Monograph provides a comprehensive review of sewage treatment, focusing on managing waste from Sewage Treatment Plants (STPs) and its subsequent use. It details various stages of effluent purification, including screening, grit removal, primary settling tank, biological reactor, and secondary settling tank. Additionally, it discusses sewage sludge management phases, covering thickening, stabilization, conditioning, drying, and sanitization. Emphasizing the importance of quality in sludge treatment, particularly as soil fertilizer, the paper conducts comparative analyses of two literature studies: one examining soil chemical changes and corn/bean growth after sewage sludge application, and another evaluating corn plant productivity and mineral composition in sewage sludge-fertilized soil. The studies confirm sewage sludge application enriches soil with zinc, copper, manganese, iron, nitrogen, organic matter, calcium, magnesium, and raises pH. Phosphorus and potassium levels remained unchanged post-sludge fertilizer implementation. Notably, heavy metals in soils and sludges met regulatory limits. Thus, sewage sludge proves suitable for fertilizing most soils, in cases of mineral deficits, mineral fertilizer supplementation can achieve optimal cultivation levels. This STP byproduct demonstrates efficiency, productivity, environmental friendliness, and low cost, enriching soil, hence highly recommended for food cultivation.