Sludge management in anaerobic swine lagoons: A review.

Sludge is nutrient and mineral rich residue of anaerobic treatment that is often utilized as a fertilizer. Sludge management is crucial to maintain the function of anaerobic treatment lagoons and ensure efficient nutrient utilization. Intensive livestock production has resulted in accumulation of sludge residue in regions where nutrients are in surplus. This situation adversely impacts the sustainability of livestock production. Alternative uses of sludge needs to be developed and adopted to reduce the negative impacts associated with the nutrients accumulation on farms and nearby crop fields. A thorough understanding of sludge composition is necessary to identify appropriate end use. This review explores swine lagoon sludge (SLS) in relation to its composition, sampling techniques, management approaches, fertilizer value, challenges and opportunities for further development. • A review of swine lagoon sludge sampling, characterization and use is presented. • Lagoon sludge sampling techniques are not standardized. • Sludge composition in swine lagoons varies considerably. • Elevated P, Cu, Zn contents in sludge limits its application as a fertilizer. • Composting and drying are promising sludge processing techniques. [ABSTRACT FROM AUTHOR]