Effect of drying on the physical and chemical properties of faecal sludge for its reuse

S Septien; S W Mirara; B S N Makununika; A Singh; J Pocock; K Velkushanova; C A Buckley

doi:10.1016/j.jece.2019.103652

Effect of drying on the physical and chemical properties of faecal sludge for its reuse

J Environ Chem Eng. 2020 Feb;8(1):103652. doi: 10.1016/j.jece.2019.103652.

Authors

S Septien¹, S W Mirara¹, B S N Makununika¹, A Singh², J Pocock², K Velkushanova¹, C A Buckley¹

Affiliations

¹ Pollution Research Group, University of KwaZulu-Natal, Howard College, 4041, Durban, South Africa.
² Chemical Engineering, University of KwaZulu-Natal, Howard College, 4041, Durban, South Africa.

Abstract

This work explores the effect of drying on the chemical and physical properties of faecal sludge, and evaluates the reuse potential of the dried material. For the purpose of this study, the nutrient content, calorific value and thermal properties were determined for faecal sludge samples dried at different moisture contents and under different drying and operating conditions. The results show that drying does not affect the nutrient content and calorific value, but it induces modifications of the chemical form of nitrogen and the thermal properties. The dried product was demonstrated to be suitable for reuse as an agricultural product and biofuel. In agriculture, dried faecal sludge could be used as an organic fertilizer with a particularly high phosphorous content and a slow release of nitrogen and phosphorous. As a biofuel, dried faecal sludge would have similar characteristics as wood.

Keywords: Calorific value; Drying; Faecal sludge; Nutrient content; Thermal properties.