Social-economic assessment of valorization of faecal sludge into value-added products: Case study of selected products in Johannesburg metropolis

Abstract

Faecal valorization is one of the viable solutions to the issue of inadequate sanitation because it encourages investment in sanitation systems. Despite the demonstration of production of value-added products from faecal sludge, information of socio-economic assessment of these products which could pave the way for their commercialization is very scarce. In this study, socio-economic assessment of some selected value-added products such as; crops treated with fertilizer derived from human waste, meat from animals fed with feed derived from human waste, energy from the combustion of products derived from human waste (biogas) was evaluated within Johannesburg metropolis (Wits University and its environs). Estimates developed from a quantitative review of existing literature demonstrated high potential revenues for products from faecal valorization and associated end products. The estimates were developed through examining current prices and consumption patterns in South Africa. Questionnaires were distributed at the University of Witwatersrand and its environs, posing as a case study of Johannesburg, in order to determine consumer interest in end products and the effect of different incentives on interest level. Statistical analysis was used to analyze the collected data due to sample size and controlling for factors such as age, sex and education level, the study mitigated sample bias. The analysis was conducted using repeated measure AN0VA testing and Tukey HSD testing. The interest level of the end product of faecal sludge was quantified using a 5- point Likert scale while a regression model was generated to understand which among the variables explored in this study were significant in predicting the participant's interest level. Analysis of the results reveals that there is demonstrated interest in products from valorized faecal sludge with 5I% of participants willing to consume crops fertilized with faecal sludge, and 43% of participants willing to consume meat from animals fed with feed derived from faecal sludge, compared to 80% of participants who were willing to use energy from the combustion of products from faecal sludge. Therefore, the information provided in this study on faecal valorization could assist in addressing inadequate sanitation and other environmental problems throughout South Africa and the rest of Africa.