Technology options for faecal sludge management in developing countries: Benefits and revenue from reuse

Abstract

This article provides technology options for the treatment of Faecal Sludge (FS) in developing countries to minimise exposure to FS and assesses its benefits along with possible revenue generation from reuse. FS that is collected from septic tanks poses management challenges in urban areas of developing countries. Currently, FS is dumped into the urban and peri-urban environment, posing great risks to the soil, surface water and groundwater quality. FS treatment technology usually consists of (1) primary treatment for the separation of the solid and liquid parts, and (2) sludge treatment, which is the final stage of treatment that is generated from the primary treatment. A decision matrix was prepared on the basis of primary and sludge treatment technological options with respect to land requirement, energy requirement, skill requirement, capital cost (CAPEX), operating cost (OPEX) and groundwater level. These parameters strongly influence the decision-making about the selection of the FS treatment technology. The selection of a FS treatment technology for a city also depends on the local conditions and priorities of the region with regard to sanitation such as population coverage, environmental and health benefits, elimination of open defecation, etc. Techno economic feasibility of different combinations of primary and sludge treatment technologies was conducted to evaluate its viability. The analysis was conducted across different classes of cities with varying population size. The combination of primary treatment technologies with solar sludge oven emerged to be the most economically viable options for FS treatments across different population size in developing countries.

Operating status of public toilets in the Hutong neighborhoods of Beijing: An empirical study

“…Hence, future sanitation investments must incorporate the FS management to achieve safe excreta management, create added value for society while protecting human and ecosystem health, and promote sustainable development of urban environmental hygiene ( Andersson et al, 2016 ). Studies have shown that the potential market-value products from FS include dry sludge as a fuel for combustion, protein derived from sludge processing as animal feed, sludge as a component in building materials, biogas/biomethane, biochar, biodiesel, and compost from co-treatment of FS, and kitchen waste/organic waste as clean energy, biofuel, and soil conditioner ( Cheng et al, 2017 ; Diener et al, 2014 ; Krueger et al, 2020 ; Singh et al, 2017 ).…”

Structured Approach for Comparison of Treatment Options for Nutrient-Recovery From Fecal Sludge

“…Elution X x x Shiba and Ntuli, 2017;Harder et al, 2019 Ammonia treatment X X X X Méndez et al, 2002;Nordin, 2010;Strande et al, 2014 Alkaline stabilization X X X X Bina et al, 2004;Strande et al, 2014;Anderson et al, 2015;Farrell et al, 2017 Thermal Carbonization X X X Strande et al, 2014;Harder et al, 2019 Incineration* X X X Rulkens, 2008;Diener et al, 2014;Strande et al, 2014 Pasteurization X X X Forbis-Stokes et al, 2016;Chapeyama et al, 2018;Septien et al, 2018 Solar drying X X X X Bennamoun, 2012;Strande et al, 2014;Singh et al, 2017 Physical-chemical Membrane nutrient extraction…”

Assessing the value of resource recovery and reuse: social, environmental and economic costs and benefits for value creation and human well-being

“…An analysis of the qualitative costs and benefits for fecal sludge management in developing countries (Singh et al 2017) focused on the benefits of resource recovery and reuse. Table 22 demonstrates that a qualitative assessment of costs and benefits can still be a valuable tool when used to make preliminary decisions in a low resource environment.…”