Abstract

Selection of appropriate sustainable treatment technologies involves satisfying user requirements, quality standards on treatment and products, and specific socio-technical constraints in the intended context. Using locally adapted multi-criteria assessment (MCA), this study investigated faecal sludge treatment technologies that enable resource recovery in Phnom Penh. A four-step structured approach was applied, involving i) identification of available options, ii) prerequi-site screening, iii) MCA and iv) stakeholder discussions and ranking. Data were collected in a literature review, stakeholder interviews and an online survey. Lists of suitable primary (n = 7) and secondary (n = 13) treatment technologies were compiled based on the literature. Four secondary treatment technologies (solar drying, co-composting, vermicomposting, black soldier fly larvae (BSFL) composting) were retained after prerequisite screening and subjected to MCA. Co-composting was ranked highest in MCA, since it performed well in multiple aspects, especially for health criteria. However, when economic return on investment was prioritised and a lower treatment class was accepted, e.g. USEPA Class B biosolids, the highest ranking was achieved by vermicomposting or BSFL composting. If institutional criteria were included in the assessment, solar drying would likely be the highest-ranked option, since this simple technology requires less logistically complex stakeholder arrangements than co-composting. These results show that the ranking obtained for different sludge treatment options depends on criteria weighting and trade-offs. Considering secondary treatment options is crucial during early planning for faecal sludge management in a city of low-and-middle income countries, as the primary treatment must yield appropriate feedstock quality for the secondary treatment step.

Keywords

Low-income country; Nutrient recovery; Onsite sanitation; Resource-oriented sanitation; Sustainable sanitation; Treatment product

Published in

Environmental technology & innovation
2023, Volume: 32, article number: 103384

SLU Authors

• Eliyan, Chea

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    
  • Royal University of Phnom Penh

• Mcconville, Jennifer

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    

• Zurbrügg, Christian

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    
  • Eawag, Swiss Federal Institute of Aquatic Science and Technology

• Vinnerås, Björn

  • Department of Energy and Technology, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG11 Sustainable cities and communities


UKÄ Subject classification

Environmental Management


Publication identifier

DOI: https://doi.org/10.1016/j.eti.2023.103384

Permanent link to this page (URI)

https://res.slu.se/id/publ/126941