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) prerequisite 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 tradeoffs. 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

Make cities and human settlements inclusive, safe, resilient and sustainable


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