Black Soldier Fly biowaste treatment – assessment of global warming potential
Cities of low and middle-income countries face severe challenges in managing the increasing amount of waste produced, especially the organic fraction. Black Soldier Fly (BSF) biowaste treatment is an attractive treatment option as it offers a solution for waste management while also providing a protein source to help alleviate the rising global demand for animal feed. However, to-date very little information is available on how this technology performs with regard to direct greenhouse gas (GHG) emissions and global warming potential (GWP).
This paper presents a study that uses a life cycle assessment (LCA) approach to assess the GWP of a BSF waste treatment facility in the case of Indonesia and compares it with respective values for an open windrow composting facility. Direct CH4 and N2O samples were extracted from BSF treatment units and analyzed by gas chromatography. Results show that direct CO2eq emissions are 47 times lower the emissions from composting. Regarding the overall GWP, the LCA shows that composting has double the GWP of BSF treatment facility based on the functional unit of 1 ton of biowaste (wet weight). The main GWP contribution from a BSF facility are from: (1) residue post-composting (69%) and (2) electricity needs and source (up to 55%). Fishmeal production substitution by BSF larvae meal can reduce significantly the GWP (up to 30%). Based on this study, we conclude that BSF biowaste treatment offers an environmentally relevant alternative with very low direct GHG emissions and potentially high GWP reduction. Further research should improve residue post-treatment.
Blue Schools. Linking WASH in schools with environmental education and practice. Catalogue of practical exercises
A Blue School offers a healthy learning environment and exposes students to environmentally-friendly technologies and practices that can be replicated in their communities. It inspires students to be change agents in their communities and builds the next generation of WASH and environment sector champions.
The Catalogue of Practical Exercises aims to inspire teachers with hand-on and low cost exercises to complement the lessons from the national curriculum. The examples provided facilitate students' learning by doing and can be replicated in the students' home and in their communities.
It provides examples of practical exercises for each topic of the Blue Schools Kit:
1. My Surrounding Environment
2. The Water Cycle
3. The Watershed around My School
4. My Drinking Water
5. Sanitation and Hygiene
6. Growth and Change
7. From Soil to Food
8. From Waste to Resources
For each topic, technical background sections are provided to facilitate understanding of basic key concepts. Each topic includes a selection of teaching, participatory or creative activities, discussions, demonstrations, games, and experiments, all requiring simple material at little to no cost. The practical exercises aim to help reaching the key learning objectives defined in each topic's first page. The level of difficulty for each exercise is indicated; depending on the class and age group, teachers can select the most appropriate activities and students can deepen their knowledge on these topics from year to year.
This catalogue is a compilation of references from the WASH in School (WINS) community of practice as well as other sectors related to the Blue Schools' topics. It can evolve: Future editions of this Catalogue will benefit from inputs and feedback from users and experts from around the world. Feedback form available on the Swiss Water and Sanitation Consortium website: waterconsortium.ch/blueschool/
Users of this document are also encouraged to refer to the other materials of the Blue Schools Kit i.e. the Concept Brief, the Facilitator‘s Guide and the Catalogue of Technologies. These can be downloaded on the Swiss Water and Sanitation website.
Leclert, L.; Moser, D.; Brogan, J.; Mertenat, A.; Harrison, J. (2018) Blue Schools. Linking WASH in schools with environmental education and practice. Catalogue of practical exercises, 104 p, Institutional Repository
Treatment technologies for urban solid biowaste to create value products: a review with focus on low- and middleincome settings
Treatment of biowaste, the predominant waste fraction in low- and middle-income settings, offers public health, environmental and economic benefits by converting waste into a hygienic product, diverting it from disposal sites, and providing a source of income. This article presents a comprehensive overview of 13 biowaste treatment technologies, grouped into four categories: (1) direct use (direct land application, direct animal feed, direct combustion), (2) biological treatment (composting, vermicomposting, black soldier fly treatment, anaerobic digestion, fermentation), (3) physico-chemical treatment (transesterification, densification), and (4) thermo-chemical treatment (pyrolysis, liquefaction, gasification). Based on a literature review and expert consultation, the main feedstock requirements, process conditions and treatment products are summarized, and the challenges and trends, particularly regarding the applicability of each technology in the urban low- and middle-income context, are critically discussed. An analysis of the scientific articles published from 2005 to 2015 reveals substantial differences in the amount and type of research published for each technology, a fact that can partly be explained with the development stage of the technologies. Overall, publications from case studies and field research seem disproportionately underrepresented for all technologies. One may argue that this reflects the main task of researchers—to conduct fundamental research for enhanced process understanding—but it may also be a result of the traditional embedding of the waste sector in the discipline of engineering science, where socio-economic and management aspects are seldom object of the research. More unbiased, well-structured and reproducible evidence from case studies at scale could foster the knowledge transfer to practitioners and enhance the exchange between academia, policy and practice.
Lohri, C. R.; Diener, S.; Zabaleta, I.; Mertenat, A.; Zurbrügg, C. (2017) Treatment technologies for urban solid biowaste to create value products: a review with focus on low- and middleincome settings, Reviews in Environmental Science and Biotechnology, 16(1), 81-130, doi:10.1007/s11157-017-9422-5, Institutional Repository