Working with a purpose: turn waste into value
At PHIS you can be involved with almost anything that revolves around agricultural and environmental sustainability, sustainable development, as well as public health.Our work goes beyond simply valorizing organic waste. We conduct action-based research that touches multiple dimensions. It's as much about improving public health as it is about protecting the environment. We address nutrient systems alongside food systems, and our focus is not just on sustainable development but also on fostering sustainable livelihoods and thriving communities.
Seizing opportunities while expanding the good.
One of the CBE projects we’re working on involves the bioconversion of municipal organic waste such as fruit and vegetable waste from the market and fruit vendors, into a biofertilizer and animal feed by leveraging the Black Soldier Fly (BSF) technology. Fruit and vegetable waste in Sub-Saharan Africa presents consequential levels of wastage at both the upstream and downstream stages of the supply chain due to poor handling during harvesting and distribution, as well as poor storage conditions exacerbated by their perishable nature (Emerta Aragie) . According to a study by Opiyo et al, more than 50% of all municipal waste in Sub-Saharan Africa is composed of organic waste from fruits and vegetables (Paul Otieno Opiyo et. al) . For instance, the study found that municipal organic waste from the Kibuye Market in Kisumu, Western Kenya - one of the largest markets in East Africa - was mainly composed of spoilt fruit and vegetables (Opiyo et al.). An average of 1214 kg of vegetables and 477 kg of fruits are dumped from the market daily(Opiyo et al.). Valorizing such unavoidable waste including other organic by-products of the food system such as potato and pineapple peels would have a considerable positive impact on the sustainability of such a food system.
“You have to add something to the magic vase for the magic to happen” - John Ruskin.
The BSF Larvae (BSFL) flourish on most organic waste substrates(Stefan Diener et al) . They consume different organic waste such as municipal organic waste growing into protein-rich biomass and eventually leaving behind a nutrient-rich residue known as frass ( G. Jolly & J. Nikiema). The harvested larvae can be used to formulate animal feeds and the frass can be used as a valuable soil amendment (Joly and Nikiema) . According to Joly and Nikiema (2019), scientists working on organic waste valorization, the BSF-based technology is one of the most promising technologies for organic waste processing and management (Joly and Nikiema). The transformation of organic waste via BSF helps to address two major global challenges of food insecurity and waste management and with more attention, it could help close the loop within CBE (Joly and Nikiema). Besides researching the quality of the nutritional composition of BSFL reared on different organic municipal waste streams that are readily available in Kisumu City, we are also exploring how the BSF technology can be harnessed to create viable small-businesses. Analysis by Joly and Nikiema revealed that the BSF technology could be a promising business opportunity for nutrient recovery from organic waste (Joly and Nikiema). This could also help reduce municipal public budget allocations to waste management (Diener et al.)
Improving and perfecting the system.
Our next steps will involve working with local entrepreneurs/youth self-help groups to support them with the technical aspects of the technology for startups/business development. Logistical challenges of collecting fruit and vegetable waste within Kisumu City for BSF rearing is one of the hurdles we face. To address this we’re working on establishing networks with traders and vendors to improve communication and coordination; the integration of convenient transportation means such as a motorbike would make such operations efficient and convenient. Nevertheless, revenues from the potential animal feed and biofertilizer can cover some, if not all, of the waste collection costs (Diener et al).
Nourishment from the world around us.
The biological transformation of organic municipal waste using BSF is more beneficial than other existing options such as landfilling, dumping, open disposal, or incineration (Gromko and Abdurasulova) and it promotes some back-end benefits such as improved sanitation and the reduction of pollution and emission of greenhouse gases (GHG) (“Circular Bionutrient Economy Network”).
Experimental Design.
Some of the organic market waste we valorized via BSFL technology included peels from common fruits and vegetables such as pineapples and potatoes. We therefore decided to use pineapple and potato peels as some of the substrates to explore. Kisumu is home to East African Breweries Limited (EABL) which produces tons of brewers' waste which we added to our list of substrates to explore. Nevertheless, Kisumu city being a tourist destination, has many restaurants. Even though these restaurants produce loads of restaurant waste from food leftovers, there is a considerable demand from pig farms around. However, there tends to be excessive food waste during the festive seasons. Moreover, the diverse nutrients in restaurant waste would allow us to compare the performance of BSFL on such with the other substrates. With four types of substrates, we prepared six reps for each type of substrate, which was followed by the inoculation of the units with the larvae. Two weeks after the inoculation, the larvae were ready to be weighed. Moving forward, our operations mainly involved tracking the larvae body weights every week for the different substrates. In the end, we would perform a comparative analysis of the growth performance and body weight of the BSFL reared on the different substrates, and the effect of different substrates on optimal growth.
BSFL and BSFL Frass.
BSFL are fascinating creatures; they appear whitish and have a small projecting head with chewing mouthparts (Andreas Stamer) . They are voracious feeders and can eat twice their body weight daily, leaving behind BSFL frass - a waste residue made of exuviae, excrements, and leftover substrate (D. Craig Sheppard et al.).
-Ends
Jensen Njagi is a senior at Cornell University majoring in Development Economics and International Development with minors in Global Health and Business. He’s a Laidlaw Research Scholar receiving mentorship from Professor. Charles Midega, and Professor. Rebecca Nelson. His research at PHIS and the Nelson Lab is focused on nutrient recovery from organic waste streams for reuse in Agriculture.
References:
Emerta Aragie, “Efficiency and Resource Implications of Food Losses and Waste in Sub-Saharan Africa,” Journal of Asian and African Studies 57, no. 3 (May 2022): 446–61, https://doi.org/10.1177/00219096211020490.
Paul Otieno Opiyo et al., “Urban Dynamics of Food Loss and Waste: Challenges and Opportunities for Improving Food Security in Kisumu, Kenya,” Journal of Food Security, 2020.
G. Joly and J. Nikiema, “Global Experiences on Waste Processing with Black Soldier Fly (Hermetia Illucens): From Technology to Business” (International Water Management Institute (IWMI), 2019), https://doi.org/10.5337/2019.214.
Diener et al., “Black Soldier Fly Larvae for Organic Wste Treatment – Prospects and Constraints.”
Andreas Stamer, “Insect Proteins—a New Source for Animal Feed,” EMBO Reports 16, no. 6 (June 2015): 676–80, https://doi.org/10.15252/embr.201540528.
D. Craig Sheppard et al., “A Value Added Manure Management System Using the Black Soldier Fly,” Bioresource Technology 50, no. 3 (January 1, 1994): 275–79, https://doi.org/10.1016/0960-8524(94)90102-3.
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