PROJECT FOR PIG MANURE COLLECTION, BIOGAS REACTORS AND BIOFERTILIZER STORAGE AT TONGOGARA REFUGEE CAMP, CHIPANGAYI, CHIPINGE, ZIMBABWE

In order to prevent the free-roaming of pigs and the corresponding hygiene concerns in TRC, a large-scale pig farm was built in the south-west corner of the camp, directly neighboring the Save River. The piggery is operated by refugees, and has the capacity to house up to 600 pigs at different stages of development.

The manure from the piggery can be pushed into small channels, and runs from there into an unsealed manure lagoon. This lagoon likely leads to the emission of greenhouse gases and to a potential contamination of groundwater. The manure is currently not used for fertilization of agricultural grounds.

In 2022, 5 flexible biogas reactors were installed at a communal piggery in TRC. This pilot project aimed at tackling the new sanitation and environmental challenges caused by the manure lagoon. While the pilot project provided a proof of concept for biogas production from manure in TRC, it does not provide a safe and hygienic disposal of manure. Furthermore, its scale is not sufficient to process all manure.

Implementing a full-scale manure management solution, including biogas reactors, is therefore needed for the communal piggery. As part of this manure management solution, the effluent from the reactor – the biofertilizer – needs to be safely stored for a later application on agricultural grounds. With the application of the biofertilizer, nutrient and carbon cycles can be closed, and agricultural plant growth is fostered.

With the current setup of the pilot project, the utilization of biogas is limited. A full-scale biogas plant has the potential to improve the wellbeing and livelihood of refugees. As there are no households close by which could use the gas for cooking, a productive use of biogas is more likely. Biogas could for example power radiant heaters of the piggery or the neighboring poultry project. Or it could be used to process agricultural products, for example for the production of pork sausages, soap, bread, dried fruits or vegetables. The definitive usage of the biogas has not yet been defined, and bidders are invited to propose solutions (cf. program of works, productive biogas use, point 9).

A map and pictures of the piggery and the reactor area are provided in the Annex below. The pig sties in TRC were built to accommodate a maximum of approximately 600 pigs. The current number of pigs  there is 225 (adult pigs: 108, piglets: 117) as of October 2022.