The composting plants in developing countries are generally based on imported ‘turnkey’ technologies. Most of the plants however are now at a standstill and only a few are still operating or operating at reduced capacity. These sophisticated and very expensive systems are often indicative of a lack of knowledge about the local character of the waste.
The aim of the project was to maximise the effectiveness and efficiency of the composting process in the light of local conditions in Lomé, Togo by building a database on the type of waste produced to serve as a decision making tool for municipal officials. To collect the necessary information and develop performance indicators, Dr Koledzi evaluated with the help of non-governmental organisations, the complete solid waste chain and the associated compost production system in Lomé, from the household to the agricultural field.
The study further involved the characterisation of the waste created in Lomé to help guide the choice of a suitable type of processing. Central to the study was the experimental research on composting carried out to assess the need for additional sources of plant nutrients (elements), calculate the germination index, quantify change in crop yield and test for eco-toxicity.
Findings suggest the waste used for composting should be collected at the household level where organic matter is proportionally high compared to the waste collected at the final disposal site. Field experiments conducted on farms showed a substantial improvement in cereal and vegetable crop yields. Lead concentration was found to be very high with actual bio-availability dependant on the maturity of the compost.
The experiment led to the creation of a compositing platform that actually takes into account the available market and local constraints, boosting the effectiveness of the (composting) process. This research was published as high-impact review articles and presented at international symposiums. It was the basis for preparing a training manual and two documentaries on making compost.