Making money out of waste

Human and animal waste may be a business of unpleasant odour, but to investors it smells like money. Martha Williams, an American student of film, has been in the country to make a documentary film on toilets, a project she has termed as ‘The grand world tour of toilets’. It is funny but some people can make money out of waste! According to Dr.Anastase Rwigema, a renewable energy expert and senior lecturer at the faculty of Engineering and science at Kigali Institute of Science and Technology (KIST), human and animal waste can be of great economic importance. H e says that what one needs is just human excrement and cow dung, then some few funds to buy the construction materials and labour to set up a biogas system and turn the residues into fertilizers. A pipe is constructed from the toilet latrine that channels human feces into the tanks where bacteria is used to emit gases, mostly methane and then instead of being vented into the air, they are piped into a storage canister in which biogas can then be processed. KIST is extending the biogas project to government institutions like prisons and schools, as a way of providing a renewable and stable source of energy. Byumba Girls’ School, Gicumbi District, Northern Province, is the one model example of the beneficiaries of KIST’s Biogas project. The school’s head teacher says she saves 1.5 million each term because of the project. The money she used to buy firewood and emptying school toilets is now being saved to buy more cows and renovating school structures. Dr. Rwigema further explains that use of compositing and biogas toilets can do a great role of protecting the environment and controlling sanitation. There is no tree cutting for firewood, and human waste overflow that would be a health hazard. The residues can then be used for fertilizers. The Fortune magazine, in February 2008, reported how, Sintext industries, a plastic and textiles manufacturer in Gujarat, India, found profit in human and animal waste where it uses a powerful biogas digester to turn human excrement, cow dung or kitchen garbage into fuel that can be used for cooking or generating electricity, simultaneously addressing two of India’s major needs: energy and sanitation. In a poor South Delhi neighborhood, 1OOO people use immaculately clean public toilets constructed by a non-profit foundation, the Sulabh Sanitation Movement. The biogas digester attached to toilets provides cooking gas for 600 students for a vocational training program the foundation runs. There is also an economic potential in composting toilets because they produce humanure. Humanure is a neologism designating human excrement (feces and urine) that is recycled via compositing for agricultural or biogas generation. This term was popularized by a 1994 book by Joseph Jenkins that advocates the use of organic soil amendment. Compositing toilets does not require water or electricity, and when properly managed does not smell. They also solve land misuse since one does not dig new pits for defecation. By disposing of feces and urine through compositing, the nutrients contained in there are returned to the soil and this aid in preventing soil degradation. Human fecal matter and urine are said to have high percentage of nitrogen, potassium, carbon and calcium. It reduces the energy consumption, and hence green house gas emissions associated with the transportation of water and waste water. According to Performance assessment of Institutional Biogas System in Rwanda November 2008 Report, the returns on investment are high as showed in the example of Remera and Kabutare prisons which invested Rwf 41 and Rwf 77 millions respectively in the biogas system and makes an annual savings of about Rwf 12 and 14 millions in firewood consumption. In addition to the high financial returns, there are additional financial returns; there are additional advantages about the positive effects like the hygienic and sanitation conditions around the institutions. There is potential market for institutional biogas system in the remaining prisons but also in the over 600 secondary schools especially those with boarding facilities and larger hospitals. Biogas will assist both in provision of a cheap and convenient source of energy as well as make a significant contribution towards improvement of sanitation and environment. Ends