The Use of Effluents from Biolatrines in Tanzania (ADF, 1996, 38 p.) Introduction I. Biogas technology in Tanzania II. The introduction of biolatrines

The Use of Effluents from Biolatrines in Tanzania (ADF, 1996, 38 p.)

Introduction

I. Biogas technology in Tanzania

Biogas technology was introduced in Tanzania in the early 1970s by the Tanzanian government's Small Scale Industries Organisation (SIDO). The primary objective was to promote renewable energy sources, in response to the crisis produced by rising prices of imported fossil fuels. Biogas technology was considered one of the best alternative sources, particularly for rural areas. SIDO adopted and promoted the Indian Gobar type of bio-digester, made of a steel floating drum to hold the gas, mounted on a masonry base. But SIDO was only successful in installing a small number of units by the late 1970s.

A nationwide survey of the installed units, conducted in the early 1980s, revealed a number of problems previously overlooked by SIDO. These included faulty installations, such as placement of the biogas digesters near kitchens but far from the animal stable, and badly mounted piping with resultant gas leaks. The focus was only on biogas as an energy source and slurry was rarely used as fertilizer. Without effective utilization of this additional output, the bio-digesters were not economically justifiable. The design requiring imported steel and trained metalworkers was costly. And there was inadequate follow-up after initial installation of the units.

Beginning in 1983, the Centre for Agricultural Mechanisation and Rural Technology (CAMARTEC), in collaboration with the German Agency for Technical Cooperation (GTZ), took over major responsibility for biogas activities from SIDO. The joint CAMARTEC-GTZ Biogas Extension Services (B.E.S.) was based in Arusha, in northern Tanzania.

B.E.S. based its plans both on the previous experience of SIDO and on new international perspectives on biogas technology. For nationwide extension, it decided to promote an adaptation of the Chinese fixed-dome design, because this required only locally available materials.

By 1986, using the original Chinese design, B.E.S. developed a new, completely different, design-the CAMARTEC fixed dome-which was then the only non-steel crackproof fixed dome ever developed. The new design won international recognition and was adopted for the nationwide extension program.

II. The introduction of biolatrines

Biolatrines were introduced in Tanzania by CAMARTEC through B.E.S in a feasibility study in 1987. On the one hand this was an extension of previous biogas efforts aimed at solving the energy shortage, particularly by making biogas available to schools, institutions, and other communities who did not keep animals or cultivate crops that might provide organic material for inputs. But there were also other important objectives, specifically improving public health through better hygienics and sanitation, and providing additional effluents to be used as fertilizer in agriculture.

Despite the feasibility study's positive results, implementation on a wider scale has been difficult. That is the context in which this research was undertaken.