Documentation : 

Due to the poor state of waste disposal in some rural areas and some schools in those rural areas, there is greater demand to come up with sustainable solutions to this problem.
The design was done as a pilot project in Maranda High School to provide for a more efficient way of dealing with human waste. The design involved the construction of twelve new latrine blocks and a bio digester with a working volume of 96.72m³.
The latrine blocks were divided into two pairs with each pair having six latrines and a total length of 7.05 metres and a width of 1.1 metres. The waste from the latrines were transmitted to the bio digester through an intermediate pit where all the waste from the individual latrines would first accumulate at and flow through one pipe into the bio digester.
The bio digester had a width of 6.13 metres, height of 3.06 metres and a section thickness of 150 mm. The Hydraulic Retention Time used in the sizing of the bio digester was a length of 30 days. The dome of the bio digester had a diameter of 4.33 metres. The base of the digester was cone shaped in order to increase the static resistance of the whole structure. A pipe was constructed at the top of the dome to be used to transport the methane gas to the school kitchen for use in cooking. The expansion chamber had a diameter of 3.42 metres with a section thickness of 150mm. The slurry pit had a width of 2.4metres with a height of 1.75 metres and a width of 5 metres.
The objectives of the design were met and this design project report shows a complete design of a bio latrine. It is however important to apply the following recommendations to the bio latrine in order to optimize and improve its use. These include: Avoiding the use of detergents in cleaning the latrines as soapy detergents kill the decomposing microorganisms; Regular monitoring and testing of the effluent ensure that the effluent is of good quality in order to be used as fertilizer in the school farm and the addition of Sodium Hydroxide periodically to maintain the pH at a level of 7.

Paul final report.pdf2.87 MB