Using Biodegradability of Sewage in Ordinary Pit Latrines to Assess their Agricultural Potentials

This research investigated the use of biodegradability of sewage in ordinary pit latrines to assess the performance of such sewage for agricultural purposes. The objective of this paper therefore was to study the biodegradability of faeces in selected pit latrines that would lead to the assessment of the performance of such pits. Both aerobic and anaerobic biodegradability of pit sludges were thus measured. Samples of fresh faecal sludges collected from pit latrines in selected households in Aku community were subjected to laboratory analyses for their physico-chemical and biological characteristics. The results showed that in terms of biochemical oxygen demand (BOD), twelve (12) pits had biodegradability of 80 Parsant and above. In the case of chemical oxygen demand (COD) and suspended solids (SS), nine (9) pits had biodegradability of 80 Parsant and above. For the volatile solids (VS), eleven (11) pits had biodegradability of 80 Parsant and above. Ten (10) pits had ratio of volatile solids to total solids (VS: TS) ranging from 0.90 – 2.93. Using COD: BOD ratio, eleven (11) pits had values ranging from 0.90–1.34 indicating that the pits sludges were readily biodegradable and good for agricultural purposes. Lower values showed lower organic contents and lower biodegradability and therefore unsuitable for agricultural purposes. High COD: BOD, VS:TS ratios should therefore be used to assess the performance of pit latrine sludges for higher agricultural productivity considering good user-behaviour, favourable soil and environmental conditions. Excreta collected from such pits should be used to enhance soil fertility.