Performance of Experimental Bio-Digestion for Pathological and Biodegradable Waste Management at Mwananyamala Regional Referral Hospital Tanzania

Abstract

The aim of the experimental trial was to evaluate the performance of the designed placenta and other pathological waste digester system on the effectiveness of digesting the placenta and its energy recovery (bio-gas) process in Mwananyamala Referral Hospital in Dar es Salaam. A 32 m 3 digester is constructed in Mwananyamala Referral Hospital, one inlet of which is to attach to the toilet of maternity ward, where the placentas are flushed directly into the digester, while food waste is fed through another inlet. The slurry of the digester is sent to a sewer/septic tank to avoid further handling. Most fraction of the waste fed into the digester is food waste. In general with the amount of 25.6 ± 4.5 kg/day of placenta and 83.1 ± 14.7 kg/day of food waste, 2.5 m 3 /d gas was produced. The pH throughout the study period (that is of 18 weeks) was found to be consistent within the range of 6.3 to 8.0, while the pressure ranged from 5 kPa - 33 kPa. Average temperature within the digester was found to be 30.3 ° C. With all the favorable condition, gas production was consistent and hence the system has been successful in management of the pathological waste along with the production of gas as an alternative source of energy for the hospital.