pelletizing of faecal sludge. processing of faecal … of faecal sludge. processing of faecal sludge...

Pelletizingoffaecalsludge.Processingoffaecalsludgeintofuelpellets. FaecalsludgemanagementWorldwide, sanitation needs of 2.7 billion peopleare met by onsite sanitation technologies such asseptictanksandpitlatrines.Thesetechnologiescanprovideadequate sanitation if theproduced faecalsludge is adequatelymanaged. However, currentlylarge amounts of faecal sludge are dischargeduntreated directly into the environment, withnegative impacts on public and environmentalhealth(seewww.sandec.ch/fsm_book).FaecalsludgeresourcerecoveryFaecal sludge is a nutrient and energy resource.Faecal sludge treatment can produce marketableendproducts such as biogas, solid fuels, animalfodder or soil conditioner. Depending on the localmarket demand, these treatment endproducts canhelp to cover faecal treatment costs. For example,in Kampala faecal sludge as a solid fuel forindustriescanprovidehigherrevenuescomparedtothe conventional use as soil conditioner inagriculture.FaecalsludgefuelpelletsPellets were produced from dewatered faecalsludge from drying beds at the LubigiWastewaterand Faecal Sludge Treatment Plant in Kampala,Uganda, operated by the National Water &Sewerage Corporation (NWSC). Pellets wereproduced without the addition of a binder at amoisture content of 40-55% at a rate of 20-35 kgperhourandpelletizingunits.

Co-managementofbiowastesFaecal sludge was also co-pelletized withother biowastes such as sawdust, coffeehusks, banana peels and brewerywaste. Co-processingwiththesebiowastesincreasesthefuel quality (e.g. ash content, calorific value)and quantity. Such pellets produced fromdifferentwastes are of high and consistentquality and can be sold as fuel on theindustrialmarket.

DryingoffaecalsludgepelletsAdvantageously, faecal sludge pellets havefaster drying rates then sludge treated withdryingbeds. InKampala,faecalsludgepelletsdriedfrom50%to90%inoneweek.Whereasondryingbeds,thisrequiresseveralweekstomonths. Pellet drying can be enhanced byactive ventilated greenhouses or silo dryer.This means that the footprint of treatmentplants could be reduced, or the treatmentcapacityincreased,whichisveryimportantinurbanareaswithlimitedspace.EnergyrecoveryTheBioburnpelletizeronlyconsumes1-5%ofthe energy that is contained in faecal sludgepellets as electricity. In Kampala, brick andcement companies are interested in usingfaecal sludge as a fuel. In addition, pelletscould be a good feedstock for gasificationtechnologies.Challengeswithenergyrecoveryof faecal sludge in Kampala include the highashcontent(>35%).

SludgetoEnergyEnterpriseinKampala(SEEK)Project

The SEEK Project is (2014-2016) an international multi-disciplinary research product implemented inKampala, Uganda, and funded by the Symphasis Foundation and REPIC platform (Promotion ofRenewableEnergyandEnergyEfficiency inDevelopingandTransitionCountries).ProjectpartnersareBioburn, the Swiss Federal Institute of Aquatic Science (Eawag), Makerere University, Centre forResearchinEnergyandEnergyConservation(CREEC)andtheNationalWater&SewerageCorporation.

Projectpartners

Eawagwww.sandec.ch

BioburnAGwww.bioburn.ch

NWSCwww.nwsc.co.ug

MakerereUniversitywww.cedat.mak.ac.ug

CREECwww.creec.or.ug

Financialpartners

REPICwww.repic.ch

Symphasiswww.symphasis.ch