Research Article
A Comprehensive Study on the Physicochemical
Characteristics of Faecal Sludge in Greater Accra Region and
Analysis of Its Potential Use as Feedstock for Green Energy
Issahaku Ahmed ,
1
Dennis Ofori-Amanfo,
1
Esi Awuah,
2
and Florence Cobbold
1
1
Sewerage Systems Ghana Ltd., Accra, Ghana
2
Department of Civil Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
Correspondence should be addressed to Issahaku Ahmed; eagleskertoozer@yahoo.co.uk
Received 29 January 2019; Revised 20 May 2019; Accepted 11 June 2019; Published 1 July 2019
Academic Editor: Nuri Azbar
Copyright © 2019 Issahaku Ahmed et al. Tis is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Design of treatment plants for faecal sludge management systems relies on a comprehensive accurate knowledge of FS (faecal
sludge) characteristics, but this information is lacking. Developing countries like Ghana, where large proportion of the urban
population (Accra) rely on onsite sanitation systems, face a lot of FSM (faecal sludge management) design challenges as a result
of lack of a comprehensive study data on physicochemical characteristics of raw faecal sludge afer primary dewatering. Achieving
a fully operational FSM chain would imply a well understanding of the characteristics of the FS and its dynamics afer primary
dewatering. A study was carried out to determine the characteristics of faecal sludge brought to the Lavender Hill treatment plant,
Accra Metropolis, and environs to ensure the treatability and uses of the products afer treatment. Te treatment plant receives an
average of 150 trucks (1350m
3
) a day with 58% coming from private homes and 42% from public toilets. Composite samples were
made from both public and private toilets facilities. Samples were taken from a reservoir holding faecal sludge from both public and
private facilities, examined on daily basis and characterized. Te values obtained showed high concentrations of BOD and COD
values. Te COD: BOD ratios showed that the faecal sludge is not stabilized yet and can be further degraded. Te calorifc value
for the dry sludge was found to be 15.16-15.82 MJ/kg and 16.39–18.31 MJ/kg for the wet sludge. Te calorifc value of the sludge
is adequate enough to be used as potential feedstock for green energy generation. Te high concentrations of COD and organic
matter of the faecal sludge make it suitable enough for biogas generation. A good correlation ( = 0.909,
2
= 82.6%) between the
calorifc value and the TVS was found to be CV = 0.122TVS + 7.44. Heavy metal concentrations were low and satisfed the EPA
Ghana guidelines for sludge. Tus products from the treatment can be used for agricultural purposes.
1. Introduction
Faecal sludge management (FSM) has not been given the
needed attention for the past decades in Africa [1, 2] making
FSM difcult and cumbersome for states to manage [3–5]
and Greater Accra Region of Ghana is not in exception.
Accra and other urban areas in Ghana are ofen faced with
poor sanitation situation [3, 6] leading to faecal sludge
management crises [3]. Lack of standardized methodologies
for the quantifcation or characterization of FS has partly
contributed to the crises [7]. It is estimated that one-third
of the world’s population, approximately 2.4 billion urban
dwellers, rely on onsite sanitation system (OSS) installations
such as public latrines, aqua privies, and septic tanks [8].
More than half of the entire population of Ghana (58%)
rely on cesspit and Kumasi ventilated improved pit (KVIP)
latrines [8]. Faecal sludge (FS) generated in Ghana and
many developing countries is mainly made up of public
toilet sludge (PTS) and septage [8] which are disposed of
untreated and indiscriminately into lanes, drainage ditches,
and open urban spaces [3, 4, 6, 9–12]. Tere are very few
faecal sludge treatment facilities available to treat the many
tons of sludge generated [9, 10, 13] specifcally in Accra,
thus making treatment of FS very abysmal. Te process
involved in FSM in Ghana within the context of FSM chain is
fourfold: collection, transportation, disposal, and treatment.
Hindawi
Journal of Renewable Energy
Volume 2019, Article ID 8696058, 11 pages
https://doi.org/10.1155/2019/8696058