Environment and Pollution; Vol. 2, No. 4; 2013 ISSN 1927-0909 E-ISSN 1927-0917 Published by Canadian Center of Science and Education 70 Processing of Fecal Sludge to Fertilizer Pellets Using a Low-Cost Technology in Ghana Josiane Nikiema 1 , Olufunke Cofie 1 , Robert Impraim 1 & Noah Adamtey 2 1 International Water Management Institute, Cantonments, Accra, Ghana 2 Biotechnology and Nuclear Agriculture Research Institute, Legon, Accra, Ghana Correspondence: Josiane Nikiema, International Water Management Institute, P.M.B. CT 112, Cantonments, Accra, Ghana. Tel: 233-302-784-753/754. E-mail: J.Nikiema@cgiar.org Received: July 16, 2013 Accepted: August 27, 2013 Online Published: September 6, 2013 doi:10.5539/ep.v2n4p70 URL: http://dx.doi.org/10.5539/ep.v2n4p70 Abstract This paper describes a study that was aimed at optimizing the pelletization of fecal sludge-based fertilizers for agricultural use. The process developed is easy to implement and increases the marketability of the products while also addressing a serious health and environmental challenge. The study took place during the period 2011-2012 in Ghana. The fecal sludge, rich in nutrients and organic matter, was dried and used to produce five different fertilizers (i.e., four formulations of compost and one with gamma irradiated material). Each material was then pelletized using locally constructed machinery. Key operating parameters, such as moisture content (10-55% in mass), binder type (clay or starch) and concentration (0-10% in mass), were varied and their impacts on the characteristics of pellets (e.g., amount of fine materials generated, length distribution or stability of pellets, and pellet disintegration rate) were also followed. Given the low analyzing capabilities of developing countries, some simple analytical methods were developed and used to compare pellets produced under different conditions. The results confirmed that the addition of 3% of pregelatinized starch is recommended during pelletization of fecal sludge-based fertilizers. Applicable moisture contents were also identified per fertilizer type, and were found to comprise between 21 and 43%. Keywords: fecal sludge, pellet, fertilizer, compost, gamma irradiation, agriculture 1. Introduction In many sub-Saharan African countries, large amounts of fecal sludge (FS) from on-site sanitation systems (i.e., non-sewered household and public toilets, latrines, septic tanks, etc.) end up being dumped in the environment without appropriate treatment. This situation contributes to the pollution of water resources and, consequently, has negative impacts on health (e.g., by promoting the spread of diseases, such as cholera and diarrhea) and the environment, especially in and around highly populated zones in urban areas (Mara, Lane, Scott, & Trouba, 2010). Raw liquid FS typically contains 8.2 g/l of nitrogen (N), 1.1 g/l of phosphorus (P), 2.2 g/l of potassium (K) and 21.3 g/l of organic carbon (C) (Asare, Kranjac-Berisavljevic, & Cofie, 2003). This explains why many farmers, in several developing countries (Asia, Africa or Latin America), are keen to use this readily available material for agriculture. The usual practice in some parts of Ghana involves informal arrangements between farmers and people that empty latrines, who are invited to empty their trucks of FS straight on to the farm during the dry season (e.g., around December). The material is then allowed to dry for 3 to 4 months, before being used for the cultivation of cereal sat the beginning of the farming season (Cofie & Adamtey, 2009). Although there may be monetary benefits for farmers, this practice raises concerns due to the possible health risks if safe handling and processing procedures are disregarded (Seidu, 2010). Moreover, the sludge itself can only be transported and placed through the septic trucks, which limits its marketing potential. One better option is to sanitize the sludge and produce a safe and easy-to-handle fertilizer material, through a controlled process. Recently, a process involving the composting of dried fecal sludge (DFS), with or without the addition of organic matter (e.g., market or domestic waste) and enrichment with inorganic fertilizer, was developed (Adamtey, Cofie, Ofosu-Budu, Danso, & Forster, 2009; Cofie, Kone, Rothenberger, Moser, & Zubruegg, 2009). These studies confirmed that the resulting products are safe and their use represents a sustainable approach to improving crop production while preventing soil fertility depletion. However, efforts are still needed to increase the densities of the products which are responsible for most of the difficulties that pertain to storage (large space