**Preface to "Waste Management Practices in Developing Countries"**

Developing countries face many challenges in the managemen<sup>t</sup> of waste. These include inadequate waste collection systems, the dumping and burning of waste in open spaces, the operation of uncontrolled or controlled dumpsites, and limited to no waste recycling or recovery. The "leakage" of waste into the environment has a direct negative impact on human and environmental health. At the same time, valuable resources are lost to local economies through the disposal of end-of-life products to land, resulting in negative social and economic impacts. The Global Waste Management Outlook (UNEP, 2015) called on developing countries to stop the uncontrolled dumping and burning of waste; to bring hazardous waste under control; to focus on the prevention of waste; and to develop feedback loops by maximizing recycling and integrating existing small-scale entrepreneurial recyclers into mainstream waste management. The International Solid Waste Association (ISWA, 2014) called for the closure and rehabilitation of dumpsites as a top priority to ensure health and environmental protection.

This book provides insights into waste managemen<sup>t</sup> practices in developing countries. It highlights the application of research and innovation in finding locally appropriate solutions to improved waste management. The chapters have been selected with a focus on organic waste beneficiation; the role of governmen<sup>t</sup> and policy interventions; citizen behaviour in driving waste recycling; and the safe managemen<sup>t</sup> of hazardous waste—particularly healthcare risk waste. Organic waste such as food, garden, and agricultural waste is a relatively large percentage of the waste stream generated in developing countries. The disposal of this waste to land often results in the generation of leachate, impacting water resources; generates odours and attracts vermin; and through its aerobic or anaerobic digestion, generates greenhouses gases, with the potential to negatively impact climates. Yet, organic waste is easily beneficiated, through various technologies such as composting, anaerobic digestion, or more advanced biorefinery technologies. The separation of organic waste at its source and its diversion to beneficiation technologies creates numerous environmental, social, and economic opportunities, and as such, must be considered by developing countries.

All spheres of governmen<sup>t</sup> have an important role to play in the improved managemen<sup>t</sup> of waste, through appropriate policy development and implementation. Effective service delivery to all citizens must be a priority, including the consideration of partnerships with the private sector, where this will lead to more effective and efficient integrated waste management.

Recognising that responsible waste managemen<sup>t</sup> starts with us, as citizens and consumers, improved education and awareness is important in supporting behaviour change towards more sustainable waste managemen<sup>t</sup> practices, including eliminating littering and illegal dumping, and driving greater recycling behaviour.

Finally, it is important for waste practitioners in developing countries to share and publish their work, through rigorous peer-review processes, so that others may learn from their insights, thereby creating global communities of practice aimed at improving waste managemen<sup>t</sup> in developing countries.

We trust that the chapters published here will provide such insights to assist communities in bringing waste under control while also unlocking the opportunities of waste as resource.

> **Linda Godfrey** *Editor*

## *Article* **Cassava Waste Management and Biogas Generation Potential in Selected Local Government Areas in Ogun State, Nigeria**

#### **David O. Olukanni \* and Tope O. Olatunji**

Department of Civil Engineering, College of Engineering, Covenant University, Ota 121101, Ogun State, Nigeria; engrolatunji@yahoo.com

**\*** Correspondence: david.olukanni@covenantuniversity.edu.ng

Received: 5 September 2018; Accepted: 12 December 2018; Published: 14 December 2018

**Abstract:** Agricultural products such as cassava produce huge amounts of waste when processed into consumable goods. The waste generated is generally considered to contribute largely to environmental pollution. This study therefore investigates the waste managemen<sup>t</sup> practice that is adopted by cassava processors in Ogun State, Nigeria. Five local governmen<sup>t</sup> areas (LGAs) dominant in processing cassava were selected for the study on the basis of spatial location distribution, landmass, and population. The survey involved the use of structured questionnaires administered to cassava processors of the selected LGAs. The Statistical Package for Social Sciences (SPSS) software application and descriptive statistics were used for data analysis. Results of the analysis show that the majority (70%) of the cassava processors are females. Cassava peel constitutes 10% of the waste produced, of which 91% is heaped at refuse dumps in most communities. Results also reveal that 86.3% of cassava residues are used for animal feeds. Other findings show that the peels, when dried, are used as biofuel for cooking and there is a significant potential for biogas production. From the data captured from respondents during the study, most processors are willing to pay for an improved waste managemen<sup>t</sup> system. The study therefore recommends the proper waste managemen<sup>t</sup> of cassava waste to minimize environmental pollution.

**Keywords:** solid waste management; environmental pollution; agricultural waste; cassava waste; biogas generation; sustainable technology
