Abattoir operations, waste generation and management in the Tamale metropolis: Case study of the Tamale slaughterhouse

Biowastes of slaughterhouses and wet markets: an overview of waste management for disease prevention

Slaughterhouse and wet market wastes are pollutants that have been always neglected by society. According to the Food and Agriculture Organization of the United Nations, more than three billion and nineteen million livestock were consumed worldwide in 2018, which reflects the vast amount and the broad spectrum of the biowastes generated. Slaughterhouse biowastes are a significant volume of biohazards that poses a high risk of contamination to the environment, an outbreak of diseases, and insecure food safety. This work comprehensively reviewed existing biowaste disposal practices and revealed the limitations of technological advancements to eradicate the threat of possible harmful infectious agents from these wastes. Policies, including strict supervision and uniform minimum hygienic regulations at all raw food processing factories, should therefore be tightened to ensure the protection of the food supply. The vast quantity of biowastes also offers a zero-waste potential for a circular economy, but the incorporation of biowaste recycling, including composting, anaerobic digestion, and thermal treatment, nevertheless remains challenging.

Biogas and bio-fertilizer production potential of abattoir waste: implication in sustainable waste management in Shashemene City, Ethiopia

Fossil fuel resources become scarce, and their combustion is a major pollutant in the environment. As a result, scientists are eager to find alternatives to fossil fuels, and biomass could be one of them. One method of turning biomass into biogas is anaerobic digestion (AD). One of the organic waste kinds used to generate biogas is abattoir waste. In developing countries, managing abattoir waste streams is a significant concern. Using these wastes to produce biogas and biofertilizers could help Ethiopia reduce its environmental hazard while also solving energy and fertilizer-related issues. Given that, the researchers in this study intend to investigate the biogas and bio-fertilizer production potential of abattoir waste in Shashemene Municipality Abattoir (SMA), Ethiopia. To this aim, the production potential of biogas, energy, biofertilizer, and Greenhouse gas (GHG) reduction was examined. The study showed about 688,755 kg (kg) per year of slaughterhouse waste is produced from 13,505 cattle, and anaerobic digestion may create approximately 206.63 × 103 m3/year of biogas. As a result, it can generate 1,018.98 Kilowatt-hour (kWh)/day and 371,927.7 kWh/year. On an annual basis, the biogas output (206.63 103 m3) can replace the 211.8 tons of energy consumed by LPG, kerosene, charcoal, furnace oil, petrol, and diesel. Moreover, the anaerobic digester has the potential to minimize the emission of greenhouse gas (GHG) by 952.4 tons CO2 eq per year. Furthermore, biogas has the potential to generate 43,184.9 kg of dry bio-fertilizer per year. Therefore, while biogas technology is the long-term solution for ensuring environmental safety and public health, proper disposal was one of the short-term options.

Country-level assessment of agrifood waste and enabling environment for sustainable utilisation for bioenergy in Nigeria

It is essential to plug inefficiencies due to agrifood losses and wastes, which pose a significant threat to the sustainable supply of nutritional agrifood commodities/products. Country-specific evaluations of the extent of agrifood losses/wastes, including the pathways and impacts on net agrifood production, are crucial to inform interventions, research, policies and investments. This kind of knowledge is scarce in sub-Saharan Africa (SSA) countries, many of which are food insecure. This paper presents an estimation of and the bioenergy potential for agrifood loss and waste (AFW) - the edible and inedible residual biogenic fractions of crops and animal commodities/products - in Nigeria. Our findings reveal that Nigeria generates 183.3 ± 8.9MT of AFW per annum. About 27% of the average annual total domestic supply of edible agrifood commodities/products is lost before reaching markets/consumers. The intrinsic bioenergy potential of the inedible AFW fraction generated annually in Nigeria is estimated to be 1,816.8 ± 117.3PJ; this is sufficient to meet 2030's bioenergy targets and replace a third of its total (grid, off-grid and self-generation) supply targets. However, Nigeria lacks regulatory, policy and institutional frameworks specific to AFW management. This study recommends a sustainable approach to managing AFW, addressing the interlinked challenges of bioenergy production, public health and environmental sustainability. Besides addressing knowledge gaps in the Nigerian agrifood sector, the information generated in this study is well-timed to inform decision-making and policy formulation on decentralised AFW-based bioenergy interventions to achieve energy supply targets in the country by 2030 and beyond. This study is also strategic to guide future research/interventions that align with AFW utilisation/clean energy generation in SSA.