Safeguarding ecosystems using innovative approaches to manage animal wastes

Abstract

Animal wastes (AWs) are excreta or discarded materials associated with animal production industries. It could be in solid, liquid, or gaseous form, such as animal dung or droppings, discarded feed, feathers, fur, decayed bodies of dead animals, blood waste, effluent from animal farms, milk wastes, urine, and fart. Animal wastes are generated in high quantity, even beyond the control of animal farmers, due to the increase in animal production globally. These wastes pollute the ecosystem. They release greenhouse gases (GHGs) such as methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O) into the atmosphere through anaerobic fermentation which deplete ozone layer. Nitrogen and phosphorus constituents of Aws alter soil texture and pollute water bodies through run-off and direct disposal into water systems. The resultant effects of the pollution include climate change, degradation of soil and burning of crops, death of aquatic biota, release of offensive odour, especially ammonia (NH₃) and hydrogen sulphide (H₂S), and cause diseases of public health concern to human beings and animals. These consequences are due to the emission of harmful gases and compounds and the presence of pathogens in the waste. Animal wastes are potential sources of income and resources, and their environmental consequences could be reduced if farmers could use innovative approaches such as vermicomposting, production of biogas using wastes, membrane filtration, liquid – solid separation, thermal treatment and chemical treatment approaches to manage animal wastes. Government regulation and policies against indiscriminate disposal and application of animal wastes, coupled with the sensitization of people to the benefits and dangers associated with animal waste, could also prevent environmental challenges.