Removal of Nitrogen and Phosphorus from Liquid Dairy Manure using Microalgae

Animal production wastes and effluents are among the most highly produced wastewaters, containing high concentrations of nutrients and microbes that could lead to contamination and eutrophication of water sources. Large-scale enterprises in cattle breeding face challenges in storing and removing a substantial volume of liquid manure (LM). Therefore, the management of LM becomes an economic burden for producers. In this case, the question arises as to whether a more economical and sustainable treatment method can be employed by utilizing LM from animal production in algal growth, which has emerged as a renewable raw material source in recent years. In this study, a microalgae Ankistrodesmus sp. was employed for nutrient removal from dairy LM at concentrations of 10%, 20%, and 30% over 35 days. The total nitrogen reduction rates in the reactors with 10%, 20%, and 30% LM were 72.8%, 69.1%, and 71%, respectively, while the total phosphorus reduction rates were 65.7%, 52.6%, and 31.5%, respectively. Overall, integrating microalgae cultivation into wastewater treatment processes shows promise for nutrient removal and biomass production. By leveraging the nutrient-rich characteristics of LM from cattle farming, microalgae provide a sustainable and effective approach to reduce environmental pollution and enhance resource recovery in agriculture. Further research and development in this field are essential for optimizing treatment methods and improving the environmental sustainability of livestock operations.