(200e) Nutrient Pollution Prevention By Implementing Nutrient Recovery Technologies in Livestock Facilities

Livestock farming is one of the main generators of organic waste, associated with considerable nitrogen and phosphorus emissions and nutrient pollution. Considering only the U.S., where the cattle population is around 51.8 million [1], and that a single dairy cow generates around 20 tons of waste per year [2], the generated annual residues are roughly 1,036 million tons. The inadequate management and disposal of these residues lead to soil degradation and runoff of nutrients to water bodies, leading to environmental issues as harmful algal blooms (HABs), dead zones, hypoxia, ground-level ozone pollution, nitrates in drinking water, and disinfection byproducts such as dioxin [3]. These environmental problems can lead to serious human health issues. In addition, nutrient pollution has a negative impact on the economy, decreasing soil fertility and crop yields, and requiring the installation of expensive water treatment systems to remedy the environmental and human health issues cause by poor water quality [4]. In addition, one of the major organic waste management constraints is its high-water content, which makes the transportation of waste to proper disposal locations (e.g., soils with nutrient deficiency) expensive and difficult. Therefore, an adequate management strategy for the satisfactory treatment of livestock waste (e.g., cattle manure) is necessary.

On the other hand, a decision-making tool for the design and selection of optimal nutrient recovery and valorization technologies has been developed. This tool evaluates different nutrient recovery technologies based on a set of parameters to describe the studied facilities: the operational parameters from each livestock installation (size and current manure collection equipment), product quality, capital investment available to implement the nutrient recovery system, and the targeted environmental footprint reduction to be achieved. Considering these input parameters, the tool determines the most appropriate technology for the evaluated facility, as well as a preliminary design of the equipment involved in the selected technology.

The developed tool is applied to a realistic case study of cattle facilities in the U.S., by considering the location of the livestock farms and their size. Therefore, optimal phosphorus and nitrogen recovery technologies are determined for different scenarios involving diverse investment budgets. In addition, current and potential U.S. government incentives for nutrient pollution prevention and product valorization are taken into consideration.

Working with facility location information, such as the pollution level of the surrounding soils, the presence of water bodies susceptible of being polluted by nutrient run-off, and the availability and location of potential agricultural product customers provide supplementary data about the technology implementation, which can be included in the decision-making strategy. Therefore, this information allows adding new elements about the context of the studied facility to the decision-making procedure, granting that the reached solution is adequate to the livestock facility and its particular setting.

References

[1] National Agricultural Statistics Service, 2018; [Online; accessed 06- September -2018].

[2] MacDonald, J.; Ribaudo, M.; Livingston, M.; Beckman, J.; Huang, W. Manure Use for Fertilizer and for Energy. United States Department of Agriculture, 2009.

[3] Aguirre-Villegas, H. A.; Larson, R. A. Evaluating greenhouse gas emissions from dairy manure management practices using survey data and lifecycle tools. J. Cleaner Prod.2017, 143, 169−179.

[4] Bylund, F.; Collet, E.; Enfors, S.; Larsson, G.A Compilation of Cost Data Associated with the Impacts and Control of Nutrient Pollution; Technical Report; U.S. Environmental Protection Agency, 2015.