2023 December Board Book

2024 – 2025 Effect of Nanobubbles on Dairy Manure Green House Gasses (GHGs) Researcher: Dr. Frank Mitloehner, UC Davis Department of Animal Science 2024 Budget: $129,128; CMAB REQUEST $96,846 2025 Budget: $79,544 Background: Nanobubbles are spherical gas-filled nano-cavities with diameters of 10 - 200 nm. Nanobubbles have been safely applied to domestic and industrial wastewaters. The technology can generate free radicals that can oxidize organic matter in wastewaters. The application of nanobubbles to different dairy manure streams could potentially reduce the emissions of methane by at least 90% because the redox potential in manure will be at least +200 mv, which is not suitable for the growth of metha nogens. It may increase the emissions of nitrous oxide but at lower rates compared with

conventional aeration. It may also improve solid separation in the treated manure (e.g., in settling basins). This will lead to less accumulation of solids in lagoons that reduces the needs for the frequency of lagoon cleaning. The technology could

also improve irrigation efficiency, soil properties, water use, and crop yield.

Industry Benefit: The proposed work will guide the dairy industry to determine the effectiveness of nanobubbles as a novel technology for mitigating emissions and improving manure characteristics. Based on the data available on wastewater treatment with the nanobubbles, it is expected that the application of nanobubbles to dairy manure will save 40%-60% of the operation maintenance costs compared with conven tional aeration. The proposed nanobubbles system is scalable and has a great chance for replicability on California dairies. The cost of applying this technology on dairies will be conducted in this project. The results will help to document the economics of implementing and operating the technology. 2024 Evaluation of Manure Treatment Technologies Researcher: Dr. Deanne Meyer, UC Davis Department of Animal Science 2024 Budget: $85,859; CMAB REQUEST $64,394

Background: Last year, the USDA-funded Dairy PLUS Program was established with CDFA. New potential technologies may be eligible for grant-funding through the Dairy PLUS program, however, these technologies need to be studied for efficacy and economic viability. Only approved technologies can be funded through the program. It is critical to continue to test and approve advanced manure management practices in California that address both GHGs and nutrient surplus since more than 90% of California’s milk is produced in the San Joaquin Valley on dairies located in priority one nitrate management zones. The quantity of nitrogen excreted out-paces the ability to utilize nitrogen for optimum crop and soil benefits while maintaining or improving groundwater quality. Additionally, implementation of plans associated with sustainable ground- water management will require modification to farming practices (fallowing land, alternative crops) to account for less water available for farming. For this project, researchers will observe several potential technologies in use on-farm, identify an appropriate sampling protocol, and sample to identify nutrient and volatile solids removal as well as determine if the technologies can be utilized on California dairy operations.