The fate of phosphate in the MixAlco process and its applicability to a Central Texas watershed.

The MixAlco process is proposed as a means to reduce phosphorus concentrations in dairy cow manure in order to help improve water quality in the Lake Waco watershed. Numerous dairy farms and intensive agricultural practices are located in this Central Texas watershed, and dairy manure is a major source of nutrients, particularly phosphorus. Nutrients, such as nitrogen and phosphorus, are the main causes of eutrophication. The MixAlco process, which can use dairy manure as a source of biomass to produce a mixed alcohol fuel, may reduce phosphorous levels in manure wastes. The dairy manure filtrate was analyzed for soluble reactive phosphorous (SRP) before and after the first two steps of the MixAlco process. An average reduction of 86 percent was observed from beginning to end. A reduction in SRP may ease the impact dairy manure has on eutrophication in the Lake Waco watershed to help improve water quality.