Versatility of the manure phosphorus extraction (Maphex) system in removing phosphorus, odor, microbes, and alkalinity from dairy manures: A four-farm case study

Animal manure contains nutrients [primarily nitrogen (N) and phosphorus (P)] and organic material that are beneficial to crops. Unfortunately, for economic and logistics reasons, most manure tends to be applied to soils near where it is generated. Over time P concentrations in soils where dairy manure is applied builds up, often in excess of crop demands, and its potential loss in runoff poses a risk to water quality. We previously described, and have subsequently built, a full-scale version of a MAnure PHosphorus EXtraction (MAPHEX) System capable of removing greater than 90% of the P from manures. While originally designed to remove phosphorus, we postulated that the MAPHEX System was also capable of removing odor and microbes, and of concentrating alkalinity into a solid, economically transported form. In this study the MAPHEX System was shown to be highly versatile at removing greater than 90% of the phosphorus from a wide range of dairy manures. In addition, the study showed that the System is also capable of concentrating and recovering alkalinity from manures, while also removing over 80% of microbes and reducing the odor of the effluent applied to fields by half.