MAPHEX System (IMAGE) Penn State Caption The system devised by Penn State and USDA scientists -- dubbed MAPHEX for MAnure PHosphorus EXtraction -- involves a three-stage process, including liquid-solid separation with an auger press and centrifuge, chemical treatment with the addition of iron sulfate, and final filtration with diatomaceous earth. The machine is designed to process manure from manure-storage tanks or pits on dairy farms. Credit Hristov Research Group/Penn State Usage Restrictions Non commercial use only License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.