Enzymatic Transformation of Soluble Nonreactive Phosphorus Compounds to Improve Phosphorus Removal and Recovery Potential from Wastewater
Faten B. Hussein, Alondra Deras Vazquez, Patrick Hogsed, Yaroslava G. Yingling, Tingyu Li, Eric McLamore, Imani Madison, Md Anik Mahmud, Md Shakil Uddin, Jehangir Bhadha, Rosangela Sozzani, Paul Westerhoff, Brooke K. MayerAbstract
A substantial fraction of total phosphorus (TP) in the environment exists as soluble nonreactive phosphorus (sNRP). These compounds can resist treatment processes and therefore persist in wastewater effluent, posing challenges for meeting stringent TP limits and long-term eutrophication risks. We employed an integrated experimental and chemoinformatics approach to evaluate the chemical diversity of sNRP and its impact on the fate of sNRP during enzymatic treatment. Transformation of selected sNRP compounds was evaluated using E. coli alkaline phosphatase (ALP). The tested compounds that were most susceptible to ALP (60–98% transformation) included phosphomonoesters with low molecular weight: beta-glycerol phosphate, 4-methylumbelliferyl phosphate, glucose-6-phosphate, phosphoenolpyruvic acid, and 2-aminoethyl dihydrogen phosphate. Michaelis–Menten kinetic analysis reinforced that transformation potential does not require uniformly high affinity or high turnover, but rather sufficient compatibility with ALP’s catalytic mechanism. Nearly all compounds were transformed as efficiently in the more complex synthetic wastewater as they were in Tris laboratory buffer. We developed a model to predict enzymatic transformation efficacy and used it to screen a data set of >600,000 P-containing molecules to identify the most potentially susceptible fraction of sNRP. Our study thus bridged from molecular-level enzymatic behavior to system-level treatment design to enhance TP removal and recovery potential.