Watershed Symposium 2018

EBPR: A Solution to Nutrient Removal and Environmental Protection

Exponential growth in population and agricultural use of phosphorus (P) nutrient rich fertilizers has drastically reduced this limited resource. Excess P in surface waters from anthropogenic activities has been linked to eutrophication and harmful algae blooms. Enhanced biological phosphorus removal (EBPR) is an economically viable solution to remedy these emerging environmental concerns.

Full Abstract
With the turn of 19th century agricultural use of nutrient rich fertilizer to meet population growth and food consumption demand has drastically increased. Anthropogenic activities have contaminated surface water with excess nutrients through storm water runoff and other point source contributions. These excess nutrients have been linked to environmental derogation in the form of eutrophication and harmful algae blooms. In response researchers and legislators have studied possible solutions to remediating these emerging contaminates in an economical and efficient way. On January 1, 2020 Utah will act with Rule R317-1-3.3, a technology-based limit of total phosphorus effluents (TBPEL). Effluent discharge concentrations from wastewater treatment facilities will be regulated to less than or equal to the annual mean of 1 mg/L. Since the late 1970s enhanced biological phosphorus removal (EBPR) reactors have operated a series of anoxic/anaerobic/aerobic environmental conditions all over the world with great nutrient removal success. Phosphorus is removed in the wasted biomass of phosphorus accumulating organisms (PAOs) who consume soluble phosphorus and use an energy resource for proliferation. PAOs compete with denitrifying bacteria, glycogen accumulating organisms (GAOs) and other heterotrophic organisms for volatile fatty acids (VFAs) and other carbon resource. Additional carbon sources can be generated from the fermentation of primary settled sludge (PS) and or recycled activation sludge (RAS) to combat resource limitations. Funded by Central Valley Water Reclamation Facility (CVWRF) the University of Utah is operating a bench top EPBR reactor with fermentation. Microbial diversity is being monitored for PAOs, with particularly attention on Tetrasphera. Tetrasphera ability to accumulate phosphorus while also carrying out glycogen fermentation and denitrification makes Tetrasphera a desirable microorganism for EBPR. EBPR with fermentation is an economical and effective solution to nutrient removal for industrial and municipal wastewater discharges. The removal of P from our wastewater effluent discharges is of vital importance, because P is a limited resource that is being depleted at exponential rates. Scientist have estimated that apatite ores, the natural phosphorus deposit, will only endure current consumption rates for the next 50-130 years. The P rich biomass from the EBPR removal process can in turn be used as fertilizer, which will considerably conserve P resources since 82% of the mined phosphorus is used for agriculture.