Achieving Low Nutrient Effluent Quality at Lagoon Facilities using MBBR Technology: Low Temperature Performance and Bacterial Community Analysis

The challenges that currently restrict the widespread application of nutrient removal processes and technologies to low flow and rural wastewater treatment facilities such as lagoons include the availability of proven, economical and low operational intensity technologies to operate as upgrade units to supplement the current infrastructure of the passive treatment systems. In addition, many lagoon treatment facilities in temperate or cold climates lose the ability to nitrify and hence discharge effluent with elevated ammonia-nitrogen concentrations, for portions of fall, winter and spring. The study investigates the use of the moving bed biofilm reactor (MBBR) technology as a low operational intensity upgrade solution to lagoon facilities in temperate and cold climates to achieve year-round, cold temperature nitrification, to achieve total nitrogen removal via conventional nitrification/denitrification, and to achieve total phosphorus removal to levels below 0.1 mg-P/L through biomass assimilation. The study includes kinetic analyses attained at the pilot scale along with advanced microscopy and molecular methods to enhance the current fundamental understanding of nutrient removal biofilms in the MBBR technology applied as lagoon upgrade units. The study demonstrates the potential of the MBBR technology as an economical, low operational intensity, small land footprint upgrade technology to achieve significant nutrient removal at lagoons. The study demonstrates that during long winter exposures the system maintains significant nitrification kinetics, significant total nitrogen removal and significant assimilation of phosphorus, achieving high quality, low nutrient effluent at a lagoon facility operated in a temperate climate.