Noosa Yoghurt’s new onsite wastewater treatment system, designed by Evoqua’s ADI Systems, replaced an unsustainable method for wastewater disposal and allowed the dairy processor to expand production. The state-of-the-art membrane bioreactor (MBR) biological wastewater treatment system generates a high-quality effluent for reuse in graywater applications using a single treatment stage, Daniel Bertoldo of ADI Systems reports.
Onsite MBR treatment keeps pace with increased production
Since Noosa Yoghurt’s inception in 2008, the company has rapidly grown in the competitive yogurt market. In less than ten years, Noosa Yoghurt’s manufacturing facility in Bellvue, Colorado, United States (US), has substantially expanded its product line in terms of flavors and tub sizes, and annual sales have steadily grown. Increased demand for Noosa Yoghurt products has also resulted in progressive increases in wastewater generation. The facility had previously mixed wastewater with cow manure and land-applied as fertilizer; however, this method of wastewater disposal became unsustainable, and Noosa Yoghurt needed a more feasible method for treating its high-strength wastewater.
Noosa Yoghurt wanted a robust, resilient treatment system that would consistently generate a final effluent to meet the direct discharge limits for biological oxygen demand (BOD); total suspended solids (TSS); fat, oil, and grease (FOG); total nitrogen (TN); and total phosphorus (TP). In anticipation of future increases in production, Noosa Yoghurt sought a system that would be easily expandable, which would allow the company to spread out capital expenditures for wastewater treatment over several years. Furthermore, the treatment system would need to be adaptable to handle potential changes in imposed direct discharge limits resulting from an increase in permitted discharge flow.
Challenges of treating dairy processing wastewater
While Noosa Yoghurt is not unique in encountering the many challenges associated with treating dairy wastewater, the company sought out an innovative solution. Dairy manufacturers typically generate wastewater with high concentrations of BOD, TSS, and FOG, which can disrupt the stability of a treatment process.
Additional challenges come along with the cleaning of vessels and processing equipment, which is typically conducted several times per day and results in significant changes in hourly flow. Cleaning and disinfection chemicals used during cleaning operations are subsequently discharged to the pretreatment facility and can contain high concentrations of compounds, which can be toxic to the biomass used to treat the wastewater if present in sufficient quantities. Furthermore, high concentrations of calcium in the wastewater can cause scaling of the surfaces of treatment tanks, piping, and equipment.
Finding the right solution
After an extensive technology search, Noosa Yoghurt selected Evoqua’s ADI Systems to provide process design services and to supply a prefabricated modular membrane tank with ancillary equipment. This modular membrane tank resulted in a plug-and-play approach, which significantly simplified onsite construction associated with the membrane tank.
The technology of choice, an ADI® aerobic membrane bioreactor (MBR) system, would be designed and installed in phases. Prior to the start-up of the components installed for Phase 1, Noosa Yoghurt signed a contract with a major American retailer, which would further increase production and wastewater generation. In effect, Noosa Yoghurt’s facility would need to be expanded much sooner than originally projected. Fortunately, the modular design of the MBR system made this change easy to implement.
The solution to increase treatment capacity while meeting the revised discharge limits involved installing a second modular membrane tank to operate in parallel with the first modular membrane tank and to expand the MBR system in order to achieve biological nutrient removal (BNR). As part of the Phase 2 expansion, components were added to the MBR system to double the hydraulic and organic load capacity, promote denitrification, and reduce alum requirements for chemical phosphorus removal.
ADI Systems’ packaged membrane tank is shipped with all internals and membrane cassettes pre-installed, resulting in a short turnaround from delivery to generating solids-free effluent. Photos by Evoqua/ADI
The prefabricated membrane tank is compact and provides a plug-and-play approach to water recovery. Photo by Evoqua/ADI