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Fixed-media biotechnology provides efficient wastewater treatment & quality effluent
Dr Pepper Snapple Group (DPS), a producer of flavored beverages, is committed to improving operating efficiency and environmental sustainability throughout its organization. As a beverage manufacturer, energy and water usage has significant cost implications, as well as environmental impacts due to the high organic content of the effluent from its bottling operations. DPS has established sustainability goals for reducing water consumption and wastewater discharges per gallon of finished product.
At the DPS bottling facility in Houston, the company saw an opportunity to support these goals and enhance its stewardship of the local community by ensuring that the water leaving the plant puts less strain on municipal resources, thus improving the city of Houston’s capacity to service other customers.
In 2011, DPS selected Baswood Corp.’s BioViper biological pretreatment system to provide an optimal wastewater solution that complements other operating efficiency and sustainability initiatives already in place at its Houston bottling plant.
According to Kendall Yorn, senior vice president of manufacturing and engineering for DPS, “Baswood’s BioViper system reduces both cost and our impact on the environment and public resources. Clean water is in everyone’s interest, and this new technology is a major step forward in our commitment to finding sustainable solutions that positively affect our community.”
The Treatment Process
The BioViper provides reliable wastewater pretreatment within a stable, fixed-film biological system. The system’s sequential, fixed-media biotechnology provides efficient treatment and improved quality effluent. Baswood’s patented aerobic/anaerobic integrated media maintain a high food-to-mass ratio within the reactors, resulting in a robust biomass that maximizes efficiency, optimizes biochemical oxygen demand (BOD) digestion and biosolids reduction, and is capable of handling fluctuating organic loads.
The DPS Houston system is composed of three reactors, each with three distinct treatment zones in a unique, vertical alignment. While aerators are used to supply air to the biomass to meet its respiratory needs, the configuration of the system eliminates the need for blowers to maintain solids or media in suspension. As a result, the energy needs and equipment maintenance requirements of the system are significantly lower.
The vertical configuration of the treatment zones within each of the reactors reduces the footprint requirements for the system. For the DPS Houston plant, the Baswood system required just a 6,000-sq-ft physical footprint, allowing it to be constructed on the existing facility property without additional land or facility expansion.
Effluent from the bottling plant first is pumped to an equalization tank; from there it is fed into the top of the first of the reactors for treatment. Wastewater flows by gravity to the bottom of the reactor as it passes through a series of three treatment zones. The wastewater then is piped from the base of the reactor to the top of the next reactor, where the treatment process is repeated in sequence. The same treatment process is used as the water flows through each of the three reactors before it is ready for discharge. By the time the effluent is discharged to the municipal sewer, it has been treated a total of nine times and BOD levels have been reduced by 75% to 90%.
The BioViper has features that minimize operational oversight and maintenance requirements, and reduce the potential for equipment failure. The system has no internal moving parts, requires limited chemicals due to internal self-buffering, uses readily available commercial off-the-shelf components, and is monitored by proprietary SCADA with remote monitoring capability.
Pilot testing ensured the solution met the need. Prior to implementing the full-scale system, Baswood conducted a pilot test at the Houston facility to demonstrate the effectiveness of the technology in treating the constituents present in the plant’s effluent and confirm the savings inherent in such a program.
Pilot testing of the biological pretreatment technology defined the appropriate operation parameters to maximize the efficiency of the treatment process to achieve the required pretreatment objectives. By implementing a pilot test, Baswood was able to define the analytical characteristics of the DPS wastewater, wastewater flow patterns and volumes, and BOD loads throughout the production week. This allowed the engineering team to define the hydraulic volume and waste-specific treatment capacity of the BioViper system, establish the final system footprint, and determine equalization volumes and storage parameters.
Upon completion of the successful pilot study, Baswood developed the design, estimate and schedule for the installation of a full-scale system comprised of equalization, three multi-zone reactors and a control building. The modularity of the BioViper made it possible for Baswood to design a system that allows for expansion as DPS increases its production, without an increase in footprint. DPS submitted the design to the city of Houston for approval.
System Installation & Startup
Construction of the Baswood system began in September 2012 and finished in February 2013, when startup of the system commenced. The system is designed to treat up to 350,000 gal per day (gpd), with initial flows between 135,000 and 165,000 gpd. It can handle loads of more than 7,500 mg/L of BOD, with an energy consumption of 2,400 kWh per day.
Because the system began operation in February, data have shown that the effluent discharged from the DPS facility to the city of Houston has seen contaminant reduction (measured as chemical oxygen demand) by a factor of 90%, far exceeding the design standard of 75%. This equates to removals of more than 7,000 lb of BOD load to the city per day, which is equivalent to approximately 9,600 homes. By reducing this load, the city will be able to take on additional customers and provide more services. Initial measurements also show that the BioViper is using less than one-third of the installed horsepower to achieve these high efficiency rates, resulting in lower energy costs.
“We are pleased that the BioViper is already performing better than expected at the DPS Houston facility,” said Mike Walker, CEO of Baswood. “We are confident that as the biomass in the system continues to build and mature, we will see even higher removal rates and efficiencies.”