Industries that must treat or pretreat their wastewater face varied challenges. Any given facility’s needs are best met by a total systems approach (TSA) — a fully integrated solution that includes all pieces of the puzzle instead of uncoordinated components and systems.

The approach includes a collaborative evaluation up front to understand a facility’s requirements, apply proven designs and materials, and select innovative products that achieve the optimum water quality at the best life cycle cost.

Why a total system?

A true TSA first identifies options to help achieve a company’s production goals. The next step is to develop a detailed design in collaboration with facility engineers. Components and equipment are then selected with an eye on durability and optimum design. The overall system is fitted together with a focus on long-term reliability and consistent performance.

Efficient installation, startup and training are important pieces of a TSA. Compliance is ensured through binding performance guarantees. Extended service plans can make the solution provider almost an adjunct to the company’s process engineering team. The final piece of the TSA is a complete system warranty.

The TSA applies custom solutions tailored to each facility’s treatment requirements. Three examples show that while a TSA may align the puzzle pieces differently, an in-depth evaluation in each case sets the stage for a truly integrated and trouble-free solution.

Dairy plant expansion

A TSA came into play with the upgrade of the wastewater treatment system for Dannon’s yogurt production facility in Utah. Just two years earlier, the company had installed a circular dissolved air flotation (DAF) pretreatment system, but found it poorly designed, with poor performance and high operating costs from chemical consumption.

Recognizing that the process would not handle additional wastewater from a facility expansion, the company decided to construct a new treatment system. After evaluating technologies, the firm selected a system that uses two rectangular high-rate DAF units, one to separate suspended solids and fats, oils and greases, and one to separate biological solids generated from the degradation of the soluble organics in the wastewater. The DAF process has the added benefit of handling pH swings without corrosion.

To degrade soluble organics, Dannon selected moving bed biofilm reactor (MBBR) technology, a biological process that has been used not only for BOD removal but also for nitrification/denitrification. The system has been applied successfully at several dairies with widely variable wastewater loads. The total system also includes rotary screening to remove debris and equalization to normalize the flow and load.

Dannon implemented the turnkey design, engineering and construction project in partnership with an engineering firm and a manufacturer of specialized, advanced wastewater treatment solutions. The project included supply of the DAF and MBBR, a slot injector system to move wastewater from the equalization tank through the treatment package, chemical feed equipment, startup and commissioning, and a performance guarantee.

Within a few weeks, the DAF units were operating at a fraction of the cost of the previous unit. The system is designed for easy expansion. The plant has won awards at environmental conferences in the food industry.

Aseptic packager system upgrade

The experience of KanPak, a family-owned aseptic packaging company in Arkansas City, Kan., shows how a TSA can reduce land, labor and operational costs versus conventional approaches such as activated sludge, while ensuring effluent permit compliance.

KanPak, which packages products such as smoothies, coffee drinks, creamers, frozen desserts, ice cream mixes, cocktail mixes and specialty beverages, prides itself on technological advancements that include stringent quality control through each step of production.

To meet discharge and pretreatment requirements at one of its facilities, the company had installed a traditional biological treatment system with an interceptor/pump station, equalization tanks, aerobic fixed-film treatment, secondary solids separation, DAF with a flocculation tank, a compressor/pressure tank, sludge dewatering on a vertical rotary screw press, and final effluent flow and pH monitoring.

Within a week of startup, the process had failed; solids would not flocculate, and the effluent was out of compliance. The plant had been quickly overwhelmed by production discharge along with hot water, sanitation products, floor foams, clean-in-place chemicals and sterilants. The design load was 2,800 pounds per day of BOD5, but the actual load was 5,600 to 14,000 pounds per day.

To resolve the challenges, KanPak embarked on a TSA, also with an engineer and manufacturer. An evaluation of the treatment system found that the equalization tank was not designed properly for dairy wastewater, which can go septic within hours if not properly handled. The resultant low pH was affecting downstream processes.

In addition, the system was not properly dewatering, and sludge quality was poor. Finally, the system lacked primary treatment — high concentrations of milk fat require long hydraulic retention times for hydrolysis by bacteria and interfere with oxygen transfer.

The evaluation also considered an in-plant source reduction initiative that used an audit to identify and eliminate excess water usage. The audit led to recommendations for batching system modifications, directing boiler blow-down and domestic wastewater straight to the municipal treatment plant, closed-loop recirculation and conversion from a retort to an aseptic bottle line. As a result, the flow to the pretreatment system was reduced from 400,000 gpd to 100,000 gpd.

Taking all that into account, the TSA included improvements installed in phases over several years. The new system improved the equalization basin to prevent anaerobic conditions, added a second DAF, replaced nitric acid for pH control with CO2, upgraded biological treatment with a new aeration system and improved sludge dewatering (from 4 percent to 18 percent solids).

In the end, the project eliminated odors, reduced sludge volume, saved on chemicals and improved TSS and organics removal. The results included savings of $100,000 per year through lower water consumption, $4.5 million per year in sludge handling and chemical costs, and $1 million per year in compliance costs.

Freeing up municipal capacity

Improved industrial treatment through a TSA can also benefit municipal treatment facilities. Sara Lee/Hillshire Farm, needing to expand wastewater facilities for its Iowa turkey processing plant, began with an EQ-DAF-DAF system and then did further evaluation to determine whether biological treatment was needed. The evaluation over nine months allowed the company to review the initial system’s performance and ask what could be achieved with the effluent if more treatment were added.

The company decided to add an MBBR, reducing effluent BOD and TSS to single digits. The load reduction means the municipal treatment plant now has significant additional capacity and will not have to expand.

It is important to focus on the total system because zeroing in on only one component may result in missing the bigger picture. Even if a company needs to replace only one piece of its system or add a new component, the project should still include a complete evaluation and a solution tailored to the facility’s needs.