This article was published in the March/April 2025 issue of Pet Food Processing. Read it and other articles from this issue in our March/April digital edition.
Wastewater management is a critical yet complex challenge for pet food processors. High organic loads, fats and cleaning chemicals create a difficult-to-treat wastewater stream, requiring a combination of physical and biological processes. At the same time, regulatory pressures continue to evolve, increasing compliance costs and adding another layer of complexity to wastewater treatment strategies.
Kemco’s dissolved air flotation (DAF) system uses a centrifugal pump to provide the maximum removal of oils, grease, skimmings and solids from wastewater.
|As sustainability goals take center stage, manufacturers are turning to advanced treatment technologies to improve efficiency, reduce costs and minimize their environmental impact. From dissolved air flotation (DAF) systems to digital monitoring tools and water reuse strategies, processors are optimizing wastewater treatment to meet both operational and regulatory demands.
Common challenges
“Pet food processing facilities often encounter a range of wastewater treatment challenges, including proposed regulations mandating nutrient reduction or removal, surcharges that can reduce profitability, and escalating costs for labor, chemicals, as well as energy,” explained Chris Knodel, professional engineer, industrial wastewater manager, Burns & McDonnell, Kansas City, Mo. “Additional hurdles include fluctuating wastewater flows from cleaning cycles, high pollutant concentrations, and the limitations of aging infrastructure.”
Beyond regulatory and infrastructure challenges, operational inefficiencies further complicate wastewater management. These inefficiencies increase wastewater volumes, drive up treatment costs and create additional compliance hurdles. Identifying and addressing them is essential for improving wastewater management and sustainability.
“Common wastewater challenges often stem from improper management of plant-level issues,” said Kunal Mehta of Ecolab.
“Common wastewater challenges often stem from improper management of plant-level issues,” said Kunal Mehta, senior global account manager, enterprise solutions, Ecolab, Saint Paul, Minn. “Valve failure, uncontrolled product losses and excessive water use can all lead to compounding wastewater problems downstream. For example, let’s say the protocol for handling spilled product within a facility is to wash it down the drain. This increases the amount of chemistry required to treat wastewater and risks increasing transportation costs (and emissions) related to transporting effluent and byproducts. In this way, one cleaning and sanitation protocol can directly affect a number of wastewater and other sustainability priorities.”
In addition to these operational inefficiencies, the composition of wastewater itself presents a significant challenge. Pet food processing generates a complex wastewater stream that contains high levels of organic matter, including fats, oils and greases (FOGs), total suspended solids (TSS), biochemical oxygen demand (BOD) and chemical oxygen demand (COD). These pollutants require specialized treatment before the wastewater can be safely discharged or reused.
“The biggest challenge is rendering and mixing, as well as using other organic ingredients to produce a finished product in pet food facilities similar to other food processing plants,” said John Richert, industrial sales manager, JWC Environmental, Santa Ana, Calif. “This generates a complex wastewater stream high in TSS, BOD/COD, FOGs, ammonia, and other chemical byproducts that must be treated before they can be sent to a municipal system or released to a surface water source.”
“The biggest challenge is rendering and mixing, as well as using other organic ingredients to produce a finished product in pet food facilities similar to other food processing plants,” said John Richert of JWC Environmental.
Fluctuating wastewater volumes introduce additional challenges to treatment efforts. Cleaning cycles and production variability can create inconsistent flow rates, making it difficult for treatment systems to operate efficiently. Many facilities are also relying on aging wastewater infrastructure that was designed for lower production capacities, which can lead to inefficiencies and increased compliance challenges.
“Plant production demands are very dynamic in the pet food industry, so robust and agile systems must be in place throughout the operation to minimize disruption,” said Eric Bradley, business development director, Hawkins, Inc., Roseville, Minn. “Wastewater infrastructure and equipment are often designed for a different operational pace from five or more years ago. Capital projects are usually slower than a current problem demands and more costly than the business desires.”
Effective treatment solutions
To address these challenges, pet food processors are implementing a range of wastewater treatment technologies designed to improve efficiency and maintain compliance.
“Flow equalization helps regulate fluctuating wastewater volumes, while screening efficiently removes large particles,” Knodel said. “Dissolved air flotation (DAF) is highly effective at eliminating oils and suspended solids. Advanced biological treatment systems, such as membrane bioreactors (MBR), moving bed bioreactors (MBBR) and sequencing batch reactors (SBR), provide efficient nutrient removal. Additionally, dewatering equipment minimizes sludge volume and hauling expenses, while asset management and capital planning strategies enable facilities to budget for component replacements and upgrades effectively.”
A key component of these treatment strategies is the use of Dissolved Air Flotation (DAF) systems, which help remove FOGs and other suspended solids from wastewater streams.
The ceramic membrane filtration system is a cost-effective way of removing contaminants from wastewater without using high volumes of treatment chemicals.
| Source: Kemco“Wastewater containing very high levels of FOGs can be pretreated with a grease trap to remove free-floating grease. After one (or both) of these pre-treatment methods, the waste stream is sent to a DAF system for further treatment,” explained John O’Hehir, regional sales manager, Kemco Systems, Clearwater, Fla. “Kemco’s DAF is designed to give the maximum operator flexibility and maximum removal of oils, greases, skimmings and solids. Kemco’s DAF technology offers a centrifugal DAF pump. The multi-phase air saturation pump provides maximum air flotation with minimum maintenance cost and upkeep. The Kemco DAF system is available with chemical coagulant/flocculant mix systems designed to optimize the effectiveness of treatment chemicals.”
In addition to physical and biological treatment, digital monitoring tools are playing an increasing role in wastewater management.
“In the area of cleaning and sanitation, digital monitoring products can help facilities optimize the amount of chemistry they’re using to clean and sanitize core equipment,” Mehta said. “Among other things, this optimization directly impacts the quality of wastewater, which can help streamline the facility’s water management strategy and keep them compliant.”
Sustainability benefits
Effective wastewater treatment not only ensures regulatory compliance but also supports broader sustainability initiatives.
“Wastewater treatment solutions help minimize water usage, reduce nutrient discharges to the environment, and support resource recovery by capturing valuable byproducts such as oils, biogas and reusable water,” Knodel said. “Additionally, advanced technologies and automation systems lower power consumption, further bolstering sustainability initiatives.”
Many processors are implementing wastewater treatment strategies that align with their sustainability objectives. Some focus on meeting discharge requirements, while others invest in water reuse technologies to maximize efficiency.
“Sustainability can be measured in varying ways,” O’Hehir said. “For some processes, the ability to achieve local publicly owned treatment works (POTW) discharge limitations utilizing DAF or ceramic membrane filtration (CMF) technologies allows the processor to provide an acceptable effluent. For other processors where reuse is a goal, the CMF/RO combination removes FOGs, suspended solids, viruses and bacteria, microplastics, per- and polyfluoroalkyl substances (PFAS), and colors and odors. Because this combination of systems relies on physical processes, it can reduce facilities’ chemical costs. Coupled with thermal stability lessening the demand on boilers and reducing natural gas consumption, the CMF/RO combined system is both an economical and environmentally friendly solution for pet food processing wastewater by recycling both water and energy.”
Ecolab’s 3D TRASAR Technology provides visibility into cleaning, sanitation and water use metrics, enabling processors to respond to wastewater issues before they become a concern.
| Source: EcolabAdvanced digital monitoring solutions are also playing a role in sustainability efforts by improving visibility into water management performance. By tracking key metrics in real time, processors can proactively address wastewater issues and optimize cleaning and sanitation practices.
“Ecolab’s 3D TRASAR Technology for CIP (3DT CIP) helps pet food processors achieve sustainability goals while simultaneously supporting better efficiency,” Mehta said. “By arming facility leadership with better visibility into core cleaning and sanitation and water use metrics, 3DT CIP enables them to respond to potential wastewater issues before they become unmanageable.”
Reducing and reusing
As water costs rise and environmental regulations tighten, pet food processors are looking for ways to minimize wastewater and maximize water reuse. Reducing overall water consumption not only helps control operating expenses but also aligns with sustainability goals and regulatory expectations.
“Pet food processors can take several practical steps to reduce wastewater volume and improve water reuse,” Knodel said. “These include making operational changes to cleaning processes, exploring water reuse opportunities such as irrigation, boiler feed and cooling towers, as well as adopting new technologies like reverse osmosis, evaporation and crystallization. These measures can significantly lower the overall water footprint of pet food processing facilities.”
Identifying the right water reuse opportunities starts with evaluating each stage of processing. Understanding where water can be repurposed within the facility helps processors optimize usage while ensuring compliance with quality and safety standards.
“The challenges presented with reusing water are typically determined by where in the overall process reuse of water would be acceptable,” O’Hehir said. “As pet food processors evaluate the overall use of water and generation of wastewater within each stage of processing, they can identify opportunities for internal reuse within the same stage if the water cannot be reused further downstream.”
Reducing wastewater at the source is just as important as finding ways to reuse it. By preventing unnecessary contaminants from entering the wastewater system, pet food processors can lower treatment costs and improve overall efficiency.
“Three contaminants are universally present in the pet food industry and are the primary drivers of cost to treat: fats, oils, and grease (FOG), total suspended solids (TSS) and biochemical oxygen demand (BOD),” Bradley said. “Additional contaminants, such as phosphorus, chlorides, selenium and bacteria load, may also be relevant depending on the site and discharge parameters. Processors should take a fresh look at their systems to find ways to reduce these contaminants before they enter the wastewater stream.
“Reclaim water wherever possible to minimize water volume purchased and wastewater treated,” he added. “Water only needs to be as clean as the use application requires. There may be locations in a plant where one-use water may be fit for a second use, or treated wastewater can be used instead of ‘new’ water.”
Innovations and advancements
As wastewater regulations evolve, pet food processors are turning to automation, digital monitoring and advanced treatment technologies to stay ahead. Investing in these innovations will help optimize efficiency, enhance sustainability, and ensure compliance with stricter environmental standards.
A Hawkins technical application specialist samples the water in this lagoon that contains a “fat cap” which occurred after the discharge of too many fats, oils, grease and suspended solids into the water.
| Source: Hawkins, Inc.“Innovations and advancements shaping the future of wastewater treatment in the pet food industry include the development of new, cost-competitive technologies for nutrient removal and water reuse, increasing opportunities for resource recovery and emerging incentives to adopt sustainable practices,” Knodel said. “Additional collaborative efforts with stakeholders are also paving the way for more integrated and efficient wastewater management solutions.”
With evolving regulations and increasing environmental concerns, wastewater treatment in the pet food industry will continue to evolve. As compliance standards become more stringent, processors will need to adopt new technologies to meet discharge requirements while maintaining operational efficiency.
“The regulatory landscape drives innovation in this market, and right now there’s a focus on de-nitrification and phosphorus removal,” Richert said. “This will require technologies that are not necessarily new but are new to the industry. Besides these, there will be more demand for further chemical removal associated with pharmaceuticals, for example.”
The next phase of wastewater treatment will focus on solutions that are more efficient, adaptable, and responsive to regulatory and economic pressures. Processors that stay informed about industry advancements and build strong partnerships with suppliers will be best positioned to navigate these changes.
“For the next five years, the demands of the pet food industry will drive focus to a few key factors in wastewater treatment chemistry: impact, versatility and safety,” Bradley said. “The most useful advancements will accomplish more with less and respond quickly to operational, regulatory and economic dynamics. To maximize the value of suppliers supporting an operation, develop a deeper compliance partnership with each key supplier to a wastewater plant.”
Read more about pet food and treat processing on our Operations page.
