Snack food manufacturers — specifically those of starch-based products — face a unique set of challenges when it comes to wastewater management. This comprehensive guide delves into the process water-specific hurdles encountered by snack foods manufacturers and those dealing with starchy products, and provides attainable solutions for responsible process water management.
As a water-intensive industry, production process water management is crucial not only for protecting the environment, but a business as well. Snack food manufacturers can face hefty fines, reputational damage and even production shutdowns if their process water is not treated and managed properly. This guide will provide the knowledge needed to design a comprehensive and effective process water management plan.
Understanding production process water challenges in snack foods manufacturing
Starchy food manufacturing typically generates process water with elevated levels of total suspended solids (TSS), organic load (BOD/COD) and fats, oils, and grease (FOG). These constituents can pose challenges for a utility treating discharged process water because of the pressures they induce on conventional wastewater treatment methods.
The key to addressing these challenges lies in comprehending the specific issues associated with a facility's unique wastewater, identifying their origins in the production process and understanding why they present challenges to effective process water management.
Here are some common challenges associated with snack food manufacturing process water:
1. Starch overload
Starchy snacks, ranging from potato chips to pretzels, contribute to high organic loads in discharged process water. The aftermath of cleaning processes leaves behind starch residues, which can solidify if not handled efficiently, creating a significant challenge for conventional wastewater treatment plants. To avoid surcharges or out of compliance fines, pretreatment of streams becomes a critical step before discharge.
2. Suspended solids
Cleaning potatoes, corn and grains generates high levels of silt, dirt and peeling residues in the rinse water, leading to high TSS. Because most conventional wastewater treatment systems are limited in the amount of solids that can be accepted, these process streams must undergo a pretreatment step to separate the solids prior to discharging to the utility or reusing in another rinse cycle.
3. Additives
Snack food production may involve the use of additives, such as colorants and/or preservatives. While these additives may enhance a product's visual appeal or flavor profile, they introduce additional complexities to discharged process water. Particularly, food coloring may require specialized treatment methods. If not addressed prior to discharge, a utility may refuse to accept process water discharge, which can impact production.
4. Waste stream variability
The production of a variety of snack products in the same facility results in diverse process streams that are variable in organic load, nutrient load (like nitrogen), suspended solids, contaminants and even volume, leading to potentially unpredictable costs from the utility and unexpected surcharges. Conventional treatment systems typically require consistent flow and wastewater composition, so this variability impacts the operational capacity of these systems and will require more energy and/or chemical inputs to maintain treatment efficiencies. The resulting cost of increasing energy and chemical consumption is ultimately passed on to rate-payers.
5. Managing water use
Potato processing and cleaning is one of the most water-intensive processes in the food and beverage industry. The peeling, slicing, trimming, cooking, blanching and washing processes all require significant use of water to ensure a quality final product. Managing water use is a constant challenge which can be addressed through treatment and reuse of process water.
Addressing these process water management challenges is vital for snack foods manufacturers to ensure responsible environmental practices, regulatory compliance and the sustainable growth of their operations.
Though these seem daunting, let’s go through some practical solutions to help snack foods manufacturers overcome these challenges.
Practical solutions for snack foods process water management
Here are some considerations and actions to transform snack foods process water challenges into opportunities for sustainable operations:
Regular monitoring and testing
Begin with understanding a facility's unique process water composition by employing sensors directly to collection and discharge systems. Consistent monitoring and testing of process water parameters are crucial for identifying issues early and ensuring compliance with environmental regulations.
Choosing the right treatment method
As discussed earlier, discharging directly to utility will cause issues due to the process water’s unique composition. Once there is a comprehensive understanding of the different constituents in a facility's process water flows, consider which treatment methods may serve best based on composition and volume.
Offsite hauling or land application of process water may not be sustainable for long-term growth and poses risks such as spills, nutrient saturation in soils, production shutdowns and increased emissions. When considering onsite process water treatment, a single conventional technology may not be able to meet all needs and a combination of physical, chemical and biological methods may be required.
Using a stream separation approach
One of the best techniques that can be implemented into snack foods process water management is a stream separation approach. Also known as side streaming, this technique involves separating the highest-strength, most challenging waste streams and treating them prior to combining with the full flow and discharging to utility.
Since much of the challenging process water is produced from potato, corn or grain processing and cleaning, facilities may already be side streaming for starch separation and recovery. By collecting these streams and treating them independently, snack food manufacturers may be able to realize significant savings for their operations.
Enabling water reuse
As stated earlier, managing water use is a challenge for potato snack manufacturers in particular due to the water-intense nature of potato processing and cleaning. Yet the opportunity for lowering water use through reuse lies within a facility's discharged process water. With smartly designed onsite process water treatment solutions, snack food manufacturers can utilize their process water as a resource and reuse those streams in multiple facility and/or production applications.
Armed with the insights and strategies outlined in this guide, snack foods manufacturers can now navigate the intricate landscape of process water management.
Luiza Moreno is a marketing specialist at Aquacycl.
