“Wastewater in the food and beverage industry is a complex issue,” says Walter Wales, Business Development Manager at WEC Projects, a South African EPC contractor in the water and wastewater industry.
“On the one hand, the industry is generally a large consumer of water and a large producer of wastewater effluent with high levels of nutrients and organic compounds. On the other hand, regulation governing effluent is strict with severe penalties for wastewater violations running up to as much R2 million per month for improperly or untreated wastewater. At the same time, the local food and beverage industry is faced with many of the same challenges as other industries including spiralling operating costs, load shedding, degrading municipal infrastructure and a growing awareness of the need to become more environmentally compatible.”
The problem is how to reduce costs while at the same time ensuring that effluent meets strict standards. No two wastewater treatment requirements are the same in the food and beverage industry and solutions can vary from the simple to the very complex depending on the type and volume of effluent produced. With municipal authorities using wastewater treatment infractions as an additional revenue stream, companies are under considerable pressure to ensure they comply with regulations. This can be costly in terms of both capex and opex. However, it is possible to engineer solutions that not only ensure compliance but also eliminate large portions of the operating costs.
There is Value in Wastewater
Around 90% of food and beverage producers can re-use the water recovered from their effluent for a variety of applications such as process water, utility feed, irrigation, and even potable water. In addition, biogas can be recovered from certain effluents (such as that produced by the chicken farming and brewery industries) which can be used to generate heat and power. In a country where load shedding and water shortages are an ongoing problem and operating costs are increasing, it is important to approach wastewater treatment with a view to recover as much value as possible, whether it is simply reducing operating costs or remaining operational during periods of loadshedding and water cuts.
As an example, a chicken abattoir, can utilise biological treatment incorporating anaerobic digestion to recover biogas. This biogas could be used to provide 20% to 40% of the facility’s power requirements. With a number of companies supplementing their power requirements with solar energy, the biogas could be stored and utilised during the hours in which the solar system is not active, resulting in considerable savings in operating costs and a reduction in downtime due to loadshedding.
Biological treatment is the most cost-effective approach to treating wastewater. Solutions integrate either aerobic or anaerobic treatment depending on the effluent. However, the biggest challenge is in the post-treatment and final stage process. In water recovery and re-use applications, once the effluent has undergone biological treatment, it needs to be further processed using, for example, the treatment process needs to incorporate processes such as oxidation; sand/activated carbon filtration; micro-, nano-, ultra-filtration, reverse osmosis and pH adjustment.
Retrofit or Greenfields
While many greenfield plants are incorporating sophisticated wastewater treatment into their designs, existing companies can also retrofit treatment systems into their existing facilities. Many opt to take a phased approach to wastewater treatment, implementing systems that enable them to meet strict effluent regulations and then later installing additional processing plants for water and resource recovery. This approach, while affordable, requires that the new plant be of a small enough footprint and flexible in design in order to be installed into an existing factory. Technologies such as vertical trickle filters are ideal for deployment in areas where space is at a premium.
WEC Projects can provide complete turnkey wastewater treatment solutions for the food and beverage industry which incorporates not only advanced technology for the effective treatment of wastewater to applicable standards, but which also provide for resource recovery, recycling, and re-use. From consultation, cost analysis and feasibility studies to plant design, engineering, construction and commissioning, solutions can be customised to meet specific requirements including small systems for retrofitting into existing plants.