Reduce, reuse, recover

16 July 2018

Taking simple steps to reduce water consumption or access wastewater treatment technology can help change the way this valuable resource in managed, says Simon Emms.

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Reusing and recycling water can be a cost-effective, viable alternative to discharging wastewater down the drain. However, changing how a company approaches its water use is not always a simple matter. In the food industry, in particular, product safety is paramount so any water recycling solutions will first need to demonstrate that there is no impact on product quality or safety. Awareness and education is key to alleviating concerns or correcting misconceptions as well as highlighting the opportunities to embrace sustainable practices while making financial savings through better water management processes.

A company’s decision to evaluate its water management is normally driven by a desire to enhance efficiency and make cost savings, although more food and beverage companies are now also recognising the need to build sustainability into their plans. The first step is to understand where water is being used and discharged. It is then possible to identify areas of potential wastage and unknown losses, helping to build an overall picture of water usage – such as the volume of water consumed per unit of product – and identifying high water consumption systems on site. Once areas for improvement have been identified, a company can begin to implement a facility-wide strategy, starting with reducing its initial water consumption, followed by recycling wastewater and potentially recovering energy resources.

Reduce and reuse
When you consider that it costs significantly more to discharge water to drain than it does to draw it from the mains supply, reducing water consumption should be a primary goal of managing water. Even simple changes like controlling the volume of water used for washing products or equipment can deliver significant savings in the long term. The next step is to start reusing and recycling wastewater across a facility. Wastewater treatment can consist of a number of steps, including screenings, clarification, biological processes and polishing treatments. Screening removes large solids from the process – such as fruit pulp and soil debris – and clarification removes the particulate pollution by removing the suspended solids. A biological process is used to remove the soluble organic pollution (COD/BOD), and a subsequent polishing treatment – such as activated carbon filtration, softening or reverse osmosis – generates water of suitable quality for an alternative purpose on site, for example to feed boilers and cooling towers, or for washing and CIP.

Waste to energy
An interesting biological wastewater treatment is anaerobic digestion which removes the soluble organic pollution in highly concentrated. Biogas is a by-product of the process and, once recovered and cleaned, it can be supplied to the facility as fuel, whether for on-site steam generation or as part of a combined heat and power plant. The ability to generate electricity on site is ultimately the direction that many facilities will want to go, and is a step on from reducing water consumption and recycling wastewater. Many facilities could meet up to 100% of their demands in this way, significantly decreasing annual expenditure while also reducing reliance on natural resources. In some instances, industrial sites may also find that they can not only fully meet their energy demand, but also have an excess of gas or electricity, which can be sold back to the grid.

There is a solid business case for adopting such an approach to water management – both in terms of developing resilience for the future and the financial incentive. The main barrier to implementing such change is generally down to a lack of awareness or understanding. If companies are not aware of the option to reuse treated wastewater as a boiler feed, for example, it simply won’t factor in their planning or projections so working with an experienced water technology company can be beneficial to help better understand the benefits of the available technology and developing the best water management solution.

Simon Emms is business development manager for Food and Beverage at Veolia Water Technologies.