Water. desalination + reuse

PROJECTS November-December 2014 | Desalination & Water Reuse | 23 | several months. This work confirmed that GAC eliminated the not fully identified foulants and improved water reclamation quality. Again the lesson is to consider pilot testing on the actual wastewater and to have influent variables occur during the pilot testing. Employing GAC from the start of the project may be over-design and expensive, so on-site pilot testing is much more economical in the long run. Indeed, following lessons learned at the snack foods facility, the potato processor deployed a more complete RO pilot system on site to determine if there were fouling chemicals in the influent. The design of the process water treatment and return plant was performed without actual data from production since the production plant was being built concurrently with the process water treatment and return plant. This required acclimatizing the biology in the EBNR process and the removal of phosphorus prior to the RO treatment pilot unit. This pilot-scale testing on site with actual in-plant MBR effluent did not show potential fouling of the RO membranes. LESSOnS fROm diffEREnCES While quite similar processes were used in the two plants there were distinguishing features in their processes. They called for different approaches to wastewater treatment for reuse in contact with food products. For instance, comparison of the design approaches for the potato and snack food plants indicates limitations in the use of pilots in similar plant as higher than expected concentrations of some metals emerged. Pilot testing limitations were highlighted also in the snack foods RO operation where unidentified compounds in the actual influent caused fouling in the plant. Full sampling and analyses should be performed over the course of a "normal" production period. This should include product changeover, seasonal variations and plant startups and shutdowns involving sanitation procedures. The chief implications for training are in addressing a frequently encountered misunderstanding by processing plant staff of the different biological start-up periods. This is exacerbated when biological nutrient D&WR on the move D&WR is the place to fi nd all the current news and latest developments from across the Desalination and Water Reuse sector worldwide. Now also available in fully interactive digital format, D&WR delivers: • Immediate, practical information and news on projects, materials, equipment and research • Easy to access and read on any device – desktop, laptop, tablet or smartphone • Downloadable and printable information For more information and subscription rates or to register for our free weekly newsletter visit www.desalination.biz D&WR-HPH ad.indd 1 09/09/2013 15:45 removal is deployed. Overall, best practice should include video recording of training programmes so that early training provide by equipment suppliers can be retained for new staff. In the design of the water reuse plant the prospect of limited turn-down capacity to deal with low loading should be given as much consideration as the maximum loadings and peaks. ThE ROad ahEad Overall, the need for water reuse is unlikely to abate. Water-stressed areas and droughts are growing in number and frequency but more broadly, reuse technology is becoming more generally accepted as proven in the search for sustainable resources. We have seen great successes in awareness building with employees and customers growing to accept, and embrace reuse. This has a significant marketing value for food processors as a growing count of customers are attracted to companies that are visibly sustainable in their operations. l

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