Wash Water Recycling System in Leafy Green Processing
The current project aimed to develop a continuous wash water recycling system for leafy green processing to maintain water quality and to enhance the microbiological quality of the product. The parameters were used to formulate a spent wash water solution to be applied in developing the water-recycling unit. The recycling unit consisted of an initial coagulation step followed by filtration and a tertiary ultraviolet disinfection step. Laboratory trials optimized the coagulation step for solids removal using different coagulating agents under a range of conditions. Sodium aluminate was selected as the superior coagulating agent for incorporation into a commercial water-recycling system. Within a commercial process, the water-recycling system could achieve >67% solids removal with a 2 log CFU reduction of endogenous bacterial counts with residual aluminum levels from the coagulating agent below regulatory levels. The water-recycling unit offers an efficient approach for more efficient use of water in fresh produce processing.