A comparative study of conventional greens washers and a prototype system recycling wash water with a mathematical model of grit concentration in wash water

A prototype system with wash water recirculation was studied as a possible method of water conservation in the food processing industry. A conventional leafy-greens washer at the Exmore Foods Company, Incorporated, Exmore, Virginia, was compared with a prototype system. Spinach and turnip greens were processed with the two systems.

The quality of the product and that of the wash water from both systems was compared by measuring grit content, bacteria contamination, and insect contamination of the product; TSS, VSS, COD, and grit concentrations in the wash water.

The results indicated the better performance of prototype system which required only 23 percent of the water used by the conventional washers. The mathematical model developed to describe the grit content in the wash water of the prototype during washing succeeded in producing predicted values generally close to measured values.