Sustainable Water Use in a Fruit Processing Plant: Evaluation of Microbiological and Physicochemical Properties of Wash Water after Application of a Modular Water Recovery System

Abstract

The reuse of wash water in the agri-food industry is in line with sustainability goals through the reduction of the water footprint. Depending on the production process and raw material type, wash waters may exhibit severe biological and physicochemical contamination. The use of traditional methods of chlorine disinfection of water may be linked to the formation of hazardous by-products. The recycling of contaminated water should be supported by the evaluation of physicochemical and microbiological parameters before and after application of a treatment to validate the process. This study aimed to assess physicochemical and microbiological properties of rinse water from a post-harvest processing plant before and after applying an innovative modular water treatment system. The test material was washing water after apple rinsing obtained from a post-harvest processing plant (Northern Poland). The water recovery system included a wash water tank, a sand pre-filter, an ultrafiltration system, and an ozonation tank. No microorganisms were found in the treated water. The physicochemical properties of the water were also improved: pH, conductivity, turbidity, ammonium ion, bromide, and nitrate content. The results indicate that rinse water from the fruit industry may be effectively purified using the tested purification system and reused in production processes.