Treatment of cauliflower processing wastewater by nanofiltration and reverse osmosis in view of recycling

The vegetable industry is a large consumer of drinking water. This paper investigates the possibilities of Reverse Osmosis (RO) or tight Nanofiltration (NF) for the treatment of cauliflower blanching wastewater with a view to recycling within the production unit. Ultrafiltration at 100 000 g mol(-1) molecular weight cut-off was necessary to decrease turbidity below 1 NTU as required before NF or RO. Three NF (DK, NF270 and SRD3) and one RO (ESPA4) membranes were tested at bench-scale in a crossflow filtration mode. Only RO allowed to reach the desired quality for a reuse purpose, with an acceptable residual COD content of 225 mg O-2 L-1. The Solution-Diffusion model was validated for the transfer of glucose and fructose, for NF270, DK and ESPA4 membranes and their permeability coefficients calculated.

Automated summary

This paper investigates the feasibility of using reverse osmosis or tight nanofiltration to treat cauliflower blanching wastewater, and validates the Solution-Diffusion model for glucose and fructose transfer.