Production of high-quality water by reverse osmosis of milk dairy condensates

Low-pollution flash cooler (FC) condensates from the direct heat treatment of milk and milk-based products were treated by means of reverse osmosis (RO) in order to obtain high-quality water for use in boilers. The behaviour of the spiral-wound membranes at the pilot-plant scale (8.2 m(2) surface area) was tested in terms of the permeate flow rate (J) and quality (conductivity and chemical oxygen demand (COD)) as a function of the operation conditions, including the pressure, temperature and volume concentration rate (VCR). Response surfaces were drawn with the aim of obtaining information regarding the permeate flow rate as well as conductivity and COD reduction in the range of the studied parameters. Based on the experimental data, a plant with a 90% recovery rate (RR) was proposed with the objective of carrying out a preliminary economic assessment, which yielded a payback of 1.16 years. (C) 2014 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.