A Case Study of Integrated Cheese Plant Water Reuse Using Membrane Technologies

The Northern California based Hilmar Cheese Company (HCC) has been challenged by new Electro-Conductivity/Total Dissolved Solids (EC/TDS) limits necessitating comprehensive salt reduction of the Water Reclamation Plant influent with Conductivity below 900 μS/cm. The existing plant utilizes advanced tertiary treatment processed for the purposes of discharging Reverse Osmosis (RO) permeate for internal and agronomic beneficial reuse. During 2010 HCC performed laboratory and pilot plant HCC investigations of numerous new and well established salt reduction technologies ZDD, EDR, NF and RO for EC/TDS reduction down-stream of biological treatment for the purpose of achieving the permitted EC/TDS below 900 μS/cm. Several ion exchange resins were assessed and a full scale duty- duty-standby three vessel Ion Exchange (IX) system was commissioned in 2011. Full scale RO operation post ion exchange has significantly decreased the former CIP cleaning chemical consumption and associated water, reduced water and energy consumption and increased the permeate flux and concentration factor, and also substantially increased the duration between CIP cleaning.