Towards sustainable production – closing water and solvent cycles at Millipore
Millipore discharges aqueous wastes contaminated with solvent from it’s membrane manufacturing operation to its on-site biological wastewater treatment plant. This approach results in the loss of valuable raw materials (ultra pure water and organic solvents). Furthermore, the wastewater treatment process is resource intensive (operating costs typically are €0.5m/annum).
The original objective of this project was to implement membrane technology to recover solvents as well as ultra-pure water, from specific process streams, for reuse in production. The projected environmental benefits were an approximate 80% reduction in COD & hydraulic load to the effluent treatment plant, and consequent savings in energy and natural resources used in the treatment process. Trials were carried out using reverse osmosis, pervaporation and vacuum distillation. These technologies were found to be not feasible due to economic and technical constraints. Therefore, the approach of the project was changed to focus on elimination of the solvent from the wastewater through process improvement. Prevention at source was implemented through the use of wiper blades to prevent solvent carryover to the next step in the process. There was insufficient time to carry out the requisite number of trials to prove this alternative technology conclusively, although initial data proved positive.
For further details, download the Millipore PDF.
