Dead-end and crossflow ultrafiltration process modelling: Application on chemical mechanical polishing wastewaters

Abstract

Dynamic simulation of ultrafiltration process is applied to the treatment of chemical mechanical polishing wastewater from microelectronic industry. The ultrafiltration of nanoparticles (NPs) contained in chemical mechanical polishing wastewater is modelled by using different mathematical equations, which are derived from the literature and optimized to the effluent and filtration modes (dead-end or crossflow). A series of ultrafiltration experiments at laboratory scale are carried out by using chemical mechanical polishing wastewater to optimize and validate the models. Complete dead-end and crossflow ultrafiltration models are developed to simulate the treatment performances of chemical mechanical polishing wastewater under dynamic full-scale and different operating conditions, thus including filtration and washing steps. Simulations show that the dead-end mode is not suitable for chemical mechanical polishing wastewater concentration higher than 100mgNPsL−1 due to the too fast fouling time and to the high frequency of washing step. The high concentration of chemical mechanical polishing P wastewater (2600mgNPsL−1) forces industries to use crossflow ultrafiltration to have a profitable process by controlling parameters such as the filtration/backwashing number of cycles, the needed filtering surface and the filtration flux.