Wastewater treatment in large-scale novel corrugated-sheet MBR

Abstract

This is a threefold study concerning a novel corrugated-sheet MBR. Besides the optimization of the hydrodynamics and of air consumption to achieve excellent amelioration of fouling, this study introduces a novel corrugated sheet (CS) membrane to the research community. The CS membrane has a general plate configuration similar to a standard flat sheet (FS) membrane but at 1.6 mm thickness, it is much thinner. The rows of hemispherical hollow units on each side create corrugations, and coupled with the thinness of the plate they give a surface area per unit volume value around that of hollow fiber systems. The hydrodynamics and fouling of the CS membrane were compared with those of FS membrane through computational fluid dynamics (CFD) simulation and experiments. Based upon these results a large-scale corrugated sheet membrane bioreactor (CS-MBR) with four decks was designed. The study included a consideration of three different designs of aerators, the spacing between the decks and the aeration rate. With the recommended partitioning design of aerator, the optimized nozzle velocity was found to be 13 m/s corresponding to a world-leading specific aeration demand, SADm (aeration amount per unit membrane area per unit time), of 0.074 Nm3m−2 h−1. This corresponds to a 70 % reduction with respect to a FSMBR operated with slug bubbling and is just one-eighth of the traditional industrial usage of 0.3 to 0.58 Nm3m−2 h−1 depending on format of the system.