Design of a microfluidic respirometer for semi-continuous amperometric short time biochemical oxygen demand (BODst) analysis

This paper presents the design of a miniaturized electrochemical respirometer to monitor organic content in water samples semi-continuously, in contrast to current biochemical oxygen demand, BOD, methods. We demonstrate the use of finite element method simulations as design tool for a novel concept microfluidic respirometer. The device is based on a flow cell separated by a thin membrane from a bioreactor. Simulations show that once membrane material and thickness are chosen, oxygen supply rate still provides sufficient flexibility to allow the measurement of samples spanning a very wide range of organic matter concentrations. The design presented here uses an electrochemical oxygen sensor, and the whole system is amenable to fabrication using standard microfabrication and rapid prototyping techniques.

► A highly compact, novel electrochemical dual flow cell has been designed.
► The design is optimized for manufacturing using mass production techniques.
► The system targets process control in wastewater treatment and food technology.
► Theory demonstrates feasibility of the semi-continuous determination of the BODst.
► The determination of a wide range of organic loadings may be accessible.