Accurately evaluating the actual removal of GSM and 2-MIB in
water treatment systems is challenging, as these compounds can
be lost to many surfaces [28]. To avoid sample loss due to non-specific binding (e.g., in pump tubing and plastic carboys), stainless
steel pressure cans were used to hold the water prior to treatment
and to apply the water to the reactor. For the laboratory evaluation
4 pressure cans were filled with 30 L each of Milli-RO water (Millipore) spiked with 2-MIB and GSM standard to achieve a concentration of 100 ng L1 of each of the off-flavour compounds in the
final solution. Triplicate samples (200 mL) were taken from each
of the pressure cans to confirm the initial concentration of both
analytes (T0). Nitrogen gas was used as propellant to drive the
water through the photocatalytic reactor at a flow rate of approximately 2 L min1. As there was limited back pressure due to the
free flow of liquid through the reactor, only a small head pressure
of 1–2 bar was required. Pressure was only applied immediately
before treatment to prevent alteration in dissolved O2 levels. Water
(30 L) was passed through the reactor without illumination to
determine system and dark adsorption with samples (triplicate
200 mL) collected directly from the outflow. To evaluate the photocatalytic removal of the 2-MIB and GSM, three 30 L batches were
passed through the reactor at 2 L min1 under constant illumination. Samples (200 mL) were collected in triplicate as each of the
three batches passed through the reactor