A plug flow reactor is planning to be designed for iron removal from a groundwater source. The iron concentration in the influent water is measured as 15 mg/L and this must be reduced below 0.1 mg/L. The water has a pH of 6 and the plan is to oxidize the iron Fe2+ to Fe3+ using air, then remove the resulting particulate matter in a sedimentation basin. It has been found that the reduction in Fe2+ concentration in the reactor equals kapp × [Fe2+] where apparent reaction rate (kapp) equals to 7.4 × 1014 L2/mol2-atm-min × [partial pressure of O2] × [OH-]2 and the unit of kapp given in this expression is min-1. Using these kinetic relations, determine the volume (m3) of the reactor required to treat 1 MGD of water.