If clean groundwater flows through an aquifer contaminated with a dense non- aqueous phase liquid (DNAPL), calculate the concentration of DNAPL in the water as a function of time if the DNAPL is dissolving into the water at a rate of k1 (mol/L/time, i.e., a zero-order process) and undergoes first-order degradation in the aqueous phase with a rate constant of k2 (time-1). Use a moving volume of water as the control volume (i.e., no water flow in or out).