Toluene has contaminated a city's drinking-water supply. An activated carbon system has been constructed so toluene concentrations are treated to below specified regulatory levels. If the toluene concentration in the water supply is 1,000 ppb, the treatment objective is 5 ppb, and the flow of water is 378 L/min (100 gpm), what mass of PAC must be placed in a contact basin on a daily basis to satisfy the treatment objective? The Freundlich parameters for toluene and the particular carbon are K = 26.1 mg/gm (L/mg)1/n and 1/n = 0.44.