You need to treat 1.9 million liters of water contaminated with 12.2 ppb of trichloroethylene (TCE). You choose to treat the water via direct addition of powdered activated carbon (PAC). You need to treat the water to comply with the US EPA's maximum contaminant level (MCL) for TCE. Use this link (US EPA National Primary Drinking Water Regulations e) to look up the following information: (1) Definition of MCL (2) The MCL for trichloroethylene (make sure you have the right compound -- others have similar names) in units of mg/L (3) The human health effects of TCE in water (4) Common sources of TCE pollution in water Note: you won't need parts 1, 3, or 4 for this calculation, but I expect you to turn them in with your practice problem writeup. Assume that the TCE adsorbs according to a linear isotherm with adsorption coefficient k= 54 (mg/g)L/mg). What mass of PAC would you need to add via direct addition to reduce the concentration of TCE to comply with the US EPA's national drinking water standards? Enter your answer with units of kg (no decimal places). You Answered 5.4 Correct Answer 51 margin of error +/- 1