. Consider a GAC system to provide protection CI CI for water customers from subsurface groundwater contamination that is migrating from a release site toward a city's well field. CI H CI trichloroethene Identified synthetic organic contaminants 1,3-dichlorobenzene methyl ethyl ketone (aka trichloroethylene) (SOCs) in the ground water include (Fig. 1): (13DCB) (MEK) (TCE) 1,3-dichlorobenzene (2.0 ppmm), Fig. 1. Chemical structures of target SOCs methyl ethyl ketone (1.0 ppmm) trichloroethene (4.0 ppmm). Calgon F-400 GAC is to be evaluated. Adsorption capacity parameters for F-400 GAC are available from table 15-6 of MWH below. A system comprised of parallel columns, each containing two columns in series, one lead and one lag, is to be configured. When the lead column becomes exhausted with the critical SOC, it is to be removed from service for replacement or regeneration of carbon. The lag column must then become the lead column and must fully contain the mass transfer zones until the other column of the pair can be serviced and placed back into service as the lag column. The carbon columns will be cylindrical in shape. For sizing, consider the cross sectional area will be based on a superficial velocity of 5 gpm/ft?, maximum column diameter of 10 ft and minimum height equal to the column diameter. A data sheet for F-400 carbon is provided containing carbon properties. The municipal water utility will process 1.75 MGD utilizing a 16 hour production day (8 AM - midnight) 3 Cyclohexanone Table 15-6 Aqueous phase Freundlich isotherm parameters K and 1 for selected organic adsorbates! TO Name of Compound K 1/ pH ["C) Carbon Reference Atrazine 182 0.18 7.1 20 F 100 Haist-Gulde (1988) Benzoic acid 0.7 1.8 7 20 F 300 Dobbs and Carbon (1980) Chlorodibromomethane 45 0.517 6 11 F 400 Crittenden et al. (1985) Chloroform 15 0.47 7.1 20 F 100 Haist-Guide (1988) 6.2 0.75 7.3 20 F 300 Dobbs and Carbon (1980) cytosine 1.1 20 F 300 F Dobbs and Carbon (1980) 1,2-Dichlorobenzene 2422 7.1 20 F100 Haist-Gulde (1988) 1,3-Dichlorobenzene 458.8 0.63 7.9 24 F 400 Speth and Mitner (1998) 1,2-trans Dichloroethene 3.1 0.51 6.7 20 F 300 Dobbs and Carbon (1980) 2.4-Dichlorophenol 141 0.29 9 20 F 300 F Dobbs and Carbon (1980) 53 0.79 7.4 20 F 300 Dobbs and Carbon (1980) Methyl ethyl ketone 19.4 0.295 8 24 Speth and Mitner (1998) N-Dimethylnitrosamine 0 0 7.5 20 F 300 Dobbs and Carbon (1980) Pentachlorophenol 150 0.42 7 20 F 300 Dobbs and Carbon (1980) Tetrachloroethene 2182 0.42 7.1 20 F100 Zimmer et al. (1988) Trichloroethene 559 0.48 F 400 Speth and Mitner (1998) 1.1.1.Trichloroethane 23.2 0.6 7.1 20 F 100 Zimmer et al. (1988) dation Freundlich isotherm parameters are available in the electronic resource E5 at the website listed in App. E. Units of Kore muell/mg) Con Carbon Corporation Ethylbenzene F400 3. (5pts) Assuming the height of a column is equal to the diameter, determine the total column volume and mass of GAC a single column would contain. See "BS-FILTR 440019-EINZE!" for information on the properties 5-400 GAC
