A new model filtration equation which incorporates the input variable, sludge concentration (C0); the state variable, specific resistance (R); and the output variables, cake concentration (C) and filtrate concentration (Cf) was derived by material balance and regression analysis. On verification using experimental data from treatment plants, the theoretical predictions of the new equation agreed closely with the practical values, yielding a correlation coefficient of 0.98. For the experimental curve, the slope and intercept are , respectively whereas the corresponding values for the theoretical curve are , respectively. The graphical optimum dosage of ferric chloride for conditioning for both the Carman’s and the new equation was found to be the same, 16% of the sludge solids by weight in each case.
Waste Management 12/1989; 9(3):141–149. DOI:10.1016/0956-053X(89)90074-3