| Abstract
| - A three-component competitive adsorption kinetic model,developed and validated in part 1 of this study, was appliedto a continuous-flow PAC/membrane system to study theeffects of various system and operating parameters on organicremoval. The model quantitatively describes the twocompetitive adsorption mechanisms that occur duringadsorption of trace organic compounds by powdered activatedcarbon (PAC) in flow-through systems where the PAC isretained in the system: pore blockage and direct competitionfor adsorption sites. Model simulations were conductedto investigate the effects of influent water composition,membrane cleaning water quality, PAC pore size distribution,and system operation conditions such as hydraulicretention time, membrane cleaning interval, and PACdosing method on treatment efficiency. Effects of thesefactors on adsorption capacity as well as surface diffusionrate and consequent removal of the trace organiccompound were discussed. It was found that optimaloperating conditions for maximum trace organic compoundremoval must be determined on the basis of the adsorptionproperties and concentrations of the competing compoundsin the influent. For the conditions investigated in this study,the small strongly competing compound, p-DCB, hadgreater impact on atrazine removal than the large pore-blocking compound, PSS-1.8k. Various process design andoperating parameters had complex and interrelatedeffects on the impact of competitive adsorption andcorresponding trace contaminant removal efficiency inhybrid PAC/membrane systems.
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