Drying of a coated paper is modeled and simulated. The paper sheet is assumed to form three zones, and each zone has its own drying mechanism. Coupling of energy and mass balances must be used in order to solve differential equations. The simulations are carried out in various drying conditions i.e., only hot air drying, only radiant drying, and mixed hot air-radiant drying. Also the effect of one side and two side assumption on evaporation is studied. Effect of venting air speed and radiant heat source presence and its distance from the drying surface on the drying of a coated paper has been studied. It is found that both distance and venting air speed are inversely related to drying in mixed hot air-radiant drying. Both surfaces participate in evaporation however, during the last time of drying, no difference between the upper and the bottom surfaces exist. Keywords: Mathematical modeling; coated paper drying; hot air drying; radiant drying; evaporation and penetration. 1350019-1 M. A. Khansary et al.

In this study, two moving-bed biofilm reactors (MBBR1 and MBBR2) filled with different size of carrier media (Kaldnes K1 and Kaldnes K1 micro, respectively) were subjected to soluble (sugar and sodium acetate (Ac)) substrate and mixture of soluble and particulate (particulate potato starch (PS)) substrate in a very high organic loading rate (12 kgCOD/m 3 •d) at different temperatures (26 and 15˚C, in MBBR1 and MBBR2, respectively). The effects of carrier type and substrate on biofilm structure and reactor performance have been studied. Starch was removed by adsorption at the biofilm surface and hydrolyzed which caused substrate gradient in MBBR1, however, hydrolyzed uniformly within biofilm in MBBR2. The biofilm of MBBR1 was irregular due to filamentous structure growth due to the substrate gradient, while, it was regular in MBBR2 due to uniform distribution of substrate. The performance of both MBBRs in ammonium, COD and TN removal decreased significantly when the amount of small particles in the reactor increased owing to feeding by starch, which led to biomass density decline. The type of media affected the quantity and distribution of attached biomass, which in turn influenced the activity of specific microbial functional groups in the biofilm. The biofilm in MBBR2 was thicker and consequently nitrogen removal by denitrification was much higher. Lower temperature did not affect negatively the reactor performance in MBBR2.