Dispersion in Granular‐Media Trickling Filters

A New Approach to the Biological Filtration Part I : The Mathematical Model

“…They are plotted in Fig. 5 against the specific surface area S (Muslu, 1984). For further verification of these flow limits and for the complement of the earlier works hydraulic measurements were conducted.…”

“…Calculate rate of flow per unit width q as a function of hydraulic loading rate Q. using the following equation: Step 2. Calculate the liquid depth from the laminar film flow equation (Muslu, 1984) Step 3. Obtain the average velocity wand time of passage t from q L 300 w =--t = -- Step 4.…”

“…With the aid of these data and the dispersion numbers calculated from the following equation 5000 d ---q . " (14 ) L determine the values of ct c; and n = 1-(clco) using equation (6) in the range'of dispersed plug flow or equation (9) in the range of complete mixing. The resulting values are given in Table 1 Calculate the BOD removal efficiencies n for a biological filter with a specific surface area of S=0.5cm 2cm-' = 50 m 2 m-' assuming the other data to be same as those in Example I.…”

“…Under this approximation the hydraulic regimes and substrate utilization in trickling filters can be studied with the aid of a dispersed flow model (Muslu 1983 and1984). The physical model is based on consideration of a fi 1ter element with a cross sectional area A and depth L.…”

“…Derivation of the dispersion equations can be found in any standard text, e. g. Levenspiel (1962 ) is now finding application in the wastewater treatment field where many removal processes follow first-order kinetics (Muslu, 1983) Co (l+a)2 exp (a/2d) -(l-a)2 exp (-a/2d) c 4a expO/2d) (6) in which, In case of both laboratory models and prototypes, the dispersion of conserved tracer substances can be used to find the values of D/wL. In a study on the determination of the dispersion coefficient for conserved tracer substances in flow over porous media as in a trickling filter the following equation was given (Muslu, 1983): (Muslu, 1984).…”