Evaluation of ammonium adsorption in biochar-fixed beds for treatment of anaerobically digested swine slurry: Experimental optimization and modeling

Amino‐functionalized material from a bio‐template for silver adsorption: process evaluation in batch and fixed bed

“…For all the evaluated concentrations, H MZT was below 2 cm; hence, the use of this new adsorbent material in the adsorption process in continuous mode becomes feasible, since this parameter has to be as low as possible so that the column can be operated for a long time before becoming totally saturated. As the initial concentration rises, H MZT increases, consistent with previous results . Once the parameters describing the mass transfer zone in the fixed bed were determined, the adsorption process in continuous mode was characterized (Fig.…”

“…To obtain Ag(I) adsorption isotherms, it was assumed that the experiments reached equilibrium when the adsorption capacity remained constant. Once experimental data were obtained, Langmuir and Freundlich models were fitted to determine the maximum adsorption capacities of the adsorbents . All models were tested by performing adjustment of the experimental data to the nonlinear equations using as an estimation method the algorithm of Levenberg–Marquardt.…”

“…The mass transfer zone (MTZ) was characterized from the obtained breakthrough curves. Calculations included MTZ formation time ( Tz ), MTZ height and MTZ movement velocity ( Uz ) . MTZ formation time ( Tz ) is the time required for the formation and movement of the MTZ along the depth of the bed.…”

“…Once experimental data were obtained, Langmuir and Freundlich models were fitted to determine the maximum adsorption capacities of the adsorbents. [8][9][10] All models were tested by performing adjustment of the experimental data to the nonlinear equations using as an estimation method the algorithm of Levenberg-Marquardt. system consisted of a 2 L capacity recipient, a peristaltic pump, a glass column and an auto-sampler installed at the column outlet.…”

“…Calculations included MTZ formation time (Tz), MTZ height and MTZ movement velocity (Uz). 10 MTZ formation time (Tz) is the time required for the formation and movement of the MTZ along the depth of the bed. It indicates the rate of mass transfer and the bed length over which adsorption occurs within the column system.…”