Ammonium Ion Removal with a Natural Zeolite in Monodispersed and Segregated Fluidized Beds

Abstract

This study focuses on the dynamic behavior of ammonium ion uptake during continuous operation with respect to liquid by means of ion exchange with a natural zeolite in fluidized and segregated fluidized beds. The major operating variables affecting the performance in both types of fluidized beds are particle size, bed expansion, and flow rate. Use of particles of about 300 μm size in monodispersed fluidized beds resulted in breakthrough capacities of about 0.5 meq/g or higher, with contact times in the order of 0.7À5.5 min. The column efficiencies in terms of breakthrough capacity/total capacity were in the order of 0.42À0.61. The segregated fluidized bed, as achieved by using two nonmixing particle size fractions, is a hybrid fluidized bed consisting of an expanded bed with reduced mixing which is topped by a regular fluidized bed. Segregation increased the column efficiency to 0.69 when a combination of 250À300 and 500À600 μm sized particles were fluidized with a contact time of 1 min. The breakthrough capacities for the segregated fluidized beds with the finer particle size combination were 0.60À0.89 meq/g. A new representation of the breakthrough curves in terms of C/C 0 versus a dimensionless time t/t f suggests that these plots are a valuable tool for comparing performances for a wide variety of experimental conditions. The results of this study indicate that fluidization can well be applied to ion exchange operations to accommodate high influent flow rates.

Evaluation of the geotechnical properties of alum sludge, zeolite, and their mixtures for beneficial usage

“…Although both AS and Z are effectively used for the removal of copper [10,[39][40][41], zinc [10,40,[42][43][44], lead [10,20,39,40,42,45,46], cadmium [20,39,42,43,47], and arsenic [48][49][50], AS is also reported to be efficient in the removal of phosphorous [1,2,8,9,51,52], mercury [53], perchlorate [54], and fluoride [55], and Z is used for the removal of ammonia [56][57][58] and nickel [20,39]. One of the main purposes of this study was to determine whether using AS and Z together would improve, worsen, or not change the geotechnical properties.…”

Physical–Chemical Processes for Nitrogen Removal

“…An additional consideration on particle size is the size distribution, which can be made narrow or cover a wider range of sizes. Ion exchange material with a narrow range of particle sizes is needed for certain reactor configurations, such as fluidized-bed reactors (Erbil et al, 2011). Figure 1 shows scanning electron microscope (SEM) images of MIEX resin, which is a strong-base quaternary ammonium, polyacrylic, macroporous anion exchange resin with iron oxide incorporated into the polymer matrix.…”

“…Common process configurations consist of several fixed-bed reactors in series or parallel such that one or two reactors are in service while the other reactor is being regenerated (Clifford et al, 2011). The fluidized-bed reactor or countercurrent two-stage reactor are variations on the fixedbed reactor configuration, which can also be applied to ion exchange (Erbil et al, 2011). …”

“…Erbil et al (2011) investigated ammonium removal using clinoptilolite in fluidized beds. Advantages of fluidized-bed reactors over fixed-bed reactors (packed columns) include high flow rate, short contact time, small reactor footprint, no clogging, and ability to use smallparticle size clinoptilolite.…”

Characterization of Granular Materials with Internal Pores for Hydraulic Calculations Involving Fixed and Fluidized Beds

“…The importance of these materials in water and wastewater treatment applications is well-known. 38,39 Five carefully sieved fractions of each of the three media were prepared and employed in all the experiments. The details of these experiments are explained below.…”