Fixed bed adsorption columns packed with natural zeolite were used to study the
kinetics of heavy metals removal from the single component solutions of Vanadium, Nikle,
Zinc, and Lead. The system parameters studied include solution flow rate and be
d height.
The effect of competing cations was also studied to establish the effectiveness of natural
zeolite in treating Industrial wastewater under continuous conditions using fixed bed
columns. The metal loaded natural zeolite was regenerated using NaCl . The results from
column studies showed that the Slower flow rates gave better removal efficiencies
compared to faster ones, Longer bed heights also resulted in greater adsorption
efficiencies. The bed depth service time (BDST) model was successfully used to simulate
experimental results at 30 % breakthrough. This model provides the necessary parameters
needed for fixed bed column design, the factor R2 ranged between 0.91 – 0.95. Natural
zeolite was exposed to 3 cycles of adsorption and desorption. The efficiency of the column
in removing heavy metals was high, The results indicate that natural zeolite can be
regenerated and re-used in removing heavy metals from solution.
studied the elimination of lead using natural zeolite by studding the the best
conditions to removal lead in a system with two phase: liquid (contaminated water with
lead)-solid (natural zeolite), correlation of the following factors: time of mixin
g phase,
granular size of solid phase, change of pH values, concentration of the calcium element as
a competitor element for the available sites for occupation on the solid phase, the ratio V/m
represents the size of the aqueous phase to the mass of the solid phase and concentration of
lead element.
On the other hand, the possibility of using natural zeolite as a template for storaging
dangerous materials such as lead, has been studied by changing water quality, pH and
temperature.
The results of this research show that and under the following experimental
conditions: time of mixing=4hour, mix of granular size of solid phase, pH< 8,
concentration of calcium = 20 ppm,V/m=100 and concentration of lead = 1000 ppm , the
rate of lead removal range from 60% to 99%.
On the other hand, the results of this research show that changing water quality has
no impact on the ability of natural zeolite for storaging lead as a hazardous waste, while
pH changes have minor effects on this ability of retention and an effect for the high
temperatures on the template was also observed.
The study was carried out on the sorption of heavy metals (Pb+2, Zn+2) under static
conditions from single- and multicomponent aqueous solutions by Syrian Zeolite mineral
extracted from south Syria. The removal has an ion-exchange nature and consis
ts of three
stages: the adsorption on the surface of microcrystals, the inversion stage, and the
moderate adsorption in the interior of the microcrystal, The study showed that equilibrium
time is 6 hours, and The slight difference between adsorption capacity of the Zeolite
toward lead, zinc from single- and multicomponent solutions may testify to individual
sorption centers of the zeolite for each metal. The maximum sorption capacity toward pb2+
is determined as 33.89 mg/g at an equilibrium concentration of 261.07 mg/L and toward
Zn+2 as 29.18 mg/g at 309.818 mg/L. Langmuir and Freundlich Adsorption Isotherms
were used to evaluate natural zeolite adsorption performance for Lead, Zinc. These
Isotherms were able to provide suitable fit with experimental data, the factor R2 ranged
between 0.95 – 0.99, with better fit to Langmuir Isotherm.
In this work the process of removal of zinc ions from aqueous solutions was studied using natural Syrian zeolite. Two samples were used: natural zeolite Z and modified zeolite with NaCl solution Z-Na. The removal percentage of zinc ions vs. time was
determined using differential initial concentrations of Zn+2: 50,100,200,300,400 mg/L. The contact time was determined and it was 360 min. The removal of Zn+2 ions as a function of temperature and pH have been studied. It was found the increasing of removal percentage by increasing temperature and increasing when pH increasing up to ~7,then the precipitation of zinc hydroxide accurse. The Langmuire adsorption isotherm equation used to calculate the maximum sorption capacity and it was 21.7 and 28.5 mg/g for Z and Z-Na respectively. Results indicate a significant potential for the natural and modified zeolite as an adsorbent/ion-exchange materials for heavy metal removal.
The study was carried out to remove of heavy metals (V+5, Ni+2)
under static conditions from aqueous solutions by Syrian Zeolite
mineral extracted from south of Syria. The results revealed that
operational conditions such as initial solution pH and concentration,
adsorbent particle size, the presence of competing cations, are able
to affect the adsorption capacity and efficiency of natural zeolite.
The Syrian natural zeolite from om'ozon area has been studied as adsorbent for Ni(II) ions from aqueous solution. The removal of Ni(II) ions under different conditions was studied adsorption of Ni(II) enhanced with an increase of initial concentratio
n, temperature and PH .all experiments were carried out at contact time 6h.
The amount of Ni(II) adsorption was increased from 16.36 mgNi/g for initial solution concentration of 100mg Ni/l to 71.33 mgNi/g (for C0=1000mgNi/L). The experimental data fitted well to Langmuir isotherm. The maximum capacity was qmax=142.85mgNi/g Adsorption amount at 298K varies from 16.36mgNi/g for initial solution concentration of 100mg Ni/l to 47.93mg Ni/g(for C0=400mgNi/L) and it increases at 333K to 16.65 mgNi/g and 51mgNi/g (for C0=100 and 400 mg Ni/L )respectively. The adsorption of Ni(II) ions was increased by increasing PH up to ~ 5 and then stabilized up to PH=6 and after that the precipitation process was accured.
