This study aimed to investigate the kinetics of the anion exchange step of ferrous ions with Na-X zeolite in a temperature range of 20 and 80°C for a period of up to 8 hours. A ferrous sulfate heptahydrate solution was used as a ferrous ion source to exchange with the sodium of the Na-X zeolite. The results showed a change in the physical appearance of the zeolite with the progress of the ion exchange process. The catalyst color was observed with the progress of the ion exchange time and changed from yellow to brown. The ferrous ion exchanged contents increased with temperature and reached 0.519 at 80°C after 8 hours. A kinetic model based on the Langmuir-Hinshelwood-Hougen-Watson model was suggested and developed to describe the ion-exchange process. The proposed model was solved numerically, and the results indicated its ability to describe the experimental results with high correlation coefficients. Finally, the activation energy for the forward reaction was 31590.7J/mole compared to 28105.5J/mole for the backward, and the frequency factors for the forward and backward reactions were investigated.

The zeolite's textural properties have a significant effect on zeolite's effectiveness in the different industrial processes. This research aimed to study the textual properties of the NaX and FeX zeolites using the nitrogen adsorption-desorption technique at a constant low temperature. According to the International Union of Pure and Applied Chemistry, the adsorption-desorption isotherm showed that the studied materials were mixed kinds I/II isotherms and H3 type hysteresis. The Brunauer-Emmett-Teller isotherm was the best model to describe the nitrogen adsorption-desorption better than the Langmuir and Freundlich isotherms. The obtained adsorption capacity and Brunauer-Emmett-Teller surface area values for NaX were greater than FeX. According to the Kelvin equation, Barrett, Joyner, and Halenda model was used to determine pore size distribution, diameter, and average pore volume for the selected zeolites. The pore size distribution for NaX was wider than FeX zeolites, the pore diameter for NaX was less than FeX, and the average pore volume for FeX was greater than the value of NaX average pore volume. The comparative study was carried out with the previous studies, and the comparison showed that the textual properties of the modified zeolites agreed with other studies.

Recently, water pollution considered a major problem that faced the human. Large quantities of water consume in various industrial oil refinery processes, where the wastewater discharged from these processes contains high organic, phosphate, ammonia, nitrite compounds, and toxic substances. Regarding that, making this resource a fresh is a major concern.  Furthermore, a great attention has been given for the removal of these contaminants discharged by Fenton process combined with coagulation process. Combined Fenton/Coagulation process was used and applied in this study as a novel wastewater treatment to remove Chemical Oxygen Demand (COD), Phosphate (PO4), Ammonia (NH3), Nitrite (NO3) compounds, and turbidity (NTU) from industrial wastewater in North Gas Company (NGC), Iraq. The industrial wastewater used in this study was characterized with 114 mg/L COD ,10.28 mg/L PO4, 4.123 mg/L NH3, 95.6 mg/L NO3, 98 NTU Turbidity. The main goal from this work was to evaluate the performance removal efficiency of combined Fenton/Coagulation process and examine the effect of various operational parameters such as Fenton’s dosages (H2O2, Fe2+), the concentration of coagulant (Alum) on the removal efficiency. The results obtained in this work revealed that maximum removal efficiency of COD, PO4, NH3, NO3, turbidity was 89.43%, 72.94 %, 91.065%, 90.96%, 89.85%, respectively was achieved using Fenton combined with coagulation process at 60 mg/L of Alum and 2.5 Fenton’s mole ratio. Overall it can be established that Combined Fenton/Coagulation process plays an important role in obtaining good results and had better removal efficiency. All the experiments were carried out using jar test apparatus at constant temperature (room temperature).

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