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In this study, the zinc oxide NPs have been synthesized from the fresh pomegranate peels extract using the precipitation method. The ZnO nanoparticles were produced from the reaction of fresh peels extract with zinc acetate salt which was used as zinc source in the presence of 2 M NaOH. The green synthesized nanoparticles were characterized through X-ray diffraction (XRD), UV-Vis diffuse reflection spectroscopy, Fourier transform infrared spectroscopy (FTIR), and Atomic force microscopy (AFM). The XRD patterns confirm the formation of hexagonal wurtzite phase structure for ZnO synthesized using pomegranate peels extract with average crystalline size of 28 nm. FTIR spectra identify the presence of many active functional groups for the pomegranate extract which is ideal to bind with zinc acetate to produce the ZnO nanoparticles during the preparation method. The reflection spectra of green synthesis ZnO with pomegranate extract observed a blue shift towards lower wavelength with (8 nm) difference compared to ZnO without the addition of any extract.  The provenance of such blue shift towards shorter wave length was due to the quantum size effect. The Atomic force microscopic (AFM) result shows average roughness value for ZnO nanoparticles of 6.26 nm. The decolorization efficiency of the methylene blue dye was investigated using the ZnO nanoparticles under sun light irradiation and it was compared with the bare ZnO synthesized without the addition of extract. The catalytic activity was about 88% after 60 min of sunlight irradiation for both prepared catalyst however, the decolorization efficiency of ZnO with the addition of extract was higher at the first 16 min compared to bare ZnO.

The present study addressed the properties affecting the activity of a new heterogeneous catalyst Fe/Ti-NaY in the ultrasonic irradiated for decolorization of amaranth dye in aqueous solution. The catalyst was prepared by the ion exchange and impregnation method. Different characterization techniques, i.e. XRD, AFM, TEM and SEM/EDAX were done to characterize the properties of the fresh and used catalyst. This catalyst was able to keep its stability and high activity without any noticeable reduction in the decolorization efficiency of amaranth after three cycles of reaction. The X-ray diffraction proved the high stability and the crystallinity for the reuse catalyst. The COD removal for the fresh and used catalyst with and without calcination was 57%, 36% and 20% respectively. The hydrophilic properties of the heterogeneous catalyst increased slightly due to the loading of Ti and Fe ions.

For a friendly environment, adsorbents are prepared from harmful natural sources to reduce their impact on the environment. The preparation of activated carbon from the Eichhornia crassipes was done by carbonization at 450C°, followed by activation step at 800C°. The adsorption processes were carried out by the batch system to determine the optimal conditions for the removal of phenol from the aqueous solutions. Different parameters were used in batch experiments such as initial concentrations of phenol (in the range from 10-100 ppm), pH (from 2-12), temperature (from 298-328k), AC dosage (from 0.09-0.4g). All the adsorption experiments were carried out in thermostat shaker at 150 rpm. The removal percentage of phenol on activated carbon was 98.2% at optimum conditions of 10 ppm initial phenol concentration, 25 minutes, pH=7, 308 k, 0.2 g of AC dosage). The thermodynamic functions of phenol adsorption were studied at different temperatures. The values of Gibbs free energy (∆G) at maximum removal with temperatures (298, 308, 318 and 328K) was (-5.17, -6.83, -8.22, -8.48) respectively and enthalpy ∆H, entropy ∆S values was 29.22 and 0.114. The activated carbon extracted from Eichhornia crassipes has a double benefit. first, to remove various organic pollutants such as phenols in aqueous solutions and the second, to create a clean water environment free of this plant found in Iraqi waters.