In this study, ZnFe2O4, ZnO nanoparticles and nanocomposites of ZnFe2O4– ZnO (core-shell) have been made via simple coprecipitation manner which is a rapid, inexpensive and economical method, impact of green surfactants such as red pepper, black pepper, lemon, saffron, as well as carbohydrates like gelatin, poly vinyl pyrrolidone, glucose, on morphology of ZnFe2O4 were investigated. These surfactants are known as biodegradable and biocompatible factors, moreover, the effect of concentration, temperature and sediment agent on the surface characteristics of core magnetic have been studied and outcomes of SEM analysis indicated that the organic solvent of the red pepper possesses a great effect on diminishing size of nanoparticles. Vibrating sample magnetometer (VSM) analysis emphasized that ZnFe2O4 and desired nanocomposites possess super-paramagnetic property and analysis such as X-ray diffraction and Fourier-transform infrared (FT-IR) spectroscopy were used to indicate pure nanoparticles and nanocomposites. As well photo-degradation of toxic dyes was applied under Solar Irradiation.

Pharmaceutical pollutants are one of the most important issues of modern life, and their negative effects on the environment and human health are undeniable. In the present work, the effectiveness of the photocatalytic process was studied by two semiconductors (ZnO and V2O5) in order to remove the Diclofenac Sodium completely under Solar Irradiation. The study examined the impact of parameters such as the high-level range concentration of pharmaceutical, catalyst dosage, pH changes, and time on the photodegradation of Diclofenac Sodium in aqueous solution. All the experiments were carried out under Solar and UV Irradiation to compare the two circumstances. The optimum conditions obtained for photodegradation of Diclofenac Sodium include a reaction time of 180 min, zinc oxide and vanadium pentoxide = 1 g L-1, Diclofenac Sodium concentration = 300 mg L-1, and pH of 4. In addition, chemical oxygen demand removal was investigated for all the conditions, and total degradation was observed by V2O5 under optimum conditions. The study of reaction kinetics was carried out in optimum conditions, and a pseudo-first-order kinetic model was approximately in agreement with experimental results in each case.

It is very useful to use the Solar Irradiation for photocatalytic property, but need to reduce the band gap by doping the ions. In this paper ZnS (zinc sulphide) nanoparticles has been synthesized via co-precipitation and hydrothermal method. The co-precipitation and hydrothermal are simple, economical methods and they were used for a green surfactant assisted method for fabrication of ZnS and ZnS– (Ni and Li) doped nanoparticles. Glucose, sucrose or fructose were applied separately as green surfactants and capping agents. The Ni and Li ions were doped in ZnS nanocrystals for improvement of band gaps. The crystalline structure of zinc sulphide nanoparticles was investigated by X-ray diffraction (XRD) spectra and crystallite size of particles were calculated by debye-scherrer equation. The shape and morphology of ZnS particles was studied via scanning electron microscope (SEM). The Fourier-transform infrared spectroscopy (FTIR) was applied for the absorption peak of Zn-S bonding atoms. The photoluminescence (PL) measurement of the ZnS nanopowder was investigated at room temperature with an excitation wavelength around 360 nm. The photo-catalyst properties of ZnS nanoparticles were studied via ultraviolet – visible spectra (UV – Vis) of four different azo dyes acids under Solar Irradiation in times less than 120 min.

The nitrogen doped TiO2 as a heterogeneous photocatalyst via sol-gel method was successfully synthesized. The as-synthesized photocatalysts were characterized with X-ray diffraction (XRD), surface area measurements (BET and BJH), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), and energy dispersive X-ray spectrum (EDX). The activities of as-prepared TiO2 photocatalysts were examined to degrade 4-Chlorophenol aqueous solution under Solar Irradiation in a photoreactor; in addition, photocatalytic degradation mechanism and pathway were investigated. The results showed that 3 % wt N-doped TiO2 nanoparticles (under conditions of solution pH of 4. 0, catalyst loading of 2 g/L, initial 4-CP concentration of 10 mg/L, and Irradiation time of 8 h) exhibited much higher photocatalytic degradation efficiency (91 %) as compared with that of 5 % wt N-doped (83 %), 1 % wt N-doped (71 %), and pure TiO2 (35 %).

Background: Tremendous amount of researches have investigated the issue of water photodisnfection. The aim of this research is to illustrate the influences of bacterial density, turbidity, exposure time and potassium persulfate (KPS) dosage on the efficacy of associated Solar disinfection (SODIS) with KPS for E. coli (ATCC: 25922) eradication as an efficient and inexpensive process.Methods: Desired bacterial density and turbidity was achieved by spiking of 0.5 Mc Farland (1.5×108 cell/ml) and sterile soil slurry in 1 liter of the commercially bottled water.Results: The highest value of UVA Solar Irradiation measured at 13.30 p.m was 5510 mW/Cm2. Increase of bacterial density from 1000 to 1500 cell/ml led to an increase in disinfection lapse time, except in 2 mMol/l KPS. Spiking of 0.1 mMol/l of KPS was not effective; however, increase of KPS dosage from 0.1 mMol/l to 0.7, 1.5 and 2 mMol/l led to the enhancement of disinfection time from 4 h to 3 h and 1 h, respectively. For bacterial density of 1000 cell/ml, increasing KPS dosage up to 0.7 mMol/l had no improved effect; however, beyond this dosage the disinfection time decreased to 1 h. Without KPS and up to 150 NTU within 4 h exposure time, E. coli disinfection was completed. In 2 mMol/l KPS and 1000 and 1500 cell/ml, the 2 h contact time was sufficient up to 150 and 100 NTU, respectively; moreover, complete disinfection was not achieved at higher turbidity.Conclusion: Association of KPS with SODIS can lead to decreasing of water disinfection time.