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Background and purpose: Chrophenols represent one of the most abundant toxic compounds of industrial which are resistant to biodegradation and persist in the environment for long time. Sunlight is the source of many photochemical reactions. The present study aimed to determine degradation of 4-chlrophenol as persistent organic compound by sunlight in the presence of zinc oxide as a catalyst. Materials and methods: This study was performed in batch conditions. Determined amount of catalyst was added to defined volume of 4-chlorophenol solution which was adjusted pH. Effects of parameters such as ZnO loading, PH, and contact time were investigated. The remaining concentrations of 4-chlorophenol were analyzed by HPLC (high-performance liquid chromatography). Results: The results showed that sunlight in present of zinc oxide as nanocatalyst lead to almost 75% degradation of 4-chlorophenol in optimum conditions (zinc oxide loading = 1.5 g/l, alkalin pH). Zinc Oxide loses photocatalytic property in acidic pH. Conclusion: Sunlight using catalyst of zinc oxide lead to degradation of persistent organic compounds significantly. The catalyst is not consumed and reusable.

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Background and purpose: Furfural compound is very harmful to health that is used or generated in many industries such as oil refineries, petrochemical, pharmaceutical, paper, etc. The composition is one of the critical pollutants that is difficult to remove using the biological methods therefore, the aim of this study was to evaluate the performance of TiO2 nanoparticles in the removal of furfural in the presence of sunlight and UV radiation. Materials and methods: In this study, TiO2 was prepared by sol – gel method and the properties of nanoparticle were determined using SEM. The number of samples was determined through the central composite statistical methods. The samples with definite concentration of furfural and nanoparticle in different operational conditions were exposed to sunlight and UV radiation, individually. The furfural concentration was measured using HPLC. Data analysis was performed using Minitab 16 software. Results: The results showed that the removal efficiency of furfural increased with rising staying time, nanoparticle dose and pH and decreased with rising of the furfural concentration in both methods. The highest removal efficiency of TiO2/UV and TiO2/sun methods were 87 and 45 percent, respectively. Conclusion: The rate of degradation and elimination furfural in both sunlight and ultraviolet radiation photocatalytic methods increased. The efficiency of TiO2/sun method in comparison with TiO2/UV method is negligible.

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Background and purpose: Polycyclic aromatic hydrocarbons (PAHS) are environmental pollutants that are caused by human activity and considered as carcinogenic and mutagenic compounds. Anthracene is a hazardous substance causing serious health problems. There are many bacteria with the ability to remove this pollutant. The aim of of this study was isolation of some bacteria from Tajan river estuary and their use in biodegradation of Anthracene. Materials and methods: In this study the samples taken from estuaries were inoculated into a synthetic medium culture. Four species of bacteria were isolated in the culture process and applied for removal of Anthracene in different environmental conditions such as pH, time, temperature and concentration of Anthracene. Spectrophotometer and HPLC were used to study the growth of bacteria and Anthracene concentration, respectively. Results: The results showed that, optimum condition for removal of Anthracene was pH= 7, temperature= 30 °C, and the dose of inoculated bacteria 107 cfu/ml. Anthracene concentration was 100 ppm. Efficiency of the Anthracene removal in the presence of Pseudomonas putida, Achrobactrum haematophilum, Klebsiella oxytoca, Enterococcus sp, was obtained 51, 45, 43 and 48 percent, respectively. Pseudomonas putida bacteria species had the highest efficiency in Anthracene removal and Enterococcus sp strains had the lowest efficiency. Conclusion: The biological method is a cheap and effective method that can be used for Anthracene removal.