We utilize isotherm models in contributing to scholarly knowledge in simple terms, to measure the forces or energy defining certain adsorption phenomenon. Gas Chromatography coupled with Mass Spectrophotometer detector (GCMS) was utilized to measure equilibrium phase atrazine after adsorption onto Shea nut Shells (SS) acid derived activated carbon. Data were fitted into the D-R and Temkin isotherm relationships for energy data estimation of Sorption energy value (BD), mean free energy (ED) and heat of sorption (B). They were estimated as 0.7600mol2KJ-2, 0.8111 kjmol-1 and 0.790Jmol-1 respectively. The parameter predicting the type of adsorption was evaluated BD, B<20kJ/mol and ED<8 which is an indication that physisorption (Non specific adsorption) dominates chemisorption and ion exchange. The D-R model with a higher correlation coefficient values, R2=0.979 proves a better choice in explaining sorption energies. Generally, shea nut shells can be used as alternative precursors for activated carbon production via the two steps and acid treatment method.

Background: Atrazine is one of the most widely used triazine herbicides which has been used for controlling broadleaf and grassy weeds for many years. Its widespread use in water has caused environmental concern because of frequent detection of atrazine in aquatic systems where this herbicide has been spilled. Therefore, the purpose of this study was to determine the herbicide removal efficiency at the optimal conditions.Methods: The effect of different parameters including pH at three different levels (3-11), the initial concentration of atrazine at three different levels (0.1-10 mg/L), and reaction time at five different levels (0-120 min) on the removal of atrazine in the aqueous phase using ultraviolet radiation (1020 mw/cm2) was investigated. Finally, the data were analyzed using SPSS software (version 16).Results: The results demonstrated that atrazine removal rate increased by increasing pH, initial atrazine concentration, and reaction time. The maximum rate of atrazine removal (99.2%) at optimal condition occurred in pH=11, atrazine concentration=10 mg/L at 30 min.Conclusion: According to the findings, it can be concluded that the UV-A process is an effective and commodious method for reducing atrazine in polluted water resources.

Adsorption desorption behaviors of widely applied atrazine soil were studied, employing a batch technique as a case study in Darehasaluie Kavar corn field in Fars Province in 2005. Samples were collected into 0 to 20 cm soil depth, where was cultivated under a crop rotation (corn-wheat) during the past 10 years. Sorption kinetics exhibited two phenomena: an immediate rapid sorption (1.31 µg/g soil after 12 hours) followed by a slow sorption process (1.37 µg/g soil after 24 hours). Desorption behavior of atrazine was similar to its adsorption, but at a very slower rate. Atrazine desorption efficiencies were much less effective and incomplete even after a long equilibration time (only 9.16% after 96 hours). The adsorption-desorption rate for most of the time was positively related to the amount of applied atrazine and the time required for equilibration (P<0.01). Desorption data exhibited hysteresis phenomena. Atrazine adsorption data described well according to Freundlich (r2=0.95), Langmuir (r2=0.82) and Temkin (r2=0.84) isotherms. However, the fit to Freundlich adsorption model in a non linear form (1/n <1) was closer than the others. Desorption isotherm could be well described by the Temkin (r2=0.96) and Freundlich (r2=0.92) isotherms, but the fit to Temkin model was closer than that of Freundlich.    

background: Atrazine (ATZ) is a common herbicide in agriculture for control of grass and broadleaved weeds. It persists in the environment and causes reproductive problems in both human and animals. The present study was aimed at protective effect of green tea against ATZ toxicity in the reproductive system of male rats.Methods: The present study was performed in Veterinary School, Shahid Bahonar University of Kerman in 2016. ATZ and treatment groups received ATZ daily 200 mg/kg BW orally for 14 d. In addition, 0.2%methanolic green tea extract was administrated in the treatment group.Results: In histopathologic investigation, number of germinal layers reduced in the most seminiferous tubules in the ATZ group and spermatids were absence. Necrotic spermatocytes, spermatids, and spermatozoa were evident in the testicular tubules. In the morphometric measurements, tubular diameter, germinal epithelium height, and meiosis index decreased significantly.Conclusion: Green tea extract had reduced testicular toxicity of atrazine significantly. ATZ induces toxicity through oxidative damage and green tea extract can protect the testes due to antioxidant activity of its polyphenols especially flavonoids.