بررسی کارایی زائدات گیاه آفتابگردان در حذف کادمیوم از محلولهای آبی

Introduction: According to the United States Environmental Protection Agency (USEPA), Cadmium is a critical leading pollutant. Priority pollutants are  pollutants that can cause Cancer, Mutagenesis, and Malformation  in exposed organisms. The aim of this study was to evaluate the effect of sunflower residuals on removal of cadmium from aqueous solutions. Methods: This experimental study was performed in laboratory scale and was performed on 200 synthetic samples in a batch system. In this study the effect of parameters such as contact time (5,10, 15,30,45,60,120 min), pH (2,4,6,7), cadmium concentration (15,30, and 60 mg) and adsorbent doses (0.2,0.6,1 grams in 100 cc) was evaluated. Finally the results were analyzed by kinetic models. Results: The results showed that, cadmium removal efficiency was 95% after 24 hours. Optimum pH range was 6. Maximum absorption occurred in 5 minutes. Investigating absorption through kinetic model showed that Cadmium absorption by sunflower residuals follows pseudo-second-order model( R2 = 0.999). Maximum binding capacity was 20.2 mg g. Conclusion: On the basis of the results, removal efficiency of cadmium increases  by increasing the solution pH from 2 to 6 and  reduces higher than 7 again. Cadmium removal efficiency would increase with contact time and  adsorbent  mass  and  decrease  with increasing initial  concentration of Cadmium .