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Azerbaijan, Iran

Arvand M.,Guilan University | Shemshadi R.,Kimya Problemleri Institutu | Efendiev A.A.,Kimya Problemleri Institutu | Zeynalov N.A.,Kimya Problemleri Institutu
Asian Journal of Chemistry | Year: 2011

In the present investigation seven synthetic polymers are used as adsorbents for the removal of Cd(II) from aqueous solution. The equilibrium studies are systematically carried out in a batch process, covering various process parameters that include agitation time, adsorbent dosage and pH of the aqueous solution. It was observed in adsorption and desorption tests that the synthetic polymers showed significant pH dependence, which affect the removal efficiency, robustly. Adsorption behaviour is found to follow Freundlich and Langmuir isotherms. A regeneration study was also carried out. Source


Arvand M.,Guilan University | Shemshadi R.,Kimya Problemleri Institutu | Efondiov A.A.,Kimya Problemleri Institutu | Zeynalov N.A.,Kimya Problemleri Institutu | And 3 more authors.
Asian Journal of Chemistry | Year: 2010

In the present investigation, gum arabic (GA) and glycidyl metha-crylate modified gum arabic (GMA-GA) were assessed as biosorbents for the removal of Hg(II) from aqueous solutions. For chemical modification of gum arabic with glycidyl methacrylate, an appropriate mixture of water and DMSo was used to dissolve gum arabic and glycidyl methacrylate. The approving of chemical modification and the presence of glycidyl methacrylate groups in the modified structure of gum arabic (GMA-GA) was confirmed by diffuse reflectance spectroscopy (DRS). The equilibrium studies are systematically carried out in a batch process, covering various process parameters that include agitation time, adsorbent dosage and pH of the aqueous solution. It was observed in adsorption and desorption tests that GMA-GA showed significant pH dependence, which affected the removal efficiency, robustly. Adsorption behaviour is found to follow Freundlich and Langmuir isotherms. The adsorption mechanism is described by a pseudo second order kinetics. A regeneration study was also carried out. Source


Arvand M.,Guilan University | Shemshadi R.,Kimya Problemleri Institutu | Zeynalov N.A.,Kimya Problemleri Institutu | Efondiov A.A.,Kimya Problemleri Institutu
Asian Journal of Chemistry | Year: 2010

In this work, effects of chemical coagulants [Fe2(SO4)3, Al2(SO4)3, FeCl3 and CaO] and biopolymers (chitin, carboxymethylcellulose (CMC) and chitosan) on sewage sludge dewatering were studied. According to the results, Fe2(SO4)3 was the most suitable substance for dewatering of the returned activated sludge and FeCl3 was found to be the best coagulant for the aerobic digested sludge. The results showed that sludge dewatering speed compared with control samples increased by about 77.6 and 80.5%, respectively. Also, among natural polymers being used, chitin having the lowest consumption level in comparison with other coagulants increased the dewatering speed for the digested sludge by about 59.5%. In this case, the sludge moisture content compared with that of the control decreased by 12.8%. In all cases, chitosan had a negative effect on the dewatering speed and reducing the sludge moisture content. The effect of carboxymethylcellulose on decreasing the sludge time to filteration was also negligible. Source

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