REMEDIATION OF PETROLEUM CONTAMINATED GROUNDWATER USING SAWDUST AS AN ADSORBENT

Among the various adsorbents used, sawdust appears to be the most attractive material in terms of cost, versatility and abundance. In the present research, synthetic contaminated water with  gasoline  was  used.  Adsorption  of  petroleum  compounds  on  four  types  of  sawdust (Walnut, Poplar,  Beech  and  Pine)  was  studied  by  using  batch  adsorption  techniques.  It  was  found  that walnut sawdust has higher adsorption capacity than other types of  sawdust. It was also  observed that equilibrium adsorption capacity was a function of pH, temperature, and H 2O2  concentration in solution. Maximum adsorption of petroleum compounds was obtained at pH 8. The adsorption of petroleum compounds was increased by decreasing the temperature and H 2O2  concentration in the solution. The  maximum  equilibrium  capacity  of  walnut  sawdust  was  84.03 sawdust gr COD mg nd  606.37  sawdust gr TPH mg obtained at pH 8 and+ a temperature of 10˚C. The  experimental  adsorption  data  were  fitted  to  a  Freundlich  and  Langmuier  adsorption model.  Calculated  correlation  coefficients  indicated  that  the  Freundlich  model  was  best  suited, indicating that the nature of walnut sawdust is heterogeneous. In this study, to illustrate the relation between q e, C e , pH and temperature, regression analysis was  taken  into  consideration.  The  obtained  model  (with  R 2 =0.985)  improved  the  correlation coefficient at least 1.13% compared to the Freundlich model. The maximum and minimum error of the  predicted  values  of  q e   to  the  experimental  data  was  obtained  as  14.29%  and  0.034%  for regression model, while these errors for the Freundlich model were 52.15% and 1.63%.