Competitive biosorption of ortho-cresol, phenol, chlorophenol and chromium(VI) from aqueous solution by a bacterial biofilm supported on granular activated carbon

Abstract

A biofilm of Arthrobacter viscosus supported on granular activated carbon was used to remove chromium and organic compounds (chlorophenol, phenol and o-cresol) from aqueous solutions. The compounds were studied as single solutes and in different combinations between them and Cr(VI). Optimum Cr(VI) adsorption was observed at a phenol concentration of 100 mg/l and at an initial concentration of the metal of 60 mg/l. The maximum values of biosorption of organic compounds were 9.94 mg/g for phenol, 9.70 mg/g for chlorophenol and 13.99 mg/g for o-cresol. In terms of removal percentage, after 15 h of experiment, the affinity order was as follows: phenol > chlorophenol > o-cresol > chromium(VI).

What is the correct form of BET isotherm for modeling liquid phase adsorption?

“…In other words, the C S value calculated by BET-Case 2 is not the actual saturation concentration of the liquid phase; it is only the inverse of K L . The large difference between the calculated values of C S by BET-Case 2 (1212.30 mg/L and 138.88 mg/L for adsorption of MTBE and phenol, respectively) and the actual value of saturation concentration of MTBE (42000 mg/L) (Stephenson 1992) and phenol (70000 mg/L) (Quintelas et al 2006) in water supports this argument. In an attempt to justify the difference between calculated values and actual values of C S some authors have stated that the value of C S calculated from the BET isotherm equation was the liquid phase concentration at which the adsorbent saturates with the adsorbate (Miller and Clump 1970) or as the concentration at which the upward curvature of the isotherm occurs (Al-Futaisi et al 2007).…”

“…If the used value of C S is sufficiently larger than the value of 1/K L then the monolayer adsorption capacity (q m ) calculated by BET-Case 1 isotherm equation will be close to the q m value calculated by the Langmuir isotherm equation. For example, the actual saturation concentration (solubility) of MTBE and phenol in aqueous medium is 42000 mg/L (Stephenson 1992) and 70000 mg/L (Quintelas et al 2006), respectively which are very large compared with their corresponding 1/K L values (1212.30 mg/L and 138.88 mg/L, respectively). As a result, the q m values calculated by BET-Case 1 and Langmuir equations for the adsorption of MTBE and phenol are very close (9.682 mg/g Fig.…”

Statistical optimization of process parameters for the simultaneous adsorption of Cr(VI) and phenol onto Fe-treated tea waste biomass

“…Adsorption is proved to be most promising conventional or traditional methods for the simultaneous removal of organic compound and heavy metal ions from wastewater in comparison with other treatment methods such as precipitation, ion exchange, catalytic reaction, etc. (Quintelas et al 2006;Aksu and Akpinar 2001). Modification of biosorbent by metal impregnation (Talreja et al 2014) and acid treatment ) improves the percentage removal of pollutants (Kuo and Bembenek 2008;FonsecaCorrea et al 2013;Owlad et al 2010;Cronje et al 2011).…”

Safety and Hazards in Petroleum Industries: Research, Studies and Surveys

“…The treatment of flue gases for removal of harmful gases is one such aspect of these investigations [8,9,10,11,12]. Also wastewater treatment for these plants is being dealt with best possible technology and many investigations are reported on the same [13,14,15]. Sludge and solid waste treatment is also important area of research [16,17,18].…”