increase in adsorbent surface area and availability of more
adsorption sites (Garg et al., 2004). Freundlich adsorption isotherm
was best fitted for Cu in distillery effluent (n = 4.25) followed by Mn
in beverage, paper mill and distillery effluent (n = 5.81, 4.95 and
7.75 respectively) and Fe and Zn in beverage industry (n = 2.31 and
7.01). Mckay et al. (1980) have reported that an n value in the range
2–10 indicates favorable adsorption. The value of R2 in Langmuir