Sorption and Desorption Studies on Toxic Metals From Brewery Effluent Using Eggshell as Adsorbent

The adsorption capacity of eggshell in removing Pb2+, Ni2+, Mn2+, Zn2+ and Co2+ from standard solution and consolidated brewery effluent was investigated in this study. The sorption process dependent on pH, contact time, initial metal ion concentration and sorbent dosage with pH 7.0 being the optimum value, and maximum sorption was attained within the first 60 minutes. The equilibrium sorption data followed the Langmuir and Freundlich isotherms with R2 ranges of 0.834 – 0.993 and 0.939 – 0.998 respectively. The kinetic data were best described with pseudo second order kinetic. Desorption of sorbed metal ions was efficient with 3.0 mol/L NaOH. The affinity of metal ion sorption was in the order of Co2+ > Pb2+ > Ni2+ > Zn2+ > Mn2+. The percentage adsorptions of Mn2+ and Zn2+ from the brewery effluent were 95.86% and 44.29% respectively, while the corresponding percentage desorption of Mn2+ and Zn2+ were 19.94% and 35.48% respectively.