Removal of heavy metals (Cu, Ni, Zn, Pb, Cd) from compost by molasses hydrolysate

Abstract

This study aimed to remove heavy metals (Cu, Ni, Zn, Pb, Cd) from composts using molasses hydrolysate, produced from molasses by-product of the sugar industry. Batch experiments were conducted to examine the effects of differing experimental conditions on the removal of heavy metals, according to contact time and solid-liquid ratio. Batch experiments achieved removal efficiencies of 66% for Cu(II), 52% for Ni(II), 57% for Zn(II), 51% for Pb (II), and 77% for Cd(II) at 60 minutes and 1:12.5 solid-liquid ratio. Column experiments achieved removal efficiencies of 91% for Cu, 86% for Ni, 99% for Zn, 61% for Pb, and 99% for Cd at 0.55 mL/minute flow rate and a solid-liquid ratio of 1:12.5 g/mL. Producing large quantities of highly acidic and heavy metal contaminated solution, compost with low pH, and decreasing some parameters' concentrations of compost such as C, TKN, total P are the disadvantages of suggested technology.