초록
<P><B>Abstract</B></P><P><B>BACKGROUND</B></P><P>The objective of this work was to process the sorghum biomass obtained from crops cultivated on heavy metals polluted soil, for the production of lignocellulosic ethanol and to determine the amount of toxic metals in the intermediary, byproducts, and final products.</P><P><B>RESULTS</B></P><P>In the process of cellulolytic enzymes production by fungi using sorghum bagasse as substrate, a small amount of heavy metals passed into the liquid phase. During pretreatment by steam and alkali, the concentration of metals increased in the solid phase, while in the liquid phase the metals were not detected. After hydrolysis and fermentation of the pretreated biomass, the metals concentration in the solid fraction of the liquid increased, due to dissolution of the main fraction of the organic solids, although a fraction of the metals was found in the liquid fraction of the fermentation medium. During the distillation, some Pb and Cu were extracted into the distillate. Zn and Cd accumulated in the distillation residue.</P><P><B>CONCLUSION</B></P><P>The highest amounts of heavy metals accumulate in the solid residue, a small part is retained in the distillation residue, with traces of Pb and Cu potentially occurring in the distilled ethanol. © 2016 Society of Chemical Industry</P>