Environmentally Benign Urea‐modifed Triticum aestivum Biomass for Lead (II) Elimination from Aqueous Solutions

Abstract

AbstractLead is among the three most toxic heavy metal ions (mercury, lead and cadmium). A number of methods are in use for the treatment of lead contaminated waters. The materials used for these are too expensive to be economical for lower concentrations of lead. Raw biological materials have been investigated as alternates. They can be chemically modified or pretreated in an attempt to increase their metal capturing capacities. A new material has been prepared from widely available wheat straw (WS) and urea using microwave radiation and its biosorptive behavior for lead ions has been studied. Modified wheat straw (MWS) was subjected to aqueous lead ions to optimize parameters like pH, contact time, MWS dose and temperature. A known amount of MWS was put in contact with certain concentrations of Pb (II) ions at specified temperatures and pH for certain periods of time. Time of contact, pH, dose and temperature were optimized. The sorption of lead by MWS followed the Langmuir model with a maximum sorption capacity (qmax) of 31.85 mg/g and pseudo second‐order kinetics under a specified set of conditions. The changes in the values of free energy (ΔG°) and enthalpy (ΔH°) indicated the spontaneous, feasible and endothermic nature of sorption process. MWS has been found to be better biosorbent for lead ions than simple wheat straw and certain other biosorbents. WS and urea are easily available, cost effective, and the modification process is simple. So, MWS appears to be a cost effective material for Pb (II) sorption.