Removal of Simulated Non-Radioactive Heavy Metals from Waste Water into Activated Carbon and Polymer

The present work investigate the removal of simulated non-radioactive heavy metal such as lead ions (Pb²⁺) from aqueous solution by sorption process into activated carbon (AC) and commercial polymer (chitosan) at the same optimum condition. Different prepared powder adsorbents were used for sorption process, which prepared from natural rice straw (R.S) and cotton straw (C.S) by using different methods of activation including chemical activation by (acids-base) and physical activation by steam. Batch experiments were used to predict the sorption capacity of Pb²⁺ions into the different prepared adsorbents. The Preliminary test was carried out to select and determine which prepared adsorbent have the highest uptake for sorption of Pb²⁺ions. (RSACNa5) activated carbon prepared from rice straw and treated chemically with NaOH (1N) was selected and characterized due to it show the highest efficiency for the removal of Pb²⁺ions from aqueous solution (85.24 %). Different parameters affecting the sorption process were carried out, which is including shaking time, ph, Ac weight, temperature and initial concentration of Pb²⁺ions. The prepared activated carbon (RSACNa5) was characterized by (FT-IR) spectrophotometer, BET surface area, Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX) techniques and Elemental Analysis. Four kinetic models were used to analyze the sorption data, the kinetics proved that the results are fitting well with the first-order model. The sorption process was investigated using Langmuir and Freundlich isotherm models. The results showed that the sorption capacity of the RSACNa5 is 63.3 mg/g for removal of Pb²⁺ ions according to Langmuir model. Thermodynamic parameters were calculated to predict the nature of the sorption process where ∆ G° had negative value, which indicate that the sorption process is spontaneous, ∆ H°was positive value, which means that the process is endothermic in nature and ∆S° was positive value also, which indicates the increase in randomness. The optimum ph value for Pb²⁺ions removal was found to be 4.5. The RSACNa5 showed BET surface areas 35.6 m² g^-1 and total pore volumes of 4.99e^-2 CCg^-1