Adsorption properties of lead and zinc ions onto iminodiacetic acid functionalized loofah from solution

Lead and zinc ions in water are very unfriendly to humans and the environment. In this experiment, an environmental friendly and hydroxyl-rich biomass materials loofah (LG) was modified by epichlorohydrin and iminodiacetic acid (IDA). IDA-LG was used to remove Pb2+ and Zn2+ as model pollutants. X-ray photoelectron spectroscopy, scanning electron microscopy, etc were used for characterizing the prepared adsorbent. The results suggested that the adsorbent had a non-mesoporous structure while IDA modification was successful. The effects of pH, salinity, temperature and time on adsorption were investigated through batch adsorption experiments. High acidity and salinity have negative effects on adsorption. The theoretical adsorption capacity of IDA-LG for Pb2+ and Zn2+ could reach 82.5 and 25.2 mg g-1 at 303 K, respectively. Mechanism of adsorption was coordination and ion exchange. In the binary system, there was higher affinity about IDA-LG for Pb2+. There was good regenerative property of spent IDA-LG. IDA-LG could be used as a novel adsorbent to remove heavy metals from the sewage.