Preparation of composite aerogels based on sodium alginate, and its application in removal of Pb2+and Cu2+from water

A novel Ethylenediamine-Modified Calcium Alginate Aerogel (ECAA) was synthesized by freeze-drying method, and used to remove Pb 2+ and Cu 2+ from aqueous solutions. The prepared adsorbent was characterized by using the FTIR spectra, SEM analysis and XPS analysis . The effects of the pH, initial metal ion concentration, adsorption kinetics , and isotherms had been studied systematically. Moreover, the ECAA can be regenerated by simple acid treatment and used repeatedly. It is interesting to note that almost no Ca 2+ can be detected after the first cycle that confirmed the adsorption process involves ion exchange.The XPS spectra analyses further indicated that Pb 2+ and Cu 2+ were adsorbed via the chelation of −CO-NH, −NH 2 and −OH. The results from these studies indicated the aerogel is a promising adsorbent to separate and recover the heavy metal ions from contaminated water.