title: A novel starch-based adsorbent for removing toxic Hg(II) and Pb(II) ions from aqueous solution.
abstract: A novel effective starch-based adsorbent was prepared through two common reactions, which included the esterification of starch with excess maleic anhydride in the presence of pyridine and the cross-linking reaction of the obtained macromonomer with acrylic acid by using potassium persulphate as initiator. The percentage of carboxylic groups of the macromonomer ranged from 14% to 33.4%. The cross-linking degree of the adsorbent was tailored with the amount of acrylic acid which varied from 10wt% to 80wt%. Both Fourier transform infrared spectra and thermogravimetric analysis results verified the structure of the adsorbent. The maximum gel fraction and swelling ratio of the adsorbent were about 72% and 6.25, respectively, and they were able to be adjusted with the amount of monomers. The weight loss percentage of the adsorbent could reach 96.9% after immersing in the buffer solution that contained α-amylase for 14h. It was found that the adsorption capacities of the adsorbent for lead and mercury ions could be 123.2 and 131.2mg/g, respectively. In addition, the adsorbent was able to remove ca. 51-90% Pb(II) and Hg(II) ions that existed in the decoctions of four medicinal herbals.
authors: College of Material Science and Engineering of Huaqiao University, Quanzhou 362021, China.
authors: Li
authors: L
authors: Huang
authors: Congming
authors: C
authors: Xiao
authors: Bingxia
authors: B
authors: Chen
mesh_terms: D000327:Adsorption; D007854:Lead / Q000737:chemistry / Q000302:isolation & purification*; D008628:Mercury / Q000737:chemistry / Q000302:isolation & purification*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013213:Starch / Q000737:chemistry*; D013818:Thermogravimetry; D014867:Water
chemical_list: D012996:Solutions; D014867:Water; D007854:Lead; D013213:Starch; D008628:Mercury