磁性可分離海藻酸顆粒之合成及其對氯酚類及2,4-D的吸附研究

Abstract

Many investigations has demonstrated that surfactants can enhance the removal of organic compounds because of hydrophobicity. However, using surfactants modified materials as adsorbents to deal with organic pollutants still can not solve adsorbents separation and recovery from aqueous phase. Recently, the use of biopolymers as adsorbents for the removal of toxic contaminants has been studied. Among biological materials alginate has become one of the important groups of adsorbents. Alginate, which is mainly obtained from brown algae, is composed of varying compositions of α-L-1,4-guluronic acids and β-1,4-D-mannuronic acids. Alginate has high affinity to divalent cations by the carboxyl groups. The gelling process occurs when alginate contacts with divalent cations. Because of the gelling property, alginate can be formed as many types such as membranes and beads. Compare with other adsorbents, it can produce a easy made and cheap adsorbent that can improve the problem of separated from aqueous phase. In this study, the removal of 2,4,5-trichlorophenol, 2-chlorophenol and 2,4-D by alginate beads and HDTMA entrapped alginate beads was investigated. Batch experiments for sorption isotherm and kinetics were conducted in the conditions of 150 rpm, 25℃ and pH5. The DFT calculation parameters of three organic compounds were discuss with Freundlich fitting parameters to suppose the interactions between organic compounds and alginate or HDTMA entrapped alginate. The results show that the removal of organic compounds by 2% HDTMA entrapped alginate beads were greater than plain , 1% and 0.2% HDTMA entrapped alginate beads. The affinity of alginate and HDTMA alginate to three organic compounds was relative to logKow and binding energy of organic compounds. Magnetic treatment can increase the convenience for adsorbents recovery after remove pollutants.