Synthesis Of Boron Absorbing Agent And Its Application In Seawater Desalination

With the development of the national economy,seawater desalination become the main method for obtaining fresh water in the 21st century.However,trace amounts of excessive boron are present in the desalinated seawater,which may cause some toxicological reactions to the organisms.Therefore,the problem of boron removal for seawater desalination s received great attention.In this experiment,chitosan was used as a carrier to prepare a new type of?CTS-Fe?microspheres by in-situ precipitation of?Fe?OH?₃?in chitosan for the study of boron removal after desalination of seawater.The carrier chitosan is a natural macromolecule flocculant which is biocompatible and easy to be degraded.The amino and hydroxyl in the molecule can form a stable chelate with the metal ions which good adsorption properties and can effectively reduce the environmental secondary pollution.The main contents of this study are as follows:?1?Through the preparation of?CTS-Fe?microspheres for boron adsorption separation,screening the best adsorbent for the separation of boron.And the surface morphology of CTS-Fe was racterized by scanning electron microscopy?SEM?and Fourier transform infrared spectroscopy?FTIR?.?2?The effects of pH,adsorbent dosage and temperature on the adsorption of boron were investigated experimentally.The results showed the adsorption efficiency of CTS-Fe to boron was relatively high at pH 9-10.The elution of?CTS-Fe?with sodium hydroxide?NaOH?at pH 11 gave an efficiency of 93.4%.The CTS-Fe also a high adsorption effect after the CTS-Fe is reused 5 times.?3?The sorption properties of CTS-Fe for boron were racterized by adsorption isotherms and kinetic models.The results show there are chemisorption,physic-adsorption and inner-layer coordination in the adsorption process.Finally,the effect of removing boron on the adsorbent in the presence of humic acid was studied.The results showed humic acid could inhibit the boron removal.