Inorganic Chemicals Industry ›› 2025, Vol. 57 ›› Issue (2): 57-67.doi: 10.19964/j.issn.1006-4990.2024-0407

• Research & Development • Previous Articles     Next Articles

Study on synthesis of FeS modified calcium silicate hydrate composites and their total Cr removal performance

SHEN Xiaoqian1(), ZHOU Fei2, LIU Wanchen2, XU Lu1, WU Junshu2   

  1. 1.Hualu Engineering & Technology Co. ,Ltd. ,Xi′an 710065,China
    2.Beijing University of Technology,Beijing 100124,China
  • Received:2024-07-15 Online:2025-02-10 Published:2024-08-09

Abstract:

Calcium silicate hydrate(CSH) is a kind of important heavy metal adsorbent,which plays an important role in both natural self-purification process and artificial environmental purification and restoration.Functionalization of CSH adsorbent for Fe3+ adsorption can achieve reduction and detoxification of heavy metal Cr(Ⅵ).Firstly,CSH was prepared by extracting steel slag filtrate from an acid leaching process as the Ca source and Na2SiO3·9H2O as the Si source.The resulting CSH was used to adsorb Fe3+ metal ions by ion exchange and electrostatic attraction.Subsequently,by using thiourea as S source,the CSH adsorbent loaded by Fe3+ was hydrothermally transformed into xFeS@CSH(x was the initial concentration of Fe3+,mg/L).When the mass concentration of Fe3+ was 150 mg/L,150FeS@CSH sample possessed the best Cr(Ⅵ) reduction property.When pH=2,the reduction conversion rate of Cr(Ⅵ) (10 mg/L,60 mL) could reach 100% after 4 minutes of reaction.Meanwhile,by adjusting the pH of the solution and reaction time(pH=3,reaction time of 30 min),Cr(Ⅲ) fixation and total Cr removal could also be achieved.The active FeS phase achieved Cr(Ⅵ) reduction,and with the increase of solution pH,the reduction product Cr(Ⅲ) was fixed on the material surface in the form of Cr(OH)3,Cr2O3,etc.

Key words: hydrated calcium silicate, adsorbent, Cr(Ⅵ) reduction, FeS modification

CLC Number: