Dried waste activated sludge as biosorbents for metal removal: Adsorptive characterization and prevention of organic leaching

J. Paul Chen, Desmond Lie, Lin Wang, Shunnian Wu, Beiping Zhang

Research output: Contribution to journalArticlepeer-review

55 Scopus citations

Abstract

Dried waste activated sludge was used for copper removal from simulated waste water in this study. Unconditioned activated sludge (UAS) bound up to 35 mg Cug-1, although there was significant leaching of organic material. Organic and copper leaching from the UAS increased significantly as the pH was reduced. Immobilization of UAS by sodium and calcium alginate was utilized in order to overcome the leaching problems, but reduced the adsorption capacity. Based on metal removal and organic leaching, calcium alginate-conditioned UAS (CACAS) was found to be the most suitable sorbent for copper removal. Kinetic experiments showed that copper removal by both sodium alginate-conditioned UAS (SACAS) and CACAS was faster than that by activated carbons, but slower than most of the other biosorbents described in the literature. FTIR spectroscopy identified a number of atomic groupings and structures in UAS relevant to copper adsorption. It suggested that hydrogen ions are replaced with copper ions. The Freundlich equation fitted the experimental isotherms better than the Langmuir equation. A computational model based on adsorption isotherm, external mass transfer and diffusion processes successfully described the kinetics of copper ion removal and suggested that the biosorption kinetics was controlled by mass transfer.

Original languageEnglish
Pages (from-to)657-662
Number of pages6
JournalJournal of Chemical Technology and Biotechnology
Volume77
Issue number6
DOIs
StatePublished - 2002
Externally publishedYes

Keywords

  • Activated sludge
  • Alginate
  • FTIR
  • Kinetics
  • Metal biosorption
  • Modelling

Fingerprint Dive into the research topics of 'Dried waste activated sludge as biosorbents for metal removal: Adsorptive characterization and prevention of organic leaching'. Together they form a unique fingerprint.

Cite this