Phosphate removal from wastewaters by a naturally occurring, calcium-rich sepiolite

  • Yin H
  • Yun Y
  • Zhang Y
 et al. 
  • 45


    Mendeley users who have this article in their library.
  • 59


    Citations of this article.


Developing an easily handled and cost-effective phosphate absorbent is crucial for the control of water eutrophication. In this study, a naturally occurring, calcium-rich sepiolite (NOCS) was evaluated for its feasibility as a phosphate absorbent candidate. Batch studies showed that phosphate sorption on NOCS followed a stepwise isotherm for concentrations between 5 and 1000mgP/l, and the phosphate sorption was fitted well by the Freundlich equation. The estimated maximum phosphorus sorption capacity was 32.0mgP/g, which was quite high compared with other natural materials and was comparable to some efficient manmade P absorbents. The NOCS sorption kinetics followed a pseudo-first-order model with an R2value of 0.999. The adsorption of phosphate was highly pH dependent. Phosphate adsorption decreased moderately with increasing pH values from 3.0 to 6.0, and it decreased sharply in alkaline conditions. Ionic strength, sulfate, nitrate and chloride anions had no effects on the phosphate removal capacity of NOCS, but fluoride and bicarbonate anions exerted large effects. Phosphorus fractionation indicated that phosphate removed from the solution was primarily formed as a calcium-bound phosphorus precipitation, which was further confirmed by SEM-EDS analysis. Moreover, phosphate was barely (

Author-supplied keywords

  • Calcium-rich sepiolite
  • Cost-effective
  • Phosphate adsorbent
  • Phosphorus fractionation

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • Hongbin YinNanjing Institute of Geography and Limnology, Chinese Academy of Sciences

  • Ye Yun

  • Yinlong Zhang

  • Chengxin Fan

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free