Skip to page content
USDA Forest Service

Research & Development Treesearch

Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help - We Participate  Government Made Easy

Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (326 KB bytes)

Title: Orthophosphate sorption onto lanthanum-treated lignocellulosic sorbents

Author: Shin, Eun Woo; Karthikeyan, K. G.; Tshabalala, Mandla A.;

Date: 2005

Source: Environmental science & technology. Vol. 39 (2005): pages 6273-6279.

Publication Series: Miscellaneous Publication

Description: Inorganic/organic hybrid adsorbents for removing orthophosphate from water were prepared by lanthanum (La) treatment of bark fiber, a lignocellulosic material obtained from juniper (Juniperusmonosperma). The La was anchored to the juniper bark (JB) fiber by ion exchange with Ca in the bark and was responsible for removing orthophosphate. Two La concentrations (0.01 and 0.1 M) were used that resulted in loadings of 0.198 (La/JB01) and 0.302 (La/JB02) mmol of La g -1 of fiber, respectively. At circumneutral pH conditions, La exhibited a strong affinity for bark, but significant La desorption occurred under acidic conditions (pH < 4.5). For La/JB02, 86% of the initial La loading was released at pH 2.5, and only 0.1% at pH 7.3. Initial La loading in the bark fiber significantly influenced its orthophosphate sorption capacity, which was determined for La/JB01 and La/JB02, respectively, to be 0.188 and 0.233 mmol of P g -1 (sorption envelopes) and 0.211 and 0.351 mmol of P g -1 (sorption isotherms when surface site saturation occurred). The P-to-La molar ratio on the bark surface was extremely high (0.12-1.77 for La/JB01 and 0.13- 2.58 for La/JB02), implying that orthophosphate removal occurred by other mechanisms in addition to surface complexation. From the orthophosphate surface loading levels and the shape of the sorption isotherms, it appears that adsorption occurred at low sorbate-to-sorbent (P-to-La-treated JB)ratios and transitioned to surface precipitation at higher ratios. When surface precipitation occurred, orthophosphate uptake continued to increase with increasing initial P levels. Results from X-ray diffraction and infrared spectrometric analyses are also suggestive of the occurrence of surface precipitation during the interaction of orthophosphate with La-treated lignocellulosic materials.

Keywords: Filtration, Lanthanum, infrared spectroscopy, X-ray spectroscopy, lignocellulose, adsorption, water pollution, bark utilization, juniper utilization, orthophosphates, Juniperus monosperma

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.



Shin, Eun Woo; Karthikeyan, K. G.; Tshabalala, Mandla A. 2005. Orthophosphate sorption onto lanthanum-treated lignocellulosic sorbents. Environmental science & technology. Vol. 39 (2005): pages 6273-6279.


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.