✦ LIBER ✦

The use of pine bark as a natural adsorbent for persistent organic pollutants – study of lindane and heptachlor adsorption

✍ Scribed by Nuno Ratola; Cidália Botelho; Arminda Alves

Publisher: Wiley (John Wiley & Sons)
Year: 2003
Tongue: English
Weight: 98 KB
Volume: 78
Category: Article
ISSN: 0268-2575
DOI: 10.1002/jctb.784

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

Pine bark obtained as a sawmill by‐product in the north of Portugal was used for the adsorption of lindane and heptachlor, two organochlorine pesticides classified as POPs (Persistent Organic Pollutants), from aqueous solutions. It is intended that this natural adsorbent be used as an alternative to activated carbon in an innovative approach for the removal of these classes of compounds, reducing significantly the regeneration costs of the process, thus providing for its intensification. The analytical methodology validated for pesticides' quantification consisted of solid‐phase microextraction (SPME) prior to gas chromatography with electron capture detection (GC‐ECD), which presented limits of detection for lindane and heptachlor of 0.067 µg dm^−3^ and 0.062 µg dm^−3^, respectively. Repeatability, reproducibility and recovery were the parameters tested for validation, yielding better results for lindane. For the bark particle size used (125–300 µm), the average efficiency of removal attained for lindane was 80.6%, and 93.6% for heptachlor with the equilibrium time set at 24 h. Both Langmuir and Freundlich models were tested for the adsorption isotherm, but only the second approach produced reliable results for the adsorption parameters. Values obtained for log K~ow~ were 3.17 for lindane (R^2^ = 0.9927) and 4.85 for heptachlor (R^2^ = 0.9401).