I remember once reading a fashion article about the rivers in one of Italy’s major textile centres. Apparently, the rivers were running red as it was that year’s ‘on trend’ colour and that’s what happens when mills empty their wastewater into rivers. That article came back to mind on reading this Mar. 27, 2013 news item on Nanowerk (Note: A link has been removed),
Researchers at Amir Kabir University of Technology and Institute for Color Science and Technology [Iran] produced a bio-adsorbent with very high performance for the removal of dye from textile wastewater by preparing a combination of chitosan and dendrimer nanostructure (“Dye removal from colored-textile wastewater using chitosan-PPI dendrimer hybrid as a biopolymer: Optimization, kinetic, and isotherm studies”).
Among the unique characteristics of these bio-adsorbents, mention can be made of high adsorption capacity, biodegradability, biocompatibility and non-toxicity.
There’s a March 28, 2013 news release on the Iran Nanotechnology Initiative Council (INIC) website, which provides more detail abut this work,
The aim of the research was to produce chitosan-dendrimer combination in order to remove dye from the wastewater containing reactive dyes. To this end, chitosan was modified in the first step by using ethylacrylate. Then in the second step, chitosan-dendrimer combination was produced by using PPI second generation of dendrimer.
Parameters that affect the dye removal process including pH, concentration of dye, time and temperature of contact were studied by RSM program in order to optimize the process. Kinetic studies and adsorption isotherms at equilibrium were evaluated too in order to measure the amount of dye adsorbed on the adsorbent.
Results showed that chitosan-dendrimer polymer bio-adsorbent could be used as a high potential and biodegradable bio-adsorbent to remove anionic compounds such as reactive dyes from textile industry wastewater. High adsorption capacity, biodegradability, biocompatibility, and non-toxicity are among the unique properties of these adsorbents.
Here’s a citation and a link for the article,
Dye removal from colored-textile wastewater using chitosan-PPI dendrimer hybrid as a biopolymer: Optimization, kinetic, and isotherm studies by Mousa Sadeghi-Kiakhan, Mokhtar Arami1, Kamaladin Gharanjig. Journal of Applied Polymer Science, Volume 127, Issue 4, pages 2607–2619, 15 February 2013. Article first published online: 16 MAY 2012 DOI: 10.1002/app.37615
Copyright © 2012 Wiley Periodicals, Inc.
The article is behind a paywall.
Plus, for anyone (like me) who needs a definition for adsorbent (from the Dictionary of Construction),
A material that has the ability to extract certain substances from gases, liquids, or solids by causing them to adhere to its surface without changing the physical properties of the adsorbent. Activated carbon, silica gel, and activated alumina are materials frequently used for this application.