Adsorption of heavy metals on marine algae.
Loading...
Date
2005
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Biosorption is a property of certain type of inactive, microbial biomass to bind and
concentrate heavy metals from even very dilute aqueous solutions. Biomass exhibits
this property, acting just as a chemical substance, as an ion exchanger of biological
origin. It is particularly the cell wall structure of certain algae that is found
responsible for this phenomenon. In these experiments, the rate and extent for
removal of copper is subjected to parameters such as pH, initial metal concentration,
biosorbent size, contact time, temperature and the ability of the biomass to be
regenerated in sorption-desorption experiments. The metal adsorption was found to be
rapid within 25 minutes. The maximum copper uptake of 30 mg of copper / g of
biomass has been observed, in the following conditions: 100 mg / L, 0.1 g of biomass,
pH 4 and at temperature of 25°C. From this study, it was found that copper uptake is
increasing with increase in pH, with optimum being pH 4. Copper uptake increases
substantially from 0 to 25 minutes.
Metal biosorption behaviour of raw seaweed Sargassum in six consecutive sorptiondesorption
cycles were also investigated in a packed-bed column, during a continuous
removal of copper from a 35 mg/l aqueous solution at pH 4. The sorption and
desorption was carried out for an average of 85 and 15 hours, respectively,
representing more than 40 days of continuous use of the biosorbent. The weight loss
ofbiomass after this time was 13.5%. The column service time decreased from 25 hrs
in the first cycle to 10 hrs for the last cycle.
Description
Thesis (M.Sc.)-University of KwaZulu-Natal, 2005.
Keywords
Sewage--Purification--Biological treatment., Heavy metals--Environmental aspects., Marine algae--Effect of heavy metals on., Theses--Chemical engineering.