Application of Organic Solid Waste in Wastewater Treatment

Sawdust is an organic solid waste material of high adsorbing potential in removal of heavy metal ions
from wastewater, so it can be used in treating industrial waste.
In this study, the removal of copper, chromium, arid nickel from laboratory prepared wastewater,
through sawdust, was investigated. Waste water containing .heavy metals was added was to sawdust to
evalute the rate of metal ion adsorption in different conditions of acidity, contact times and conceritrations.
The results indicated that the adsorption of these heavy metal ions increased with an increase in pH
and reached a maximum at pH=5. In addition percent adsorption depended on kind of ion, so that at
pH.=5 the percent adsorptions for Cu (II), Ni (II) and Cr (III) were 65%,56% and 50% respectively.
Adsorption increased with the initial concentration of metal ions and then decreased, because of
sawdust saturation. Saturation capacity per gram of sawdust for copper, nickel and chrome ions was
28.2, 11.8 and 23.2 ppm respectively. Also adsorption increased with contact time. However, this
process was rapid, and in the initial 10 minutes, percent adsorption got to between 45% and 65%. And
finally the favorable needed time was determined to be 60 minutes.