Effect of Metal Ions on the Optical Properties of Chemomechanical Pulp of Hardwoods Species

Abstract

The effect of transition metal ions ' on optical properties of hydrogen peroxide bleached
chemomechanical pulp of a mixture of northern Iran hardwoods was studied. Handsheets were made using deionized water, tap water and water containing AI+3,Cu+2,Mn+2,Fe+3,Fe+2 ions. Also, the effect
'of DTPA Spray on minimizing the impact of these metal ions in the processing water on brightness as well as its stability both before and after accelerated photo aging was investigated. The results indicated that brightness loss due to metal ions is as high as 4-5 points. It was also shown that using DTPA in small amounts could recover the brightness that was lost due to the presence of transition
metal ions.