Controlling the amount of starch entering the drains in a paper mill 2

[Naeema]

Hi

I just started work in a paper mill that produces business paper as well as newsprint from recycled fibre. I have been assigned to research methods to reduce COD levels. Testing on effluent lines has concluded that the starch is the highest contributor to the COD levels, especially the surface starch. The company now wants to look at ways to prevent the starch from entering the drains. One proposal has been to isolate it and dispose of it separately. Any ideas on how to do this??

The company uses acidified cationic tapioca starch for the wet end and local corn starch for the surface

 

[HEC]

On the wet end investigate reuse of the white water in repulpers/pulping circuit rather than fresh water. Need to be careful not to increase the amount of fines in the circuit. If fines become a problem cyclones may be an option. This is all additional capital and operating complexity that the mill cannot justify, however to make omelette eggs need to be broken.

On the coating side of things reduce bleeds and isolate the drains in that area is probably the only solution.


Mark Hutton

 

[ck1999]

You can look using enzymes to reduce the starchs and COD you will need a holding tank for this to work. I have heard they are very effective in cardboard facilities

ck1999