Reducing COD in paper mill effluent 1

[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??

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

 

[aquaseaulutions]

What is the flow rate? Do you have an analysis of that wastewater? What is the temperature?

 

[bimr]

Naeema,

What you are proposing is a common technique in environmental and waste management. Waste segragation.

It is very common to keep concentrated solutions out of the wastewater and dispose of the solutions separately.

You will have to determine what degree of waste separation is economical for your facility.

 

[Naeema]

Hi

I am not certain of the temperature at this stage.
An analysis I have been given of the most problematic stream is as follows:

COD: 8000 kg/day
% solids: 10000 kg/day
Sulphates: 800 kg/day
Nitrates: 11 kg/day
Sulphides: 29 kg/day
pH: 7.5
Conductivity: 900 us/cm

What are possible treatment methods for the streams once they are isolated? I have read that enzymatic treatment can be used to degrade the starch. Is this viable?

Thanks fo all the help

 

[bimr]

The common procedure is sending off concentrated materials for disposal. If the material is a solid or can be solidified, you can landfill the material.

Some materials are sent to incinerators. Some materials can be evaporated. Some materials are recycled if you can find an alternate use for the material.

It is ususally not economical to try to treat these waste streams onsite.