Removal of colour from effluent water, reducing consumption of water and utilizing waste generated in paper mill
Industrial Problem for Innovation / / Featured
A unit is engaged in making paper (writing & printing grade) out of wheat-straw. Unit has to do washing of wheat-straw at several stages to remove foreign material like clay, sand etc. Thereafter processing is done in a pressurized vessel called digestor where specific temperature & pressure is maintained. This is a continuous process with cycle time of 22 minutes. Pulp so generated is pushed in storage vessels and then it is again washed in rotary wahers. Then the pulp is brought in chemical recovery boiler where it is burned and soda ash is generated as a by-product. Soda ash becomes raw material for glass manufacturers, soap manufacturers and sodium silicate users. Pulp has a golden yellow colour and is subjected to multi-stage bleaching, chlorination, treated with hydrogen peroxide etc. It is again washed and brightness of about 85% is obtained. Effluent water has PH below 5 and is treated to bring PH near neutral around 7.5-7.6. Effluent water has a light colour and the unit is looking for collaboration with academia for removing colour. Unit is also keen to collaborate with academia for reducing consumption of water in their unit. Unit is also looking for collaboration with academia for proper utilization of waste generated in the unit. Interested academicians should contact Technology Enabling Centre (TEC), Panjab University, Chandigarh to take the matter forward.