Modification of a paper manufacturing process resulted in a reduction of process wastewater discharged. Pulp is produced by chemical digesting wood chips with caustic soda and reduction in a disk refiner. The liquors are concentrated and processed with lime to recover the caustic soda. Fibers extracted from the resultant sludge can be commercialized. The pulp is then bleached and the water is settled, and the sludge is incinerated in a lime kiln.
Paper is made from pulp with lime carbonate as a filler.
The sludge generated here is also incinerated. Part of the process water is recycled for paper making and bleaching, while the reminder is discharged. Modifications to the paper manufacturing process reduces wastewater discharge. In the standard technology water and pulp requirements are identical and the mineral filler is made up of 175 kg of kaolin. Also, this low-waste technology generates a smaller volume of wastewater.