Water and wastewater management in kraft paper industry

It is accepted that one of today?s most important environmental problem is the depletion and pollution of water resources. Due to industrialization and the increase in the consumption, these resources decline and are more polluted every passing day. To meet the future needs of water in domestic and industrial purposes and to protect the quality of them, the development of methods to reduce water use and water-wastewater management strategies need to be improved. Therefore, studies on re-use and recovery of waste water in industries gain more and more importance.Being recyclable, paper products are assumed as environmentally friendly and the use of them have always been encouraged. But, the amount of water being used in the process of paper production is very high. Therefore, it leads to quite high amount of waste water at the end of production. Additionally, this wastewater, besides dangerous inorganic pollutants, includes many organic substances that are hard to biologically degrade. For this reason, paper manufacturing plants are among the businesses that should be paid particular attention in terms of the use of water resources and water pollution.In this study, how water and waste water management of an integrated plant that produces kraft and pulp paper, should be was examined. The study was carried out in two main phases.In the first phase, all the water (fresh water) consuming units were detected and the results of the studies, being done until today, on reducing the amounts of fresh water used in plant were compiled. And, determining additional measures and revisions that may be taken at the plant, the amount of water saving by this way was calculated.In the second phase of the study, all the discharge points at the plant were located and the physical and chemical properties of the waste water being discharged from here were specified. Later, measures to reduce the generation of wastewater were revealed. Besides, places where waste water may be used at the plant within the present or possible-to-reach quality through partial treatment were determined; and, in this way, the amount of obtainable savings from the use of clean water was calculated.As a result of these studies, through improvements in the past 7 years, 1032 m3/hour of fresh water consumption was reduced to 771 m3/hour. In addition to this, through measures such as revisions at some units, optimization works and prevention of water leakage, a still potential of 286 m3/hour saving of fresh water consumption of the plant was seen. And, the potential of re-use of some waste water, the plant reduces, directly or by partial treatment was ascertained. Through this approach, it was calculated that an indirect additional saving of 100 m3/hour of fresh water consumption can be achieved. By the mentioned savings, it is estimated that the burden of the wastewater treatment unit of the plant will decrease and significant increases in the efficiency of treatment will be provided.