Utilization of Carbon Dioxide for Neutralization of Alkaline Wastewater

Publisher Summary Strong mineral acids such as sulfuric and hydrochloric acid have been used to neutralize alkaline wastewater from various processes. However, mineral acids have some drawbacks such as difficulties in process control, handling, maintenance of equipments, and chemical cost. Since 1999, two exhaust gas utilization facilities have been installed at the final wastewater treatment plant for the iron and steel making area in Pohang Works and at the calcination plant in Kwangyang Works of the POSCO. From the test runs over 6 months of these processes, total alkaline wastewater of 16,000 tons per day could be neutralized and chemical costs of $200,000 per year saved. This technology can reduce carbon dioxide emission by 15,000 tons per year. This chapter discusses the experiences and the results of these two cases of exhaust gas utilization technology.