Kinetic Aspects of Methylene Blue Adsorption on Blast Furnace Sludge

In the global steel industry, more than 400 kg of solid byproduct is generated per ton of steel produced. Most of this by-product (70–80 %) is in the form of slag, which is used largely in the cement industry and for road and civil construction. The remaining solid by-products can be classified as dusts, sludge and oily/non-oily mill scale. Traditionally, the majority of generated dust, sludge and scale are recycled back to the blast furnace by means of the sintering process. The fraction of solid by-products classified as “fine particles” (60 % of dusts and sludge) is very difficult to recycle without extensive pre-treatment and until recently, it has been deposited in landfills. These by-products are problematic to recycle not only because of their small particle size, but also for their high content of impurities, of which the saleable content is not high enough to make further processing economical1. In recent years the costs for depositing in landfills have increased due to lack of space and due to increasing environmental restrictions. years, the costs for depositing in landfills have increased due to lack of space and increasing environmental restrictions. The latest regulations have changed the industry’s perception of the problems related to hazardous by-products. The combination of toxicity and reactivity, as well as the quantity of released compounds may lead to serious pollution of the natural environment. Environmental concerns have also increased over the years from a global viewpoint, especially in the regions with thermo-power energy pollution, vehicular traffic and heavy industries that release chemical effluents. Current policies at regional and national levels necessarily lead to an increase in efforts for purification of surface water, ground water, and industrial or household wastewater that contains many different types of pollutants. These pollutants include inorganic and organic compounds and are more or less hazardous to humans, animals and plants. Dyes are important pollutants in wastewater, which are mainly discharged from textile, printing, food and leather industries2. Various types of dyes including basic, acidic, reactive, and dispersive dyes are widely used. Dyes in waters affect the nature of the water, inhibiting sunlight penetration Kinetic Aspects of Methylene Blue Adsorption on Blast Furnace Sludge