Novel sorbents from low-cost materials for water treatment

Great attention has been paid in many studies to the environmental problems in mining. One of these is how to reduce water consumption during the ore mining and metal extraction process. Another ecological problem of mining includes solid waste management.The main method for reducing water consumption is recycling water. In this case, problems may be encountered, such as water treatment before reusing it. The purification methods will depend on the set of pollutants that should be removed and the type of water that should be treated. For example, the term "mine water" includes waters with different compositions and quality that depend on the chemical composition of ore, extraction methods, and environmental conditions. Process water is also a general term for water, which is used for various technological processes and therefore has a different composition. Process water should be treated in accordance with technological requirements before use. Mine water, such as acid mine drainage (AMD), should also be treated before being released into the environment. AMD and process water from metal extraction were investigated in this work as objects for finding new solutions for their treatment and reuse.Traditional methods for the treatment of mine water are expensive. Adsorption is the most cost-efficient method of water purification. Therefore, adsorption has been applied as a low-cost, efficient, and environmentally friendly methodology for AMD and process water treatment.Approximately 80% of ore is waste after the extraction of metals. The amount of solid wastes is increasing significantly in mining countries. The development of sorbents from solid wastes is one promising solution to the management of solid wastes. The first part of this chapter presents a literature review considering the main points of adsorption theory with a focus on the interaction between the liquid and solid phases. On the basis of the results obtained by numerous research groups, the various methods of modification have been reported with a focus on low-cost materials.The experimental results and discussion section are presented for the chosen adsorbents, including physicochemical characteristics and capacity to adsorb various pollutants. The chemical composition and structure of the materials were characterized with X-ray diffraction, X-ray fluorescence, organic elemental analysis, scanning electron microscope/energy-dispersive X-ray spectroscopy, and a Fourier transform infrared spectroscopy. The determination of pollutant concentration before and after adsorption was conducted with inductively coupled plasma optical emission spectrometry and high-performance liquid chromatography. Various adsorption isotherms were used in the characterization of behavior between adsorbent and adsorbate.The results of this research work show that some low-cost materials and industrial by-products could be used as adsorbents for wastewaters.