Industrial wastewaters are the main source of pollution with heavy metals, which are toxic and can harm the human health. These metals, which include cadmium, zinc, nickel, copper, mercury and arsenic, are inclined to accumulate in organisms and can cause negative impacts to the environment. That is why different technologies are being researched and evolved for treating industrial wastewater to insure removal of all harmful and dangerous pollutants. Methods for treating industrial wastewaters containing heavy metals often involve a variety of technologies that are based on physical, chemical and biological processes or their combinations, aiming to minimize the environmental impact and comply with required regulations. The focus of the diploma thesis is on two methods for removal of heavy metals. Ion exchange is a reversible chemical reaction between unwanted ions and an ion exchanger, while a membrane filtration is a separation process, where with the use of different membranes, can filter out the unwanted suspended heavy metal ions and the water can go through the pores of the membrane. Depending on the particle size of heavy metal ions, they are different types of membrane filtration, which include microfiltration, ultrafiltration, nanofiltration and reverse osmosis. The aim of this thesis is to review the literature of the ion exchange and membrane filtration use and the main differences between them.
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