THE IMPACT OF ENVIRONMENT ON THE REMOVAL OF CD IONS FROM POLLUTED WATERS USING UNMODIFIED RICE HUSK AS A BIOSORBENT

Water is a resource that is decreasing every day, which is why urgent measures are needed to preserve resources or even purify water and return it to use for drinking and in the food industry. The first option is to use water more rationally, but this is not enough, since heavy industries are the ones that cause the greatest pollution by discharging impurities into surface or groundwater, which in a chain way pass into the human body and cause the death of living organisms. It is precisely the ions of toxic metals discharged from various industries that create ecological disasters and cause the death of organisms as well as harm human health. Depending on the degree of pollution, adequate methods are also applied for their treatment. In the best case, the waters are only subjected to the filtration process and the removal of mechanical pollutants, and the same water is used in households or even in the food industry. For highly polluted waters with toxic and carcinogenic metal ions, a more specialized treatment is required by applying different methods, which are often not so efficient. Methods of cleaning using chemical adsorbents belong to the past, and today natural adsorbents are required which have high adsorption capacity, have affinity towards toxic metal ions, and maintain ecological balance. Biosorption is the most advanced method for ecological cleaning of waters using various mosses with high adsorption affinity, biomass deposited as bottoms after extraction or bottoms of various products, among them is rice husk, which has a very high affinity for adsorption of toxic metal ions. The removal of Cd ions has been proven for different pH values.