The contamination by heavy metals in water bodies has been extensively treated because of great concern mainly on environmental aspects and effects on human health. Heavy metals present deleterious responses to humans, causing acute and chronic intoxications, besides the development of diseases, to the environment bioaccumulation and adverse effects species can create the environmental imbalance of ecosystems. Sources of heavy metals in bodies of water often come from domestic and industrial sewage, treated or untreated, so that conventional sewage treatment systems are not able to remove heavy metals from their systems, so it is necessary other technologies for its removal. The adsorption, ion exchange, membrane filtration, liquid-liquid extraction, and other technologies are used for the extraction of heavy metals from effluents. Activated carbon for adsorption is an efficient technique for removal of organic and inorganic contaminants. Considering that the rice husk is an abundant residue, it has a wide potential of application in several processes, this has been applied in the production of activated carbons. Thus, this work investigated the efficiency of the removal of copper in aqueous media using activated carbons of rice husk. The activation process by acid and basic impregnation produced activated carbons with different chemical characteristics and responses in copper extraction in aqueous medium. The trials for evaluation of the independent variables used experimental planning by factorial model. Potassium hydroxide-activated rice husk charcoal (CA-KOH) is a good solution of copper ions adsorbent with removal efficiencies greater than 96%. While the best condition for the application of activated carbon by phosphoric acid rice husk (CA-H3PO4) occurred in pH of 7.3 for 65 minutes of contact time with the removal of 92.9% copper solution. The regression models for copper extraction prediction, as well as their response surfaces, were estimated from the experimental design. The CA-KOH presented high potential for application in effluent treatment systems, and it is recommended to apply this in pH between the intervals below 4 and higher 7 using a dosage of 15-20 g of coal / L of effluent.
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