Biosorción de Cd, Pb y Zn por biomasa pretratada de algas rojas, cáscara de naranja y tuna.

Because of their mobility in ecosystems and their toxicity to higher forms of life, heavy metals Cd, Pb and Zn are identified as some of the most important inorganic contaminants due to the order to decrease their concentration, a system to orange peel (Citrus sp.) and tuna Guajira (Opuntia sp.) was designed. The influence of pretreatment and packaging was studied through batch type tests using solutions of sodium and calcium. The results showed greater sorption capacity of 0.1N NaOH modified algae and of orange and tuna with NaOH andCaCl2 0.2M subsequent modification, as well as a minimal effect (≤1%) on the sorption process when packing biomass in tulle polyester flat plates. The removal efficiency was measured with a fixed-bed continuous flow reactor, with a liquid volume of 400 mL, 75 g of biomass, and average retention times of 1 to 2 h. The results showed similar efficiency of the three types of biomasses to remove Cd and Pb, with an average greater than 95%, while Zn was removed with improved efficiency (62%) using modified tuna as a sorbent. Finally, the material was charred at 700 °C resulting in an ash stable against acid solutions (pH 2.5 to 4.5), which ensures the capture of the removed metals.