%0 Journal Article %J Environmental Science and Pollution Research %D 2017 %T Study of the removal mechanism of aquatic emergent pollutants by new bio-based chars %A Bernardo, Maria Manuel Serrano %A Madeira, Catarina Alexandra Catanas %A dos Santos Nunes, Nuno Carlos Lapa %A Dias, Diogo André Costa Messias %A Godinho, Delfina Maria Barbosa %A de Jesus Pinto, Maria Filomena %A do Nascimento Matos, Inês Alexandra Morgado %A Carvalho, Ana Paula Batista %A de Figueiredo Ligeiro Fonseca, Isabel Maria %P 22698–22708 %R 10.1007/s11356-017-9938-9 %U https://doi.org/10.1007/s11356-017-9938-9 %V 24 %X

This work is dedicated to study the potential application of char byproducts obtained in the gasification of rice husk (RG char) and rice husk blended with corn cob (RCG char) as removal agents of two emergent aquatic contaminants: tetracycline and caffeine. The chars presented high ash contents (59.5–81.5{%}), being their mineral content mainly composed of silicon (as silica) and potassium. The samples presented a strong basic character, which was related to its higher mineral oxides content. RCG char presented better textural properties with a higher apparent surface area (144 m2 g−1) and higher micropore content (V micro = 0.05 cm3 g−1). The alkaline character of both chars promoted high ecotoxicity levels on their aqueous eluates; however, the ecotoxic behaviour was eliminated after pH correction. Adsorption experiments showed that RG char presented higher uptake capacity for both tetracycline (12.9 mg g−1) and caffeine (8.0 mg g−1), indicating that textural properties did not play a major role in the adsorption process. For tetracycline, the underlying adsorption mechanism was complexation or ion exchange reactions with the mineral elements of chars. The higher affinity of RG char to caffeine was associated with the higher alkaline character presented by this char.

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