Unidade de Biotecnologia Ambiental, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
J Colloid Interface Sci. 2013 Nov 1;409:158-65. doi: 10.1016/j.jcis.2013.07.050. Epub 2013 Aug 2.
The effectiveness of chars from the co-pyrolysis of pine, used tires and plastic wastes for the removal of lead (Pb(2+)) from aqueous medium, was investigated. The chars were predominantly of macroporous nature, but the introduction of tires in the pyrolysis feedstock enhanced their mesoporous content as well as surface area. Pb(2+) sorption with the chars was a slow and unstable process in which sorption-desorption seems to be competing. The highest Pb(2+) removal (88%) was attained by the char resulting from the pyrolysis of a mixture composed by equal mass ratios of used tires and plastics, at 48 h of contact time. This char was also the one with the overall better performance for Pb(2+) sorption, achieving almost 100% of Pb(2+) removal on the study of the effect of adsorbent dose. Mixing the three raw materials for pyrolysis had no advantage for the resulting char concerning the removal efficiency of Pb(2+). The sorption mechanisms varied according to the pyrolysis feedstock: in chars from feedstock with pine, chemisorption involving complexation with oxygenated surface functional groups followed by cation exchange was the presumable mechanism. In tire rubber derived chars, cation exchange with Ca(2+), K(+), and Zn(2+) played the major role on Pb(2+) sorption.
研究了松木、废旧轮胎和塑料废物共热解得到的炭对水溶液中铅（Pb(2+)）的去除效果。这些炭主要具有大孔性质，但在热解原料中引入轮胎会增强其介孔含量和表面积。炭对 Pb(2+)的吸附是一个缓慢而不稳定的过程，其中吸附和解吸似乎在竞争。在 48 小时的接触时间内，用等质量比的废旧轮胎和塑料混合物进行热解得到的炭的 Pb(2+)去除率最高（88%）。对于 Pb(2+)的吸附，这种炭的整体性能也更好，在研究吸附剂用量的影响时，几乎可以达到 100%的 Pb(2+)去除率。与去除 Pb(2+)的效率相比，将三种原料混合用于热解对得到的炭没有优势。吸附机制根据热解原料而有所不同：在松木原料热解得到的炭中，涉及与含氧表面官能团络合并随后进行阳离子交换的化学吸附是推测的机制。在源自轮胎橡胶的炭中，与 Ca(2+)、K(+)和 Zn(2+)的阳离子交换对 Pb(2+)的吸附起主要作用。
