Modelling of Lead Migration from Electronic Waste to Mixtures of Kaolinite, Iron Oxides and Organic Matter

Abstract

Improper disposal of electronic waste in the environment facilitates migration of heavy metals, especially lead, into the soil and can contribute to the bioavailability of this species. Based on a simplex-centroid mixture experimental design, small-scale tests were performed for incubation of printed circuit boards (PCBs) in mixtures containing organic matter (OM), kaolinite (KA) and iron oxides (IO) to verify lead migration. Regression equations were acquired and were adjusted to the obtained responses. Results showed high total content of Pb, ranging from 400 to 4000 mg kg -1 , depending on the mixture and incubation time. Mobility and/or bioavailability of lead in the mixtures were evaluated by a three-step sequential extraction. The bioavailability factor (BF) was obtained from the ratio of the sum of exchangeable fraction (F1) and the organically bound fraction (F2) by F1, F2 and the residual fraction (F3) and the values of bioavailability factor for Pb, the heavy metal considered of greatest environmental concern in this study, ranged between 0.16 and 0.52.

Desenvolvimento e estudo de materiais baseados em AgNbO3 para armazenamento de energia

“…Dos últimos elementos mencionadas, estimasse que 40% é chumbo [7]. No entanto, embora o chumbo não seja encontrado em maior proporção, quando comparado a outros elementos, este possui maior impacto ambiental devido à agressividade em reações adversas e, portanto, representa hoje em dia a principal preocupação devido à possibilidade de contaminação do solo e do lençol freático [8].…”

“…Estudos mostram que a poluição ambiental causada pelo chumbo provoca consequências devastadoras ao organismo, principalmente à saúde humana (causando danos severos ao sistema nervoso central e aos rins), e graves problemas ambientais tendo efeitos tóxicos devastadores em plantas, animais e microrganismos [8].…”