REMOVAL OF CONTAMINANTS FROM AQUEOUS SOLUTIONS BY BEDS MADE OF REJECTS OF THE LIGHTWEIGHT AGGREGATES PRODUCTION

摘要

This work describes the reuse of rejects generated in the production of lightweight aggregates as filtration beds, in alternative of the common landfilling practices. In this way, we attempt to contribute to accomplish with Portuguese and European Union strategies about industrial solid wastes. As it is known, this strategy highlights the sustainable development, i.e., a symbiotic relation between industry and the surrounding environment. In this scenario, recycling/reusing routes should be perspective. The characterization of waste particles involves determinations of chemical (XRF) and mineralogical (XRD) compositions. Grain size distribution was also determined and selected fractions were prepared by sieving. Small depth filtration beds were used, being the corresponding packing density determined. Preliminary results of the removal efficiency of single heavy metals (Pb and Ni) from aqueous solutions through those particulated beds are given. Experiments were performed at different contaminant concentrations (10 - 1000 ppm) and by testing several operational conditions (filtration rate and adsorption regime). The concentration of heavy metals before and after filtration/adsorption treatments was determined by ICP Spectrometry.