Chapters authored
The Use of Biochar of High Growth Rate Plants to Agriculturally Remediate Heavy Metal Polluted Acidic Mine Wastes
The chapter is meant to expose how a sound methodology can be instrumented to both, remediate acidic metal polluted mine wastes, taking advantage of the neutralizing power and high metal sorption affinity of biochar, and to utilize pyrolyzed material derived from high-rate growth plants (water hyacinth, Eichhornia crassipes Mart, and Eucalyptus, Eucalyptus globulus Labill), which have become of ecological relevance due to their unwanted proliferation over specific terrestrial, lacustrine or riverine environments. In addition, the proposal considers not only neutralizing the mine tailings and abating the toxic levels of specific heavy metals like Pb, Cd, Cu, Zn, etc., to fulfill the international and national standards and norms, but to conveniently combine biochar with widely used soil amendments to pass widely recognized biological tests of growth using heavy metal-sensitive plants. The approach addresses firstly: a) characterizing physiochemically mine tailings and biochar, in terms of their properties (metal speciation and contents, potential acidity and neutralization potential, chemical oxygen demand, heavy metal-biochar sorption-complexing affinities, among others), and secondly; b) creating a” fertile environment” by reconditioning, agriculturally, the heavy metal-polluted acidic mine waste to allow native vegetation, or other reforesting species, to regrow on the reclaimed site, based on the bioassay tests performances.
Part of the book: Recent Perspectives in Pyrolysis Research
Heavy Metal Speciation, and the Evaluation and Remediation of Polluted Mine Wastes and Soils
The chapter exposes how a sound methodology can be instrumented to both, biogeochemically speciate heavy metal (HM) polluted mine wastes and soils, and to develop solid strategies to agriculturally stabilize and remediate HM-polluted terrestrial environments. Using single- and sequential extraction procedures, polluted environments can be chemically speciated to successfully remediate impacted sites. Once metal(loid) toxic levels are determined, common amendments (compost, P-fertilizers, lime, gypsum) can be added to abate HM levels, and to re-sustain vegetation, based on bioassay results of HM-sensitive plants. The approach addresses first: a) a discussion of concepts and relevant chemistry that apply to study mine tailing materials and soils, via single or multiple HM-fractionation schemes; b) characterizing chemically mine tailings and soils, in terms of the metal(loid)-sorption-complexing affinities, and c) creating a “fertile environment” by agriculturally reconditioning the HM-polluted acidic mine waste to allow the vegetation regrowth, based on bioassay test performance. Results of two successful cases of study are included; one showing the use of single extraction procedures to evaluate phytoavailable/toxic HM levels to agriculturally remediate polluted sites, and another showing the role of sequential extraction procedures to discriminate heavy metal(loid)s of a spill from other metal deposits of the same ore.
Part of the book: Heavy Metals