Mineralogical Characterization Of Urban Construction And Demolition Waste: Potential Use As A Nutrient Source For Degraded Soils
Free (open access)
399 - 413
E. Mejía, J. I. Tobón, L. Osorno, W. Osorio
The consumption of raw materials in the construction industry is a non-sustainable activity because in this process large amounts of natural resources are consumed. Moreover, Construction and Demolition Waste (CDW) represents around 50% of waste produced in the urban region of world. For example, in the Medellin Metropolitan Area (MMA), 10,400 t.day−1 of CDW are produced, of which only 9.7% is recycled. It is for this reason that CDW management is currently unsustainable and generates significant adverse environmental impacts. It is today acknowledged that this waste can be used as a by-product material for the production of recycled coarse aggregate, showing industrial applicability. However, CDW with small particle sizes (less than 4 mm that represents around 16% of this waste), do not have applicability in these processes. Therefore, it is necessary to reduce CDW volume dumped. An alternative to the final disposal of finer CDW is to use it to improve the physical and chemical properties of degraded soils and improve vegetation and ecosystem services. This paper evaluated the potential use of CDW as a source of nutrients for degraded soils after it was submitted to bioacidulation process by Aspergillus niger and Mortierella sp. Insoluble minerals such as quartz, calcite, wollastonite, albite, anatase and actinolite were found in the CDW by mineralogical and chemical characterization techniques. CDW mesh could improve the physical properties of degraded soils since these particles are similar in size to silt and clay. Furthermore, after CDW were bioacidulated an increased concentration of Ca2+ were found, an essential nutrient for the growth and development of plants.
construction and demolition waste (CDW), bioacidulation, degraded soil