Nanomineralogy in the real world: A perspective on nanoparticles in the environmental impacts of coal fire.

Detailed geochemistry similarities between the burning coal cleaning rejects (BCCRs) and non-anthropogenic geological environments are outlined here. While no visible flames were detected, this research revealed that auto-combustion existed in the studied area for many years. The occurrence of several amorphous phases, mullite, hematite and many other Al/Fe-minerals formed by high temperature was found. Bad disposal of coal-dump wastes represents significant environmental concerns due to their potential influence on atmosphere, river sediments, soils and as well as on the surface and groundwater in the surroundings of these areas. The present work using multi-analytical techniques were performed to provide an improved understanding of the complex processes related with sulphide-rich coal waste oxidation, spontaneous combustion and newmineral creation. It recording huge numbers of rare minerals with alunite, montmorillonite, szmolnockite, halotrichite, coquimbite and copiapite at the BCCRs. The information presented the presence of abundant amorphous Si-Al-Fe-Ti as (oxy-)hydroxides and Fe-hydro/oxides with goethite and hematite with various degrees of crystallinity, containing potential hazardous elements (PHEs), such as Cu, Cr, Hf, Hg, Mo, Ni, Se, Pb, Th, U, Zr, and others. Most of the nano-particles and ultra-fine particles found in the burned coal-dump wastes are the same as those commonly associated with coal cleaning rejects, in which oxidation of sulphides plays an important impact to environment and subsequently animal and human health.

Potential utilization for the evaluation of particulate and gaseous pollutants at an urban site near a major highway.

Works of particle number and mass concentration variability have a great importance since they may indicate better the influence of vehicle emissions in an urban region. Moreover, the importance of this work lies in the fact that there are few studies in Brazil, where the fuel used has unique characteristics. Consequently, this paper presents measurements of particle number (size range 0.3-10 µm), particle mass (PM10, PM2.5, PM1), O3 and NOx (NO, NO2), in a site near a major highway at the Metropolitan Area of Porto Alegre, south Brazil. Measurements were carried out during two years: 2012 and 2013. Particle number and mass concentrations were measured using an optical counter with a PM10 analyzer. Results showed that concentrations of N0.3-1 (0.3-1 µm) were the highest, although similar to N1-2.5 (1-2.5 µm). Daily variability of the analyzed pollutants followed the traffic pattern. Moreover, NO2, O3, and particle number were higher during the day, whereas NO, NOx, and particle matter showed higher concentrations during nighttime. Traffic influence was evidenced by the mean concentrations of weekends and weekdays, being higher for the latter. Correlation of particles and gases with meteorological variables, together with the application of PCA confirmed the influence of vehicle exhaust discharges.