Rock magnetic and micro-morphological analysis on snow deposits: recognition of anthropogenic origin of particulate matter in urban and wilderness areas (central Italy)

Low field magnetic susceptibility and other rock magnetic analyses are applied to inspect the magnetic nature of solid residuals in snow samples collected in downtown Rome and in two Natural Parks in central Italy. Field emission scanning electron microscope and energy dispersive spectroscopy (FESEM-EDS) analyses are utilized to reveal the nature of Fe-rich particles and discriminate their anthropogenic origin. The results indicate that magnetite (Fe3O4) is the main magnetic carrier in almost all samples and that the variations in concentration are directly associated with local sources of particulate matter (PM) from anthropogenic pollution related to automotive circulation in both environments. Magnetic minerals of other provenance are found as accessories. The snow deposits revealed to be an efficient neutral tool for fine particle collections, also in environments characterized by different concentration and source of pollutants.

A Mixture of Green Waste Compost and Biomass Combustion Ash for Recycled Nutrient Delivery to Soil

The use of major nutrient-containing solid residuals, such as recycled solid waste materials, has a strong potential in closing the broken nutrient cycles. In this work, biofuel ash (BA) combined with green waste compost (GWC) was used as a nutrient source to improve soil properties and enhance wheat and triticale yields. The main goal was to obtain the nutrient and heavy metal release dynamics and ascertain whether GWC together with BA can potentially be used for concurrent bioremediation to mitigate any negative solid waste effects on the environment. Both BA and GWC were applied in the first year of study. No fertilization was performed in the second year of the study. The results obtained in this work showed the highest spring wheat yield when the GWC (20 t ha−1) and BA (4.5 t ha−1) mixture was used. After the first harvest, the increase in the mobile forms of all measured nutrients was detected in the soil with complex composted materials (GWC + BA). The content of heavy metals (Cd, Zn, and Cr) in the soil increased significantly with BA and all GWC + BA mixtures. In both experiment years, the application of BA together with GWC resulted in fewer heavy metals transferred to the crops than with BA alone.

Leaching of polymetallic Cu-Zn-Pb concentrate with sodium nitrate in sulphuric acid

The results of polymetallic sulphide Cu-Zn-Pb concentrate leaching with sulphuric acid in the presence of sodium nitrate as an oxidizing agent, at atmospheric pressure, are presented and discussed. Chemical composition and phase ratio of the starting concentrate and solid residuals after the leaching process are shown. Chemical reactions of leaching and their thermodynamic probabilities are predicted based on the calculated Gibbs energies and analysis of E-pH diagrams. The influence of temperature and time on the leaching degree of the concentrate's components is experimentally determined. It is shown that it is possible to obtain copper, zinc and iron in a solute form, while lead in the anglesite (PbSO4) form remains in the solid residual after the leaching process. The iron is being oxidized to Fe(III)-sulphate, which takes part in a sulphide leached minerals and turns into Fe(II)-sulphate.

Managing solids residuals from pulp and paper production at STORA

Solid residuals form a significant part of the flow of materials in forest industry processes. These residuals, are important sources of energy, primarily, and are therefore efficiently utilized. Only a small proportion of the residuals is deposited. Developments are moving toward an even greater degree of utilization of the residuals' potential value. The paper reviews the way STORA uses its resources, the residuals that are generated and how they are utilized. It also intends to provide a picture of how work on residuals forms one part of the environmental quality work that STORA sums up in the word Ecobalance.

Feasibility of polyethylene composites reinforced by distillers dried fibers with solubles (DDFS) after different generations of ethanol fermentation

Flowchart of the process for prepares polyethylene/DDFS composites. Solid residuals after 1 G, 1.5 G and 2 G SSF bioethanol plants were used as the reinforcement.