Global NEST Journal

Ashes, formed as a result of combustion of biomass are a new class of by-products of combustion and due to the large variety of these materials their chemical composition has not been fully determined. Their use is limited, despite the fact that their production has increased.
This work presents the results of studies on the possibility of limiting the potential availability of Cu, Mn, Pb and Zn for plants by use of an inorganic stabilizer - ash from biomass combustion. In this study the usefulness of ash from biomass for binding mobile fractions of heavy metals (Cu, Mn, Pb and Zn) was evaluated. The investigations were executed using three extraction tests with the use of the following extraction solutions: 1 M HNO3 – acid soluble forms (As), 0.05 M EDTA – bioavailable forms (Bio), 2.5% CH3COOH – exchangeable forms (Ex). The values of the following parameters: Mobility Index (MI), Contamination Factor (CF), Pollution Load Index (PLI), Geo – accumulation Index (Igeo) and Ecological Risk Index (RI) were defined and determined for their suitability as a test soil stabilizer. Furthermore, a multivariate statistical analysis was carried out.
It was found, that a phytoremediation process using investigated ash from biomass combustion can be applied to soil contaminated by heavy metals.

The present study systematically and comprehensively reviewed different aspects of treating Acid Mine Drainage (AMD) with active treatment and waste materials. The work also critically reviews the status and the factors associated with the treatment process. Although, conventional active methods are very efficient but they are mainly associated with costly material as well as high maintenance cost which enhances the cost of entire treatment system. Waste materials such as fly ash, metallurgical slag, zero valent iron (ZVI), cement kiln dust (CKD), organic waste such as peat humic agent (PHA) and rice husk can be efficiently used for the treatment of AMD. However, efficiency of different waste material varied from each other due to the variation in their physical and chemical characteristics. The results from the investigation showed that fly ash, metallurgical slag and CKD raise the pH of acidic solution more, in comparison to ZVI and organic waste, due to their richness in lime content. Furthermore, fly ash can be efficiently converted and utilized in its other derivative such as chemically modified fly ash and zeolite. Efficiency of ZVI is hindered by the presence of higher concentration of total dissolved solids. PHA can treat AMD that is mild acidic in nature. Besides, long retention time is required for the removal of heavy metals and sulfur with organic waste and sulfate reducing bacteria (SRB). The study also potentially reviewed that metal removal from AMD varied due to composition of AMD and the characteristics of waste materials. However, waste materials demand more attention for its practical applicability in field conditions due to its richness, higher possibility for recycling and reuse, low installation cost and harmless nature towards the environment.

Sustainable recovery of critical metals (CM) from Waste Electrical and Electronic Equipment (WEEE) in the European Union (EU) requires information for detailed analysis, monitoring and decision-making. Related knowledge is currently insufficient or disseminated through the network of stakeholders. This paper assesses the requirements of an adequate Database Management System (DBMS) with participation of different actors involved in the recovery of critical metals and analyses the difficulties and the possibilities found for its implementation. The authors define a conceptual scheme of a DBMS to assess the information requirements and to establish the interactions between different actors of the WEEE supply chain, with the aim of supplying standardized information for management and research. Barriers are studied through a survey to identify obstacles for its elaboration. Limitations for its development are addressed and practical solutions for its elaboration are presented.

A facile strategy toward modification of aluminium filings (AF), a waste material from aluminium manufacturing industry, into a highly efficient adsorbent was examined. AF was simply treated with thermal modification to form a cheap adsorbent for Phosphorus (P) removal from aqueous solutions. The results showed that increasing the calcination temperature from 500 to 900 ˚C improved the P removal. P adsorption occurred quite fast and 70% of P removal observed in 15 minutes. Adsorption efficiency was increased by increasing pH, decreasing P initial concentration as well. The presence of coexisting anions, except HCO3-, showed a negligible effect on P adsorption by AF. Thermodynamic studies revealed that P adsorption onto AF was endothermic in nature. Kinetic modelling demonstrated that the adsorption rate was controlled by the chemisorption. The process also fitted well with the Langmuir isotherm model, indicating that the process proceeds via monolayer coverage with 49.97 mg g-1 maximum monolayer capacity. Overall, in addition to beneficial environmental and economic aspects, the results demonstrated excellent adsorption characteristics which make thermally treated AF a promising adsorbent material for phosphorus removal from polluted streams.