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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-21 20:44 |
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Conference: Bucharest University Faculty of Physics 2008 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Treating waste containing heavy metals by using other type of wastes
Authors:
Steluta Nisipeanu(1), Raluca Stepa(1), Gilda Rusu- Zagar(1), Laurentiu Zagar(2), Robert Stepa(2)
Affiliation:
(1)National Institute of Labory,
(2)University of Bucharest, Paculty of Physics, P.O.Box. MG-11, Magurele, Bucharest, Romania
E-mail
Keywords:
wastes, heavy metals, recycling wastes
Abstract:
The paper deals with three of the major environmental issues of our days: waste management, global acidification and recycling. The technology proposed aims at treating wastes containing heavy metals by using other wastes as reagents. It has been developed for wastes generated in etching workshops that have a very low pH value, are almost liquid and contain toxic heavy-metals like Cr, Ni, Cd, Zn, Cu , but it can be applied to similar wastes from other sources. In the first stage of the technology consists in adjusting the pH to a value of about 6-7. In the following stage the waste heavy metals are converted into insoluble combinations in order to make then less aggressive to health and environment. Then the mixture is stabilised by adding cementation materials that will allow for the moulding of the mixture in rectangular, brick-like patterns. The treated waste then dries naturally and can easily be disposed at specially organized sites or used as construction material. The advantages of the procedure are that it uses other wastes as treating agents. Waste form oxy-acetylene welding can be used to adjust pH and waste from sandblasting can be used along with cementing materials to stabilize the final treated material and to allow it to be recycled as construction material. The waste treated according to the proposed technology has been tested for leaching according to the procedure specified by the Romanian legislation. The results show that the treatment lowers the risk to the environment, allowing the treated waste to be considered non-hazardous according to Romanian classification of wastes. A further development of the technology would be the use of carbon dioxide emissions as treatment agent converting it into carbonates in the mass of treated waste that will be stable, and would have a lighter yet stabilized structure.
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