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This paper refers to the management of the construction and demolition (C&D) waste since, according to the EU Waste Strategy, C&D waste is considered to be one of the priority waste streams and appropriate actions need to be taken with respect to its effective management. Initially, the paper presents the state-of-the-art of the problem of C&D waste, including the amount and composition of C&D waste in EU countries, differences in the characteristics of this waste stream depending on its origin, as well as collection and management practices that are applied. A methodology is described for the estimation of the quantities of the waste stream under examination, since in most cases quantitative primary data is not available. Next, the fundamentals for the development of an integrated scheme for the management of C&D waste are presented and discussed, such as appropriate demolition procedures and location of waste management (off-site waste management, on-site waste management, direct on-site recovery, centralized on-site recovery). Finally, taking into consideration all relevant parameters, alternative systems that could be applied for the management of the C&D waste are suggested.

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Sludge samples were found to contain significant amounts of heavy metals (Cr, Cu, Ni, Pb and Zn) and were subjected to acid treatment using either hydrochloric, sulfuric, nitric or phosphoric acid. The optimum combination, in terms of metal removal efficiency and environmental impacts was sought through a variety of tests by applying a ratio of 1:5 of sludge quantity (g) per volume of acid (ml). The concentrations of the different acids used, were in the range of 5%-20% and the contact times ranged between 15 and 60 minutes. The optimum combination was achieved when the sludge samples were in contact with H2SO4 20% v/v for 60 minutes. In order to estimate the metal leachability, the heavy metal content as well as the metal distribution in the residue were investigated and it was found that most of the heavy metal content was extracted while the remaining was removed from the initial mobile phases to the more stable ones.

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