No abstract

The construction and demolition sector is one of the biggest consumers of natural resources in the world and consequently, one of the biggest waste producers worldwide. The proper management of construction and demolition waste (CDW) can provide major benefits for the construction and recycling industry. However, the recycling rate of CDW is relatively low, as there is still a lack of confidence in the quality of recycled CDW materials. Therefore, new research projects are looking for innovative solutions within recycling of CDW in order to overcome uncertainties currently associated with the use of construction products made from recycled or re-used CDW. In this paper, a “cradle-to-cradle” life cycle assessment (LCA) study has been conducted to investigate the environmental performance of the prefabricated geopolymeric façade cladding panels made from large fractions of CDW. The LCA results indicate that the majority of the environmental burden arises within the manufacturing stage; however, the environmental burden can be reduced with simple optimisation of the manufacturing process. Furthermore, the environmental impact of the prefabricated geopolymeric façade cladding panels is generally lower than the environmental burden associated with the façade cladding panels made from virgin materials.

We discuss modeling of the transport and decease of bacteria Escherichia coli in marine environments. We calculated the spatially variable decease coefficient of E. coli from the extrapolated measurement data on environmental parameters in accordance with Mancini's equation for bacteria stemming from the Rižana River and entering into the computational domain – the eastern part of the Koper Bay. Using pre-computed circulation data and the modified particle-tracking model Nafta3D we performed two-day simulations of an instantaneous and a continuous release from a single source. We analyzed locations of two particle types: free E. coli (ECF) and E. coli bound to suspended solids (ECA). We then analyzed the ECA and ECF activity decrease with a newly developed decease model, applying a first-order kinetics equation. In the given conditions a vast majority of ECA remained in the second basin of the Port of Koper and sank to the bottom layers. The decease time of 90% of the ECA (T90) was about 48 hours. The ECF remained closer to the surface; they moved more quickly and for the most part abandoned the second basin. The determined T90 was 6 and 10 hours in instantaneous and continuous release, respectively.