Nitrate Removal in aContinuous-Flow Stirred Reactor

The presence of excess nitrate in natural water resources is determined worldwide and therefore the methods for reduction and prevention of water pollution are still being investigated. The main objective of the present study was the use of natural zeolite that was interacted with bacterial cells to obtain biozeolite particles (Bio-ZPs). The resulting Bio-ZPs were applied for nitrate removal from the surface water (SW) in a continuous-flow stirred reactor. In the first set of experiments, the nitrate removal was monitored at dilution rates (D) of 0.027, 0.043, 0.095, 0.429, and 0.755 h–1 in order to achieve the optimal dilution rate. During the second test set, the removal of 100 mg NO3–-NL–1 from the SW with Bio-ZPs was monitored at 0.429 and 0.755 h–1 during 21 days. The use of Bio-ZPs in the continuous-flow stirred reactor was demonstrated as an efficient method for nitrate removal from the SW

Kinetic modelling of Fe³⁺ ion uptake by zeolite from water

56-62The ability of the natural clinoptilolite (Cp), and its Na–enriched form (Na–Cp) to remove iron ions from acid aqueous solutions has been investigated in the batch system at the initial concentration of 100 mg Fe3+/L, <i style="mso-bidi-font-style: normal">pH value of 1.90, and the equilibration time of 30–300 min. In order to establish the Fe3+ uptake behaviour, the rate controlling step of the process and to determine the coefficients, the ion exchange kinetics have been investigated and the different models usually applied are used for description of adsorption kinetics. The Fe3+ uptake by Cp and Na-Cp is evaluated based on the first–order kinetics, modified Freundlich and Elovich models, parabolic diffusion and heterogeneous diffusion models. Developed models can successfully describe the ion exchange processes between Fe3+:Cp and Fe3+:Na–Cp. In addition, the results show that the natural Croatian clinoptilolite enables efficient removal of iron from water

Influence of temperature, chlorine residual and heavy metals on the presence of Legionella pneumophila in hot water distribution systems

The microbiological colonisation of buildings and man-made structures often occurs on the walls of plumbing systems; therefore, monitoring of opportunistic pathogens such as Legionella pneumophila (L. pneumophila), both in water distribution mains and in consumers’ plumbing systems, is an important issue according to the international and national guidelines that regulate the quality of drinking water. This paper investigates the presence of L. pneumophila in the Dalmatian County of Croatia and the relationship between L. pneumophila presence and heavy metals concentrations, free residual chlorine and water temperature in hot water distribution systems (WDS). Investigations were performed on a large number of hot water samples taken from taps in kitchens and bathrooms in hotels and homes for the elderly and disabled in the Split region. Of the 127 hot water samples examined, 12 (9.4%) were positive for Legionella spp. with median values concentration of 450 cfu × L-1. Among positive isolates, 10 (83.3%) were L. pneumophila sg 1, and two of them (16.6%) belonged to the genera L. pneumophila sg 2–14. The positive correlation between the water temperature, iron and manganese concentrations, and L. pneumophila contamination was proved by statistical analysis of the experimental data. On the contrary, zinc and free residual chlorine had no observed influence on the presence of L. pneumophila. The presence of heavy metals in water samples confirms the corrosion of distribution system pipes and fittings, and suggests that metal plumbing components and associated corrosion products are important factors in the survival and growth of L. pneumophila in WDS

GREENET An Early Stage Training Network in Enabling Technologies for Green Radio

In this paper, we describe GREENET (an early stage training network in enabling technologies for green radio), which is a new project recently funded by the European Commission under the auspices of the 2010 Marie Curie People Programme. Through the recruitment and personalized training of 17 Early Stage Researchers (ESRs), in GREENET we are committed to the development of new disruptive technologies to address all aspects of energy efficiency in wireless networks, from the user devices to the core network infrastructure, along with the ways the devices and equipment interact with one another. Novel techniques at the physical, link, and network layers to reduce the energy consumption and carbon footprint of 4G devices will be investigated, such as Spatial Modulation (SM) for Multiple-Input-Multiple-Output (MIMO) systems, Cooperative Automatic Repeat reQuest (C-ARQ) protocols, and Network Coding (NC) for lossy networks. Furthermore, cooperation and cognition paradigms will be exploited as additional assets to improve the energy efficiency of wireless networks with the challenging but indispensable constraint of optimizing the system capacity without degrading the user's Quality-of-Service (QoS).Peer Reviewe