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Cadmium is a highly toxic element and can cause serious damages to the health of human beings. It is on the seventh position on the Agency for Toxic Substances and Disease Registry (ATSDR, 2015) list for dangerous elements. The Environmental Protection Agency (EPA) and the International Agency for Research on Cancer (IARC) have also recognized cadmium as a carcinogen. For all these reasons, in the recent years stringent limits have been set for this element both in industrial and drinking water. In this paper the potential of spent coffee grounds (SCG) for the removal of cadmium from contaminated water was investigated. Batch experiments were performed at different temperatures, i.e. 10, 25 and 40°C on untreated SCG. The size range of the SCG particles studied was ≤ 500 μm. The results obtained showed that the equilibrium of cadmium on SCG was reached after 3 hours. The Langmuir isotherm provided the best correlation for the adsorption process, with a maximum adsorption capacity of 4.48 mg g–1at 10 °C. Thermodynamic analysis confirmed the exothermicity and spontaneity of the phenomenon. Kinetic studies have revealed that the cadmium adsorption onto SCG followed a pseudo-second order kinetic model and the activation energy value calculated was of 14.5 kJ mol-1, which have evidenced the physical nature of the process. Overall, this study strongly supports the use of SCG as an effective and economical adsorbent for the removal of cadmium from both industrial and drinking water., Facultad de Ciencias Exactas, Centro de Investigación y Desarrollo en Ciencias Aplicadas (CINDECA)

Industrial water and drinking water contamination by lead is recognized as a public health problem in several countries of the world, including Italy. Lead is on the second position on the Agency for Toxic Substances and Disease Registry (ATSDR) list for dangerous elements. The Environmental Protection Agency (EPA) has also recognized lead as a probable human carcinogen. In this study the potential of spent coffee grounds (SCG) for the removal of lead from contaminated water was investigated. Batch experiments were performed at 25 °C on untreated SCG. The results obtained showed that the adsorption equilibrium of lead on SCG is well described by the Langmuir equation, with a maximumadsorption capacity of 2.46 mg g–1. Overall, this study strongly supports the use of SCG for the removal oflead, and probably of other metal species, from industrial and drinking waters.

Until 2005 in the European Union (EU) approximately 12 M vehicles were yearly shredded, and 8 or 9 M t/ year of waste was produced. About 14 million tons of End of Life Vehicles (ELVs) are foreseen by 2015. This huge amount of waste must be treated and disposed of in a sustainable way. The most common treatment technologies, involve ELVs shredding to recover iron and steel (70%) and non ferrous metals (5%) from vehicles. The remaining fraction, called Automotive Shredder Residue (ASR), and representing about 25% wt. of each vehicle, is generally landfilled. For more than two thirds, this last residue deals with combustible materials (fibers, polyethylene etc..), suitable to be reused as a fuel, but a substantial amount of soil particles, metals, glasses and plastics residues are also present. Consequently, a new sustainable way to reuse ASR is to separate the organic from the inorganic fraction, and use them in combustion plants, gasification and in the cement industry, respectively. Regarding this second way of recovery, several studies have been already successfully performed with the aim of transforming ASR into aggregates for asphalt or cement mixes, by thermal treatment followed by chemical treatment, or by physical processes, such as granulation. In this work, a selected fraction of non metallic automobile shredder residue was immobilized in granules produced at room temperature in a pilot scale granulator. Granules were obtained by mixing selected amount of ASR with a binder (cement or lime) in the presence of additions (fly ash) and admixtures. The final aim of this work was to investigate the mechanical properties of concrete samples produced using the artificial aggregate obtained through different combinations of ASR, fly ash and binder. Additional freeze and thaw tests were finally performed to assess concrete durability along time.

Spent tea leaves (STL), a solid waste that is available in large amounts worldwide, was investigated as a potential low-cost adsorbent for the removal of two azo dyes, Reactive Green 19 (RG19) and Reactive Violet 5 (RV5), from contaminated waters. Preliminary experiments conducted on untreated STL showed that this material exhibited very low removal efficiencies (

Preliminary experimental results on the solification/stabilzation of dredged marine sediments (MS) and the non-metallic fraction of automotive shredder residues (NMASR) with coal fly ashes (CFA) are reported. Lab scale experiments of wet granulation at room temperature of these wastes are presented and discussed: cement was used as a binder, while water addition was dosed to optimize granules amount and size. The obtained granules were then subjected to standard leaching tests according to Italian regulation. The results of the leaching tests showed, for all the experimented wastes, a good level of stabilization: heavy metals and ions content was within the limits provided by Italian regulation for landfill disposal as not dangerous waste, while a COD content exceeding the above mentioned limit was detected. This was attributed to plastics and an organic contamination by vehicles fluids in the case of NMASR, and to sulphides and iron content in the case of marine sediments.

Drinking water contamination by fluoride is recognized as a major public health problem in many parts of the world. In fact, although fluoride is an essential trace element for animals and humans, excessive fluoride intake may cause adverse health effects. In this study we investigated the potential of a natural, high alumina content, bauxite for the removal of fluoride from contaminated water. Both batch and continuous experiments were performed. In continuous-flow column experiments, the effects of inlet fluoride concentration (5–50 mg L–1) and flowrate (up to 2.5 mL min–1) on breakthrough time and adsorption capacity were studied. Batch equilibrium data were found to be well described by the Freundlich equation. Column studies showed that the dynamic adsorption capacity of the bed decreased as the inlet fluoride concentration and the flow rate increased. A maximum fluoride uptake capacity of 3.125 mg g–1 was determined. Overall, the results obtained indicate that this bauxite could be effectively used for defluoridation of drinking water.