Search results for "Disposal"

Magnesium recovery from exhausted brine

2015

Mg and MgCO3 are among the 20 EU critical raw materials. Interestingly, Mg can be found at very high concentration in brines generated as waste stream from salt works. Literature works have demonstrated the feasibility of Mg extraction from brines [1–3] by reactive precipitation, for the production of Mg(OH)2. Here we present an overview of the experimental campaigns carried out using exhausted brine from real salt works (Italy) to produce Mg(OH)2 with high purity and conversion. Lab – and pilot-scale batch and semi-continuous CSTR crystallisers were developed and tested, eventually leading to a continuous process by a quasi-PFR pilot reactor. Different alkaline solutions have been adopted …

A continuous plug flow reactor for magnesium recovery from concentrated brine

2015

Magnesium is one of the eight most abundant elements on the world and the third most abun- dant in the sea, buc practically only two countries (Russia and China) control the world market for this compound. Product purity, Mg recovery, crystal morphology and granulometric distribution of precipitated particles were examined through careful laboratory analysis and results from different tests were compared, in order to identify the effect of allcaline species’ nature and concentration on precipitation phenomena.

Reed canary grass transportation costs – Reducing costs and increasing feasible transportation distances

2009

Abstract Reed canary grass is used in several heat and power plants in Finland and it is estimated that about 70–80 plants could utilise reed canary grass as a co-firing fuel. Long-distance transport of reed canary grass forms a significant share of the production and delivery costs. Reed canary grass can be transported in bales or as loose matter. The density of the matter and shape of the bales influence the load-size and the cost. At present it is impossible to obtain the full load-bearing capacity of a lorry even with bales, and with light bulk matter the obtainable load is less than one-third of the load-bearing capacity of a lorry. By using Orkel local-baler it has been possible to ob…

Combination of ozonation and photocatalysis for purification of aqueous effluents containing formic acid as probe pollutant and bromide ion

2014

The treatment by advanced oxidation processes (AOPs) of waters contaminated by organic pollutants and containing also innocuous bromide ions may generate bromate ions as a co-product. In the present work heterogeneous photocatalysis and ozonation have individually been applied and in combination (integrated process) to degrade the organic compounds in water containing also bromide anions. The results show that: i) the sole photocatalysis does not produce bromate ions and in the case of its presence, it is able to reduce bromate to innocuous bromide ions; ii) the integration of photocatalysis and ozonation synergistically enhances the oxidation capabilities; and iii) in the integrated proces…

Brønsted and Lewis acid catalyzed conversion of pulp industry waste biomass to levulinic acid

2019

Enormous amounts of fiber sludge are generated annually by the pulp industry as a by-product. As a cellulose-rich material, its current usage, mainly as fuel, is inefficient from a material efficiency point of view. This work studied the utilization of fiber sludge from a Finnish and a Swedish pulp mill as a potential feedstock to produce levulinic acid, a valuable platform chemical. The conversion experiments of fiber sludge to levulinic acid were performed in a microwave reactor with a mixture of H2SO4 and Lewis acid as the catalyst. The reaction conditions, which included reaction time and temperature as well as the H2SO4 and Lewis acid concentrations, were studied in detail. The highest…

Environment, wealth, inequality and the burden of disease in the Accra metropolitan area, Ghana

2005

The study examines environmental problems and adverse impacts on the health of urban households in the Accra metropolitan area, Ghana. Accra is faced with severe inadequacy of urban infrastructure in the face of rapid population growth in the metropolis. More than half of the city's population do not have access to solid waste collection services. Only 39.8% of households have indoor pipe and over 35.0% of households depend on unsanitary public latrines whilst 2.5% do not have access to toilet facilities. Human excrement, garbage and wastewater are usually deposited in surface drains, open spaces and streams in poor neighbourhoods. The resultant poor sanitation has serious health impacts as…

A Glance at the World

2016

Cathodic reduction of CO2 to formic acid: Effect of the nature of the cathode for pressurized systems

2023

Electrochemical conversion of CO2 into formic acid (FA) in an aqueous electrolyte is considered a promising strategy to valorise waste-CO2. Some studies, mainly performed using Sn cathodes, have shown that the performance of the process can be strongly improved using pressurized systems. On the other hand, other studies, usually carried out in non-pressurized systems, have indicated that the nature of the cathode can strongly affect the process. Hence, in this work, we have investigated the coupled effect of nature of the cathode and CO2 pressure (PCO2 ) on the electrochemical conversion of CO2 to FA. Four electrodes (Sn, Sn/C-NP, Bi, Bi/C-NP) have been used as model cathodes. The results o…

Biogenic habitat shifts under long-term ocean acidification show nonlinear community responses and unbalanced functions of associated invertebrates

2019

Este artículo contiene 8 páginas, 4 figuras.

EPI-CT: design, challenges and epidemiological methods of an international study on cancer risk after paediatric and young adult CT

2015

Computed tomography (CT) has great clinical utility and its usage has increased dramatically over the years. Concerns have been raised, however, about health impacts of ionising radiation exposure from CTs, particularly in children, who have a higher risk for some radiation induced diseases. Direct estimation of the health impact of these exposures is needed, but the conduct of epidemiological studies of paediatric CT populations poses a number of challenges which, if not addressed, could invalidate the results. The aim of the present paper is to review the main challenges of a study on the health impact of paediatric CTs and how the protocol of the European collaborative study EPI-CT, coor…