Solidification/stabilization of ash from medical waste incineration into geopolymers

In the present work, bottom and fly ash, generated from incinerated medical waste, was used as a raw material for the production of geopolymers. The stabilization (S/S) process studied in this paper has been evaluated by means of the leaching and mechanical properties of the S/S solids obtained. Hospital waste ash, sodium hydroxide, sodium silicate solution and metakaolin were mixed. Geopolymers were cured at 50 °C for 24 h. After a certain aging time of 7 and 28 days, the strength of the geopolymer specimens, the leachability of heavy metals and the mineralogical phase of the produced geopolymers were studied. The effects of the additions of fly ash and calcium compounds were also investigated. The results showed that hospital waste ash can be utilized as source material for the production of geopolymers. The addition of fly ash and calcium compounds considerably improves the strength of the geopolymer specimens (2–8 MPa). Finally, the solidified matrices indicated that geopolymerization process is able to reduce the amount of the heavy metals found in the leachate of the hospital waste ash.     

Mechanistic insights into acetaminophen removal on cashew nut shell biomass-derived activated carbons

Environmental Science and Pollution Research - Activated carbons prepared from cashew nut shells by chemical activation with phosphoric acid were tested for the removal of acetaminophen. It was...     

Qualitative and quantitative determination of heavy metals in waste cellular phones

Twenty four waste cellular phones, manufactured between 2002 and 2011, were selected in order to determine the total heavy metal content in each of their parts (printed circuit boards (PCBs), plastic housing (PH) and liquid crystal display monitors (LCDs)) and compare the results with the permissible limits set by the 2003 Directive on Restriction of Hazardous Substances (RoHS). All the selected samples were pulverized and digested with strong acids. Inductively coupled plasma-mass spectrometry was used to measure the heavy metal content in each sample. The results revealed that concentration levels of the examined heavy metals were higher in PCBs, followed by PH and LCD in that particular order (PCB > PH > LCD). With the exception of Pb and Cr present in PCBs of mobile phones released before the year 2006, all the other metal concentrations were according to the Directive. Concentration levels of Cd, Hg were lower than the permissible limits set by the EU, either before or after the validity of the 2003 RoHS Directive. Considering their significant heavy metal content, coupled with their large quantities produced worldwide in an annual rate, waste cellular phones need to be treated under an environmentally sound management scheme, prioritizing recycling and at the same time eliminating the possibility of any harm.     

Environmental Information, Asymmetric Information, and Financial Markets: A Game-Theoretic Approach

This paper examines the problem of asymmetric information in financial markets due to a lack of essential environmental information. The literature indicates that asymmetric information generates various problems for the actors of financial markets such as incomplete information for investment decisions and lending procedures, misallocation of financial market funds, the underestimating of stock price securities, and poor environmental risk management choices. To this end, this paper develops a game-theoretic approach to examine both the persistent nature of asymmetric information caused by the absence of accurate environmental information and to indicate how a well-organized, trustworthy, internationally agreed auditing accounting certification scheme could play a critical role in limiting the magnitude of this problem.     

Prenatal findings in generalized amyoplasia

Amyoplasia is a rare, sporadic condition characterized by different degrees of maldevelopment of the skeletal muscles, which are replaced by fibrous and fatty tissue. In this report, we present a case of generalized amyoplasia presenting at 19 weeks' gestation. The most striking finding was the absence of fetal movements, resulting in severe multiple congenital contractures, hydrops, and polyhydramnios. At autopsy, histological examination of the skeletal muscle showed small groups of poorly developed fibres within areas of fat. This report suggests that generalized amyoplasia could be a common cause of severe forms of multiple congenital contractures, but is probably underdiagnosed at post-mortem because of inadequate examination of muscles. Definitive diagnosis is important in determining the risks of recurrence in these cases.     

Immobilized cell augmented activated sludge process for enhanced nitrogen removal from wastewater.

The immobilized cell augmented activated sludge (ICAAS) system combines a cell immobilization technique and an offline enricher-reactor for the bioaugmentation of the activated sludge system to improve treatment performances. In this study, enhanced nitrogen removal using ICAAS was investigated. Laboratory-scale, offline, batch enricher-reactors were used to maintain nitrification and denitrification activities of coimmobilized nitrifiers and denitrifiers used to augment a laboratory-scale completely mixed activated sludge system (CMAS) treating synthetic wastewater. Cellulose triacetate was the media used to entrap nitrifiers and denitrifiers at a 2:1 mass ratio. The ICAAS augmented with the coimmobilized cells between 5 and 20% by volume gained 24 +/- 5% higher nitrogen removal than a control CMAS, which provided nitrogen removal of 28 +/- 7%. The ICAAS scheme is a viable alternative for upgrading existing activated sludge systems to gain better nitrogen removal. .     

Optimum Dose Of Lime And Fly Ash For Treatment Of Hexavalent Chromium–Contaminated Soil

The presence of hexavalent chromium, Cr(VI), in soil is an environmental concern due to its effect on human health. The concern arises from the leaching and the seepage of Cr(VI) from soil to groundwater. In this paper, a stabilization technology to prevent this problem was simulated on an artificial soil contaminated with hexavalent chromium. The process is a physico-chemical treatment in which the toxic pollutant is physically entrapped within a solid matrix formed by the pozzolanic reactions of lime and fly ash to reduce its leachability and, therefore, its toxicity. This paper presents the optimum ratio of fly ash and lime in order to stabilize artificial soils contaminated with 0.4 wt.% of Cr (VI) in a brief term process. The degree of chromium released from the soil was evaluated using a modified Toxicity Characteristic Leaching Procedure (TCLP) by US Environmental Protection Agency (EPA). Overall, experimental results showed reduced leachability of total and hexavalent chromium from soils treated with both fly ash and quicklime, and that leachability reduction was more effective with increasing amount of fly ash and quicklime. Stabilization percentages between 97.3% and 99.7% of the initial chromium content were achieved, with Cr(VI) concentration in the TCLP leachates below the US EPA limit for chromium of 5 mg/l. Adequate treatment was obtained after 1 day of curing with just 25% fly ash and 10% quicklime.     

Challenges and opportunities for sustainability in regional universities: a case study in Mytilene,Greece

Regional Higher Education Institutions (HEIs) may contribute significantly to the promotion of sustainability through several means connected with their functioning. Nevertheless, several challenges can present themselves during the planning and implementation of such initiatives. The aim of this paper is to underline these limitations through the relevant literature and highlight their main consequences on the achievement of sustainability. An empirical study, investigating the perception of students regarding the constraints to achieving sustainability in a regional university of Greece, was conducted and is discussed in relation to the university's specific characteristics – its fragmented nature with campuses situated on five Aegean islands, its public status as well as its role in creating and dispersing knowledge in less developed areas of the country.     

Modelling the fate of persistent organic pollutants in Europe: parameterisation of a gridded distribution model

A regionally segmented multimedia fate model for the European continent is described together with an illustrative steady-state case study examining the fate of gamma-HCH (lindane) based on 1998 emission data. The study builds on the regionally segmented BETR North America model structure and describes the regional segmentation and parameterisation for Europe. The European continent is described by a 5 degrees x5 degrees grid, leading to 50 regions together with four perimetric boxes representing regions buffering the European environment. Each zone comprises seven compartments including; upper and lower atmosphere, soil, vegetation, fresh water and sediment and coastal water. Inter-regions flows of air and water are described, exploiting information originating from GIS databases and other georeferenced data. The model is primarily designed to describe the fate of Persistent Organic Pollutants (POPs) within the European environment by examining chemical partitioning and degradation in each region, and inter-region transport either under steady-state conditions or fully dynamically. A test case scenario is presented which examines the fate of estimated spatially resolved atmospheric emissions of lindane throughout Europe within the lower atmosphere and surface soil compartments. In accordance with the predominant wind direction in Europe, the model predicts high concentrations close to the major sources as well as towards Central and Northeast regions. Elevated soil concentrations in Scandinavian soils provide further evidence of the potential of increased scavenging by forests and subsequent accumulation by organic-rich terrestrial surfaces. Initial model predictions have revealed a factor of 5-10 underestimation of lindane concentrations in the atmosphere. This is explained by an underestimation of source strength and/or an underestimation of European background levels. The model presented can further be used to predict deposition fluxes and chemical inventories, and it can also be adapted to provide characteristic travel distances and overall environmental persistence, which can be compared with other long-range transport prediction methods.