Heavy metals removal/stabilization from municipal solid waste incineration fly ash: a review and recent trends

Waste treatment using thermal technologies, such as incineration, leads to the production of pollutants and wastes, including fly ash (FA). Fly ash contains heavy metals (HMs) and other contaminants and can potentially pose high risks to the environment and negatively impact health and safety. Consequently, stabilizing fly ash prior to either use or landfilling is crucial. The toxicity of fly ash through heavy metal leaching can be assessed using leaching tests. The leaching rates of heavy metals primarily depend on the surrounding conditions as well as fly ash properties and metal speciation. Physical separation, leaching or extraction, thermal treatment and solidification/chemical stabilization are proposed as suitable approaches for fly ash treatment. Economic considerations, environmental concerns, energy consumption and processing times can define the efficiency and selection of the treatment approach. This review considers the latest findings and compares the advantages and shortcomings of different fly ash treatment methods with the aim of highlighting the recent advances in the field. The review concludes that the simultaneous implementation of various methods can lead to highly efficient heavy metals removal/stabilization while simultaneously taking economic and environmental considerations into account

Collective Effects of Fire Intensity and Sloped Terrain on Wind-Driven Surface Fire and Its Impact on a Cubic Structure

The combined effects of percent slope and fire intensity of a wind driven line fire on an idealized building has been numerically investigated in this paper. The simulations were done using the large eddy simulation (LES) solver of an open source CFD toolbox called FireFOAM. A set of three fire intensity values representing different heat release rates of grassland fuels on different inclined fuel beds have been modeled to analyze the impact of factors, such as fuel and topography on wind-fire interaction of a built area. An idealized cubic structure representing a simplified building was considered downstream of the fire source. The numerical results have been verified with the aerodynamic measurements of a full-scale building model in the absence of fire effects. There is a fair consistency between the modeled findings and empirical outcomes with maximum error of 18%, which acknowledge the validity and precision of the proposed model. The results show that concurrent increase of fire intensity and terrain slope causes an expansion of the surface temperature of the building which is partially due to the increase of flame tilt angle upslope on the hilly terrains. In addition, increasing fire intensity leads to an increase in the flow velocity, which is associated with the low-pressure area observed behind the fire front. Despite limitations of the experimental results in the area of wind-fire interaction the result of the present work is an attempt to shed light on this very important problem of fire behavior prediction. This article is a primary report on this subject in CFD modeling of the collective effects of fire intensity and sloped terrain on wind driven wildfire and its interaction on buildings

Time parameterization and stationary distributions in a relativistic gas

In this paper we consider the effect of different time parameterizations on the stationary velocity distribution function for a relativistic gas. We clarify the distinction between two such distributions, namely the J\"{u}ttner and the modified J\"{u}ttner distributions. Using a recently proposed model of a relativistic gas, we show that the obtained results for the proper-time averaging does not lead to modified J\"{u}ttner distribution (as recently conjectured), but introduces only a Lorentz factor $\gamma$ to the well-known J\"{u}ttner function which results from observer-time averaging. We obtain results for rest frame as well as moving frame in order to support our claim.Comment: 5 pages, 2 figure

Numerical study the effect of the ratio of distance between the center the central axis of the tunnel and center of structures to tunnel’s diameter parameter on the interaction of the tunnel-surface structures, Case Study- Niayesh Tunnel, Tehran

Population growth in most cities increases the need for building surface and subsurface infrastructures. Tunneling causes the deformation of the surface and subsurface structures. Also the structures have effects on ground movements that caused by tunneling influence. Therefore, evaluating the interaction between tunnels and surface structures, which have the effect of surface structure on the rate of settlement and horizontal displacement that caused by tunneling is so crucial. In recent decades, researchers have conducted studies that focus on a variety of factors and in recent years, some researchers have examined the impact of geometric parameters separately on the interaction tunnels and surface structures. However, due to the influence of the geometric parameters on each other’s, Evaluation of combinations of these parameters with regard to the impact of each one’s to others seems necessary. In this paper, the influence of distance between the center the central axis of the tunnel and center of structures to tunnel’s diameter parameter on the settlement and horizontal displacement curves that cause by tunneling investigated. Therefore the numerical finite element method (FEM) has been used. Based on numerical modeling results, with decreasing of this ratio, the amount of settlement is reduced. It is also observed that by reducing of this the inflection point of the settlement curve’s, from a distance of 38 meters is reduced to 28 meters distance from the tunnel axis, which means reducing the impacted area of the settlement. The variations of this parameter, has no impact on the longitudinal settlement curves above the central axis of the tunnel, this is due to the distance from the central axis of the tunnel structures. With decrease in this ratio, in the center of the structure, the maximum of longitudinal settlement increased; so that the maximum amount of longitudinal settlement with a ratio of 1.45 is 3.5 mm that with the reduction in the this ratio to 0.84, the maximum amount of longitudinal settlement increased to 8 mm. Also with decreases in this ratio, the amount of horizontal displacement increased

Effects of a Saffron Alcoholic Extract on Visual Short-Term Memory in Humans: a Psychophysical Study

The effects of an extract from saffron (Crocus sativus L.) on visual short-term memory (STM) were examined in 20 volunteers. The extract was obtained from saffron petals using 100% ethylic alcohol, concentrated by vacuum evaporation, dried, and encapsulated (30 mg per capsula). Ten participants received the extract each day for three weeks, while other 10 subjects received encapsulated placebo. Then, the contrast sensitivity of a subject was estimated; sinusoidal grating patches with different contrast levels (0 – 100%) were used (experiment 1). In experiment 2, the retention of STM was assessed in two-force choice tests, using a delayed match to sample paradigm. In experiment 3, the n-back memory test with different interstimulus intervals (up to 14 sec) was used. It was found that subjects after medication with the saffron extract demonstrated better correct memorizing of the preceding visual stimuli (from two to five). At the same time, extract medication somewhat improved retention of visual STM, but only for several intermediate interstimulus intervals, and the effect was not very remarkable. Our findings buphasize the expedience to research of the effects of physiologically active dietary constituents in humans.На групі з 20 добровольців досліджували впливи екстракту шафрану (Crocus sativus L.) на візуальну короткочасну пам’ять (КЧП). Екстракт отримували з пелюсток шафрану, використовуючи 100 %-вий етиловий спирт, концентрували за допомогою випаровування під вакуумом, висушували та капсулювали (30 мг у капсулі). 10 учасників приймали екстракт один раз на добу протягом трьох тижнів, тоді як інші 10 тестованих отримували плацебо (також у капсулах). В експерименті 1 визначали контрастну чутливість кожного випробуваного. Використовували зображення решіток із ліній, контраст яких змінювався за синусоїдальним законом; контрастність пред’явлених зображень варіювали від 0 до 100 %. В експерименті 2 оцінювали ємність КЧП випробуваних у тестах дворівневого вибору, застосовуючи парадигму відтермінованої оцінки збігу зі зразком. В експерименті 3 використовували n-зворотний тест збереження пам’ятного сліду при різних інтервалах між візуальними стимулами (до 14 с). Після курсового приймання екстракту шафрану тестовані демонстрували кращий рівень коректного запам’ятовування двох–п’яти попередніх візуальних стимулів. У той же час позитивний вплив екстракту на збереження зорових слідів у КЧП хоч і проявлявся, проте лише для деяких проміжних міжстимульних інтервалів, і він був менш значним. Наші спостереження підкреслюють доцільність дослідження ефектів фізіологічно активних компонентів, які входять до складу продуктів харчування

Metal-organic and supramolecular lead(II) networks assembled from isomeric nicotinoylhydrazone blocks : the effects of ligand geometry and counter-ion on topology and supramolecular assembly

A new series of six structurally diverse lead(II) coordination compounds was assembled from two isomeric nicotinoylhydrazones as neutral ligands and three Pb(II) salts with different monoanions (chloride, nitrate and thiocyanate) as starting materials. The products were isolated in good yields and were fully characterized, including by single-crystal Xray diffraction and theoretical methods. Within the six compounds, three feature 2D metal-organic networks, two are 1D coordination polymers, and another one comprises discrete 0D dimeric units. The structures of the latter low dimensional compounds are extendable into 2D supramolecular networks. The topology of the coordination or supramolecular networks is primarily dictated by the geometry of the nicotinoylhydrazone used as a main building block. In contrast, supramolecular interactions are greatly influenced by the choice of the anion in the starting lead(II) salt, which is demonstrated by Hirshfeld surface analysis. In fact, the topological analysis and classification of metal-organic or supramolecular underlying networks in the obtained compounds was performed, disclosing the hcb, 2C1, gek1, SP 1-periodic net (4,4)(0,2) and 3,4L83 topological types; the latter topology was docummented for three compounds, including both coordination and supramolecular networks. In two compounds containing thiocyanate moieties there are supramolecular contacts between thiocyanate anions and lead centres. These were shown by DFT calculations to be strong tetrel bonds (–15.3 and –16.7 kcal/mol) between the σ-hole of the lead atom and the π-system of the thiocyanate S–C bond

IDES-EDU: Comprehensive multidisciplinary education programme to accelerate the implementation of EPBD in Europe

This paper presents a new education and training programme on integrated energy design developed by fifteen European universities collaborating within the IDES-EDU project (2010-2013), funded by Intelligent Energy Europe. IDES-EDU aims to accelerate the implementation of the Energy Performance of Buildings Directive (EPBD) by proposing Master and Post Graduate education and training in multidisciplinary teams. To speed up transition from traditional, sub-optimised building projects with discipline-oriented, segregated budgets and operations, IDES-EDU developed comprehensive, multidisciplinary educational programmes targetting integrated project design at the interface of architecture and engineering. Taking into account local variations in climate, construction and pedagogical approaches, the programme facilitates gradual implementation towards full integration of energy efficiency in building education according to local capacity and legislation. This paper summarises the evaluation process of the first implementation of the educational material in the 15 universities, by academic staff, national industry and professional organisations, and reference students from each university. Included are expected learning outcomes, level of integration in existing curricula and alignment with theory and assessment methods. Measures for improvement as well as further dissemination to other European educational facilities are proposed. In this manner, the project will contribute to make the multiple opportunities for energy efficiency a reality.Intelligent Energy Europe programme for its financial support, Grant agreement no.IEE/09/631/SI2.55822

Lead(II) coordination polymers driven by pyridine-hydrazine donors : from anion-guided self-assembly to structural features

In this work, we report extensive experimental and theoretical investigations on a new series of PbII coordination polymers exhibiting extended supramolecular architectures, namely [Pb2(LI)(NCS)4]n (1), [Pb(HLII)I2]n (2), [Pb(LIII)I]n (3) and [Pb(HLIV)(NO3)2]n·nMeOH (4), which were self-assembled from different PbII salts and various pyridine-hydrazine based linkers, namely 1,2-bis(pyridin-3-ylmethylene)hydrazine (LI), (pyridin-4-ylmethylene)isonicotinohydrazide (HLII), 1-(pyridin-2-yl)ethylidenenicotinohydrazide (HLIII) and phenyl(pyridin-2-yl)methylenenicotinohydrazide (HLIV), respectively. It is recognized that the origin of self-assembling is fundamentally rooted in a dual donor (6s2/6p0 hybridized lone electron pair) and electrophilic behaviour of PbII. This allows production of extended topologies from a 1D polymeric chain in 4 through a 2D layer in 2 to the 3D frameworks in 1 and 3, predominantly due to the cooperative action of both covalent and non-covalent tetrel interactions of the overall type Pb-X (X = O, N, S, I). Counterintuitively, the latter, seemingly weak interactions, have appeared to be even stronger than the typical covalent bonds due to the presence of a bunch of supportive London dispersion dominated contacts: ππ, Lpπ, C-HO, C-HI, C-HH-C as well as more typical mainly electrostatically driven N-HO or N/O-HO hydrogen bonds. It is revealed that the constituting generally strong tetrel type Pb-X (X = O, N, S, I) bonds, though dominated by a classic Coulomb term, are therefore characterized by a very important London dispersion constituent, extremely strong relativistic effects and the two way dative-covalent Pb ↔ X electron charge delocalization contribution as revealed by the Extended Transition State Natural Orbital for Chemical Valence (ETS-NOCV) charge and energy decomposition scheme. It unravels that the pyridine-hydrazine linkers are also excellent London dispersion donors, and that together with the donor-acceptor properties of the heavy (relativistic) PbII atoms and nucleophilic counterions lead to extended self-assembling of 1-4

Towards eco-flowable concrete production

Environmental concerns have increased due to the amount of unused/expired plastic medical waste generated in hospitals, laboratories, and other healthcare facilities, in addition to the fact that disposing of such wastes with extremely low degradation levels causes them to remain in the environment for extended periods of time. These issues have led researchers to develop more environmentally friendly alternatives for disposing of plastic medical waste in Australia. This study is an attempt to assess the impacts of using expired plastic syringes as fine aggregate on fresh and hardened characteristics of flowable concrete, which might provide a solution to environmental concerns. Six mixtures of flowable concrete with water-to-cement ratios of 0.38 were studied. It was found that using recycled aggregate in up to 20% can improve the workability and increase the V-funnel values of flowable concrete mixtures. However, using waste aggregates in more than 30% caused an inapt flowability. Adding waste aggregate at the 30%-50% replacement level led to a decrease in the L-box ratio. To verify the utility and the efficacy of this experiment, the connections between different rheological test measurements were also compared by implementing the Pearson correlation function. The mechanical properties of the mixes containing recycled aggregates were decreased at the age of seven days; however, at later ages, waste aggregates increased the strength at the 10%-30% replacement levels