Investigation of the usage of centrifuging waste of mineral wool melt (CMWW), contaminated with phenol and formaldehyde,in manufacturing of ceramic products

Large amounts of centrifuging waste of mineral wool melt (CMWW) are created during the production of mineral wool. CMWW is technogenic aluminum silicate raw material, formed from the particles of undefibred melt (60–70%) and mineral wool fibers (30–40%). 0.3–0.6% of organic binder with phenol and formaldehyde in its composition exists in this material. Objective of the research is to investigate the possibility to use CMWW as an additive for the production of ceramic products, by neutralising phenol and formaldehyde existing in CMWW. Formation masses were prepared by incorporating 10%, 20% and 30% of CMWW additive and burned at various temperatures. It was identified that the amount of 10–30% of CMWW additive influences the following physical and mechanical properties of the ceramic body: lowers drying and firing shrinkage, density, increases compressive strength and water absorption. Investigations carried out show that CMWW waste can be used for the production of ceramic products of various purposes.     

Approximate bilateral symmetry in evaporation-induced polycrystalline structures from droplets of wheat grain leakages and fluctuating asymmetry as quality indicator

The present paper reports on an observation that dendrite-like polycrystalline structures from evaporating droplets of wheat grain leakages exhibit bilateral symmetry. The exactness of this symmetry, measured by means of fluctuating asymmetry, varies depending on the cultivar and stress factor influence, and seems to correspond to the seed germination rate. In the bodies of plants, animals, and humans, the exactness of bilateral symmetry is known to reflect the environmental conditions of an organism’s growth, its health, and its success in sexual selection. In polycrystalline structures, formed under the same conditions, the symmetry exactness depends on the properties of the crystallizing solution such as the composition and viscosity; however, it has never been associated with sample quality. We hypothesize here that, as in living nature, the exactness of approximate bilateral symmetry might be considered a quality indicator also in crystallographic methods applied to food quality analysis.     

The Climate Value of Cycling

The reduction of CO₂ emissions constitutes one of the largest challenges of the current era. Sustainable transportation, and especially cycling, can contribute to the mitigation of CO₂ emissions since cycling possesses an intrinsic zero‐emission value. Few studies have been conducted that appraise the CO₂ reduction potential of cycling. Opportunity costs enable the estimation of avoided CO₂ emissions resulting from bicycle trips. The methodology developed in this research allows the attribution of a climate value to cycling by substituting bicycle trips with their most likely alternative transportation modes and calculating the resulting additional CO₂ emissions. The methodology uses data on the current modal shares of cycling mobility, the competition of cycling with other transportation modes, and CO₂ emission factors to calculate the climate value of cycling. When it is assumed that the avoided CO₂ emissions of cycling mobility could be traded on financial carbon markets, the climate value of cycling represents a monetary value. Application of the methodology to the case of Bogotá, Colombia — a city with a current bicycle modal share of 3.3% on a total of 10 million daily trips — results in a climate value of cycling of 55,115 tons of CO₂ per year, corresponding to an economic value of between 1 and 7 million US dollars when traded on the carbon market.     

Impact of municipal solid waste incineration bottom ash on the properties and frost resistance of clay bricks

Journal of Material Cycles and Waste Management - This paper presents an experimental study on the properties, structure and durability (frost resistance: one-side and all-sides freezing and...     

The use of plate heat exchangers to improve energy efficiency in phosphoric acid production

This paper originated as a part of a comprehensive research project designed to develop ecologically sustainable, environmentally friendly, resource- and energy-saving industrial process technology for the production of a wide class of phosphorus containing substances. The essential feature of the research was designed for the replacement of tubular heat exchangers with Plate heat exchangers (PHEs) and for the installation of these units in new locations in the processes to optimally improve energy efficiency and to prevent pollution. Despite the severe operating conditions in the production of phosphoric acid PHEs of various designs find the application in these processes. For such a corrosive environment as a phosphoric acid production plant, the Hastelloy G30 alloy is used as the material for the plates and synthetic rubber EPDM is used as the material for inter-plate gaskets. The analysis of the data shows, that using mixed groupings of plates in the unit allows one to obtain optimal solutions. The simulation of barometric mixing condenser recycled water cooling with plate heat exchanger shows the possibility of an application which minimizes the waste water pollution by closing the condenser cooling water circuit. Software was developed for calculations of units working both with liquid and phase changing streams.     

Improving the adsorption capacity and solid structure of natural volcanic soil using a foaming-sintering process based on recycled polyethylene terephthalate (PET).

The volcanic soils of southern Chile have demonstrated a high capacity to adsorb environmental pollutants, but for an industrial application, a stable solid material is necessary. The objective of this work was to produce a stable ceramic material through a process involving volcanic soil-polyurethane foam produced with recycled polyethylene terephthalate (PET)-polyols, and further thermal treatment. The selected foam formulation with 35.4% volcanic soil (< 63 microm) seems to be the most suitable for thermal treatment, with temperature steps at 700, 850, 1000 and 1200 degrees C. The porous ceramic material obtained has a stable solid form and an improved chlorophenols adsorption capacity (comparable to natural zeolites) that makes it suitable for advanced wastewater treatment and landfill leachate depuration.     

Treatment of cork boiling wastewater using chemical oxidation and biodegradation

Three cultures were enriched from cork boiling wastewater using tannic acid as the selective carbon substrate, at 25 degrees C and pH 7.2, 25 degrees C and pH 4.7 and 50 degrees C and pH 4.7. The enrichment culture obtained at neutral pH was composed of five culturable isolates, whereas from each acidic enrichment two bacterial strains were isolated. Mesophilic isolates were Gram negative bacteria belonging to the genera Klebsiella, Pseudomonas, Stenotrophomonas and Burkholderia. Thermophilic isolates were members of the genus Bacillus. Despite the capability of the enrichment cultures to use tannic acid as single carbon and energy source, those cultures were unable to reduce the total polyphenols or the total organic carbon content of cork boiling wastewater. In order to increase the bioavailability of the organic carbon in cork boiling wastewater, biodegradation was preceded by Fenton oxidation. It was demonstrated that the combined process, using small amounts of Fenton reagents and biodegradative inoculum added almost simultaneously to cork boiling wastewater, leads to TOC reductions of more than 90%.     

High mercury bioaccumulation in Pacific salmons from the Sea of Okhotsk and the Bering Sea

Mercury (Hg) accumulation in fishes is a serious threat for food security because mercury induces dieseases. Here we studied the total mercury content in four species of Pacific salmon (pink, chum, sockeye and chinook), caught in the Sea of Okhotsk, the Bering Sea, and the Kuril oceanic waters. Results show that the lowest concentration of mercury was found in the pink salmon, and the highest was 5–6 times higher in sockeye. Hg concentrations exceed several times those in other species of Pacific salmon from the North Pacific     

Job control and occupational health: the moderating role of national R&D activity

Workers (n = 17 275) from 14 European Union (EU) member states provided data on job control, job dissatisfaction, perceived risk of occupational stress, and absence. For each state, level of research and development (R&D) activity was assessed. Associations between individual levels of control and occupational health were stronger where national R&D activity was higher. The moderation occurred for individuals' levels of control in relation to job dissatisfaction, perceived risk of occupational stress, and absence. The findings with job dissatisfaction and absence were replicated in a sample of workers from 10 Eastern European former Communist countries (n = 7926). Copyright © 2007 John Wiley & Sons, Ltd.