Particulate matter in the indoor and outdoor air of a gymnasium and a fronton

An indoor/outdoor monitoring programme of PM₁₀ was carried out in two sports venues (a fronton and a gymnasium). Levels always below 50 μg m^?3 were obtained in the fronton and outdoor air. Due to the climbing chalk and the constant process of resuspension, concentrations above 150 μg m^?3 were registered in the gymnasium. The chalk dust contributed to CO₃ ^2? concentrations of 32?±?9.4 μg m^?3 in this sports facility, which represented, on average, 18 % of the PM₁₀ mass. Here, the carbonate levels were 128 times higher than those registered outdoors. Much lower concentrations, around 1 μg m^?3, were measured in the fronton. The chalk dust is also responsible for the high Mg²⁺ concentrations in the gym (4.7?±?0.89 μg m^?3), unfolding a PM₁₀ mass fraction of 2.7 %. Total carbon accounted for almost 30 % of PM₁₀ in both indoor spaces. Aerosol size distributions were bimodal and revealed a clear dependence on physical activities and characteristics of the sports facilities. The use of climbing chalk in the gymnasium contributed significantly to the coarse mode. The average geometric mean diameter, geometric standard deviation and total number of coarse particles were 0.77 μm, 2.79 cm^?3 and 28 cm^?3, respectively.     

Dibenzothiophene desulfurization by Gordonia alkanivorans strain 1B using recycled paper sludge hydrolyzate

Enzymatic hydrolyzates of recycled paper sludge were tested as suitable feedstock for biological desulfurization by Gordonia alkanivorans strain 1B. Only the hydrolyzate obtained after enzymatic mixture dialysis (dialyzed hydrolyzate) allowed dibenzothiophene (DBT) desulfurization, in spite of faster bacterial growth did occur on non-dialyzed hydrolyzate. For dialyzed hydrolyzate, 250microM DBT was consumed after 96h displaying a maximum specific productivity of 2-hydroxybiphenyl of 1.1micromol g(-1)(dry cell weight) h(-1). A comparison of the kinetics of biodesulfurization was assessed according to the type of hydrolyzate supplementation. Complete consumption of DBT was observed upon the addition of only phosphates and ammonia although further addition of zinc did increase the 2-hydroxybiphenyl production by 14%. Strain 1B was able to desulfurize a model oil containing DBT, 4-methylDBT and 4,6-dimethylDBT, reducing by 63% the total sulfur content in 168h.     

Kinetics assessment and modeling of biogas production by anaerobic digestion of food wastes and acclimated sewage sludge

Journal of Material Cycles and Waste Management - In this work, food wastes (FWs) and domestic sewage sludge (DSS) were used as raw materials for energy recovery by anaerobic digestion (AD). AD was...     

Environmental performance policy indicators for the public sector: the case of the defence sector

The development of environmental performance policy indicators for public services, and in particular for the defence sector, is an emerging issue. Despite a number of recent initiatives there has been little work done in this area, since the other sectors usually focused on are agriculture, transport, industry, tourism and energy. This type of tool can be an important component for environmental performance evaluation at policy level, when integrated in the general performance assessment system of public missions and activities. The main objective of this research was to develop environmental performance policy indicators for the public sector, specifically applied to the defence sector. Previous research included an assessment of the environmental profile, through the evaluation of how environmental management practices have been adopted in this sector and an assessment of environmental aspects and impacts. This paper builds upon that previous research, developing an indicator framework--SEPI--supported by the selection and construction of environmental performance indicators. Another aim is to discuss how the current environmental indicator framework can be integrated into overall performance management. The Portuguese defence sector is presented and the usefulness of this methodology demonstrated. Feasibility and relevancy criteria are applied to evaluate the set of indicators proposed, allowing indicators to be scored and indicators for the policy level to be obtained.     

Geologic materials and gamma radiation in the built environment

Human exposure to natural ionizing radiation is due to both internal sources such as ingestion and inhalation of radioactive isotopes, and external sources from cosmic radiation and primordial radionuclides present in the Earth crust. Primordial radionuclides are ⁴⁰K and radioisotopes of the decay series of ²³⁸U and ²³²Th, which emit gamma radiation at low doses. Gamma emission can occur both in outdoor, due to background geologic radiation, and in indoor spaces, due to the use of geologic materials in dwellings. This radiation has received less attention than man-made sources because it contributes less to the total doses that affect humans, on the average. However, there are geographical areas and rocks used as building materials that contain high concentrations of radionuclides, thus being a source of relatively high gamma dose exposures. Assessing exposure is difficult, especially in indoor situations where there are marked variations regarding materials application. Nonetheless, some measures and regulations to control such dose exposures on building materials have been suggested. This article reviews gamma radiation in geologic materials used for buildings. We discuss: (1) procedures that relate radionuclide contents in building materials to external gamma radiation, considering namely indoor applications and that are used for establishing restrictions on building materials commerce; (2) relation of rock radionuclide contents with their geologic history that can lead to listing of some geologic materials as potentially hazardous in terms of gamma radiation; and (3) the implications for the European regulation, which has an universal criteria that might be excessively restrictive for the commerce of geologic materials used in small amounts, and does not have provisions regarding existing structures where geologic materials are used in extended amounts.     

Emission factors from residential combustion appliances burning Portuguese biomass fuels

Smoke from residential wood burning has been identified as a major contributor to air pollution, motivating detailed emission measurements under controlled conditions. A series of experiments were performed to compare the emission levels from two types of wood-stoves to those of fireplaces. Eight types of biomass were burned in the laboratory: wood from seven species of trees grown in the Portuguese forest (Pinus pinaster, Eucalyptus globulus, Quercus suber, Acacia longifolia, Quercus faginea, Olea europaea and Quercus ilex rotundifolia) and briquettes produced from forest biomass waste. Average emission factors were in the ranges 27.5-99.2 g CO kg(-1), 552-1660 g CO(2) kg(-1), 0.66-1.34 g NO kg(-1), and 0.82-4.94 g hydrocarbons kg(-1) of biomass burned (dry basis). Average particle emission factors varied between 1.12 and 20.06 g kg(-1) biomass burned (dry basis), with higher burn rates producing significantly less particle mass per kg wood burned than the low burn rates. Particle mass emission factors from wood-stoves were lower than those from the fireplace. The average emission factors for organic and elemental carbon were in the intervals 0.24-10.1 and 0.18-0.68 g kg(-1) biomass burned (dry basis), respectively. The elemental carbon content of particles emitted from the energy-efficient "chimney type" logwood stove was substantially higher than in the conventional cast iron stove and fireplace, whereas the opposite was observed for the organic carbon fraction. Pinus pinaster, the only softwood species among all, was the biofuel with the lowest emissions of particles, CO, NO and hydrocarbons.     

Single-stroke mechanical joining of sheet panels to tubular profiles

This paper proposes an innovative mechanical joining process for fixing sheet panels against tubular profiles with a single ram stroke.The presentation includes independent determination of the mechanical properties of sheets and tubes, finite element modelling and experimentation under laboratory conditions. The aim is to identify the key parameters of the process, to diagnose possible sources of failure and to understand the routes for selecting the most appropriate joining conditions.Results and observations show that fixing sheet panels to tubular profiles by tube forming with a single ram stroke is a flexible and cost-effective mechanical joining process that can be easily industrialized in a small capacity press. Applications may span for a wide range of engineering applications where conventional technologies based on fasteners, glueing with structural adhesives, brazing and soldering or welding cannot be employed due to technical, aesthetical or economic constraints.