Examination of a New Remedial Technology for Capping Contaminated Sediments: Large-Scale Laboratory Evaluation of Sediment Mixing and Cap Resistance to Erosive Forces

The potential effectiveness of a new composite-aggregate capping technology, AquaBlok^TM—in physically isolating contaminated, fine-grained sediments derived from an Ohio, Lake Erie tributary—was evaluated in the laboratory. In particular, large-scale settling-column studies were conducted to determine the degree to which composite-aggregate material penetrates into and/or mixes with the sediment, perhaps affecting the degree to which sediment could be physically isolated through capping. Additionally, large-scale flume studies were conducted to determine resistance of the composite-aggregate material to significant and long-term, fluvial-like erosive forces; the resistance of other potential capping materials was also evaluated for comparison. Experimental results indicate that the composite-aggregate material effectively isolates sediment through the formation of a continuous and relatively erosion-resistant, hydrated capping layer atop the sediments.     

Analysis of 3-D Urban Databases with Respect to Pollution Dispersion for a Number of European and American Cities

Dispersion models require as input various geometrical parameters to calculate the flow field and dispersion characteristics in the urban environment. As a result of recent advances in digital photogrammetry and remote sensing, databases of the actual 3-D geometry of city centre areas are now increasingly available. In this work we outline a procedure to reduce this large amount of data to a structured input for urban pollution dispersion models, i.e. to extract the important flow and dispersion parameters from the urban databases. Based on a review of the scientific literature, we have identified a number of parameters relevant to the modelling of pollution dispersion and atmospheric flows in urban areas. These parameters are: the plan and frontal area densities, the plan and frontal area density as a function of height, the distribution of heights, their standard deviation, the aerodynamic roughness length and the sky view factor.These parameters are obtained by analysing urban Digital Elevation Models (DEMs) which are regularly spaced grids of elevation values. Examples of the parameters calculated from high-resolution databases (with pixel size of about 1 m) for three European (London, Toulouse and Berlin) and two North American (Salt Lake City and Los Angeles) cities are presented and discussed. The calculated aerodynamic roughness length was smaller for the European cities than for the North American ones. A multiplicative correction factor to the aerodynamic roughness length is proposed to include the effect of the variability of the building heights.     

Monitoring and Analysis of Water,Salt and Nutrient Fluxes at the Mouth of a Lagoon

An intensive sampling program of physical and chemical parameters has been undertaken at Vassova lagoon, northeast Greece, in order to examine water circulation and estimate the instantaneous and residual fluxes of water, salt, nutrients and chlorophyll-a through the entrance canal of this lagoon. Field data of hydrographic and water quality parameters were collected under neap and spring tidal cycles, and under winter and summer conditions, to account for the fortnight and seasonal effects in the lagoon. The analysis showed that the Eulerian residual transport is positive in direction during both tidal cycles, thus pushing water, salt, nitrate-nitrogen, phosphate-phosphorus and chlorophyll-a inward Vassova lagoon. Tidal pumping was mostly positive during the neap tide and negative during the spring tidal cycle, thus pushing water, salt, phosphorus and chlorophyll-a outwards of Vassova lagoon.     

An Analysis of the Indoor Air Quality and Mould Growth in a Multi-zone Building

The effects of poor indoor air quality and mould growth in working environment are major problems in built environment, and there is a need to look for improvement of the health, comfort and productivity of the building occupants. Airborne mould sampling studies were conducted in a reference building located in Rockhampton, Central Queensland, Australia. Both indoor culturable and mould spore levels were observed. It was found through the indoor–outdoor ratios of the species that indoor concentrations are mostly related to the outdoor mould levels. The moulds differ in their relative humidity and temperature requirements to support surface growth. Indoor humidity has a significant effect on occupants comfort, perceived air quality, occupants’ health, building durability, emissions and energy efficiency. Practical hygrothermal simulation models are employed to analyse the combined heat and moisture behaviour within the built environment. A review of the current modelling options available to predict building performance based on energy and mass transport simulation is presented, and then a case study is presented with the assessment of indoor built environment to avoid mould problem.     

Baseline levels of bioaerosols and volatile organic compounds around a municipal waste incinerator prior to the construction of a mechanical-biological treatment plant

New waste management programs are currently aimed at developing alternative treatment technologies such as mechanical–biological treatment (MBT) and composting plants. However, there is still a high uncertainty concerning the chemical and microbiological risks for human health, not only for workers of these facilities, but also for the population living in the neighborhood. A new MBT plant is planned to be constructed adjacently to a municipal solid waste incinerator (MSWI) in Tarragona (Catalonia, Spain). In order to evaluate its potential impact and to differentiate the impacts of MSWI from those of the MBT when the latter is operative, a pre-operational survey was initiated by determining the concentrations of 20 volatile organic compounds (VOCs) and bioaerosols (total bacteria, Gram-negative bacteria, fungi and Aspergillus fumigatus) in airborne samples around the MSWI. The results indicated that the current concentrations of bioaerosols (ranges: 382–3882, 18–790, 44–926, and <1–7 CFU/m³ for fungi at 25 °C, fungi at 37 °C, total bacteria, and Gram-negative bacteria, respectively) and VOCs (ranging from 0.9 to 121.2 μg/m³) are very low in comparison to reported levels in indoor and outdoor air in composting and MBT plants, as well in urban and industrial zones. With the exception of total bacteria, no correlations were observed between the environmental concentrations of biological agents and the direction/distance from the facility. However, total bacteria presented significantly higher levels downwind. Moreover, a non-significant increase of VOCs was detected in sites closer to the incinerator, which means that the MSWI could have a very minor impact on the surrounding environment.     

火电厂生产准备阶段环保工作的认识与实践

根据国家环保法规和生产实践,提出火电厂生产阶段需要整理的环保文件,标准,需要进行的施工监督,培训,制度制定等方面的工作。     

Assessing the impact of land-applied biosolids from a thermomechanical (TMP) pulp mill to a suite of terrestrial and aquatic bioassay organisms under laboratory conditions

The potential impact on a variety of bioassay organisms when pulp-mill biosolids from a thermomechanical pulp mill (western Canada) were applied to a reference soil has been investigated in a laboratory setup. The current research assessed acute, chronic, and reproductive impacts using a battery of terrestrial and aquatic organisms. Terrestrial organisms were exposed to soil amended with different concentrations of biosolids, while aquatic organisms were used to assess the impact of biosolids' runoff into receiving waters. The former bioassays showed that an application rate of 20 tonneshectare(-1) (tha(-1)) "bone-dry" biosolids applied to reference soil produced no observable adverse impact on the terrestrial organisms. In the latter assays, undiluted (100%) and 50% diluted biosolids' runoff into receiving water had a detrimental impact on the aquatic organisms. However, concentrations not exceeding 25% (environmentally relevant concentrations) had neither an acute nor chronic impact compared to reference populations. The organisms' abilities to reproduce were also unaltered. While this study only examined the biosolids from one mill, there is the potential that land-application of characteristically well-defined pulp mill biosolids may constitute an acceptable way of disposing of pulp and paper mill biosolid residues. However, the biosolids coming from different mills, with differing processes, must be dealt with on a case-by-case situation. Each series of biosolids must be rigorously tested for toxicological impact in the laboratory under tightly controlled conditions. Subsequently, field experimentation must be conducted before definitive conclusions can be made.     

Application of passive soil gas technology to determine the source and extent of a PCE groundwater plume in an urban environment

In situations where groundwater supplies have been impacted by volatile organic compounds (VOCs), such as tetrachloroethene (PCE), and the source has not been identified, the costs to identify the source and plume migration patterns may be extremely high. The costs for an investigation increase with the number and depth of borings and the number of samples that are collected and analyzed. An environmental investigator and the Arizona Department of Environmental Quality (ADEQ) have successfully utilized passive soil gas (PSG) surveys in Arizona to cost‐effectively investigate VOC impacts to groundwater and identify potential sources of impact. PSG surveys are minimally intrusive, and more samples can be collected for the same cost when compared to active soil gas surveys and conventional soil and groundwater sampling programs. The result is a surficial representation of the contaminant plume and the location of “hot spots,'' which are the potential sources. This provides a better understanding of the nature and extent of the impact and allows for a focused subsurface investigation, which subsequently reduces drilling and sampling costs. © 2008 Wiley Periodicals, Inc.     

Lessons learned for a more efficient knowledge and technology transfer to South American countries in the fields of solid waste and contaminated sites management.

The present paper describes the development, performance and conclusions derived from three know-how and technology transfer projects to South American countries. The first project comprised a collaborative study by European and South American universities to find sustainable solutions for Chilean and Ecuadorian leather tanneries which had underachieving process performances. The second project consisted of investigations carried out in a Brazilian municipality to enhance its municipal solid waste management system. The final collaborative programme dealt with the initial identification, evaluation and registration of suspected contaminated sites in an industrial region of Chile. The detailed objectives, methods and procedures applied as well as the results and conclusions obtained in each of the three mentioned projects are presented, giving special attention to the organizational aspects and to the practical approach of each programme, concluding with their main advantages and disadvantages for identifying a set of qualitative and quantitative suggestions, and to establish transferable methods for future applications.     

Utilizing a 'systems' approach to improve the management of waste from healthcare facilities: best practice case studies from England and Wales.

Changes in environmental legislation and standards governing healthcare waste, such as the Hazardous Waste Regulations are expected to have a significant impact on healthcare waste quantities and costs in England and Wales. This paper presents findings from two award winning case study organizations, the Cardiff and Vale NHS Trust and the Cornwall NHS Trust on 'systems' they have employed for minimizing waste. The results suggest the need for the development and implementation of a holistic range of systems in order to develop best practice, including waste minimization strategies, key performance indicators, and staff training and awareness. The implications for the sharing of best practice from the two case studies are also discussed.     

Using Design-Expert to Optimize the Properties of a Polyethersulfone Ultrafiltration Membrane Through the Incorporation of NH2-MIL-53(Fe) and PVP for Maximum Cr(VI) Removal and Flux

Journal of Polymers and the Environment - In this study, an NH2-MIL-53(Fe) functionalized membrane was fabricated for Cr(VI) removal from contaminated groundwater. Design-Expert was employed to...     

Physical and Thermal Analysis of the Degradation of Poly(3-Hydroxybutyrate-<Emphasis Type="Italic">co</Emphasis>-4-Hydroxybutyrate) Coated Paper in a Constructed Soil Medium

The degradation of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)) coated brown Kraft paper and its components in a constructed soil environment was investigated. Soil burial tests were carried out over 8 weeks. Weight loss measurements, photographic analysis, environmental scanning electron microscopy (ESEM), dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) were conducted to assess the physical, structural, mechanical and thermal behavior before and after the soil burial test. Paper showed the highest physical degradation and weight loss. With respect to the control samples, the stiffness of the partially degraded samples decreased. The overall crystallinity of the biopolymer and the coated paper was affected significantly by burial. The pure biopolymer’s weight loss was substantially enhanced when coated on paper. This result reveals a possible increased microbial population in the coated paper relative to the pure biopolymer.