Public participation in municipal solid waste source-separated collection in Guilin,China: status and influencing factors

Currently, China is facing critical problems regarding the management of municipal solid waste (MSW). The failure of existing pilot programs in implementing MSW source-separated collection highlights the need to analyze the factors significantly influencing public participation in this activity. To this end, a comprehensive analysis of MSW source-separated collection in Guilin, which is representative of wider areas located in inland China and with a GDP around the national average, was conducted. The research consisted of in-person interviews involving a questionnaire and theoretical analyses in terms of public perception, public awareness, public attitude, and willingness to pay. The analytical results identify the status of waste source-separated collection and influencing factors in implementation, and provides exercisable suggestions for decision makers in both China and more generally in industrializing countries to design promotion programs and education campaigns.     

Investigating the key indicators for evaluating post‐disaster shelter

This study sought to identify the primary indicators for evaluating shelter assistance following natural disasters and then to develop a shelter evaluation instrument based on these indicators. Electronic databases and the ‘grey’ literature were scoured for publications with a relation to post‐disaster shelter assistance. Indicators for evaluating such assistance were extracted from these publications. In total, 1,525 indicators were extracted from 181 publications. A preliminary evaluation instrument was designed from these 1,525 indicators. Shelter experts checked the instrument for face and content validity, and it was revised subsequently based on their input. The revised instrument comprises a version for use by shelter agencies (48 questions that assess 23 indicators) and a version for use by beneficiaries (52 questions that assess 22 indicators). The instrument can serve as a standardised tool to enable groups to gauge whether or not the shelter assistance that they supply meets the needs of disaster‐affected populations.     

Elemental concentrations and in vitro bioaccessibility in Canadian background soils

Elemental concentrations and bioaccessibility were determined in background soils collected in Canada as part of the North American Geochemical Landscapes Project. The concentrations of As, Cr, Cu, Co, Ni and Zn were higher in the C-horizon (parent material) compared to 0–5 cm (surface soil), and this observation along with the regional distribution suggested that most of the variability in concentrations of these elements were governed by the bedrock characteristics. Unlike the above-stated elements, Pb and Cd concentrations were higher in the surface layer reflecting the potential effects of anthropogenic deposition. Elemental bioaccessibility was variable decreasing in the order Cd > Pb > Cu > Zn > Ni > Co > As > Cr for the surface soils. With the exception of As, bioaccessibility was generally higher in the C-horizon soils compared to the 0–5 cm soils. The differences in metal bioaccessibility between the 0–5 cm and the C-horizon and among the provinces may reflect geological processes and speciation. The mean, median or 95th percentile bioaccessibility for As, Cr, Cu, Co, Ni and Pb were all below 100 %, suggesting that the use of site-specific bioaccessibility results for these elements will yield more accurate estimation of the risk associated with oral bioavailability for sites where soil ingestion is the major contributor of human health risk.     

Detention Outlet Retrofit Improves the Functionality of Existing Detention Basins by Reducing Erosive Flows in Receiving Channels

By discharging excess stormwater at rates that more frequently exceed the critical flow for stream erosion, conventional detention basins often contribute to increased channel instability in urban and suburban systems that can be detrimental to aquatic habitat and water quality, as well as adjacent property and infrastructure. However, these ubiquitous assets, valued at approximately $600,000 per km² in a representative suburban watershed, are ideal candidates to aid in reversing such cycles of channel degradation because improving their functionality would not necessarily require property acquisition or heavy construction. The objective of this research was to develop a simple, cost‐effective device that could be installed in detention basin outlets to reduce the erosive power of the relatively frequent storm events (~ < two‐year recurrence) and provide a passive bypass to maintain flood control performance during infrequent storms (such as the 100‐year recurrence). Results from a pilot installation show that the Detain H₂O device reduced the cumulative sediment transport capacity of the preretrofit condition by greater than 40%, and contributed to reduced flashiness and prolonged baseflows in receiving streams. When scaling the strategy across a watershed, these results suggest that potential gains in water quality and stream channel stability could be achieved at costs that are orders of magnitude less than comparable benefits from newly constructed stormwater control measures.     

The climate adaptation imperative: local choices targeting global problems?

When confronted with the demands of global climate change, what causes some policy-makers to move the climate adaptation agenda forward in their communities, while others seemingly get little accomplished? To answer this question, we first discuss work on policy-drivers in a coupled human–natural systemic context. This summary review of past research helps us develop a set of competing and complementary explanations for why some communities aggressively pursue climate adaptation policies, while others do less. Following the discussion of policy-drivers, we then undertake an aggregate-level analysis of data collected across the 169 towns in Connecticut regarding climate adaptation, thus linking policy to its fundamental global cause. The quantitative data are augmented with interview data from policy-makers and activists from around the New England region.     

Modelling remediation scenarios in historical mining catchments

Local remediation measures, particularly those undertaken in historical mining areas, can often be ineffective or even deleterious because erosion and sedimentation processes operate at spatial scales beyond those typically used in point-source remediation. Based on realistic simulations of a hybrid landscape evolution model combined with stochastic rainfall generation, we demonstrate that similar remediation strategies may result in differing effects across three contrasting European catchments depending on their topographic and hydrologic regimes. Based on these results, we propose a conceptual model of catchment-scale remediation effectiveness based on three basic catchment characteristics: the degree of contaminant source coupling, the ratio of contaminated to non-contaminated sediment delivery, and the frequency of sediment transport events.     

Speciation and persistence of doxycycline in the aquatic environment: Characterization in terms of steady state kinetics

The aim of the present work was to establish the kinetics for the degradation of doxycycline in the aquatic environment with a view to arriving at a kinetic model that can be used to predict the persistence of antibiotic with confidence. The degradation of doxycycline in both water and sediment phases of aquatic microcosm experiments, as well as in distilled water control experiments, was studied over a period of 90 days. An initial 21% loss due to adsorption by the sediment was observed in the microcosm experiment soon after charging. Biphasic zero-order linear rates of degradation, attributed to microbial degradation of the free and sediment or colloidal particle-adsorbed antibiotic, were observed for both water phase (2.3 × 10^?2 and 4.5 × 10^?3 μgg^?1 day^?1) and sediment phase (7.9 × 10^?3 and 1.5 × 10^?3 μgg^?1 day^?1) of the microcosm experiment. The covered distilled water control experiment exhibited a monophasic zero-order linear rate (1.9 × 10^?3 μgg^?1 day^?1) attributed to hydrolysis, while the distilled water experiment exposed to natural light exhibited biphasic liner rates attributed to a combination of hydrolysis and photolysis (2.9 × 10^?3 μgg^?1 day^?1) and to microbial degradation (9.8 × 10^?3 μgg^?1 day^?1). A kinetic model that takes into account hydrolysis, photolysis, microbial degradation as well as sorption/desorption by colloidal and sediment particles is presented to account for the observed zero-order kinetics. The implications of the observed kinetics on the persistence of doxycycline in the aquatic environment are discussed.     

Emission Impacts of Electric Vehicles

Alternative vehicular fuels are proposed as a strategy to reduce urban air pollution. In this paper, we analyze the emission Impacts of electric vehicles In California for two target years, 1995 and 2010. We consider a range of assumptions regarding electricity consumption of electric vehicles, emission control technologies for power plants, and the mix of primary energy sources for electricity generation. We find that, relative to continued use of gasoline-powered vehicles, the use of electric vehicles would dramatically and unequivocally reduce carbon monoxide and hydrocarbons. Under most conditions, nitrogen oxide emissions would decrease moderately. Sulfur oxide and particulate emissions would Increase or slightly decrease. Because other areas of the United States tend to use more coal in electricity generation and have less stringent emission controls on power plants, electric vehicles may have less emission reduction benefits outside California.     

Site Sampling and Treatability Studies for Demonstration of WasteChem’s Asphalt Encapsulation Technology Under EPA’s SITE Program

ABSTRACT

Exposures from indoor environments are a major issue for evaluating total long-term personal exposures to the fine fraction (<2.5μm in aerodynamic diameter) of particulate matter (PM). It is widely accepted in the indoor air quality (IAQ) research community that biocontamination is one of the important indoor air pollutants. Major indoor air biocontaminants include mold, bacteria, dust mites, and other antigens. Once the biocontaminants or their metabolites become airborne, IAQ could be significantly deteriorated. The airborne biocontaminants or their metabolites can induce irritational, allergic, infectious, and chemical responses in exposed individuals.

Biocontaminants, such as some mold spores or pollen grains, because of their size and mass, settle rapidly within the indoor environment. Over time they may become nonviable and fragmented by the process of desiccation. Desiccated nonviable fragments of organisms are common and can be toxic or allergenic, depending upon the specific organism or organism component. Once these smaller and lighter fragments of biological PM become suspended in air, they have a greater tendency to stay suspended. Although some bioaerosols have been identified, few have been quantitatively studied for their prevalence within the total indoor PM with time, or for their affinity to penetrate indoors.

This paper describes a preliminary research effort to develop a methodology for the measurement of nonvi-able biologically based PM, analyzing for mold and ragweed antigens and endotoxins. The research objectives include the development of a set of analytical methods and the comparison of impactor media and sample size, and the quantification of the relationship between outdoor and indoor levels of bioaerosols. Indoor and outdoor air samples were passed through an Andersen nonviable cascade impactor in which particles from 0.2 to 9.0 um were collected and analyzed. The presence of mold, ragweed, and endotoxin was found in all eight size ranges. The presence of respirable particles of mold and pollen found in the fine particle size range from 0.2 to 5.25 um is evidence of fragmentation of larger source particles that are known allergens.     

Solvent Extraction Processes: A Survey of Systems in the SITE Program

Solvent extraction of contaminated soils, sludges and sediments has been successfully completed at a number of Superfund sites. Each commercialized process uses a unique operating system to extract organic contaminants from solids. These operating systems may be classified by the properties of the solvents each utilizes: (1) standard solvents, (2) near-critical fluids/liquified gases, and (3) critical solution temperature solvents. Pretreatment and post-treatment requirements vary depending upon the operating systems of the solvent extraction system. Future demonstrations of these technologies by the U.S. EPA’s Superfund Innovative Technology Evaluation Program will provide additional information regarding the efficacy of these processes.