Non-native vascular flora of the Arctic: Taxonomic richness,distribution and pathways

We present a comprehensive list of non-native vascular plants known from the Arctic, explore their geographic distribution, analyze the extent of naturalization and invasion among 23 subregions of the Arctic, and examine pathways of introductions. The presence of 341 non-native taxa in the Arctic was confirmed, of which 188 are naturalized in at least one of the 23 regions. A small number of taxa (11) are considered invasive; these plants are known from just three regions. In several Arctic regions there are no naturalized non-native taxa recorded and the majority of Arctic regions have a low number of naturalized taxa. Analyses of the non-native vascular plant flora identified two main biogeographic clusters within the Arctic: American and Asiatic. Among all pathways, seed contamination and transport by vehicles have contributed the most to non-native plant introduction in the Arctic.     

Bringing it all together: researcher dialogue to improve synthesis in regional climate adaptation in South-East Queensland,Australia

The effectiveness of climate adaptation policies in one sector can be compromised or aided by policies developed in another sector. When the focus of adaptation is a single geographical region, this potential for interaction between sectoral policies is heightened due to spatial, political and functional proximities. This paper analyses interactions within three suites of climate adaptation options developed for Australia’s ‘South-East Queensland’ region relating to: (1) wetland migration, coastal infrastructure and planned retreat; (2) urban water security and energy demand; and (3) terrestrial biodiversity and agricultural viability. Using the concept of ‘institutional interplay’ to structure a process of dialogue amongst researchers, we identify a number of critical implementation requirements for successful regional-scale adaptation. There is a need for greater focus on neighbourhood or sub-regional scales of policy design and intervention, particularly for the coordination of adapted infrastructure and services to households. Policy-makers must also be more explicit in considering broader drivers of land-use change and economic adjustment likely to impact on proposed adaptations. In considering these issues, our paper also demonstrates a process for conducting cross-sectoral syntheses that can be employed in other regional-scale adaptation studies.     

Managing the negative impacts of groundwater flow on electrothermal remediation

Rapid groundwater fluxes often influence subsurface temperature distributions during in situ thermal remediation using electrothermal or conduction heating technologies. This study used a numerical approach to evaluate the impact of groundwater flow on electrothermal heating, as well as the effectiveness of several upgradient heat loss management strategies, in a hypothetical treatment volume. Design alternatives using upgradient (i) hydraulic barriers, (ii) physical barriers, and (iii) increased energy input are evaluated. Results indicate that target temperatures can be achieved, despite the presence of local groundwater flow velocities greater than 0.3 m/day, through the careful design and implementation of the alternatives evaluated. However, physical barriers need to be designed to prevent groundwater flow through the heated volume to be effective. Field data from an electrothermal application are also presented, where boiling temperatures were achieved after steam injection and upgradient pumping wells were implemented.     

Development and Application of Protocols for the Determination of Response of Real-Time Particle Monitors to Common Indoor Aerosols

Abstract

Protocols have been developed and applied for the generation of aerosols that are likely to be comparable to those encountered in field settings for the calibration of easily transportable/portable real-time particle monitors. Aerosols generated were simulated environmental tobacco smoke, cedar wood smoke, cooking oil fumes, and propane stove particles. The time-integrated responses of three nephelometers and a monitor for particle-bound polynuclear aromatic hydrocarbons (PAH) were compared with gravimetric respirable suspended particulate matter (RSP) in a controlled-atmosphere chamber. In general, the monitor responses increased linearly with increasing mass concentration. However, the two monitors that reported mass per volume concentrations tended to overreport the actual RSP concentrations by factors up to 4.4. The real-time PAH monitor did not respond to cooking oil fumes, indicative of little PAH being present in the aerosol. One of the monitors that has been used in a variety of studies reported in the literature (DustTrak) was collocated with gravimetric RSP samplers in several hospitality venues in the Louisville, KY, area. Field studies indicated that the units overreported actual RSP concentrations by factors of 2.6–3.1, depending on whether the sampling was conducted in the nonsmoking or smoking sections of the facilities.     

Effect of turbulence on the disintegration rate of flushable consumer products

A previously developed model for the physical disintegration of flushable consumer products is expanded by investigating the effects of turbulence on the rate of physical disintegration. Disintegration experiments were conducted with cardboard tampon applicators at 100, 150, and 200 rotations per minute, corresponding to Reynold's numbers of 25,900, 39,400, and 52,900, respectively, which were estimated by using computational fluid dynamics modeling. The experiments were simulated with the disintegration model to obtain best-fit values of the kinetic and distribution parameters. Computed rate coefficients (ki) for all solid sizes (i.e., greater than 8, 4 to 8, 2 to 4, and 1 to 2 mm) increased strongly with Reynold's number or rotational speed. Thus, turbulence strongly affected the disintegration rate of flushable products, and the relationship of the ki values to Reynold's number can be included in mathematical representations of physical disintegration.     

Brine reuse in ion-exchange softening: salt discharge, hardness leakage, and capacity tradeoffs

Ion-exchange water softening results in the discharge of excess sodium chloride to the aquatic environment during the regeneration cycle. In order to reduce sodium chloride use and subsequent discharge from ion-exchange processes, either brine reclaim operations can be implemented or salt application during regeneration can be reduced. Both result in tradeoffs related to loss of bed volumes treated per cycle and increased hardness leakage. An experimentally validated model was used to compare concurrent water softening operations at various salt application quantities with and without the direct reuse of waste brine for treated tap water of typical midwestern water quality. Both approaches were able to reduce salt use and subsequent discharge. Reducing salt use and discharge by lowering the salt application rate during regeneration consequently increased hardness leakage and decreased treatment capacity. Single or two tank brine recycling systems are capable of reducing salt use and discharge without increasing hardness leakage, although treatment capacity is reduced.     

泥炭对甲苯的吸附-解吸行为研究

用热处理方法对泥炭进行活化改性,探讨了对甲苯的吸附性能及影响因素,并研究了甲苯在泥炭上的吸附/解吸行为。结果表明,粒径在0.6～1 mm之间的泥炭在160℃热处理5 h,在pH为7的条件下对甲苯有良好的吸附效果,对甲苯的吸附量为0.32 mg/g。泥炭对甲苯的吸附在20 min内基本达到平衡,可用二级吸附速率方程进行拟合。甲苯在泥炭上的吸附和解吸均呈现明显的非线性,用Langmuir模型能较好地描述,泥炭对甲苯的饱和吸附量为0.939 mg/g。甲苯在泥炭上的平均解吸率为6.393%,并且出现了滞后现象,表明苯系物与泥炭有较强的结合能力。研究结果为应用泥炭作为PRB装填介质进行原位修复甲苯污染的地下水提供了理论依据。     

An environmental justice analysis of caribou recovery planning, protection of an Indigenous culture, and coal mining development in northeast British Columbia, Canada

Environmental justice theory postulates that communities that predominately consist of minorities and those of a lower socioeconomic status are compelled to bear a disproportionate distribution of burdens resulting from land use decisions. In this article, we present a case study of West Moberly First Nations (an Indigenous group) in British Columbia, Canada, and their fight to protect a threatened herd of caribou from coal mining activities. We examine the role of caribou in maintaining the First Nations’ cultural integrity and the adverse effects of several decisions made by the Provincial Government of British Columbia that would allow a mining company to destroy the critical habitat of the species. Analysis shows that the decisions negate federal law, disregard the best available scientific and traditional knowledge, and fail to uphold the constitutional and treaty rights of the First Nation to meaningfully exercise its cultural practices and customs. A disproportionate share of environmental burdens was therefore placed onto the shoulders of the First Nation while the interests of the government and the mining industry were protected. We conclude that the decisions are a clear case of intentional environmental injustice on the part of the British Columbia government.     

A Study of Field Burning Under Varying Environmental Conditions

A field study on grass field burning was conducted in the Willamette Valley of Oregon during the summer of 1965. Approximately 230,000 acres of grass fields are burned in the valley during August and September. Serious air pollution problems result from this burning. The purposes of the study were to determine the effect of environmental variables on grass field burning and to determine if conditions exist when significant air pollution reduction can be achieved. The environmental variables investigated were time from harvest to burning, time of day, air temperature, relative humidity, soil and straw moisture, wind speed and direction, and fuel density. The dependent variables measured were particulate emission and size distribution, combustion temperature, burn rate, amount of ash, percent of organics in the particulate, and smoke appearance. The results were analyzed statistically to determine the significant variables and their relationship.