Occurrence and formation of trihalomethanes in marine aquaria studied using solid-phase microextraction gas chromatography-mass spectrometry

The occurrence and formation of chlorinated and brominated trihalomethanes (THMs) were studied in artificial saltwater and natural seawater marine aquaria as well as in groundwater and surface waters. A new headspace solid-phase microextraction method was used, which included gas chromatography-mass spectrometry and provided method detection limits of less than 0.1 microg/L, with a signal-to-noise ratio of 3 to 5. The results showed that disinfection by using either chlorine or ozone caused a significant formation of THMs in situ. Speciation of the THMs was a strong function of the water matrix, with initial bromide concentrations playing a pivotal role. These results provide a tool for understanding and monitoring the formation of key disinfection byproducts in marine aquaria that may cause respiratory, eye irritation, or other health concerns.     

An Air Quality Study in the Vicinity of Lewiston,Idaho, and Clarkston,Washington

This report summarizes data and conclusions from a one-year, interstate air quality study conducted in 1962 in the vicinity of Lewiston, Idaho, and Clarkston, Wash.^{1, 6, 7} The sampling and analyses techniques were selected to permit differentiation between possible sources and types of air pollutants.     

Designing a Filter System to Meet Specified Efficiency and Emissions Levels

Fabric filter technology in conjunction with existing system designs holds promise for submicron pariiculate capture. Field data to support this position are only now becoming available with improved tools for submicron particulate testing.     

Sulfur Gas Emissions From Stored Flue Gas Desulfurization Sludges

The emissions of volatile sulfur-containing compounds from 13 flue gas desulfurization (FGD) sludge field storage sites have been characterized. Sulfur gas emissions from the sludge surfaces were determined by measuring the sulfur gas enhancement of sulfur-free sweep air passing through a dynamic emission flux chamber placed over selected sampling sites. Samples of the enclosure sweep air were cryogenically concentrated in surface-deactivated Pyrex “U” traps. Analyses were conducted by wall-coated, open-tubular, capillary column, cyrogenic gas chromatography using a sulfur-selective, flame photometric detector. Several major variables associated with FGD sludge production processes were examined in relation to the measured range and variations in sulfur fluxes including: (a) the sulfur dioxide scrubbing reagent used, (b) sludge sulfite oxidation, (c) “unfixed” or “fixed” FGD sludge, and (d) ponding or landfill storage. The composition and concentration of the measured sulfur gas emissions were found to vary with the type of sludge, the effectiveness of rainwater drainage from the landfill surface, the method of impoundment, and the sulfate/sulfite ratio of the sludge. Hydrogen sulfide, carbonyl sulfide, dimethyl sulfide, carbon disulfide, and dimethyl disulfide were identified in varying concentrations and ratios in the FGD sludge emissions. In addition, up to four unidentified organo- sulfur compounds were found in the emissions from four FGD sludges. The sulfur flux from one FGD storage pond was analyzed by gas chromatography-single ion monitoring mass spectrometry. In addition to the four identified sulfur compounds, this flux contained large concentrations of benzene, toluene, and α-pinene. The measured, total sulfur emissions ranged from less than 0.01 to nearly 0.3 kg of sulfur per day for an equivalent 100 acre (40.5 hectare) sludge impoundment surface.     

A Reassessment of the Economic Effects of Ozone on U.S. Agriculture

The potential adverse effects of environmental change on agriculture have motivated considerable public research on this topic. Acid deposition, gaseous air pollutants, stratosphere ozone depletion and "green house" phenomena, individually and in combination, have been or are being evaluated in terms of effects on agricultural productivity. Assessments of the economic consequences of such effects have also been performed as input into the regulatory process. As with any applied bioeconomic analysis, the credibility of these economic assessments is dependent on the quality of the natural science and other data on the pollutant In question.

The ability of economists to assess the agricultural effects of one important pollutant, tropospheric ozone, has been Improved by the recently completed National Crop Loss Assessment Network (NCLAN). The structure, protocols and initial plant science findings of this U.S. Environmental Protection Agency program have been presented in this journal (see, for example, Heck et al).^1-2 In a related article,³ we reported the economic consequences of those preliminary ozone crop yield effects. Summary plant science findings have now been published.⁴

We provide here a more complete analysis of estimated benefits from reductions in troposphere ozone based on the final results of the NCLAN plant science research. In doing so, we concentrate on improvements in the modeling and underlying data which are reflected In this current assessment. While uncertainties still remain, these improvements should result in more defensible estimates of the magnitude of ozone’s effects on U.S. agriculture.     

An updated assessment of the acute impacts of ocean carbon sequestration by direct injection

This paper evaluates the expected environmental impact of several promising schemes for ocean carbon sequestration by direct injection of CO₂, and serves as a major update to the assessment by Auerbach et al. (1997) and Caulfield et al. (1997) of water quality impacts and the induced mortality to zooplankton. Three discharge approaches are considered, each designed to maximize dilution over the water column: a point release of negatively buoyant CO₂ hydrate particles from a moving ship; a stationary point release of CO₂ hydrate particles forming a sinking plume; and a long, bottom-mounted diffuser discharging buoyant liquid CO₂ droplets. Two of these scenarios take advantage of the enhanced dilution offered by CO₂ hydrate particles, and are based on recent laboratory and field studies on the formation and behavior of such particles. Overall, results suggest that it is possible with present or near present technology to engineer discharge configurations that achieve sufficient dilution to largely avoid acute impacts. In particular, the moving ship hydrate discharge is identified as the most promising due to its operational flexibility. In addition to lethal effects, sub-lethal and ecosystem effects are discussed qualitatively, though not analyzed quantitatively. Our main conclusion is that ocean carbon sequestration by direct injection should not be dismissed as a climate change mitigation strategy on the basis of environmental impact alone. Rather, it can be considered as a viable option for further study, especially in regions where geologic sequestration proves impractical.     

The benefits of Q + PPGIS for coupled human-natural systems research: A systematic review

Managing complex problems in socio-ecological systems (SES) requires innovative approaches, which account for multiple scales, large datasets, and diverse lived experiences. By combining two commonly utilized mixed-methods, public participation GIS (PPGIS) and Q-method (Q), Q + PPGIS has the potential to reveal competing agendas and reduce conflict, but its benefits and weaknesses are comparatively understudied. Using a systematic review, we evaluated how different studies have employed and implemented the Q + PPGIS method. We found 16 studies, comprising 30 publications, with considerable variation in their geographic foci, research disciplines, and addressed SES challenges. These studies exhibit a lack of cohesion between methodological design and implementation and the absence of a consistent application of the method. Nonetheless, Q + PPGIS offers a tool that can guide policy, better inform stakeholders, and reduce conflict based on misconceptions. Resolving the shortcomings identified here will broaden Q + PPGIS utility in geographically situating and representing multiple realities within complex socio-ecological systems challenges.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-022-01709-z.     

Particle laden flows through an inverted chimney with applications to ocean carbon sequestration

Plumes of negatively buoyant hydrate particles, formed by reacting liquid CO₂ with seawater at ocean depths of 1000–1500 m, have been suggested as a way to help sequester CO₂. The vertical flux of CO₂ can be increased by constructing a shroud around the hydrate particle source to shelter the plume from effects of ambient stratification and current. The shroud also serves as an inverted chimney, inducing a down draft that will transport the dissolving particles to a depth of lower ambient disturbance. Laboratory PIV measurements are compared to an analysis of an idealized shroud that is long, frictionless and driven by a single phase source of buoyancy distributed uniformly over the shroud base. Results indicate that induced draft, and hence dilution of dissolved CO₂, increases with plume buoyancy, and shroud length and diameter, but efficiency decreases with increasing ratio of particle slip velocity divided by the characteristic induced draft velocity. While larger particles show reduced plume-like behavior and hence are less efficient in inducing draft, they still generated about half of the theoretically predicted flow.