Demonstration of Microfiltration Technology

The U.S. Environmental Protection Agency (EPA), in cooperation with E.I. DuPont de Nemours & Company, Inc. (DuPont) and the Oberlin Filter Company (Oberlin), undertook a field demonstration project to evaluate microfiltration technology for removal of zinc and suspended solids from wastewater. The microfiltration system utilized DuPont's Tyvek T-980 membrane filter media in conjunction with the Oberlin automatic pressure filter. The project was undertaken at the Palmerton Zinc Superfund site in April 1990 to verify the ability of the technology to remove dissolved zinc from the site's shallow groundwater. Pretreatment of the groundwater with lime for pH adjustment to precipitate dissolved zinc and other metals was included as part of the technology demonstration program. Analysis of the treated filtrate indicated that the system removed precipitated zinc and other suspended solids at an efficiency greater than 99.9 percent. The filter cake produced during the study passed both the Extraction Procedure (EP) Toxicity and the Toxicity Characteristic Leaching Procedure (TCLP) tests.     

Species composition of the international shark fin trade assessed through a retail‐market survey in Hong Kong

The shark fin trade is a major driver of shark exploitation in fisheries all over the world, most of which are not managed on a species‐specific basis. Species‐specific trade information highlights taxa of particular concern and can be used to assess the efficacy of management measures and anticipate emerging threats. The species composition of the Hong Kong Special Administrative Region of China, one of the world's largest fin trading hubs, was partially assessed in 1999–2001. We randomly selected and genetically identified fin trimmings (n = 4800), produced during fin processing, from the retail market of Hong Kong in 2014–2015 to assess contemporary species composition of the fin trade. We used nonparametric species estimators to determine that at least 76 species of sharks, batoids, and chimaeras supplied the fin trade and a Bayesian model to determine their relative proportion in the market. The diversity of traded species suggests species substitution could mask depletion of vulnerable species; one‐third of identified species are threatened with extinction. The Bayesian model suggested that 8 species each comprised >1% of the fin trimmings (34.1–64.2% for blue [Prionace glauca], 0.2–1.2% for bull [Carcharhinus leucas] and shortfin mako [Isurus oxyrinchus]); thus, trade was skewed to a few globally distributed species. Several other coastal sharks, batoids, and chimaeras are in the trade but poorly managed. Fewer than 10 of the species we modeled have sustainably managed fisheries anywhere in their range, and the most common species in trade, the blue shark, was not among them. Our study and approach serve as a baseline to track changes in composition of species in the fin trade over time to better understand patterns of exploitation and assess the effects of emerging management actions for these animals.     

An Ergonomics Study of a Semiconductors Factory in an IDC for Improvement in Occupational Health and Safety

The study aimed to conduct an ergonomic intervention on a conventional line (CL) in a semiconductor factory in Malaysia, an industrially developing country (IDC), to improve workers’ occupational health and safety (OHS). Low-cost and simple (LCS) ergonomics methods were used (suitable for IDCs), e.g., subjective assessment, direct observation, use of archival data and assessment of noise. It was found that workers were facing noise irritation, neck and back pains and headache in the various processes in the CL. LCS ergonomic interventions to rectify the problems included installing noise insulating covers, providing earplugs, installing elevated platforms, slanting visual display terminals and installing extra exhaust fans. The interventions cost less than 3 000 USD but they significantly improved workers’ OHS, which directly correlated with an improvement in working conditions and job satisfaction. The findings are useful in solving OHS problems in electronics industries in IDCs as they share similar manufacturing processes, problems and limitations.     

Just space or spatial justice? Difference,discourse, and environmental justice

Amidst recent moves to rethink environmental justice, this article cautions against retention of distributive conceptions of injustice. Instead, analysis of production and normalisation of difference is explored as a way to shift the lens of environmental justice scholarship away from distributional explanations of injustice and towards critical engagement with the politics of meaning that structure environmental practice. I argue that such a shift would offer an alternative to the liberal spatial frameworks that articulate understandings of environmental justice and environment society relations, facilitating instead relational conceptions of space and engagement with space as a representational media and medium of power. I also propose that methodologically such a shift would require discursive analysis of practices of difference making. Examples from research into the management of nuclear fuel waste in Canada are used to illustrate the arguments.     

Retention of chromium (VI) on a macroporous char following ChemChar gasification and successive leaching with water and acids.

A granular macroporous char, triple-reverse-burn (TRB) char, was loaded with 23.40 mg Cr/g TRB char from an aqueous solution, and the retained metal was leached by water, 0.66 M nitric acid, concentrated nitric acid, and concentrated hydrochloric acid before and after treatment by a reductive thermal gasification process (ChemChar process developed by ChemChar Research, Inc., Columbia, Missouri). The chromium leachate was analyzed by flame atomic adsorption. Reverse- and forward-mode gasifications were performed on the metal-laden char. With the exception of a 10% mass loss of carbon, the reverse mode gasification process does not change the physical characteristics of the granular char, but does increase the retention of the chromium from 16.7 to 24.2%, depending on the leachant. The forward mode gasification process produces a vitrified (or glasslike) ash residue. There was an 11.6 to 13.1% increase in the retention of the chromium by the slag and ash when compared to the nongasified chromium-loaded TRB char. Chromium (VI) was effectively removed from solution by TRB char and found to be retained to a higher degree on the char after a reductive thermal treatment.     

GEOMORPHIC ANALOGIES FOR ASSESSING PROBABLE CHANNEL RESPONSE TO DAM REMOVAL1

ABSTRACT: There is a pressing need for tools to predict the rates, magnitudes, and mechanisms by which sediment is removed from a reservoir following dam removal, as well as for tools to predict where this sediment will be deposited downstream and how it will impact downstream channel morphology. In the absence of adequate empirical data, a good initial approach is to examine the impacts of dam removal within the context of the geomorphic analogies of channel evolution models and sediment waves. Channel changes at two dam breaching sites in Wisconsin involved a succession of channel forms and processes consistent with an existing channel evolution model. Sediment transported downstream after removal of other dams suggests that reservoir sediment may be translated downstream either as a distinct wave or gradually eroded away. More extensive data collection on existing dam removals is warranted before undertaking the removal of a large number of dams. However, if removal is to proceed based on current knowledge, then geomorphic analogies can be used as the foundation for sediment management and stabilization schemes.     

HARVESTING AS A CONTROL FOR AQUATIC PLANTS1

Studies of the effects of harvesting on hydrophytes in Lake Mendota, Wisconsin indicate that one harvest reduced growth by at least 50%, two harvests reduced it by 75% and three harvests virtually eliminated plant material for the year. The studies also indicated that harvesting one year reduced the biomass the following year, especially in deep water. Three harvests during the previous year were most effective in controlling biomass the second year.