Baseline mercury and zinc concentrations in terrestrial and coastal organisms of Admiralty Bay, Antarctica

This paper provides the first quantitative information on mercury in soil, coastal sediment, and in characteristic organisms of terrestrial and shallow coastal marine ecosystems from Admiralty Bay (King George Island, Antarctica). As expected for a remote area, mercury content is low in abiotic components of the ecosystem, and probably similar to natural levels. Mercury also occurs in very low concentrations in the vegetation, invertebrates and fish. These low mercury levels may be due to sulphide formation in reducing sediments of this environment. Higher concentrations of mercury occurred in bird feathers and mammal hair, indicating biomagnification. This was not found for Zinc. These results may be useful as a reference background to detect future inputs of trace elements in this remote area of the earth. Terrestrial vegetation and bird feathers are suggested as target regional biomonitors.     

Environment and industrialization in Puerto Rico: disenfranchising the people

This paper explores the effects of industrialization policy on environmental regulation in Puerto Rico, focusing on implementation of the Environmental Impact Statement (EIS) review process. Adopted in 1970, the EIS process has been transformed to pave the way for extensive use of a concise, alternative mechanism for analysing project environmental impacts, one with less opportunity for public input. This policy shift, virtually replacing the full‐scale EIS, occurred as a way to mediate the conflict between environmental policy and industrialization policy. Formal public participation in environmental decision‐making became the target of reform by the Puerto Rican Government because it perceived that public review was interfering with the location of industry.     

The Water Quality Of The CÉrtima River Basin (Central Portugal)

The aim of this study was to evaluate the water quality of the Cértima River basin (Central Portugal). For that purpose, surface water samples were collected in March, May and July 2003, at 10 selected sampling sites, and were analysed for physicochemical parameters, namely temperature, conductivity, pH, total suspended solids, dissolved oxygen, biochemical oxygen demand (BOD₅), Kjeldahl nitrogen and total phosphorus. Results revealed an acceptable water quality during the spring season. Maxima of 64 mg dm⁻³ for BOD₅, 39 mg dm⁻³ for Kjeldahl nitrogen, and 5.2 mg dm⁻³ for total phosphorus, were recorded during summer, indicating a significant degradation of the water quality in a river stretch located downstream of the town of Mealhada. These values, which did not comply with the objectives of minimum quality for surface waters prescribed by the Portuguese legislation, were related to domestic wastewater discharges and runoff waters from a cattle farm. Besides their effects on the middle stretch of the river, these pollution sources were the most likely cause of the high nutrient load in downstream waters, and thus may have a major impact on the trophic status of Pateira de Fermentelos, a sensitive wetland area located in the lower Cértima basin.     

Electroremediation part II: A study of the movement of heavy metals during an electroremediation process in Andisol soil

In the Summer 2004 issue of Remediation, the authors presented a study of the influence of buffering behavior in contaminated Andisol soil. This article, Part II, expands on this research by presenting the results of laboratory tests conducted to study the movement of heavy metals in contaminated Andisol soil during the first stage of an electrochemical remediation process. The analysis was performed on the soil after treatment and also on the washing solutions collected during the first four hours. In order to analyze the effectiveness of fast and simple techniques for monitoring the electroremediation process, computer‐aided modeling of speciation in the soil solution was performed in connection with the remediation treatment. The results show that the metals moved mainly as positive species in the soil and later occurred as insoluble forms relative to the pH value in the washing solution from the cathode chamber. © 2005 Wiley Periodicals, Inc.     

ALGAL PRODUCTIVITY AND NITRATE ASSIMILATION IN AN EFFLUENT DOMINATED CONCRETE LINED STREAM1

This study examined algal productivity and nitrate assimilation in a 2.85 km reach of Cucamonga Creek, California, a concrete lined channel receiving treated municipal wastewater. Stream nitrate concentrations observed at two stations indicated nearly continuous loss throughout the diel study. Nitrate loss in the reach was approximately 11 mg/L/d or 1.0 g/m²/d as N, most of which occurred during daylight. The peak rate of nitrate loss (1.13 mg/l/hr) occurred just prior to an afternoon total CO₂ depletion. Gross primary productivity, as estimated by a model using the observed differences in dissolved oxygen between the two stations, was 228 mg/L/d, or 21 g/m²/d as O₂. The observed diel variations in productivity, nitrate loss, pH, dissolved oxygen, and CO₂ indicate that nitrate loss was primarily due to algal assimilation. The observed levels of productivity and nitrate assimilation were exceptionally high on a mass per volume basis compared to studies on other streams; these rates occurred because of the shallow stream depth. This study suggests that concrete‐lined channels can provide an important environmental service: lowering of nitrate concentrations similar to rates observed in biological treatment systems.     

Combining Ion‐exchange (IX) technology and biological reduction for perchlorate removal

Ion‐exchange (IX) resin is perhaps the most promising technology to remove the contaminant perchlorate (ClO₄^?) from waters. However, ion exchange is only a separation technology that transfers the perchlorate from waters to the waste solutions used to regenerate the resins. The waste solutions contain high perchlorate concentrations, and treatment technologies for these regenerant solutions are needed. In this article, we review the latest knowledge on perchlorate removal by ion‐exchange resins; propose three systems that combine ion‐exchange resins (for perchlorate removal) and biological reduction for treating the waste solutions resulting from resin regeneration; and discuss the challenges and research needed to fully develop the proposed technology. © 2002 Wiley Periodicals, Inc.     

Valuing diversity: a group‐value approach to understanding the importance of organizational efforts to support diversity

Using Leventhal's rules as well as the group‐value model of procedural justice, we first examined how the negative effects of perceived racial discrimination on procedural justice judgments can be attenuated by perceived organizational efforts to support diversity. Secondly, we examine how these effects ultimately impact affective commitment and organizational citizenship behavior. We found that employees who believe some individuals in the workplace are discriminating against them on the basis of race tend to report lower levels of procedural justice from the organization. However, this negative relationship was attenuated when employees perceived that their organization was making efforts to support diversity. Results suggest that individuals' perceptions of organizational efforts to support diversity can help restore perceptions of procedural justice for employees who experience racial discrimination at work. Improving procedural justice also positively impacts affective commitment and organizational citizenship behavior directed at the organization. Copyright © 2009 John Wiley & Sons, Ltd.     

Influence of salinity and temperature on the activity of biosurfactants by polychaete-associated isolates

Influence of different parameters on biosurfactant (BS) activity was carried out on strains that were isolated from the polychaetes Megalomma claparedei, Sabella spallanzanii and Branchiomma luctuosum and additional 30 strains that were previously identified as potential BS producers from crude oil enrichments of the same polychaete specimens. The selection of BS-producing strains from polychaete natural samples was carried out by using standard screening tests. The BS activity by each isolate was evaluated for the effect of salinity and temperature on emulsion production and surface tension reduction, during incubation in mineral medium supplemented with tetradecane or diesel oil. All isolates showed a similar time course of BS activity, and the latter was more influenced by salinity rather than temperature. Some of the BS producers belonged to genera that have not (i.e. Citricoccus, Cellulophaga, Tenacibaculum and Maribacter) or have poorly been (Psychrobacter, Vibrio, and Pseudoalteromonas) reported as able to produce BSs. This is remarkable as some of them have previously been detected in hydrocarbon-enriched samples. Results confirm that filter-feeding polychaetes are an efficient source for the isolation of BS producers.     

Does seston size structure reflect fish-mediated effects on water quality in a degraded semiarid wetland?

This study evaluates whether the size structure of seston (the sum of living and nonliving particles in the water column) reflects the effects of fish on wetland water quality. Using enclosures, we measured water quality and zooplankton community structure in the presence and absence of two fish species with distinct foraging strategies [benthivorous carp (Cyprinus carpio) and planktivorous mosquitofish (Gambusia holbrooki)]. Seston collected from the enclosures was counted and sized automatically with a Coulter counter, and the size structure in the range of 1–60 μm was modelled using the underlying Pareto distribution of particles. Only Cyprinus contributed to a loss of water quality (increased nutrient levels, algal and non-algal turbidity, hypoxia), while both fish species changed zooplankton community composition compared to fishless controls. However, these changes were not reflected in parameters [goodness of fit (r ²) and parameter c (slopes)] of Pareto models. Multivariate statistics suggest that seston size structure responded more to environmental gradients related to water depth but the relationships were also weak. Our overall result contrasts with the regulation of size spectra constructed from living organisms. Although seston integrates many structural and functional features of the water column, the lack of strong relationships between Pareto model parameters and water quality suggests that a size-based approach to characterise seston structure has a limited potential for assessing biota-mediated effects in wetlands in a straightforward manner.     

Fast characterization of non domestic load in urban wastewater networks by UV spectrophotometry

Urban wastewater treatment plant efficiency, as well as biosolid quality, depends on urban wastewater quality, which can be affected by non domestic discharges (industrial, commercial etc.). The characterization of wastewater quality and non domestic discharge is complex, expensive and time consuming. However, these discharges must be controlled and reduced if possible. The development of a simple and fast methodology, namely based on alternative methods such as UV spectrophotometry, has been carried out and applied to different areas of a medium sized town of Southern Québec (Canada). Several autosamplers and on line/on site measurements have been used in critical control points of the network areas, for a dry weather campaign in four areas (industrial, commercial, hospital and university). The flow rate study, completed by the exploitation of conductivity measurements and the qualitative examination of UV spectra allows the discrimination of non domestic loads and their variability study from one point to another. The identification of critical discharges and organic shock loads has been possible with low investment, and mitigation actions have been proposed.