Hazardous electric arc furnace dust containing dioxins/furans and heavy metals is blended with harbor sediment, fired at 950–1100°C to prepare lightweight aggregates. Dust addition can lower the sintering temperature by about 100°C, as compared to a typical industrial process. After firing at 950°C and 1050°C, more than 99.85% of dioxins/furans originally present in the dust have been removed and/or destructed in the mix containing a dust/sediment ratio of 50:100. The heavy metals leached from all fired mixes are far below Taiwan EPA legal limits. The particle density of the lightweight aggregates always decreases with increasing firing temperature. Greater addition of the dust results in a considerably lower particle density (mostly <2.0gcm−3) fired at 1050°C and 1100°C. However, firing at temperatures lower than 1050°C produces no successful bloating, leading to a denser particle density (>2.0gcm−3) that is typical of bricks.

Bioavailable polycyclic aromatic hydrocarbon (PAH) concentrations in the estuarine water of Kaohsiung Harbor were measured using XAD-2 resin and semipermeable membrane devices (SPMDs) calibrated with performance reference compounds (PRCs). The sum of the PAH concentrations from XAD-2 resin (Cw) in the surface and bottom water samples was 6.63 and 9.58ngL−1, respectively. The variation in PAHs was higher in surface water. Cubic polynomial regressions using the sampling rate for five PRCs (Rs-PRC) provided estimated in situ sampling rates (Rs). The turbulent condition in the surface water was important in enhancing Rs; however, diffusion was relevant to the bottom water, which was less turbulent and showed decreasing Rs at high MW PAHs. The sum of the dissolved PAH concentrations estimated with the SPMDs (CSPMD) was 5.87 and 9.15ngL−1 in the surface and bottom water samples, respectively. The surface and bottom water PAHs were derived from different sources.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).This article has been retracted at the request of the Editor-in-Chief and the Authors.This paper has to be retracted as the authors have noticed a procedural error with regards to their data which affects the results and discussion of the paper. It is important to note that this is not considered to be the result of scientific misconduct, but rather honest errors by the authors.

Analyses of faecal steroids in coastal sediments from Cienfuegos Bay Cuba indicate chronic sewage contamination at the main outfalls from the city, where concentrations of coprostanol up to 5400ngg−1 (dry wt) were measured. In contrast, steroid concentrations and compositions from sites from the south part of the Bay are characteristic of uncontaminated sewage environments. The levels of coprostanol in the Cienfuegos sediments compares to the lower to mid-range of concentrations reported for coastal sediments on a world-wide basis, with sedimentary levels markedly below those previously reported for heavily impacted sites. This study delivers baseline data for further investigation of the effectiveness of the proposed sewerage plan promoted by the GEF project in Cienfuegos. Investigations on the correlations between faecal steroids and other organic contaminants confirmed that the major source of petroleum hydrocarbons within the bay was associated with the sewage effluents from the Cienfuegos city.

The interactive effects of cadmium (Cd) and pyrene (Pyr) on contaminant removal from co-contaminated sediment planted with Kandelia obovata were investigated by a pot experiment. We found that dry weight of plant was significantly decreased under high level of Cd–Pyr combined stress. High Pyr caused the increase of Cd toxicity to K. obovata under high Cd stress because more Cd translocated to the plant tissues. Cd toxicity inhibited Pyr degradation in co-contaminated sediments and higher Pyr degradation was found in the rhizosphere than that in the non-rhizosphere sediment under high Cd treatment. The total number of microorganisms in sediments tended to decrease with increasing Cd under Cd–Pyr combined stress and more amount existed in the rhizosphere sediment. In conclusion, Cd and Pyr removal by K. obovata can influence interactions between these two pollutants in co-contaminated sediment. This suggests that this mangrove can effectively remedy sites co-contaminated with these two types of contamination.

Marine hypoxic episodes are affecting both marine and freshwater bodies all over the world. Yet, limited data exists with regard to the effects of decreasing oxygen on protist metabolism. Three ciliate species were therefore isolated from Hong Kong coastal waters. Controlled hypoxic conditions were simulated in the lab environment, during which time growth, respiration and grazing rates were measured. Euplotes sp. and a Oxytrichidae-like ciliate showed decreased growth and respiration below 2.5mgO2L−1, however Uronema marinum kept steady growth and respiration until below 1.5mgO2L−1. Euplotes sp. and the Oxytrichidae-like ciliate had the highest ingestion rate, which dropped significantly below 3.0mgO2L−1. U.marinum grazing rates were affected at and below 1.5mg O2L−1, correlating with their drop in growth and respiration at this lower concentration. This study illustrates the slowing metabolism of key grazing protists, as well as species-specific tolerance in response to hypoxia.

Biofilms on submerged surfaces are important in determining larval settlement of most marine benthic invertebrates. We investigated if exposure of biofilms to hypoxia would alter the larval settlement pattern and result in a shift in benthic invertebrate community structure in the field. Biofilms were first exposed to hypoxia or normoxia in laboratory microcosms for 7days, and then deployed in the field for another 7days to allow for larval settlement and recruitment to occur. Using terminal-restriction fragment length polymorphism of the 16S rRNA gene, this study showed that hypoxia altered the biofilm bacterial community composition, and the difference between the hypoxic and normoxic treatments increased with the time of exposure period. This study also demonstrated significantly different benthic invertebrate community structures as a result of biofilm exposure to hypoxia and that the hypoxic and normoxic treatments were dominated by Hydroides sp. and Folliculina sp., respectively.

We measured total selenium and total mercury concentrations ([TSe] and [THg]) in hair (n=138) and blood (n=73) of harbor seals (Phoca vitulina) from California to assess variation by geography and sex, and inferred feeding relationships based on carbon, nitrogen, and sulfur stable isotopes. Harbor seals from Hg-contaminated sites had significantly greater [THg], and lesser [TSe] and TSe:THg molar ratios than seals from a relatively uncontaminated site. Males had significantly greater [THg] than females at all locations. Sulfur stable isotope values explained approximately 25% of the variability in [THg], indicating increased Hg exposure for seals with a greater use of estuarine prey species. Decreased [TSe] in harbor seals from Hg-contaminated regions may indicate a relative Se deficiency to mitigate the toxic effects of Hg. Further investigation into the Se status and the potential negative impact of Hg on harbor seals from Hg-contaminated sites is warranted.

The influence of early diagenesis on the vertical distribution of metal forms in the sediments of Bohai Bay was discussed in this paper. The results showed that the concentrations were: Al>Fe≈Ca>Mn>Cr>Zn>Cu>Pb>Cd. In vertical distribution, the forms of Cr and Pb were stable from the top to the bottom. However, the exchangeable forms and acid-extracted forms of Cd, Cu and Zn presented an obvious declining trend. The metals would be transformed to more stable forms during the early-diagenesis process. Further analysis found that early diagenesis can change the sedimentary environment, affecting pH, oxidation–reduction potential (ORP), total dissolved solid (TDS) and the structure of organic matter (OM), all main factors influencing metal forms in the sediments of Bohai Bay.

The distribution of dissolved lead in the coastal waters of the East China Sea was investigated seasonally. The average concentrations in surface waters during the spring and autumn were 0.52nM and 0.27nM, respectively. In the spring, the concentration of dissolved Pb in the surface waters and bottom waters ranged from 0.13 to 1.86nM and from 0.15 to 0.94nM, respectively. For both the surface water and the bottom water, the highest values were observed at the Yangtze River Estuary. Seasonal variability of D-Pb between spring and autumn in the ECS was observed. These results suggested that riverine inputs and atmospheric inputs may be the main sources of lead in this area, while adsorption and co-precipitation on suspended particles at the river estuary and biological process may be the major sinks.