Assessing metal bioaccumulation from estuarine sediments: comparative experimental results for the polychaete Arenicola marina

Purpose

The purpose of this paper is to compare three approaches for providing information on the bioaccumulation potential of metals from contaminated sediments to the deposit-feeding polychaete Arenicola marina.

Materials and methods

We present metal (Ag, As, Cd, Cu, Pb and Zn) bioaccumulation results from field-collected sediments quantified through direct measurements of bioaccumulated concentrations in A. marina over a period of 30 days under controlled laboratory exposures and compare these results with bioaccumulated metal concentrations in field-collected organisms from the same sites of collection of the sediments used in the laboratory exposures. For the metals for which model parameters are available (Ag, As, Cd and Zn), we also compare these results with biodynamic model predictions. We considered three UK estuaries characterised by a well-reported history of trace metal contamination and bioavailability in addition to the (control) site of collection of the worms.

Results and discussion

The results from laboratory-exposed organisms showed that the standard 28-day exposure duration may be adequate to identify the potential for metal bioaccumulation in this polychaete at the sites considered here. However, the time course of bioaccumulated concentrations and the comparison with measured concentrations in field-collected worms show that a steady state has not been reached, confirming the need for extended exposure periods. The worms showed symptoms of stress in feeding and growth during the initial 10 days of exposure and subsequent partial recovery during the following 20 days, suggesting that stress was not always caused by sediment contamination but that it was likely associated with handling and acclimation. At this last stage of the exposure, a generalised biodynamic model was used to provide estimates of bioaccumulated metal concentrations and net accumulation rates in worms.

Conclusions

The results of this study highlight the number of factors that should be considered for the interpretation of bioaccumulated metal concentrations in A. marina under laboratory exposures for contaminated sediment assessment, factors that appear to be common to most deposit-feeding polychaetes. A general biodynamic model proved to be a cost-effective method for an initial estimation of the extent and pattern of metal bioaccumulation under specified exposure conditions.     

The effects of pH,redox, and salinity on metal release from a contaminated sediment

Levels of total Hg were determined in the muscle tissue of Helicolenus dactylopterus (mean=0.29 ug.g⁻¹ ±0.025 S.E.; range=0.041.10 ug.g⁻¹) and Pontinus kuhlii (mean=0.16 ug.g⁻¹ ±0.092 S.E.; range=0.05-0.50 ug.g⁻¹) caught in the Azores between August 1989 and May 1990. Mercury concentrations were related to sex, length, weight, age, growth and condition of both fish species. There were highly significant positive correlations between Hg levels and these variables. In P. kuhlii a significant sex-related difference in Hg levels was found; the rate of Hg accumulation is significantly faster in females than in males and mean Hg levels were higher in females. Relationships describing Hg vs size and age dependence were determined for both species and sexes and patterns and rates of Hg accumulation were discussed in relation to a number of biological and ecological factors with influence on it. A comparison of Hg content of Azorean and Mediterranean populations of H. dactylopterus was conducted and its suitability as an indicator in pollutant monitoring of benthic compartment of marine ecosystems is discussed.     

Effects of sediment and contaminated sediment on structural and functional components of experimental stream ecosystems

Three experimental stream ecosystems were used to determine the effects of sediment and contaminated sediment: one stream received 1.7 g L^?1 uncontaminated sediment for 2 hr each week for 6 wk; one stream received 1.7 g L^?1 contaminated sediment (50 to 1600 ppm triphenyl phosphate applied in increasing doses each week) for 2 hr each week for 6 wk; and the third stream was maintained as a control. Each stream was monitored for changes in nutrient dynamics, leaf decomposition, primary production, and invertebrate dynamics. Both sediment and sediment/triphenyl phosphate altered the drift dynamics of benthic invertebrates. Invertebrates in the sediment treatment exhibited delayed nocturnal drift, while those in the sediment/triphenyl phosphate treatment drifted immediately once a threshold of toxicity was reached. Both sediment and sediment/triphenyl phosphate decreased the percent similarity of benthic invertebrates, reduced the drift of filamentous algae, increased the production of rooted flora, and increased net nutrient retention. However, neither treatment altered leaf decomposition rates, nor affected benthic invertebrate dynamics (total number, number of species, or diversity) or insect emergence.     

Chemical species of organotin compounds in sediment at a marina.

A bottom sediment collected in a marina was analyzed for organotin species, and >20 organotin compounds including biodegraded ones were confirmed by comparison with the synthesized standards using gas chromatography (GC)/mass spectrometry and a GC/atomic emission detection system. Their structures were also determined in comparison with those in a technical grade of tri-n-butyltin chloride (TBTC). Eleven organotin compounds were found in the technical TBTC. Among them, unexpected organotin compounds, such as di-n-butyl(2-ethylhexyl)tin chloride and di-n-butyloctyltin chloride, were identified, although the levels were low. These compounds were also found in the sediment sample. The relationship between organotin compounds in the technical TBTC and those in marine products was also discussed.     

Sublethal effects of oil on mollusc species from the Baltic Sea

Water, Air, & Soil Pollution - Sublethal effects of Iranian crude oil were studied using molluscs from the brackish Baltic Sea (salinity: 6 to 7%o S). In blue mussels (Mytilus edulis) low...     

Sublethal effects of insect growth regulators upon crab larval behavior

Both swimming speeds and phototaxis by the four larval stages of the crab Rhithropanopeus harrisii were monitored upon chronic exposure to sublethal concentrations of the insect growth regulators methroprene (Altosid^R: ZR-515), hydroprene (Altozar^R: ZR-512) and dimiline (TH-6040). Larvae were reared under conditions of salinity (20orbo) and temperature (25°C) which produce the greatest developmental success. Sublethal concentrations of methroprene had no effect on swimming rates or phototaxis as compared to the acetone control larvae. For hydroprene, swimming rates by stage I, II and III zoeae were unaffected while a significant increase in swimming speeds occurred in Stage IV zoeae exposed to concentrations of 0.05 and 0.1 ppm. Only Stage III zoeae exposed to 0.l ppm showed a significant decrease in the level of positive phototaxis. Dimilin was much more potent, as significant increases in swimming speeds occurred in Stage I, II and III zoeae, with 0.3 ppb being the lowest effective concentration. Although swimming by Stage IV zoeae was unaffected, phototaxis was altered at concentrations as low as 0.1 ppb. Concentrations, which alter behavior, are related to levels which are reported to control mosquitoe larvae.     

Electrokinetic approach to assess the behaviour of a contaminated marine sediment

Journal of Soils and Sediments - The present study focuses on the laboratory-scale application of an electrokinetic technique for the remediation of a contaminated marine sediment dredged from a...     

Sublethal effects of nickel on carbohydrate metabolism,blood and mineral contents of Tilapia nilotica

Effects of three sublethal levels (19.2, 32 and 51.2 mg L^?1) of Ni on carbohydrate metabolism, hematology and mineral contents of Tilapia nilotica at 6 time intervals from 6 to 96 hr have been evaluated. Prominent dose-dependent hyperlacticemia and hyperglycemia were showed at the three Ni levels. Liver glycogen showed a general decrease at all Ni levels and muscle glycogen showed a decrease only at the two higher levels of Ni. High Levels of Ni elevated red blood cell count, hemoglobin content and packed cell volume and caused leucopenia and lymphopenia. The presence of Ni resulted in its accumulation in the blood, kidney, liver and muscle. Nickel accumulated to the greatest extent in the kidney. It had no statistical influence on the blood Cu content but considerably increased the Zn content of blood and Fe content of all the tissues investigated.     

Potential effects of food addition to sediment on test conditions in sediment toxicity tests

Purpose  

Standardized sediment toxicity assays often employ periodic additions of uncontaminated food to sustain energy and growth requirements of the test organisms. Consequently, selective feeding on this uncontaminated food may reduce exposure to sediment particles containing the test substance. To address this issue, some standard guidelines propose to add food to the sediment before spiking with the test substance to account for multiple exposure routes, including ingestion of contaminated food. The present study focused on the influence of different feeding regimens and compositions of the aqueous medium on water quality (ammonia concentrations) and test organism development.     

过碳酰胺对土壤中非离子表面活性剂的修复研究

过碳酰胺是一种新型精细化工品,也是一种新型N肥,其应用和开发在国外已得到广泛的研究,而在我国还刚刚起步.为考察过碳酰胺作为一种N肥去除土壤中有机污染物的作用和潜力,将修复与施肥结合,为过碳酰胺应用于环境污染修复提供新的理论依据,特进行了本研究.本文采用室内土培试验等手段,研究了1种酸性土壤中施入过碳酰胺后对2种非离子表面活性剂TritonX-100和Tween80的降解效果.试验结果表明:过碳酰胺对2种非离子表面活性剂都有明显的降解效果,降解速度均是在第2周时较快,此后.随着降解时间的延长,降解速率逐渐下降.8周后1000mg/kg Tween80的残留浓度仅有195.46mg/kg土,降解率高达80%以上.5 mmol/kg的过碳酰胺降解2周后已有明显降解效果,但继续增加过碳酰胺浓度.其降解效果并非相应增加.     

Interaction dynamics between a contaminated dredged sediment and extracting solutions of different nature

Purpose

The purpose of this work is to study the dynamics between the matrix of a contaminated marine sediment, its contaminants and various desorbing solutions by means of equilibrium tests, sedimentation trials and zeta potential, with the focus on assessing optimum enhancing solutions for decontamination purposes.

Materials and methods

The sediment samples were analysed to determine their physico-chemical characteristics: particle size distribution, solids concentration, total organic carbon (TOC), content of heavy metals, organic contaminants, mineralogical phases, zeta potential and buffer capacity. Twelve extracting solutions of different nature were used for equilibrium tests, in which the dynamic behaviour of the sediment was evaluated. Elemental analysis was carried out for the sediment samples and the solutions before and after the tests.

Results and discussion

The sediment was mainly composed of clay and lime, with a high content of iron, which has a strong influence on sorption-desorption processes. The sediment had a considerable buffer capacity at low and high pH values. The desorption of the metals was not proportional to pH. The highest decrease in the concentration of metals from the sediment was obtained with 0.2 M ethylenediaminetetra-acetic acid (EDTA) and 1 M nitric acid, while the lowest degree of metal extraction occurred in pure water and potassium iodide (KI).

Conclusions

The most important parameters for contaminant release were complexation ability of the solution for the sediment components and pH of the solution. A promising design for the remediation treatment for the investigated sediment includes complexation and strong acid agents.

     

添加凹凸棒土和钠基蒙脱石对铜锌镉污染红壤的改良效应研究

通过温室盆栽试验.开展了凹凸棒土和钠基蒙脱石处理对铜锌镉污染红壤的改良效应研究.结果表明:添加凹凸棒土和钠基蒙脱石处理能显著增加黑麦草(Lolium multiflorum Lam)两茬的地上部生物量(鲜重).未施入改良剂时,两茬黑麦草地上部的生物量分别为是7.60 g/盆和5.67 g/盆,添加80 g/kg 凹凸棒土处理的两茬地上部生物量分别增加了184%和15%添加80 g/kg钠基蒙脱石处理的两茬地上部生物量分别增加了113%和99.3%.黏土矿物的加入使土壤的pH提高了0.26～1.02个单位.从而降低了植株对Cu、Zn、Cd的生物有效性.随着添加量从20 g/kg增加到80 g/kg,黑麦草地上部Cu、Zn、Cd的含量降低,钠基蒙脱石钝化Cu、Cd的效果好于凹凸棒土,但两者钝化Zn的效果没有显著差异性.添加40 g/kg和80 g/kg的凹凸棒土或钠基蒙脱石处理都显著降低了污染上壤TCLP提取液中Cu、Zn的浓度,对于TCLP提取液中Cd浓度的显著降低只有添加80 g/kg的凹凸棒上这一种处理达到.     

An investigation of the effects of breakwaters on beach sediment characteristics

The south-east reach of Castiglione della Pescaia beach, Italy, has been studied to demonstrate the effect of the breakwaters on sediment characteristics as regards as the cuspate shape of the shoreline.Several samples have been collected to investigate the longshore distribution of sediment parameters such as mean size, sorting and skewness. In addition, comparison with data from natural cuspate beaches has been made. It shows an opposite sediment size distribution while sorting and skewness are almost the same for cusps and bays. That is a consequence of different hydrodynamic processes evenly resulting in a similar shoreline morphology.The grain size analysis has also allowed to state that the sediment of the protected beach is substantially of the same quality of that where natural conditions prevail and that the influence of breakwaters can be neglected in terms of skewness sign.Statistical tests, using mean size, confirmed the main longshore direction of sediment transport, calculated theoretically.Core samples have been taken in order to examine the subsurface sediment characteristics in the breakwater protection area.The core sediments show a predominant positive skewness while the grab and the berm samples are more frequently negatively skewed.The analysis of core stratigraphy taken in different periods shows a sea-bed scour of at least 1 m in the aggradational protected area during ordinary sea-storms.     

An investigation of the effects of breakwaters on beach sediment characteristics

The south-east reach of Castiglione della Pescaia beach, Italy, has been studied to demonstrate the effect of the breakwaters on sediment characteristics as regards as the cuspate shape of the shoreline.Several samples have been collected to investigate the longshore distribution of sediment parameters such as mean size, sorting and skewness. In addition, comparison with data from natural cuspate beaches has been made. It shows an opposite sediment size distribution while sorting and skewness are almost the same for cusps and bays. That is a consequence of different hydrodynamic processes evenly resulting in a similar shoreline morphology.The grain size analysis has also allowed to state that the sediment of the protected beach is substantially of the same quality of that where natural conditions prevail and that the influence of breakwaters can be neglected in terms of skewness sign.Statistical tests, using mean size, confirmed the main longshore direction of sediment transport, calculated theoretically.Core samples have been taken in order to examine the subsurface sediment characteristics in the breakwater protection area.The core sediments show a predominant positive skewness while the grab and the berm samples are more frequently negatively skewed.The analysis of core stratigraphy taken in different periods shows a sea-bed scour of at least 1 m in the aggradational protected area during ordinary sea-storms.     

Chlorinated and methylated dibenzothiophenes in sediment samples from a river contaminated by organochlorine wastes

Eleven sediment samples from the lower Kymijoki River were analyzed for the occurrence of polychlorinated and polymethylated dibenzothiophenes (PCDT and PMeDTs). The area was heavily polluted by wastes from a pulp chlorobleachery and by leakage from a factory producing wood preservative chlorophenol formulation Ky-5. Levels in the sediments were from <5 to 400, 200 and 50 pg g^-1 dw for tetra, penta and hexa-CDT, respectively. The concentrations of mono, di, tri and tetra-MeDTs were in the range of 1–5, 5–85, 5–500 and 15–2300 ng g^-1 dw, respectively. PCDT contents in surface sediment (0–3 cm layers) decreased by distance downstream from the bleachery and Ky-5 factory similar to those of the bound polychloroguaiacols (PCG) and polychlorinated dibenzofurans (PCDF). In contrast, PMeDT contents showed a steep increase by distance with a maximum at 32 km downstream.     

拟除虫菊酯在底泥中的归趋及其生物效应

拟除虫菊酯是一类高疏水性仿生杀虫剂,进入环境中易被颗粒物或油滴吸附,最终聚积在底泥沉积物中;同时它可以随水流或胶体等途径发生迁移,已被研究证实在使用及未使用拟除虫菊酯地区的河流、湖泊底泥中均检测到其残留。本文介绍了底泥中拟除虫菊酯的来源、归趋、生物效应,重点分析了拟除虫菊酯的吸附/解吸、降解作用及湿地生态系统对其归趋的影响;讨论了拟除虫菊酯的水生生物毒性、生物富集作用等生物效应,评述了其疏水性及生物可利用性对其毒性的影响,可为拟除虫菊酯水生生态系统风险评价等研究提供重要参考信息。     

Patterns of effects of arbuscular mycorrhizal fungi on plants grown in contaminated soil

Arbuscular mycorrhizal fungi (AMF) are integral functioning parts of plant root systems and are widely recognized for enhancing plant growth on severely disturbed sites, including those contaminated with heavy metals. However, the generality of detailed patterns observed for their influence on various metals and oxidative‐stress parameters in multiple plant species is not clarified. The goal of this study was to investigate the patterns of metal‐stress alleviation by AMF in four plant species. For this purpose, clover, sunflower, mustard, and phacelia were inoculated with Glomus intraradices and compared to noninoculated plants grown under heavy metal–stressed conditions. The study focused on the effect of AMF inoculation on plant biomass, assimilating pigments, total protein, superoxide dismutase and peroxidase activity, lipid peroxidation and As, Cd, Co, Cu, Fe, Mn, P, Pb, U, and Zn contents. As a result of inoculation very different patterns of variation were obtained for concentrations of elements and for biochemical parameters in plants. The particular effect of AMF inoculation on plants was species‐ and metal‐specific, although there was a general enhancement of plant growth.     

Correction to: Interaction dynamics between a contaminated dredged sediment and extracting solutions of different nature

Journal of Soils and Sediments - Figure 4 is not correct in the PDF format of the originally published article. Please note that in the HTML or online format, the image is correct.     

草被减流减沙效应及其力学机制分析

 利用人工模拟降雨试验,定量研究不同降雨强度下20°坡面草地的减流减沙效应,探讨草被坡面固土作用的力学机制。结果表明:在45、87和127mm/h降雨强度下,草地坡面土壤的平均入渗率是裸地坡面入渗率的2.1～4.2倍;与裸地相比,草地径流流速减少77.3%～79.8%,径流量减少51.9%～99.1%,产沙量减少93.6%～99.2%;从力学角度分析坡面土壤颗粒的受力情况,建立的坡面产沙量与径流切应力的关系模型可用于草被坡面土壤流失量预测;试验条件下,草地临界径流切应力值为2.857N/m2,裸地临界径流切应力值为0.861N/m2,坡面产沙量随径流切应力的增大而增大。研究结果对定量评价草被减流减沙作用和深化土壤侵蚀力学过程有一定的参考意义。     

The effects of suspended sediment on walleye (Sander vitreus) eggs

Purpose

Sediment resuspension is among the most widely cited concerns that lead to restricted dredging timeframes. Protection of fish species is a primary concern regarding the effects of dredging operations, yet experimental data establishing thresholds for uncontaminated suspended sediment effects are largely lacking. We conducted research to determine suspended sediment effects on walleye (Sander vitreus) egg hatching success and gross morphology following exposures mimicking sediment resuspension during dredging operations.

Materials and methods

Newly spawned eggs of northern and southern walleye strains were continuously exposed for 3?days to suspended sediment concentrations of 0, 100, 250, and 500?mg?l^?1, using sediment from Maumee Bay, OH, USA. These concentrations spanned the range measured in the vicinity of dredging operations in the Western Basin of Lake Erie.

Results and discussion

Northern and southern strain egg hatching rates were 53% and 39% of exposed eggs and 82% and 74% of viable eggs exposed, which are within reported ranges for this species. Data indicated no statistically significant effects of suspended sediment on hatching success. Gross morphological observations of exposed fry yielded no evidence of detrimental effects.

Conclusions

Experimental results indicated that walleye eggs are relatively tolerant to exposures likely to be encountered at dredging projects as performed in the Great Lakes region. Our results suggest that, given detailed knowledge of dredging project site-specific conditions and the mode of dredging to be used, better informed decisions can be made regarding adequate protective management practices. In many cases, flexibility could be given to the dredging contractor while maintaining a very low probability of risk to walleye spawning habitat.