The modified BCR three-step sequential extraction procedure was used to examine the temporal dynamics of trace elements in soils contaminated by an accidental spill from an opencast mine in south-west Spain. Soils were mainly contaminated with pyritic sludge and acidic wastewater, whereas some soils were affected only by acidic wastewater. The distributions obtained for both some major (Ca, Fe and Mn) and trace elements (As, Cd, Cu, Pb and Zn) in the sludge and soil samples taken at different times after the accident, 1-3 months and 21 months, were compared. Sequential extractions were useful in identifying different sources of contamination, and in obtaining additional information on the solubility of secondary minerals formed by pyrite oxidation. Thus, the effectiveness of the BCR procedure has proved to be a useful tool for predicting short- and long-term mobility of trace elements, even in complex environmental scenarios. The modified BCR three-step sequential extraction procedure has proved a useful prediction tool for short- and long-term mobility of trace elements in contaminated soils.

We determined metal contents of co-occurring algae Padina crassa and Sargassum sp. in Port Jackson (Australia), and relationships between metal levels and the abundance of epifaunal amphipods. Copper, lead and zinc concentrations were amongst the highest yet recorded in these algae. Copper, manganese and lead concentrations were far greater in P. crassa than Sargassum sp., possibly due to the low growth of P. crassa in proximity to contaminated sediments. However, in manipulative experiments the proximity of algae to sediments did not explain these differences. The abundance of herbivorous amphipods correlated negatively with the copper content of P. crassa, but not with the lower concentrations in Sargassum sp. The greater contamination of P. crassa led to patchy distributions of metals in algal beds and recolonisation experiments showed Sargassum sp. acts as a refuge from contaminants for epifauna. The contamination of macroalgae may pose threats to epifauna in harbours around the world. The accumulation of metals by macroalgae may pose ecological threats to herbivorous epifauna in ports and harbours worldwide.

In this study, heavy metal content (Cr, Cu, Mn, Ni, Zn) was determined in sediments and different organs of Rumex obtusifolius L. and Polygonum lapathifolium L. (Polygonaceae), Urtica dioica L. (Urticaceae) and Xanthium strumarium L. (Asteraceae) species. These species grow ubiquitously and vigorously on the periodic flooding areas of Nilüfer stream which have been polluted by different local industrial activities. Below and above-ground parts of plant samples and their sediments were analyzed by ICP-MS for their elemental contents. In general, the variations in the heavy metal content in sediments are reflected in heavy metal status of plant organs. However, this variation depends on plant species and heavy metals. R. obtusifolius, U. dioica and X. strumarium species have elevated levels of Cr, Cu, Ni, and Zn whereas Mn was observed only in P. lapathifolium. The contribution of different organs to the accumulation capacity of the total phytomass is specific to species.

The concentrations of Pb, Cd, Cr, Mn and Fe were evaluated in leaves, stem and root of the Scirpus americanus and Typha latifolia aquatic macrophytes, which were collected from Tanque Tenorio, an artificial lagoon highly polluted by municipal and industrial wastewater. Some S. americanus and T. latifolia plants were collected from four different sites within Tanque Tenorio. The sites were chosen regarding their proximity with the main channel discharging wastewater into the lagoon. The results showed that S. americanus and T. latifolia have the ability to extract Pb, Cd, Cr, Mn and Fe from their water surroundings; on the whole, the roots presented higher concentrations of heavy metals than the stem and the leaves. The highest accumulation of heavy metals was observed in plants growing at the site near the channel entering the lagoon. S. americanus accumulated more Pb, Cr, Mn and Fe than T. latifolia; Cd concentrations were comparably the same in both species. This study provides information in relation to aquatic plants growing in polluted waters, which accumulate heavy metals. These findings are of interest pertaining to the removal processes for treating aquatic systems with heavy metal content.

A conceptual model of solute transport with bioremediation processes using sawdust as a matrix to improve the efficiency of bioremediation in porous media is presented. The transport part of the model solves the advection dispersion differential equations and the reaction part describes the heterotrophic metabolisms of several groups of bacteria. The bacterial growth is formulated using the double Monod kinetic equation. The model depicts the utilization of oxygen, nitrate, manganese, iron oxides and sulfate as electron acceptors for oxidation of organic carbon in porous media. Exchange between the different phases (mobile pore water phase, bio phase and matrix phase) is also considered in this model. Model parameters were adopted from literature on bioremediation processes. Feasibility and applicability of parameters were assessed by conducting a laboratory soil-sawdust columns experiments and comparing the simulated results with the experimental data. The results indicate that sawdust could be employed as low-cost materials to enhance the bioremediation processes in porous media. While the availability of organic carbon is one of the most important factors that affect bacterial activity in porous media, this study demonstrates that using sawdust as a carbon source can improve the bacterial activity and increase the column permeability.

Metal (Cu, Mn, Ni, Zn, Fe) concentrations in marine sediment and zooplankton were investigated in Izmir Bay of the Eastern Aegean Sea, Turkey. The study aimed to assess the levels of metal in different environmental compartments of the Izmir Bay. Metal concentrations in the sediment (dry weight) ranged between 4.26-70.8 μg g-¹ for Cu, 233-923 μg g-¹ for Mn, 14.9-127 μg g-¹ for Ni, 25.6-295 μg g-¹ for Zn, 12,404-76,899 μg g-¹ for Fe and 38,226-91,532 μg g-¹ for Al in the Izmir Bay. Maximum metal concentrations in zooplankton were observed during summer season in the inner bay. Significant relationships existed between the concentrations of certain metals (Al, Fe, Mn and Ni) in sediment, suggesting similar sources and/or similar geochemical processes controlling such metals. Higher concentrations of Cu, Zn and percent organic matter contents were found in the middle-inner bays sediments. Based on the correlation matrix obtained for metal data, organic matter was found to be the dominant factor controlling Cu and Zn distributions in the sediment. In general, mean Cu and Zn levels in the bay were above background concentrations in Mediterranean sediments. Zooplankton metal concentrations were similar to sediment distributions.

Due to very high concentration of organic matter there is a great need for alternative solutions for drinking water disinfection in the world. Chlorine dioxide has been successfully used for almost 50 years for disinfection and later for taste removal, odor control, color reduction and oxidation of inorganic compounds such as iron and manganese. An advantage of using chlorine dioxide instead of chlorine is that it does not directly react with organic matter and form halogenated byproducts when it is used for disinfection. THMs, such as CHBr3, ChCl3 etc, are considered as most dangerous for people health. In this article we are to represent the results got from raw water disinfection treatment with chlorine dioxide.