Pathways utilized by heavy metal pollutants in urban stormwater runoff

The research concerned the assessment of the pathways utilized by heavy metal pollutants in urban stormwater runoff. A separately sewered urban residential catchment of approximately 107 hectares in Chelmsley Wood, north-east Birmingham was the subject of the field investigation. The catchment area, almost entirely residential, had no immediate industrial heavy metal input, however, industry was situated to the north of the catchment. The perimeter of the catchment was bounded by the M6 motorway on the northern and eastern sides and was believed to contribute to aerial deposition. Metal inputs to the ground surface were assumed to be confined to normal suburban activities, namely, aerial deposition, vehicular activity and anthropological activities. A programme of field work was undertaken over a 12 month period, from July 1983 to July 1984. Monthly deposition rates were monitored using a network of deposit cannisters and roadside sediment and soil samples were taken. Stormwater samples were obtained for 19 separate events. All samples were analysed for iron, lead, zinc, copper, chromium, nickel and cadmium content. Rainfall was recorded on site with additional meteorological data obtained from local Meteorological Offices. Use was made of a simple conceptual model designed for the catchment to substantiate hypotheses derived from site investigations and literature, to investigate the pathways utilized for the transportation of heavy metals throughout the catchment.

Identification of industrial sources of airborne heavy metal pollution in urban areas

The research examines the deposition of airborne particles which contain heavy metals and investigates the methods that can be used to identify their sources. The research focuses on lead and cadmium because these two metals are of growing public and scientific concern on environmental health grounds. The research consists of three distinct parts. The first is the development and evaluation of a new deposition measurement instrument - the deposit cannister - designed specifically for large-scale surveys in urban areas. The deposit cannister is specifically designed to be cheap, robust, and versatile and therefore to permit comprehensive high-density urban surveys. The siting policy reduces contamination from locally resuspended surface-dust. The second part of the research has involved detailed surveys of heavy metal deposition in Walsall, West Midlands, using the new high-density measurement method. The main survey, conducted over a six-week period in November - December 1982, provided 30-day samples of deposition at 250 different sites. The results have been used to examine the magnitude and spatial variability of deposition rates in the case-study area, and to evaluate the performance of the measurement method. The third part of the research has been to conduct a 'source-identification' exercise. The methods used have been Receptor Models - Factor Analysis and Cluster Analysis - and a predictive source-based deposition model. The results indicate that there are six main source processes contributing to deposition of metals in the Walsall area: coal combustion, vehicle emissions, ironfounding, copper refining and two general industrial/urban processes. |A source-based deposition model has been calibrated using facctorscores for one source factor as the dependent variable, rather than metal deposition rates, thus avoiding problems traditionally encountered in calibrating models in complex multi-source areas. Empirical evidence supports the hypothesised associatlon of this factor with emissions of metals from the ironfoundry industry.

(Table 1) Grain size composition and heavy metal speciations in bottom sediments of the Ussuri Bay, Sea of Japan

Changes in concentration levels and speciation of heavy metals during sedimentation on example of a typical semi-closed bay, where bottom sediments have formed due to river run-off, are under consideration. It is shown that due to desorption of mobile manganese, zinc and copper entered the bay with river suspended matter, their total contents in bottom sediments decrease and percentages of lithogenic forms increase. Contents and speciation of iron in bottom sediments are determined by its participation in coagulation of river colloids in the mixing zone and by mechanical differentiation of sedimentary material.

A heavy metal P-type ATPase OsHMA4 prevents copper accumulation in rice grain

Acknowledgements We thank B. Lahner, E. Yakubova and S. Rikiishi for ICP-MS analysis, N. Komiyama, Iowa State University Plant Transformation Facility and Prashant Hosmani for generation of transgenic rice, K. Wang for providing pTF101.1 vector and N. Verbruggen for providing pYES2 and pYEC2/CT-GFP vectors. We also thank Rice T-DNA Insertion Sequence Database center for providing the T-DNA insertion line and X. Wang, T. Zheng and Z. Li for accessing 3 K rice genome sequence, and Graeme Paton for helpful discussions on Cu bioavailability in water-logged soils. This research was supported by a Grant-in-Aid for Specially promoted Research (JSPS KAKENHI Grant Number 16H06296 to J.F.M), and the US National Science Foundation, Plant Genome Research Program (Grant #IOS 0701119 to D.E.S., M.L.G. and S.R.M.P.).

Mobility and toxicity of heavy metal(loid)s arising from contaminated wood ash application to a pasture grassland soil

The authors acknowledge the financial support the Scottish Government’s Rural and Environmental Sciences and Analytical Services (RESAS) in order to complete some of the soil and pore water sample analysis as well as the Czech Ministry of Education, Youth and Sports (COST CZ LD13068), the Czech Science Foundation (GAČR 14-02183P) and EU COST actionFP1407 (‘ModWoodLife’) short term scientific mission grant in order to complete the column leaching test.

Chemical changes and heavy metal partitioning in an oxisol cultivated with maize (Zea mays, L.) after 5 years disposal of a domestic and an industrial sewage sludge.

The need for solutions to minimize the negative environmental impacts of anthropogenic activities Fhas increased. Sewage sludge is composed of predominantly organic matter and can be used to improve soil characteristics, such as fertility. Therefore, its application in agriculture is an adequate alternative for its final disposal. However, there is a lack of information on its long-term effects on soil changes in tropical areas. Thus, the objectives of this study were to determine (i) the effect of sewage sludge application on heavy metal build-up in soil and maize grains and leaves, and (ii) the effects of soil amendment with sewage sludge on the chemical properties of a Brazilian oxisol. Besides the increasing levels of Zn, Cu, Ni, and Cr, amending soil with sewage sludge also alters the distribution of these metals by increasing the mobile Phases, which correlated significantly with the increase in metal extraction with two single extractants, Mehlich 1 and DTPA (Diethylene triamine pentaacetic acid). The levels of Fe, Mn, Zn, and Cu in maize grains and leaves increased with the type and rate of sewage sludge application. Nevertheless, metal build-up in soil and plants was within the allowed limits. Significant differences were also found in soil characteristics like humic fractionation with the applied sewage doses. The data obtained does not indicate any expressive drawbacks in the use of sewage sludge as a soil amendment, as the heavy metal concentrations observed are unlikely to cause any environmental or health problems, even overestimated loadings, and are in accordance with the Brazilian regulations on farming land biosolid disposal.

Heavy metal release due to aging effect during zero valent iron nanoparticles remediation

Zero valent iron nanoparticles (nZVI) represent a promising agent for environmental remediation. Nevertheless, their application presents some limitations regarding their rapid oxidation and aggregation in the media. The aim of this study was to determine the effect that nZVI aging has in heavy metal remediation in water. Contaminants studied were Zn, Cd, Ni, Cu and Cr, which are typical elements found in ground and wastewater. Results show a high contaminant removal capacity by the nZVI in the first 2 h of reaction. Nevertheless, for longer reaction times, some of the metal ions that had already been adsorbed in the nZVI were delivered to the water. Cd and Ni show the maximum delivery percentages (65 and 27% respectively after 21 days of contact time). The starting delivery time was shortened when applying lower nZVI amounts. No re-dissolution of Cr was observed in any circumstance because it was the only element incorporated into the nanoparticles core, as TEM images showed. Contaminant release from nZVI is probably due to nanoparticles oxidation caused by aging, which produced a pH decrease and nZVI surface crystallization.