Two species of sunflower, i.e., Tithonia diversifolia and Helianthus annuus, were investigated for their potential to remove heavy metals from contaminated soils. Dried and mature T. diversifolia (Mexican flower) seeds were collected along roadsides, while H. annuus (sunflower) seeds were sourced from the Department of PBST, University of Agriculture Abeokuta, Nigeria. The contaminants were added as lead nitrate (Pb (NO3)2) and zinc nitrate (Zn (NO3)2) at 400 mg/kg which represents upper critical soil concentration for both Pb and Zn. The results indicated that T. diversifolia mopped up substantial concentrations of Pb in the above-ground biomass compared to concentrations in the roots. The concentrations in the leaf compartment were 87.3, 71.3, and 71.5 mg/kg at 4, 6, and 8 weeks after planting (AP), respectively. In roots, it was 99.4 mg/kg, 97.4 mg/g, and 77.7 mg/kg while 79.3, 77.8, and 60.7 mg/kg were observed in the stems at 4, 6, and 8 weeks AP, respectively. Observations with H. annuus followed the pattern found with T. diversifolia, showing significant (p < 0.05) accumulation of Pb in the above-ground biomass. Results obtained from Zn contaminated soils showed significant (p < 0.05) accumulation in the above-ground compartments of T. diversifolia and H. annuus compared with root. However, the highest accumulation of Zn was observed in the leaf. The translocation factor and enrichment coefficient of Pb and Zn with these plant species are greater than 1, indicating that these metals moved more easily in these plants. However, this result also showed that the translocation of Zn from root to the shoot of the two plants was higher than Pb. In conclusion, this experiment showed that these plants accumulated substantial Pb and Zn in their shoots (leaf and stem) at 4 weeks AP which diminished with time. This implies that the efficiency of these plants in cleaning the contaminated soils was at the early stage of their growth.

A meso-scale pilot plant was set up to test the efficiency of a phytoremediation technique applied to slightly contaminated marine sediments dredged from the port of Livorno (central Italy). The technique applied involved the use of plants (a grass species, Paspalum vaginatum and a shrub species, Tamarix gallica) and earthworms (Eisenia foetida sp.) in order to recreate an active ecosystem in which plants, micro- and macroorganisms could interact with each other through the rhizosphere, for the adsorption, extraction and/or degradation of pollutants. This system enables plants to grow in a fine textured and salt medium highly unsuitable for plant species, and a physical, chemical and biological amelioration of the matrix was observed at the end of the experimentation (after 9 months). The sediment was bio-physically pre-conditioned by mixing it with calcareous material from excavating activities (5:1 v/v) and applying green compost. The presence of microorganisms in the rhizosphere and the earthworms produced a reduction by about 50% of the initial total petroleum hydrocarbon content. The use of a natural chelator with phyto-hormonal properties (humic substances) showed their capability of forming stable complexes, especially with Pb, and their contribution as an agronomic fertiliser. The combined effect of the P. vaginatum and T. gallica in the extraction of heavy metals from the sediment showed promisingly high percentages of metal effectively extracted in comparison with its available fraction (e.g. available Ni = 6.2%; Ni extracted = 15.7%). The technique proposed could be promising for an operational re-use of dredged marine sediments for agricultural purposes, a suitable final destination for the great majority of these contaminated materials from rivers and harbour docks.

This paper examines whether multiple regression analysis and neural network models can be applied successfully for the indirect prediction of the runoff treatment performance with water quality indicator variables in an experimental storm water detention system rig. Five biologically mature experimental storm water detention systems with different designs treating concentrated gully pot liquor (spiked with dog droppings) were assessed. The systems were located on The King's Buildings campus at The University of Edinburgh and were monitored for a period of 18 months. Multiple regression analyses indicated a relatively successful prediction of the biochemical oxygen demand and total suspended solids for most systems, but due to a relatively weak correlation between the predictors and both microbial indicators, multiple regression analyses were not applied for the prediction of intestinal enterococci and total coliform colony-forming units. However, artificial neural network models predicted microbial counts relatively well for most detention systems.

The effects of alkaline dust emitted from a cement plant for over 40 years on the anatomy of needles of Scots pine and lignin accumulation were analysed. Comparative analytical studies were conducted in stands similar as to their silvicultural indicators, climate and age in alkalised and in a relatively unpolluted area. Cross-section of needles were stained, photographed under microscope and measured. It was found that, due to the alkalisation of the environment, the total area of the needle cross-section, needle width and thickness and the area of mesophyll had decreased. At the same time, the vascular bundles and epidermis had increased. The greatest anatomical and biochemical differences between the needles from trees growing under optimum conditions and in the alkalised area were observed in the oldest needles. Visual analysis of cross-sections and biochemical analysis showed accumulation of lignin in older needles but more intensively in alkalised areas than in control.

The purpose of this study was to understand the dynamic conditions of soil/organic mixtures in order to contribute to the study of remediation processes at hydrocarbon spill sites. Induced polarization (IP) and physical, chemical, and microbiological parameters for uncontaminated and artificially contaminated soil samples with diesel oil were evaluated under controlled conditions (constant temperature and soil moisture) during a period of 12 months. In contaminated samples, the resistivity and IP parameters (chargeability and polarizability) decreased during 8 months and remained relatively stable between 8 and 12 months. The observed reduction on resistivity and IP parameters was related to the increase on the granular aggregation of the soil and a decrease on total porosity, caused by diesel-degrading microorganisms. The behavior of the IP parameters observed after 8 months can be explained by a reduction in the microbial activity and, consequently, a decrease of the degradation rate of diesel. In the studied loamy soil with high content of organic matter (96.16 g/kg), the results demonstrate that IP time domain measurements can be used in the evaluation of the evolution of the hydrocarbon degradation even when the concentration is not very high.

In order to find out a new effective accumulator of polycyclic aromatic hydrocarbons (PAHs) useful for monitoring studies on a large scale and low costs, the accumulation capacity of both biological and artificial matrixes (mosses and polyester fibers, respectively) has been tested. For this purposes, Hypnum cupressiforme and dacron® were exposed to pollution airborne in two sites located nearby an active iron industry and in center of the town of Trieste, where high PAH pollution spots, due to vehicular traffic, are usually detected. The samplers were exposed in six sampling sessions for 21 days. The results obtained were compared with data collected by active PAH samplers, usually employed for official widespread monitoring. The level of correlation between the data sets was calculated. Furthermore, a repeatability study of data was performed. According to the results, both matrixes are good PAH accumulators, though they show different skills.

Samples of airborne particulate matter (PM₂.₅) were collected at a site in Lahore, Pakistan from November 2005 to January 2006. A total of 129 samples were collected using an Andersen Reference Ambient Air Sampler 2.5-400 sampler and analyzed for major ions, trace metals, and organic and elemental carbon concentrations. The data set was then analyzed by positive matrix factorization (PMF) to identify the possible sources of the atmospheric PM collected in this urban area. Six factors reproduced the PM₂.₅ sample compositions with meaningful physical interpretation of the resolved factors. The sources included secondary PM, diesel emissions, biomass burning, coal combustion, two-stroke vehicle exhaust, and industrial sources. Diesel and two-stroke vehicles contributed about 36%, biomass burning about 15%, and coal combustion sources around 13% of the PM₂.₅ mass. Nearly two thirds of the PM₂.₅ mass is carbonaceous material. Secondary particles contributed about 30% of PM₂.₅ mass. The conditional probability function (CPF) was then used to help identify likely locations of the sources present in this area. CPF analysis point to the east and northeast, which are directions of urban and industrial areas located across the border near Amritsar, India as the most probable source for high PM₂.₅ concentration from diesel and two-stroke vehicles exhaust in Lahore. Analysis of those days within three different ranges of PM₂.₅ concentration shows that most of the measured high PM₂.₅ mass concentrations were driven by diesel and two-stroke vehicle emissions including the associated primary sulfate. The use of the potential source contribution function (PSCF) to find the source locations of regionally transported particles is inapplicable in situations when high PM₂.₅ concentrations are dominated by local sources and local meteorology.

Lake Vela (Littoral Centre of Portugal) is considered a natural habitat with community interest and consequently was included in the Natura 2000 Network. However, this freshwater ecosystem has been potentially exposed to diffuse pollution generated by agricultural and livestock activities, which seriously compromise its ecological balance. As part of the Ecological Risk Assessment (ERA) proposed for Lake Vela, this study aimed to evaluate the occurrence of pesticides in different compartments: surface water, groundwater, sediments, and fish tissues. Moreover, to assess potential concerning effects on ecosystem and human health, the measured concentrations of pesticides were compared with regulatory and toxicological benchmarks. The results confirmed the presence of high concentrations of pesticides, including organochloride pesticides banned decades ago, in surface water, groundwater, and sediment. The measured concentrations of pesticides, compared with toxicological benchmarks, indicated that harmful effects are likely for aquatic species due to the presence of alachlor, aldrin, and dieldrin. Additionally, the concentrations of pesticides detected in groundwater were also above the recommended safety levels for drinking water, which constitutes a concern for the local population's health. Results also showed an accumulation of alachlor in predator and benthic fish species which could represent a risk to human consumers and particularly to the regular fish predators (e.g., otters and birds). This study, as the first exposure characterization performed on the Lake Vela system, constitutes valuable and useful information for the ERA process. Although this preliminary assessment of risks should be continued and confirmed through a weight-of-evidence approach, it had already unraveled how concerning are the problems in this ecosystem and the urgency of implementing restoration measures to guaranty its sustainability. Furthermore, this study reinforces the importance of evaluating similar freshwater ecosystems that are also highly threatened by diffuse pollution.

The main objective of this study was to examine the efficacy and capacity of constructed wetlands for metal removal. Between January 2006 and December 2008, removal of Cr, Cu, Cd, Zn, Pb, B, Ni, As, Fe, Hg, and Mn was measured on a monthly basis at a hierarchical mosaic of artificial ecosystems which has been in operation since 1998. The results showed a great variety of average removal efficiencies, in the range of 55% for chromium and −73% for manganese. Four elements presented negative removal: nickel, iron, arsenic, and manganese. Seasonal removal efficiencies were also studied for each element. Moreover, a correlation assessment among metal removal efficiencies and different parameters of each basin in the hierarchical mosaic of artificial ecosystems was performed. Negative significant correlations were found among Fe, Zn, Cu, Mn, As, Ni, Cd, and Hg removal and the inlet concentrations. In general, the treatment system was not a good system for removal of metals from wastewater as, in relation to other constructed wetlands, the system was not able to provide efficient removal of metals.

An exploratory survey of the mercury content of some common California biomass feedstocks shows that the concentrations are well below EPA toxicity levels with representative feedstock concentrations of 20 ppb for rice straw, 28 ppb for wheat straw, and 32 ppb for whole-tree wood chips. The temporal variability for rice straw (17-20 ppb) is near the analytical uncertainty (∼2 ppb). Saline-irrigated feedstock does not contain greatly higher mercury contents (17-38 ppb) compared to normally irrigated feedstock. Water leaching has likewise no detectable effects on mercury mobility, despite an up to 30% increase in the Hg concentrations attributable to mass losses during leaching. Combustion at temperatures of at least 575°C results in complete volatilization of mercury leaving solid ash and slag residuals with mercury contents at or near the lower limit of detection (5 ppb). The mercury strongly concentrated in fly ash can reach concentrations up to 40 times (<1,166 ppb) the corresponding fuel concentrations.