Clays such as kaolin, bentonite and zeolite were evaluated as support material for nanoscale zero-valent iron (nZVI) to simultaneously remove Cu²⁺ and Zn²⁺ from aqueous solution. Of the three supported nZVIs, bentonite-supported nZVI (B-nZVI) was most effective in the simultaneous removal of Cu²⁺ and Zn²⁺ from a aqueous solution containing a 100 mg/l of Cu²⁺ and Zn²⁺, where 92.9 % Cu²⁺ and 58.3 % Zn²⁺ were removed. Scanning electronic microscope (SEM) revealed that the aggregation of nZVI decreased as the proportion of bentonite increased due to the good dispersion of nZVI, while energy dispersive spectroscopy (EDS) demonstrated the deposition of copper and zinc on B-nZVI after B-nZVI reacted with Cu²⁺ and Zn²⁺. A kinetics study indicated that removing Cu²⁺ and Zn²⁺ with B-nZVI accorded with the pseudo first-order model. These suggest that simultaneous adsorption of Cu²⁺and Zn²⁺ on bentonite and the degradation of Cu²⁺and Zn²⁺ by nZVI on the bentonite. However, Cu²⁺ removal by B-nZVI was reduced rather than adsorption, while Zn²⁺ removal was main adsorption. Finally, Cu²⁺, Zn²⁺, Ni²⁺, Pb²⁺ and total Cr from various wastewaters were removed by B-nZVI, and reusability of B-nZVI with different treatment was tested, which demonstrates that B-nZVI is a potential material for the removal of heavy metals from wastewaters.

In 2009, hexachlorocyclohexane (HCH) isomers (α-HCH, β-HCH, and γ-HCH [lindane]) were listed as persistent organic pollutants (POP) in the Stockholm Convention. Accordingly, the legacy of HCH/lindane production with the associated large HCH waste deposits has become recognized as an issue of global concern and is addressed in the implementation of the Convention. The current paper gives an overview of the major contaminated sites from lindane production of the INQUINOSA Company. This company operated from 1975 to 1988 in the city of Sabiñánigo, Spain. HCH production resulted in the production of approximately 115,000 tonnes of waste isomers which were mainly dumped in two unlined landfills. These two landfill sites, together with the former production site, are recognized sources of environmental pollution. Assessment and remediation activities at these sites are described. A dense nonaqueous phase liquid (DNAPL) contaminated inter alia with HCH isomers, benzene, chlorobenzenes, and chlorophenols as the main contaminants and an associated contaminated groundwater plume have been discovered at both landfill/dumpsites and at the former production site. The approximately 4,000 t of DNAPLs constitute a serious risk for the environment due to the proximity of the Gállego River. Since 2004, more than 20 tonnes of this DNAPL has been extracted using “pump and treat” techniques. The Aragon Regional Government and the Spanish Environmental Ministry are taking action, focusing on the treatment of DNAPL and on the transfer of the large quantities of solid POP wastes to a new landfill. A range of laboratory tests has been performed in order to plan the aquifer remediation.

The rhizosphere plays an important role in altering cadmium (Cd) solubility in paddy soils and Cd accumulation in rice. However, more studies are needed to elucidate the mechanism controlling rice Cd solubility and bioavailability under different rhizosphere conditions to explain the discrepancy of previous studies. A rice culture with nutrient solution and vermiculite was conducted to assess the effects of pH, Eh, and iron (Fe) concentration on Cd, Fe fractions on the vermiculite/root surface and their uptake by rice. The solution pH was set from 4.5 to 7.5, with additions of Fe (30 and 50 mg L ⁻¹) and Cd (0.5 and 0.9 mg L ⁻¹). At pH 5.5, the Eh in the rice rhizosphere was higher whereas transpiration, Cd ²⁺, and Fe ²⁺ adsorption on the vermiculite/root surface and accumulation in rice were lower than the other pH treatments. Cadmium addition had no impact on pH and Eh in rice rhizosphere while Fe addition decreased pH and increased Eh significantly. Compared with control, Fe addition resulted in the decrease of rhizosphere Cd, Fe solubility and bioavailability. Higher redox potential in the rice rhizosphere resulted in the decline of transpiration, Cd, and Fe accumulation in the rice tissues, suggesting that the transfer of two elements from soil to rice was depressed when the rhizosphere was more oxidized.

Metal wastes are produced in large quantities by a number of industries. Their disposal in isolated waste deposits is certain to cause many subsequent problems, because every material will sooner or later return to the geochemical cycle. The sealing of disposal sites usually starts to leak, often within a short time after the disposal site has been filled. The contained heavy metals are leached from the waste deposit and will contaminate the soil and the groundwater. It is evident that storage as metal sulfides in a permanently anoxic environment is the only safe way to handle metal wastes. The world's largest anoxic basin, the Black Sea, can serve as a georeactor. The metal wastes are sustainably transformed into harmless and immobile solids. These are incorporated in the lifeless bottom muds, where they are stored for millions of years.

The adsorption of Pb(II) onto the surface of microwave-assisted activated carbon was studied through a two-layer feedforward neural network. The activated carbon was developed by microwave activation of Acacia auriculiformis scrap wood char. The prepared adsorbent was characterized by using Brunauer–Emmett–Teller (BET) surface area analyzer, scanning electron microscope (SEM), and X-ray difractometer. In the present study, the input variables for the proposed network were solution pH, contact time, initial adsorbate concentration, adsorbent dose and temperature, whereas the output variable was the percent Pb(II) removal. The network had been trained by using different algorithms and based on the lowest mean squared error (MSE) value and validation error, resilient backpropagation algorithm with 12 neurons in the hidden layer was selected for the present investigation. The tan sigmoid and purelin transfer function were used in the hidden and the output layers of the proposed network, respectively. The model predicted and experimental values of the percent Pb(II) removal were also compared and both the values were found to be in reasonable agreement with each other. The performance of the developed network was further improved by normalizing the experimental data set and it was found that after normalization, the MSE and validation error were reduced significantly. The sensitivity analysis was also performed to determine the most significant input parameter.

The copper production in Bor (East Serbia) during the last 100 years presents an important source of the pollution of environment. Dust, waste waters, tailing, and air pollutants influence the quality of soil, water, and air. Over 2,000 ha of fertile soil have been damaged by the flotation tailing from Bor’s facilities. The goal of the present work has been to determine the content of Pb, Cu, and Fe in wild plants (17 species) naturally growing in the damaged soil and in fodder crops (nine species) planted at the same place. The content of Pb, Cu, and Fe has been analyzed in damaged soil as well. This study has also searched for native (wild) and cultivated plants which are able to grow in contaminated soil in the area of the intense industrial activity of copper production in Bor, which means that they can accumulate and tolerate heavy metals in their above-ground tissues. It has been found out that the content of all metals in contaminated soil decreases considerably at the end of the experiment. As it has been expected, all plant species could accumulate investigated metals. All tested plants, both wild-growing and cultivated plants, seem to be quite healthy on the substrate which contained extremely high concentrations of copper.

Ion imprinting has become one of the fast-growing technologies that have gained a lot of attention recently especially in the area of materials science. One of them is called the ion-imprinted polymers (IIPs). The IIPs are synthesized on the principles of enzyme phenomenon whereby a polymer is altered by a polymerization that takes place in the presence of a template that will be later removed to create cavities that will recognize only the analyte of interest. This specific and selective affinity for the target species decreases the chances of competition with other different types of ions. The imprinting technique started with the discovery of the bulk polymerization method where by the monomer, initiator, crosslinker, and template are mixed together and allowed to polymerize, and then the resulting polymer is ground and sieved to get particles with sizes suitable for the polymer's application. The IIPs have got some attractive qualities for use in environmental applications which include their stability and inexpensiveness and have a wide range of synthesis options with each suiting a certain unique application. Apart from environmental work, IIPs have applications in many other areas such as in membranes, in drug delivery, and in biosensors as alternatives to antibodies just to mention a few. This review focuses on the synthesis, types of imprinting, characterization, and applications of IIPs.

Urban soil is an important component of urban ecosystems. This study focuses on heavy metal contamination in soils of Wien (Austria) and results are compared to those for a few large European cities. We analysed the elemental contents of 96 samples of topsoil from urban, suburban and rural areas in Wien along a dynamic (floodplain forest) and a stable (oak–hornbeam forest) urbanization gradient. The following elements were quantified using ICP-OES technique: Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Pb, P, S and Zn. For heavy metals PI (pollution index) values were used to assess the level of pollution. The PI values indicated high level of pollution by Pb in the suburban and rural area of stable gradient and in the urban area of dynamic gradient; moderate level of pollution was indicated for Cd in the urban area of stable gradient. The level of pollution was moderate for Co in the suburban and rural area of the stable gradient, and for Cu in suburban area of stable gradient, and urban area of dynamic gradient. The pollution level of Zn was moderate in all areas. Urban soils, especially in urban parks and green areas may have a direct influence on human health. Thus, the elemental analysis of soil samples is one of the best ways to study the effects of urbanization. Our results indicated that the heavy metal contamination was higher in Wien than in a few large European cities.

Many studies indicate that lead (Pb) and cadmium (Cd) exposure may alter bone development through both direct and indirect mechanisms, increasing the risk of osteoporosis later in life. The aim of this study was to investigate the association between Pb and Cd exposure, physical growth, and bone and calcium metabolism in children of an electronic waste (e-waste) processing area. We recruited 246 children (3–8 years) in a kindergarten located in Guiyu, China. Blood lead levels (BLLs) and blood cadmium levels (BCLs) of recruited children were measured as biomarkers for exposure. Serum calcium, osteocalcin, bone alkaline phosphatase, and urinary deoxypyridinoline were used as biomarkers for bone and calcium metabolism. Physical indexes such as height, weight, and head and chest circumference were also measured. The mean values of BLLs and BCLs obtained were 7.30 μg/dL and 0.69 μg/L, respectively. The average of BCLs increased with age. In multiple linear regression analysis, BLLs were negatively correlated with both height and weight, and positively correlated with bone resorption biomarkers. Neither bone nor calcium metabolic biomarkers showed significant correlation with cadmium. Childhood lead exposure affected both physical development and increased bone resorption of children in Guiyu. Primitive e-waste recycling may threaten the health of children with elevated BLL which may eventually cause adult osteoporosis.

A method was developed for the determination of benzotriazoles (BTs) in dishwasher tabs. BTs consist of 1H-benzotriazole and/or tolyltriazole, i.e., a technical mixture of the two isomers 4-methylbenzotriazole and 5-methylbenzotriazole (5-MBT). The method consisted of weighing of an aliquot of the tab, addition of the internal standard 5-MBT, precipitation of the soaps with CaCl₂and KOH, derivatization of the filtrate with acetic acid anhydride in a two-phase system, and analysis of the organic toluene layer by gas chromatography with mass spectrometry in the selected ion monitoring mode. Eleven of 12 different dishwasher tabs from the German market were tested positive with BTs ranging from 2 to 66 mg/tab. Dishwashing experiments were performed to show that at least 99 % of the BT amount used in the dishwasher did not remain on the dishes but was released into the wastewater treatment system. The annual release of BTs into the water system was estimated to be ~80 tons. Since 70 % or less of the BTs can be degraded in wastewater treatment plants, at least 24 tons are annually released into rivers in Germany.