The polluted site object of our study was located on an island nourished using different materials, including industrial by-products, inside the area of Porto Marghera (Venice Lagoon, Italy). Until the 1970s, this area was one of the most important chemical districts in Italy and was largely subjected to heavy metals and metalloids pollution. In the year 2004, some Populus and Salix spp. had been planted in this polluted site in order to investigate both the hydrological control and the phytoremediation capability of these trees. In the present work, polluted soil was analyzed at different depths for both metals content and culturable microbial communities with the aim to evaluate the establishment of previously planted poplar and willow plants. Bacteria were characterized on the basis of the r/K-strategists distribution since r-strategists (fast-growing bacteria) and K-strategists (slow-growing bacteria) are characteristic for unstable and stable environments, respectively. A better characterization of bacterial communities composition was obtained from colony development and eco-physiological indices. Results appeared to confirm a good establishment of poplar and willow plants in the heavy metal contaminated site.

The protected area “Bohemian Switzerland National Park” with its characteristic sandstone landscape was influenced by the long-term air pollution and acidic deposition within the area known as Black Triangle (located where Germany, Poland, and the Czech Republic meet, is one of the Europe’s most polluted areas). The local Upper Cretaceous sandstone is subhorizontally stratified, fine- to coarse-grained, quartz dominated, with low content of clay minerals. One of the significant negative effects of the intensive acidic deposition on sandstone outcrops has been identified as chemical (salt) weathering, i.e., a process when the porous sandstone rock is except of chemical influence attacked also by force of crystallization of growing salts crystals. Anions NO3 − together with SO4 2− and cation NH4 + were the most abundant solutes in bulk precipitation samples. Current (2002 to 2009) bulk deposition fluxes of SO4 2− determined at three sites directly in the National Park indicate decline from 23 to 16 kg−1 ha−1 year−1. Infiltration of bulk precipitation solutes into the sandstone mediates the weathering processes. Natural outflow of sandstone pore-water (sandstone percolates) can be sampled only during certain days of year when the sandstone becomes saturated with water and percolates drip out on small number of sites from roofs of overhangs. Under usual conditions percolation water evaporates at the sandstone surface producing salt efflorescences—the typical example is Pravčická brána Arch locality. The average pH of the dripping sandstone percolates was 3.76. Concentration of SO4 2− and Al in sandstone percolates reached up to 46 and 10 mg L−1. The concentration of Al in percolates has been 160-fold greater the one in the precipitation samples suggesting the sandstone as a source. The water O and H isotopic composition of percolates has been virtually identical to precipitation samples, indicating thus relatively short residence time of the solutions within the sandstone pore-spaces. Evaporation experiments with bulk precipitation and percolate samples proved possible origin of some Ca in bulk precipitation and the sandstone rock as the source of Al and possibly of K for the salt efflorescence identified on Rock Arch body.

A rhizospheric biotest, consisting of a thin layer of substratum in close contact with roots of Lolium multiflorum, was used on two contrasting contaminated soils (Cabezo and Brunita) issued from a former mining area in La Union (Spain). On top of this biotest, soil characterisation, including CaCl2 selective extractions, was performed. Total heavy metal concentrations were the highest in the soil from Cabezo, but CaCl2 extractions indicated higher heavy metal mobilities in Brunita soil. On the base of heavy metal concentrations and biomass production in L. multiflorum seedlings, availability assessed by the rhizospheric biotest was higher than the values obtained from CaCl2 extraction, except for Mn and Pb. Rhizospheric biotest also revealed higher heavy metal bioavailability for Cabezo. The low pH of Brunita (3.47) could explain the high CaCl2-extractable heavy metal concentrations as well as the high transfer factor found for Cu, Mn and Zn in this substrate. Cu, Mn and Zn toxicities were also detected for shoot tissues. Transpiration rates were clearly lower for seedlings exposed to Brunita than for those exposed to Cabezo, while water use efficiency was higher for the former (4.8 mg DW ml−1) than for the latter (3.8 mg DW ml−1). Iron nutrition was found to interfere with heavy metal root absorption, mainly through negative interactions during root absorption. It is concluded that rhizospheric test offers the advantage to consider the root–soil interactions in a dynamic perspective and constitutes a useful tool for the assessment of heavy metal availability on contaminated soils. Heavy metal bioavailability assessment should not be based on only one measure alone, but on different and complementary approaches.

Sorption and desorption of Hg(II) on clay minerals can impact the biogeochemical cycle and bio-uptake of Hg in the environment. We studied the kinetics of the desorption of Hg(II) from kaolinite as affected by oxalate and cysteine, representing the ligands with carboxylic and thiol groups of different affinities for Hg(II). The effects of pH (3, 5, and 7), ligand concentration (0.25 and 1.0 mM), and temperature (15°C, 25°C, and 35°C) on the Hg(II) desorption were investigated through desorption kinetics. Our study showed that the Hg(II) desorption was pH dependent. In the absence of any organic ligand, >90% of the previously adsorbed Hg(II) desorbed at pH 3 within 2 h, compared to <10% at pH 7. Similar results were observed in the presence of oxalate, showing that it hardly affected the Hg(II) desorption. Cysteine inhibited the Hg(II) desorption significantly at all the pH tested, especially in the first 80 min with the desorption less than 20%, but the inhibition of the desorption appeared to be less prominent afterwards. The effect of the ligand concentration on the Hg(II) desorption was small, especially in the presence of oxalate. The effect of temperature on the Hg(II) desorption was nearly insignificant. The effect of the organic acids on the Hg(II) sorption and desorption is explained by the formation of the ternary surface complexes involving the mineral, ligand, and Hg(II). The competition for Hg(II) between the cysteine molecules adsorbed on the particle surfaces and in the solution phase probably can also affect the Hg(II) desorption.

BACKGROUND, AIM, AND SCOPE: Textile industry produces wastewater which contributes to water pollution since it utilizes a lot of chemicals. Preliminary studies show that the wastewater from textile industries contains grease, wax, surfactant, and dyes. The objective of this study was to determine the treatment efficiency of the nickel catalysts supported on hydrotalcites in three-dye model compounds and two types of wastewater. MATERIALS AND METHODS: Hydrotalcites were employed to prepare supported nickel catalysts by wetness impregnation technique. Metal loadings from 1 to 10 wt% were tested. Catalysts were characterized by several techniques. They were tested in a catalytic wet air oxidation of three dyes and two wastewaters with different origins. RESULTS AND DISCUSSION: It could be observed that the higher the metal content, the lower the BET area, possibly due to sintering of Ni and the consequent blocking of the pores by the metal. In addition, metallic dispersion was also higher when the metal content was lower. Dye conversion was more than 95% for every catalyst showing no differences with the nickel content. A high degree of dye conversion was achieved. Wet air oxidation (WAO) and catalytic wet air oxidation (CWAO) processes have been proved to be extremely efficient in TOC removal for wastewaters. CONCLUSIONS: The CWAO process can be used to remove dyes from wastewater. Three different dyes were tested showing satisfactory results in all of them. TOC degradation and dye removal in the presence of the catalyst were effective. Also, the HTNi catalyst is very active for organic matter and toxicity removal in wastewaters.

BACKGROUND, AIM, AND SCOPE: Indiscriminate use of insecticides leads to environmental problems and poses a great threat to beneficial microorganisms. The aim of the present work was to study chlorpyrifos degradation by a rice field cyanobacterium Synechocystis sp. strain PUPCCC 64 so that the organism is able to reduce insecticide pollution in situ. MATERIAL AND METHODS: The unicellular cyanobacterium isolated and purified from a rice field was identified by partial 16S rRNA gene sequence as Synechocystis sp. strain PUPCCC 64. Tolerance limit of the organism was determined by studying its growth in graded concentrations (2.5–20 mg/L) of chlorpyrifos. Chlorpyrifos removal was studied by its depletion from the insecticide supplemented growth medium, and its biodegradation products were identified in the cell extract, biomass wash, and growth medium. RESULTS AND DISCUSSION: The organism tolerated chlorpyrifos up to 15 mg/L. Major fraction of chlorpyrifos was removed by the organism during the first day followed by slow uptake. Biomass, pH, and temperature influenced the insecticide removal and the organism exhibited maximum chlorpyrifos removal at 100 mg protein/L biomass, pH 7.0, and 30°C. The cyanobacterium metabolized chlorpyrifos producing a number of degradation products as evidenced by GC-MS chromatogram. One of the degradation products was identified as 3,5,6-trichloro-2-pyridinol. CONCLUSION AND RECOMMENDATIONS: Present study reports the biodegradation of chlorpyrifos by Synechocystis sp. Biodegradation of the insecticide by the cyanobacterium is significant as it can be biologically removed from the environment. The cyanobacterium may be used for bioremediation of chlorpyrifos-contaminated soils.

Purpose Hexachlorocyclohexane (HCH) isomers (α-, β- and γ- (Lindane)) were recently included as new persistent organic pollutants (POPs) in the Stockholm Convention, and therefore, the legacy of HCH and Lindane production became a contemporary topic of global relevance. This article wants to briefly summarise the outcomes of the Stockholm Convention process and make an estimation of the amount of HCH waste generated and dumped in the former Lindane/HCH-producing countries. Results In a preliminary assessment, the countries and the respective amount of HCH residues stored and deposited from Lindane production are estimated. Between 4 and 7 million tonnes of wastes of toxic, persistent and bioaccumulative residues (largely consisting of alpha- (approx. 80%) and beta-HCH) are estimated to have been produced and discarded around the globe during 60 years of Lindane production. For approximately 1.9 million tonnes, information is available regarding deposition. Countries are: Austria, Brazil, China, Czech Republic, France, Germany, Hungary, India, Italy, Japan, Macedonia, Nigeria, Poland, Romania, Slovakia, South Africa, Spain, Switzerland, Turkey, The Netherlands, UK, USA, and former USSR. The paper highlights the environmental relevance of deposited HCH wastes and the related POPs' contaminated sites and provides suggestions for further steps to address the challenge of the legacy of HCH/Lindane production. Conclusion It can be expected that most locations where HCH waste was discarded/stockpiled are not secured and that critical environmental impacts are resulting from leaching and volatilisation. As parties to the Stockholm Convention are legally required to take action to stop further POPs pollution, identification and evaluation of such sites are necessary.

Purpose The Pb absorption processes on a heavy textured calcareous soil, typical of central Italy, were studied using synchrotron X-ray absorption spectroscopy (XAS) in order to probe, at molecular scale, the structure and chemical nature of Pb in contaminated soils and achieve precise description of Pb ions localization into these contaminated soils. Materials and methods In order to distinguish the role of the different components of soils in Pb retention, samples were prepared from the original soils removing the carbonate fractions, the organic matter, the metal oxides, or selecting the clay fractions. Then these samples were fortified with Pb simulating the natural interactions processes of heavy metal solutions with soils. The quantitative analysis of near edge (XANES) as well extended (EXAFS) regions of Pb LIII edge absorption spectra, in comparison with Pb XAS data of selected reference compounds, allowed the precise determination of local structure and chemical environment of Pb ions in these soil samples. Results Four components were individuated as the major responsible of Pb retention in calcareous soils: the carbonates, the metal oxide surfaces, the organic matter, and the colloidal inorganic surfaces containing clay components. The structural analysis suggests that, within these experimental conditions, the Pb adsorbed on the soil is generally present as Pb hydroxide with poor crystallization degree. However, the presence of carbonates (CaCO₃) induces the co-precipitation of PbCO₃-like phases with some degree of crystallinity.

Background, aim, and scope The Jiangsu section of the Yangtze River is the downstream of the whole river, serving as an important drinking water source. Persistent toxic substances (PTS), from the industries such as automobile, textile, chemical, and electronic production, are not listed in the National Standard yet and not monitored and controlled. However, pollution of PTS can threaten the environment and human health. In order to understand the pollution status of the PTS contamination and recommend future rationalization of countermeasure, the PTS including organochlorine pesticides (OCPs), polyaromatic hydrocarbons (PAHs), polychlorobiphenyls (PCBs), and phthalates (PAEs) were investigated. Materials and methods Samples were collected at 15 sites from five main stream sections of the Yangtze River in Jiangsu Province. PTS were extracted using solid phase extract method. The analysis of OCPs, PCBs was performed using GC/ECD and PAHs, PAEs was performed by GC/MS. Results and discussions The method detection limits are low and the recoveries are from 58.1% to 110.3%. The total concentrations of OCPs, PCBs, PAHs, and PAEs were 0.27∼2.15 ng l⁻¹, <0.21∼44.4 ng l⁻¹, 0.012∼3.576 μg l⁻¹ and 0.178∼1.474 μg l⁻¹, respectively. γ-HCH, PCB28, PCB101, phenanthrene, anthracene, di-n-butyl phthalate, diethyl phthalate, and di-(2-ethylhexyl) phthalate are the major detected PTS. The concentration of most of the PTS was below the environmental quality standards for surface water of China. Conclusions The pollution status of OCPs, PCBs, PAHs, and PAEs were analyzed. PTS contamination levels of the five main stream sections were relatively low.

Introduction and aims The Chilean Altiplano ecosystem is conserved free from contaminants and pollutants because of the absence of major local human activities such as agriculture or other industries. We studied the effects of paraoxon on proliferation and apoptosis of testicular cells during active spermatogenesis in Dugesia gonocephala collected from a pristine river (Guacollo) in the Altiplano region nearby Visviri town, Chile. Materials and methods Adult planarians were incubated in varying concentrations of paraoxon (0.8, 0.4, 0.04, 0.004, and 0.0004 mM) for 4 h. After 3 h of incubation, bromodeoxyuridine (BrdU) was added. Effects on cell proliferation (BrdU) and apoptosis (Apaf-1) were determined by immunohistochemistry. Results Paraoxon concentrations of 0.4 and 0.8 mM caused 100% mortality in the respective treatment groups. The lowest tested concentration (0.0004 mM) caused a significant increase on cell proliferation in the seminiferous tubules, as well as an increase in the number of apoptotic cells. All other tested concentrations significantly inhibited cell proliferation and induced apoptosis. Conclusions Paraoxon inhibits DNA synthesis and induces apoptosis during spermatogenesis in adult planarians from a high-altitude, pollution-free environment. This could suggest its use as a biosensor or biomarker for contamination with agro pesticides.