Historic lead mining, milling and smelting on the floodplain soils of the upper reaches of the Vils River, Eastern Bavaria, Germany has led to heavy metal contamination within the younger floodplain sediments downstream. This study aims to date the lead pollution and possible primary sources, display and quantify its spatial distribution within the Vils River floodplain in accordance to soil horizons and characterise the binding forms of lead. One hundred fifty profiles were sampled to detect total contents of heavy metals. Sequential extractions were carried out to determine the binding forms; thus, the potential of lead mobility was characterised. The contamination of the floodplain soils act as an alluvial archive, providing a stratigraphical indicator of mining activities and related sedimentation. The age of the sediments displaying the initial lead peak in the alluvial loams corresponds with sediment accumulations at the onset of the mining period and its first phase of prosperity in the sixteenth century. Enrichments of lead in the oxidic gleysols revealed that dissolved fractions of lead precipitate in the groundwater table fluctuation zone. The sequential extraction proved that lead mobility increases in the psammic and hypersceletic fluvial horizons below the flood loams due to the modest salt contents of the extractants and low pH given in these layers. Thus, the risk of the particulate transport of lead has to be extended to include the danger of potential lead solubility in ground and surface waters. Further, the polluted alluvial sediments also act as a source of contamination, leading to the grave danger of the further pollution of so far uncontaminated areas downstream, especially if the reworking and dredging of the material is allowed to occur.

In the present work a method for the evaluation of the importance of the VOCs species is presented, aiming to provide criteria for the incorporation of these species into atmospheric photochemical mechanisms and for the successful application of secondary pollution reduction strategies. According to the method presented here, the species can be divided into more important and less important ones, taking into account their mixing ratios and emission values in combination with their reactivity. For this classification three quantitative and one qualitative criteria were introduced. Overall, it is concluded that alkenes with more than a few carbon atoms in their chain appear to be more important in urban and suburban areas, while in background conditions the alkanes, having the smaller chain (ethane, propane), become more important. In the case of alkenes there is no clear species classification, except for the biogenically emitted compounds, isoprene and limonene. In general, more important alkenes appear to be those with the smaller chain (ethene, propene, butene). Most abundant aromatics are benzene, toluene, and xylene. In background conditions higher aromatics are also important, especially 1,2,3-, 1,3,5-, and 1,2,4-trimethylbenzene. The most important carbonylic compounds are formaldehyde, acetaldehyde, and acetone. Finally, taking into account the results mentioned above, a new photochemical mechanism was developed. The species and species groups used in the proposed mechanism are: ethane, higher alkanes, ethene, propene, 2- butene, 1-alkenes, 2-alkenes, higher alkenes, benzene, toluene, m-, o-, p-xylene, 1,3,5-, 1,2,3-, 1,2,4-trimethylbenzene, higher aromatics, formaldehyde, acetaldehyde, higher aldehydes, isoprene, limonene, and other biogenic VOCs.

Inkjet printing of metal nanoparticles is an attractive method for front-side metallization of silicon solar cells. It is owing to noncontact, low-cost, low-waste, and simple process. In this work, we proposed the ink-jet printing and electroless technology to fabricate the seed layer and electrode layer, respectively. Furthermore, we used electroplating method to increase the electrode conductivity. In this way, the energy conversion efficiency up to 12.22% without AR coating can be obtained on 100 × 100 mm c-Si cell.

The aim of this study was to justify the method to determine biochemical methane potential (BMP) of biosludges and investigate the effect of ozonation and sonication on the biosludge from textile mill effluent to its biodegradability and toxicity. This study revealed that the exented anaerobic toxicity assay at a chemical oxygen demand (COD) concentration in the assay of about 1,500 mg/L was the appropiate technique to determine BMP of the biosludge. Moreover, it was found that the biodegradability of biosludge was satisfactorily increased by both of ozonation and sonication. The use of ozone dose of 0.005 g O₃/g COD and 0.01 O₃/g COD increased the biodegradability from 62% to 69% and 76%, respectively. While for sonication on frequency 51 kHz ±6%, 120 W for 30 and 60 min increased the biodegradability from 62% to 68% and 73%, respectively.

A novel method is developed to capture and analyze several experimental flow regimes through a gross pollutant trap (GPT) with fully and partially blocked screens. Typical flow conditions and screen blockages are based on findings from field investigations that show a high content of organic matter in urban areas. Fluid motion of neutral buoyant particles is tracked using a high-speed camera and particle image velocimetry (PIV) software. The recorded fluid motion is visualized through an image-based, line integral convolution (LIC) algorithm, generally suitable for large computational fluid dynamics (CFD) datasets. The LIC method, a dense representation of streamlines, is found to be superior to the point-based flow visualization (e.g., hedgehog or arrow plots) in highlighting main flow features that are important for understanding litter capture and retention in the GPT. Detailed comparisons are made between the flow regimes, and the results are compared with CFD data previously obtained for fully blocked screens. The LIC technique is a useful tool for identifying flow structures in the GPT and areas that are subjected to abnormalities difficult to detect by conventional methods. The novel method is found to be useful both in the laboratory and in the field, with little preparation and cost. The enhancements and pitfalls of the LIC technique along with the experimentally captured flow field are presented and discussed.

The promotion of good indoor air quality in schools is of particular public concern for two main reasons: (1) school-age children spend at least 30% of their time inside classrooms and (2) indoor air quality in urban areas is substantially influenced by the outdoor pollutants, exposing tenants to potentially toxic substances. Two schools in Curitiba, Brazil, were selected to characterize the gaseous compounds indoor and outdoor of the classrooms. The concentrations of benzene, toluene, ethylbenzene, and the isomers xylenes (BTEX); NO₂; SO₂; O₃; acetic acid (HAc); and formic acid (HFor) were assessed using passive diffusion tubes. BTEX were analyzed by gas chromatography-ion trap mass spectrometry and other collected gasses by ion chromatography. The concentration of NO₂ varied between 9.5 and 23 µg m⁻³, whereas SO₂ showed an interval from 0.1 to 4.8 µg m⁻³. Within the schools, BTEX concentrations were predominant. Formic and acetic acids inside the classrooms revealed intermediate concentrations of 1.5 µg m⁻³ and 1.2 µg m⁻³, respectively.

The concentrations and distribution of selected heavy metals in epipelic and benthic sediments of Cross River Estuary mangrove swamp were studied to determine the extent of anthropogenic inputs from industrial activities and to estimate the effects of seasonal variations on geochemical processes in this tropical estuarine ecosystem. The analysis shows that the mean concentrations (mg/kg, dw) of Cu, Cr, Fe, Ni, Pb, V and Zn vary from 24.1-32.4, 19.9-27.4, 666.7-943.5, 15.2-30.3, 8.8-24.7, 2.2-6.9 and 140.1-188.9, respectively. An important observation is that, in general, lowest metal concentrations are found during the dry season, compared to wet season. Pollution load index (PLI) and index of geoaccumulation (I geo) revealed overall low values but the enrichment factors (EFs) for Cr, Zn, and V were high, and this reflects the intensity of anthropogenic inputs related to industrial discharge into the estuary. The mean concentrations of Zn, Cu and to some extent Ni exceeded the Effects Range--Low (ERL) and Threshold Effect Level (TEL) values in majority of the samples studied, indicating that there may be some ecotoxicological risk to organisms living in these sediments. The inter-element relationship revealed the identical source of elements in the sediments of the studied area. The concentration of heavy metals reported in this work will be useful as baselines for comparison in future sediment quality studies.

Commonly occurring plant species on metal-contaminated soils and noncontaminated soils adjoining Kanpur Tanneries, Uttar Pradesh, India were surveyed for arbuscular mycorrhizal association. In the present study, pH, electric conductivity (E.C.), organic carbon, macronutrients (available phosphorus, available potassium), micronutrients (Cu and Zn), and toxic metals (Cr, Cd, Pb) were higher in metal-contaminated site compared to noncontaminated site. These factors were also significantly different between metal-contaminated and noncontaminated soils. High E.C. along with toxic concentrations of metals like Cr, Cd, and Pb may have acted as selection pressure for vegetation cover, making the metal-contaminated site hostile for cultivation purpose. The study recorded Arum type of arbuscular mycorrhiza. The highest mean total root colonization levels in metal-contaminated and noncontaminated soils were 100% (Parthenium sp.) and 34.16% (Parthenium sp.), respectively. Maximum mean spore density in metal-contaminated and noncontaminated soils was 19 spores rhizosphere soil⁻¹ (Parthenium sp.) and nine spores rhizosphere soil⁻¹ (Desmostachya bipinnata and Cynodon sp.), respectively. Studies revealed that for a particular plant species, the root colonization levels and spore density (except Cynodon sp.) were higher in contaminated soil compared to noncontaminated soils. A total of six species of arbuscular mycorrhizal fungi belonging to two genera viz., Glomus and Scutellospora were recovered during the study. Species richness of arbuscular mycorrhizal fungi was maximum in the noncontaminated site compared to the metal-contaminated site. This result suggests that continuous exposure of plants and associated arbuscular mycorrhizal fungi to heavy metals can result in tolerant species which can be used for phytoremediation.

In a few cases, atmospheric particulate matter characterization was taken into account together with aerobiological monitoring but never in an archive. The aim of this study was to estimate the air quality, by means of both chemical-physical and microbiological studies, at the Ca' Granda Historical Archive (Milan, Italy) that houses an important collection of documents from the 12th century. Temperature and relative humidity were measured in the rooms. Particulate matter (PM2.5) concentrations were quantified and the chemical composition, in terms of ionic components, elements, and carbonaceous fraction (total, organic, and elemental carbon) determined. The gaseous pollutants NO₂, SO₂, and O₃ and indoor acidity were also measured. Aerobiological monitoring (aerobic heterotrophic bacteria and fungi) was performed as volumes stored in the Archive were composed of organic materials, a potential energy and carbon source. In this paper, we present our findings and propose some guidelines for a better preservation of the documents.

This study characterizes the effects of water-soil flooding volume ratio and flooding time on copper (Cu) desorption and toxicity following multiple floodings of field-collected soils from agricultural sites acquired under the Comprehensive Everglades Restoration Plan (CERP) in south Florida. Soils from four field sites were flooded with three water-soil ratios (2, 4, and 6 [water] to 1 [soil]) and held for 14 days to characterize the effects of volume ratio and flooding duration on Cu desorption (volume ratio and flooding duration study). Desorption of Cu was also characterized by flooding soils four times from seven field sites with a volume ratio of 2 (water) to 1 (soil) (multiple flooding study). Acute toxicity tests were also conducted using overlying waters from the first flooding event to characterize the effects of Cu on the survival of fathead minnows (Pimephales promelas), cladocerans (Daphnia magna), amphipods (Hyalella azteca), midges (Chironomus tentans), duckweed (Lemna minor), and Florida apple snails (Pomacea paludosa). Acute tests were also conducted with D. magna exposed to overlying water from the second and third flooding events. Results indicate that dissolved Cu concentrations in overlying water increased with flooding duration and decreased with volume ratio. In the multiple flooding study, initial Cu concentrations in soils ranged from 5 to 223 mg/kg (dw) and were similar to Cu concentration after four flooding events, indicating retention of Cu in soils. Copper desorption was dependent on soil Cu content and soil characteristics. Total Cu concentration in overlying water (Cuw) was a function of dissolved organic carbon (DOC), alkalinity, and soil Cu concentration (Cus): log(Cuw) = 1.2909 + 0.0279 (DOC) + 0.0026 (Cus) - 0.0038 (alkalinity). The model was validated and highly predictive. Most of the desorbed Cu in the water column complexed with organic matter in the soils and accounted for 99% of the total dissolved Cu. Although total dissolved Cu concentrations in overlying water did not significantly decrease with number of flooding events, concentrations of free Cu²⁺ increased with the number of flooding events, due to a decrease in DOC concentrations. The fraction of bioavailable Cu species (Cu²⁺, CuOH⁺, CuCO₃) was also less than 1% of the total Cu. Overlying water from the first flooding event was only acutely toxic to the Florida apple snail from one site. However, overlying water from the third flooding of six out of seven soils was acutely toxic to D. magna. The decrease in DOC concentrations and increase in bioavailable Cu²⁺ species may explain the changes in acute toxicity to D. magna. Results of this study reveal potential for high Cu bioavailability (Cu²⁺) and toxicity to aquatic biota overtime in inundated agricultural lands acquired under the CERP.