This study is focused on micro-scale measurement of metal (Ca, Cl, Fe, K, Mn, Cu, Pb, and Zn) distributions in Spartina alterniflora root system. The root samples were collected in the Yangtze River intertidal zone in July 2013. Synchrotron X-ray fluorescence (XRF), computed microtomography (CMT), and X-ray absorption near-edge structure (XANES) techniques, which provide micro-meter scale analytical resolution, were applied to this study. Although it was found that the metals of interest were distributed in both epidermis and vascular tissue with the varying concentrations, the results showed that Fe plaque was mainly distributed in the root epidermis. Other metals (e.g., Cu, Mn, Pb, and Zn) were correlated with Fe in the epidermis possibly due to scavenge by Fe plaque. Relatively high metal concentrations were observed in the root hair tip. This micro-scale investigation provides insights of understanding the metal uptake and spatial distribution as well as the function of Fe plaque governing metal transport in the root system.

An experimental study of the homogeneous Fenton and photo-Fenton degradation of 4-amidophenol (paracetamol, PCT) is presented. For all the operation conditions evaluated, PCT degradation is efficiently attained by both Fenton and photo-Fenton processes. Also, photonic efficiencies of PCT degradation and mineralization are determined under different experimental conditions, characterizing the influence of hydrogen peroxide (H₂O₂) and Fe(II) on both contaminant degradation and sample mineralization. The maximum photonic degradation efficiencies for 5 and 10 mg L⁻¹Fe(II) were 3.9 (H₂O₂ = 189 mg L⁻¹) and 5 (H₂O₂ = 378 mg L⁻¹), respectively. For higher concentrations of oxidant, H₂O₂ acts as a "scavenger" radical, competing in pollutant degradation and reducing the reaction rate. Moreover, in order to quantify the consumption of the oxidizing agent, the specific consumption of the hydrogen peroxide was also evaluated. For all operating conditions of both hydrogen peroxide and Fe(II) concentration, the consumption values obtained for Fenton process were always higher than the corresponding values observed for photo-Fenton. This implies a less efficient use of the oxidizing agent for dark conditions.

The aim of this study was to determine the pH and the concentration of lead, cadmium, nickel, copper and zinc in aqueous extracts of necrotic bark Pinus sylvestris L. and in adjacent soil, located in two types of forest habitat in different parts in the Niepołomice Forest in southern Poland. The Niepołomice Forest is located about 35 km east of an urban-industrial agglomeration Kraków. Despite the lack of significant differences in pine bark reaction studied, there was a clear difference in contamination of both bark and soil with heavy metals. There was a correlation between the distribution of pollutants in the forest, and the direction of the prevailing winds. More heavy metals were accumulated in the pine bark and soil from the west than the east. The high content of lead, zinc, cadmium and copper in the soils most likely results from the inflow of gas and dust pollutants from the urban-industrial agglomeration of Kraków.

In developing optimal groundwater remediation strategies, limited effort has been exerted to solve the uncertainty in environmental quality standards. When such uncertainty is not considered, either over optimistic or over pessimistic optimization strategies may be developed, probably leading to the formulation of rigid remediation strategies. This study advances a mathematical programming modeling approach for optimizing groundwater remediation design. This approach not only prevents the formulation of over optimistic and over pessimistic optimization strategies but also provides a satisfaction level that indicates the degree to which the environmental quality standard is satisfied. Therefore the approach may be expected to be significantly more acknowledged by the decision maker than those who do not consider standard uncertainty. The proposed approach is applied to a petroleum-contaminated site in western Canada. Results from the case study show that (1) the peak benzene concentrations can always satisfy the environmental standard under the optimal strategy, (2) the pumping rates of all wells decrease under a relaxed standard or long-term remediation approach, (3) the pumping rates are less affected by environmental quality constraints under short-term remediation, and (4) increased flexible environmental standards have a reduced effect on the optimal remediation strategy.

In January 2013, several serious haze pollution events happened in North China. Cimel sunphotometer measurements at an urban site of Beijing (Chinese Academy of Meteorological Sciences—CAMS) from 1 to 30 January 2013 were used to investigate the detailed variation of aerosol optical properties. It was found that Angstrom exponents were mostly larger than 0.80 when aerosol optical depth values are higher than 0.60 at the urban region of Beijing during January 2013. The aerosol optical depth (AOD) at the urban region of Beijing can remain steady at approximately 0.40 before haze happening and then increased sharply to more than 1.50 at 500 nm with the onset of haze, which suggests that the fine-mode AOD is a factor of 20 of the coarse-mode AOD during a serious haze pollution event. The single scattering albedo was approximately 0.90 ± 0.03 at 440, 675, 870 and 1,020 nm during the haze pollution period. The single scattering albedo at 440 nm as a function of the fine-mode fraction was relatively consistent, but it was highly variable at 675, 870 and 1,020 nm. Except on January 12 and 18, all the fine-mode particle volumes were larger than those of coarse particles, which suggests that fine particles from anthropogenic activities made up most of the haze. Aerosol type classification analysis showed that the dominant aerosol types can be classified as both “mixed” and “urban/industrial (U/I) and biomass burning (BB)” categories during the heavy haze period of Beijing in January of 2013. The mixed category occurrence was about 31 %, while the U/I and BB was about 69 %.

Photocatalysts supported on polymers are not frequently used in heterogeneous photocatalysis because of problems such as wettability and stability that affect photocatalysis conditions. In this work, we used polypropylene as support for TiO₂sol-gel to evaluate its stability and efficiency under UV radiation. We also tested the effect of the thermo-pressing PP/TiO₂system on the photocatalytic efficiency and stability under UV radiation. The films were characterized by scanning electron microscopy (SEM), UV-Vis spectroscopy and X-ray diffraction (XRD). The SEM micrographs showed that the films of TiO₂sol-gel onto PP has approximately 1.0-μm thick and regular surface and the generation of polypropylene nanowires on hot-pressed samples. XRD showed the formation of TiO₂anatase on the surface of the films made by dip-coating. All photocatalysts were tested in decontaminating air-containing gaseous formaldehyde (70 ppmv) presenting degradation of the target compound to the limit of detection. The photocatalysts showed no deactivation during the entire period tested (30 h), and its reuse after washing showed better photocatalytic performance than on first use. The photocatalyst showed the best results were tested for 360 h with no observed deactivation. Aging studies showed that the film of TiO₂causes different effects on the photostability of composites, with stabilizing effect when exposed to most energetic UVC radiation (λmax = 254 nm) and degradative effects when exposed to UVA radiation (λmax = 365 nm).

Molecularly imprinted polymers are synthetic polymers possessing specific cavities designed for target molecules. They are prepared by copolymerization of a cross-linking agent with the complex formed from a template and monomers that have functional groups specifically interacting with the template through covalent or noncovalent bonds. Subsequent removal of the imprint template leaves specific cavities whose shape, size, and functional groups are complementary to the template molecule. Because of their predetermined selectivity, molecularly imprinted polymers (MIPs) can be used as ideal materials in wastewater treatment. Especially, MIP-based composites offer a wide range of potentialities in wastewater treatment. This paper reviews the latest applications of MIPs in wastewater treatment, highlights the development of MIP-based composites in wastewater, and offers suggestions for future success in the field of MIPs.

In this study, the effectiveness of six soil amendments (ferrihydrite, manganese dioxide, gibbsite, calcium carbonate, biochar, and organic fertilizer) was investigated to assess the feasibility of minimizing possible environmental contaminant leaching during S,S-ethylenediaminedisuccinic acid (EDDS)-enhanced phytoextraction process based on 0.01-M CaCl₂ extraction. Results showed that the application of EDDS could significantly increase Cu concentrations in the leaching solution. Compared with control, incorporation of six amendments (excluding organic fertilizer) significantly decreased CaCl₂-extractable Cu concentrations in both soils. When EDDS-containing solutions leached from the soil columns (mimicking the upper soil layers) were added to soils with different amendments (mimicking the subsoil), CaCl₂-extractable Cu in the soils amended with ferrihydrite, manganese dioxide, gibbsite, and calcium carbonate was significantly lower than that in the control soil (no amendments) and remained relatively constant during the first 14 days. Incorporation of biochar or organic fertilizer had no positive effect on the immobilization of Cu in EDDS leachates in soils. After 14 days, CaCl₂-extractable Cu concentration decreased rapidly in soils incorporated with various amendments. Integrating soil washing with biodegradable chelating agents or chelant-enhanced phytoextraction and immobilization of heavy metals in subsoil could be used to rapidly reduce the concentration of bioavailable metal fractions in the upper soil layers and minimize environmental risks of secondary pollution.

Polycyclic aromatic compounds (PACs) are widespread environmental pollutants with a high potential to act as human carcinogens and mutagens. The behavior of PACs is significantly affected by their interactions with dissolved organic matter (DOM), such as their transport, solubility, bioavailability, and bioaccumulation in the aquatic environment. Being a basic PAC, benzo(h)quinoline (BQ) is the dominant species, as the solution’s pH value is higher than BQ’s pK ₐ (pK ₐ of BQ = 4.2). In contrast, benzo(h)quinolinium (BQH⁺) is the major species, as the solution’s pH value is lower than its pK ₐ. The binding constant (K DOC), measured by fluorescence quenching, between BQ/BQH⁺ and Leonardite humic acid (LHA) would decrease 70 to 95 % and 20 to 90 % when increasing the ionic strength in acidic and neutral to basic conditions, respectively. The results can be attributed to the added cation (Na⁺ and Mg²⁺), which forms a bridge with LHA and enhances the intramolecular reaction among these functional groups, therefore inducing the coiling up within the LHA molecule. In addition, the decrease of the K DOC with added MgCl₂/MgSO₄ (75–95 %) is higher than that with added NaCl/Na₂SO₄ (20–75 %), indicating that the K DOC was affected by the charge density of cations. The fluorescence intensity of BQH⁺ in the absence of LHA (F ₀) was found to decay only in the acidic solution with Cl⁻, suggesting that Cl⁻ might be a heavy atom serving as a quencher in an acidic solution.