There are concerns over the environmental risks posed by Cu-based fungicide use, and there is community and regulatory pressure on viticultural industries to restrict the use of Cu-based fungicides. This study assesses the relative environmental risks posed by Cu-based and alternative synthetic organic fungicide compounds used in Australian vineyards, giving particular consideration to their adverse effects on soil microbial activity and how risks vary across different viticultural regions. The study was guided by key steps in the ecological risk assessment framework to analyse the risks of Cu-based fungicides towards soil organisms and involved four key steps: (1) problem formulation, (2) analysis (characterise exposure and effects), (3) risk characterisation and (4) risk assessment. There is evidence of a build-up of Cu-based fungicide residues in Australian vineyard soils, although this has occurred over many years, thus allowing the availability of Cu in the soil to be attenuated over time due to aging processes. On the whole, it appears that Cu-based fungicide residues are currently unlikely to pose a significant risk to soil organisms in Australian vineyard soils. However, there are indicators that continued applications of Cu-based fungicides may well have implications on the use of impacted land for sustainable agricultural production. Further detailed studies are required to enable a more definitive characterisation of the risks posed by Cu-based fungicide residues, such as establishing a clearer link between the laboratory and agricultural settings, investigating effects on other indicators of microbial activity and biodiversity and understanding the resilience of soil microbes to additional stressors. The challenge for agricultural industries and governments, both in Australia and globally, is to formulate appropriate plans to reduce the risks associated with Cu-based fungicide use. Further research is required to consider the relative risks of a wide range of alternative fungicide compounds to ensure that they pose a lower environmental risk than the Cu-based fungicides they may replace.

In this study, high surface area porous carbons were synthesized by chemical activation using petroleum coke as the precursor and KOH as the activation agent. The pore structure of the as-synthesized activated carbons was characterized by nitrogen adsorption, and their CO₂ sorption capacities were measured by a magnetic suspension balance at 1 and 10 bar, respectively. The effects of activated carbon preparation parameters (preheating temperature, preheating time, activation time, heating rate during the pyrolysis, and particle size of the precursor) on porous texture, CO₂ adsorption capacity, and CO₂/N₂ selectivity of the activated products were investigated. It has been found that at 1 bar, the CO₂ adsorption capacity is determined by the micropore contribution, i.e., the ratio between micropore surface area and Brunauer–Emmett–Teller (BET) surface area of the sorbents, while at 10 bar, CO₂ adsorption capacity is related to the BET surface area of the activated products. The maximum CO₂ adsorption uptake of 15.1 wt% together with CO₂/N₂ selectivity of 9.4 at 1 bar were obtained for a sample activated at 700 °C indicating its high potential in the capture of CO₂.

The concentration of a range of endocrine disruptors: 17-β-estradiol, estrone, 17-α-ethinylestradiol, bisphenol-A, pentachlorophenol, triclosan, and butylbenzylphthalate, was analyzed by gas chromatography/mass spectrometry in the Wetland zone of Xochimilco, a periurban area of Mexico City, during an annual cycle. Samples were taken based on their level of use and by selecting sampling points related with activities such as agriculture, livestock, and urban, as well as their potential presence in water at the Cerro de la Estrella Wastewater Treatment Plant (WWTP) which supplies the majority of water (>90 %) to the study area. The compounds analyzed are present in a wide range of products from cosmetics to home care, pharmaceuticals, and subproducts of the food industry. The importance of identifying these compounds lies in the fact that they can disrupt the endocrine system of vertebrates, in particular reproductive gland function, affecting the development of organisms and their offspring. Pentachlorophenol, triclosan, bisphenol-A, butylbenzylphthalate, estrone, and 17-β-estradiol were detected in concentrations in nanogram-per-liter levels; 17-α-ethinylestradiol was always below the detection limit. The compounds showed a trend toward greater concentrations in the rainy season, probably due to the runoff that carries these compounds into the system.

In this study, we have reported the synthesis of new amino-substituted p-tert-butylcalix[4]arene (3) and its application for the removal of two carcinogenic azo dyes, i.e., Chicago Sky Blue (CSB) and Tropaeolin 000 (TP) from aqueous environment. The newly synthesized calix–ligand 3 is characterized by FT-IR and ¹H NMR spectroscopy as well as elemental analysis. The extraction efficiency of newly calix–ligand 3 for CSB and TP dyes from aqueous media was evaluated through liquid–liquid extraction experiments. The newly synthesized calix–ligand 3 showed outstanding extraction percentage and maximum percent extraction, i.e., 97 and 96 % of CSB and TP dyes was achieved at pH 9, respectively. During the extraction process, effect of various parameters was monitored and found that extraction is highly dependent on pH and salinity. Moreover, cyclic structure, cavity size, functional groups of the calixarene derivative, hydrophobicity, and the ionic property of guest molecules also affect the extraction efficiency. The comparative data prop up calix–ligand 3 as an effective extractant for both CSB and TP dyes.

Emissions of volatile organic compounds (VOCs) were studied from three heavily polluted rivers (Huijiang, Nancun, and Zengbian Rivers) in Guangzhou, South China. A total of 49 species of VOCs were identified. Nancun River had the highest concentration of total VOCs (TVOCs), which ranged from 1,467 to 5,522 μg m⁻³. Trichloroethene, benzene, toluene, ethylbenzene, m/p-xylene, o-xylene, styrene, and 1,3,5-trimethylbenzene were the main pollutants. The levels of VOCs evaporated from the three rivers exhibited different patterns. Correlations between the concentrations of major VOCs were established and found to be statistically significant, except for o-xylene. The ratios of toluene/benzene, ethylbenzene/benzene, and xylene/benzene were estimated and found to be higher than widely reported in the literature. TVOC fluxes in the three rivers were calculated to be the range from 24.8 to 765 μg m⁻² h⁻¹. This study provides a regional background for the emission inventories of VOCs from heavily polluted rivers in southern China and provides resource managers with important information to guide remediation and policy concerning VOC emissions to the environment.

Thus far, members of the genus Dehalococcoides are the only microorganisms known to dehalogenate chlorinated ethenes to ethene and thereby detoxify these common groundwater pollutants. Therefore, it is important to characterize the taxonomic and functional diversity of these key microorganisms and their reductive dehalogenase (RDase) genes in contaminated aquifers for assessing the natural attenuation potential. Little is known about the diversity of RDase genes under field conditions or in laboratory systems under selective pressure during dechlorination activities. Here, we evaluate the diversity of Dehalococcoides sp. and three RDase genes in groundwater as well as in water from a constructed wetland and microcosms setup with contaminated groundwater from the same field site in Bitterfeld (Saxony-Anhalt, Germany). The presence and relative abundance of Pinellas and Cornell subgroups of Dehalococcoides was evaluated by a novel direct sequencing method, which revealed that all sequences were identical and affiliated to the Pinellas subgroup. Contrarily, our results showed remarkable differences at the functional gene level between the systems. Of the vinyl chloride reductase genes, vcrA was detected in samples from the groundwater, wetland, and microcosms, whereas bvcA was only found in wetland and microcosm samples. The trichloroethene dehalogenase gene, tceA could not be detected at all, although complete dehalogenation activity of higher chlorinated ethenes was observed. Our study demonstrates that although the Dehalococcoides 16S rRNA gene sequences retrieved from the investigated systems were identical, the RDase gene diversity varied among the systems, according to the spectrum of the chlorinated ethenes present.

It is known that peat can be a potential adsorbent to remove contaminants from wastewaters. When raw peat is used, many limitations exist: Natural peat has a low mechanical strength, high affinity for water, poor chemical stability and tendency to shrink and/or swell. In this work, in order to obtain a more manageable substrate, to be used as adsorbent, peat was entrapped in calcium alginate beads. Box–Behnken factorial design was used to obtain the best condition for the immobilization of peat in calcium alginate beads. The independent variables studied were: peat concentration, sodium alginate concentration and calcium chloride concentration, whereas the dependent variables studied were based on the variation of colour parameters after the treatment of vinasses with entrapped peat. High colour reductions can be achieved using entrapped peat formulated by mixing 2 % of peat with 3 % of sodium alginate and pumped it on calcium chloride (0.05 M).

Field experiments were conducted in the 2008–2009 soybean and winter wheat-growing seasons to assess soil respiration (SR) and nitrous oxide (N₂O) emission as affected by enhanced UV-B radiation and straw incorporation. The SR rate was measured using a soil CO₂ flux system; the N₂O flux was measured using a static chamber–gas chromatograph technique. The results showed that in the soybean and winter wheat-growing seasons, enhanced UV-B radiation significantly decreased the SR rates and that straw incorporation increased the SR rates compared to the control treatment. The combined treatment of UV-B and straw incorporation had no obvious influence on the SR rates. Enhanced UV-B radiation, straw incorporation, and the combination treatment increased the temperature sensitivity of SR in the soybean-growing season. The study also showed that N₂O emissions were reduced by enhanced UV-B radiation and that straw incorporation had no significant effects on the mean N₂O emission fluxes in the soybean and winter wheat-growing seasons. Our findings suggest that enhanced UV-B radiation may lead to a decrease in SR and in N₂O emissions, straw incorporation may increase SR, and the combined treatment may have no significant influence on SR and N₂O emissions from soybean–winter wheat rotation systems.

The feasibility of a sequentially enhanced process for the remediation of soils contaminated by mixed contaminants, specifically multiple polycyclic aromatic hydrocarbons (PAHs) and heavy metals, was investigated. This process consists of sequential flushing using two chemical agents: a surfactant and a chelate. A series of laboratory column experiments was conducted with three different sequential schemes, designated as SEQ1, SEQ2, and SEQ3, in two distinct flushing stages, to remove PAHs and heavy metals from a field-contaminated soil. The SEQ1 scheme involved flushing 0.2 M ethylenediaminetetraacetic acid (EDTA) followed by flushing 5 % Igepal. The SEQ2 scheme involved flushing 5 % Igepal followed by flushing 0.2 M EDTA. SEQ1 was investigated under a constant hydraulic gradient of 1.2, while the SEQ2 scheme was investigated under hydraulic gradients that increased from 1.2 to 4.0. The SEQ3 scheme consisted of sequential flushing of 5 % Igepal (first stage) and 0.2 M EDTA (second stage) under a constant low hydraulic gradient of 0.2. The selected sequential schemes allowed an assessment of the efficacy of sequencing the surfactant and chelating flushing for the removal of multiple heavy metals and PAHs under various hydraulic gradients. The hydraulic conductivity (or flow) was found to vary depending on the flushing agent and the sequence scheme. Under the high hydraulic gradient, the hydraulic conductivity was lower during chelant flushing stage as compared with surfactant flushing stage in both SEQ1 and SEQ2. However, under a low gradient condition (SEQ3), the hydraulic conductivity was approximately the same during both chelant and surfactant flushing stages. The contaminant removal was also significantly affected by the flushing agent and sequence and the applied hydraulic gradient. Heavy metals were removed during chelant flushing, while PAHs were removed during surfactant flushing. The total removal efficiencies of Pb, Zn, and Cu were 76 %, 63 %, and 11 % in SEQ1 and 42 %, 40 %, and 7 % in SEQ2, respectively, while the total removal efficiencies of phenanthrene, anthracene, benz(a)anthracene, and pyrene were 51 %, 35 %, 58 %, and 39 % in SEQ1 and 69 %, 50 %, 65 %, and 69 % in SEQ2, respectively. Overall, the total mass removal of heavy metals and PAHs was higher in SEQ1 as compared with SEQ2, demonstrating that SEQ1 is the effective sequence scheme. Comparison of the results of high and low gradient conditions (SEQ2 and SEQ3) reveals that the removal of contaminants, especially heavy metals, is rate-limited. Overall, this study showed that the removal of co-existing heavy metals and PAHs from soils is possible through the careful selection of the sequence under which the flushing of chelant and surfactant occurs and depends on the site-specific soil and contaminant conditions. Additional research is needed to establish the most optimal flushing scheme (sequence duration and flow velocity) to remove the mixed contaminants effectively and efficiently. © 2013 Springer Science+Business Media Dordrecht.

Remediation of anthracene from soil was faster in the topsoil than in the lower layers. It was not clear whether this was due to a higher anthracene bioavailability or an increased microbial degradation in the topsoil layer. Therefore, an arable soil was contaminated with 500 mg anthracene kg⁻¹ dry soil, and its removal was monitored with an exhaustive technique and with n-butanol to determine its bioavailability in three layers. Additionally, part of the contaminated soil was stored aerobically for 112 days (considered the aged soil), and the anthracene was monitored thereafter. After 112 days, 360 mg anthracene kg⁻¹ was removed from the soil, but its dissipation was not affected by the layer, depth, and fluctuations in water content or the interaction between. In the aged soil stored for 112 days, only 170 mg anthracene kg⁻¹ was removed. In the subsequent incubation of the aged soil, 273 mg anthracene kg⁻¹ was removed within 28 days, and after 112 days, no contaminant was detectable in the soil. An additional experiment confirmed the hypothesis that simply mixing the soil accelerated the removal of anthracene. Mixing the soil every 7 days removed all anthracene from the soil within 28 days, while in the undisturbed soil, 301 mg anthracene kg⁻¹ was still extractable. It can be concluded that mixing the soil accelerated the removal of anthracene, but fluctuations in water content did not. The anthracene extracted with n-butanol was not related to the amount removed and is thus not a good indicator of bioavailability of anthracene in soil.