Biomixtures comprise the active part of biopurification systems (BPS) for the removal of pesticide-containing wastewater from agricultural origin. Considering that biomixtures contain an important amount of lignocellulosic substrates, their bioaugmentation with degrading ligninolytic fungi represents a promising way to improve BPS. The fungus Trametes versicolor was employed for the bioaugmentation of rice husk-compost-soil (GCS) biomixtures in order to optimize the removal of the highly toxic insecticide/nematicide carbofuran (CFN). Composition of biomixtures has not been optimized before, and usually, a volumetric composition of 50:25:25 (lignocellulosic substrate:humic component:soil) is employed. Optimization of the biomixture composition was performed with a central composite design, using the volumetric content of rice husk (pre-colonized by the fungus) and the volumetric ratio compost/soil as design variables. Performance of biomixtures was comprehensively assayed considering CFN removal, the production of toxic transformation products (3-hydroxycarbofuran/3-ketocarbofuran), the ability to mineralize [¹⁴C]carbofuran, and the residual toxicity in the matrix. According to the models, the optimal volumetric composition of the GCS biomixture is 30:43:27, which maximizes removal and mineralization rate, and minimizes the accumulation of transformation products. Results support the value of assessing new biomixture formulations according to the target pesticide in order to obtain their optimal performance, before their use in BPS.

The use of synthetic dyes is commonplace in many industries, and the effluent is often dumped into the environment with no prior treatment. The aim of the present study was to analyze the use of an industrial strain of Saccharomyces cerevisiae (Meyen) for the removal of the textile dye Acid Blue 161 from an aqueous solution. Kinetic, isotherm, and thermodynamic models were created to evaluate the biosorption mechanisms. Fourier transfer infrared (FT-IR) spectroscopy was used to characterize and identify possible binding sites. A toxicity test was also performed using Artemia salina to analyze the degree of toxicity of the dye following treatment. The kinetic results demonstrated the occurrence of intraparticle diffusion in the yeast cells as the controlling mechanism of the sorption process. Biosorption followed the Langmuir model, except at pH 8.50, when it fit the Freundlich model. The thermodynamic results demonstrate that the biosorption process is spontaneous and endothermic. The FT-IR analyses confirmed the occurrence of a chemical reaction in acid pH, but physical adsorption only occurred at pH 8.50. The toxicity test showed that the use of the yeast biomass led to the complete removal of toxicity from the dye solution, demonstrating the effectiveness of the biosorption process in the treatment of effluents contaminated with these compounds.

We investigated the horizontal and vertical distribution of heavy metals (Hg, Pb, Zn, Cu, Cd, As, Ni, and Cr) in soils in the water source protection zone for Shanghai to study the origins of these metals, their connections with urbanization, and their potential risk posed on the ecosystem. Determination of metal concentrations in 50 topsoil samples and nine soil profiles indicated that Hg, Pb, Zn, and Cu were present in significantly higher concentrations in topsoil than in deep soil layers. The spatial distributions of Hg, Pb, Zn, and Cu and contamination hotspots for these metals in the study area were similar to those near heavy industries and urban built-up areas. Emissions from automobiles resulted in increased soil concentrations of Cu, Pb, and Zn along roadsides, while high concentrations of Hg in the soil resulted from recent atmospheric deposition. Calculation of the potential ecological risk indicated that the integrative risk of these heavy metals in most areas was low, but a few sites surrounding high density of factories showed moderate risks.

Biodegradable polymer poly(3-hydroxybutyrate) (P3HB) has been used as a matrix to construct slow-release formulations of the fungicide tebuconazole (TEB). P3HB/TEB systems constructed as films and pellets have been studied using differential scanning calorimetry, X-ray structure analysis, and Fourier transform infrared spectroscopy. TEB release from the experimental formulations has been studied in aqueous and soil laboratory systems. In the soil with known composition of microbial community, polymer was degraded, and TEB release after 35 days reached 60 and 36 % from films and pellets, respectively. That was 1.23 and 1.8 times more than the amount released to the water after 60 days in a sterile aqueous system. Incubation of P3HB/TEB films and pellets in the soil stimulated development of P3HB-degrading microorganisms of the genera Pseudomonas, Stenotrophomonas, Variovorax, and Streptomyces. Experiments with phytopathogenic fungi F. moniliforme and F. solani showed that the experimental P3HB/TEB formulations had antifungal activity comparable with that of free TEB.

In recent years, high concentrations of hexavalent chromium, Cr(VI), have been observed in the groundwater system of the Asopos River Basin, raising public concern regarding the quality of drinking and irrigation water. The work described herein focuses on the development of a groundwater flow and Cr(VI) transport model using hydrologic, geologic, and water quality data collected from various sources. An important dataset for this goal comprised an extensive time series of Cr(VI) concentrations at various locations that provided an indication of areas of high concentration and also served as model calibration locations. Two main sources of Cr(VI) contamination were considered in the area: anthropogenic contamination originating from Cr-rich industrial wastes buried or injected into the aquifer and geogenic contamination from the leaching process of ophiolitic rocks. The aquifer’s response under climatic change scenario A2 was also investigated for the next two decades. Under this scenario, it is expected that rainfall, and thus infiltration, will decrease by 7.7 % during the winter and 15 % during the summer periods. The results for two sub-scenarios (linear and variable precipitation reduction) that were implemented based on A2 show that the impact on the study aquifer is moderate, resulting in a mean level decrease less than 1 m in both cases. The drier climatic conditions resulted in higher Cr(VI) concentrations, especially around the industrial areas.

Medium-pressure (MP) ultra violet (UV) disinfection was suggested as a pre-treatment to control biofouling in a semi-scale flow-through model water system. Water, spiked with Pseudomonas aeruginosa, nutrients, and carbon source, was flowed through the system and biofilm formation on glass, PVC, and stainless steel 316 slides was examined following 24 h runs. Following UV exposure a ∼99 % reduction in biovolume and average thickness of the biofilm was observed on all surfaces examined, despite clear differences in the virgin surface characteristics analyzed using contact angle, zeta potential, and atomic force microscopy (AFM). The findings support the stochastic behavior of biological systems in relation to predictions derived from conventional theories. The reduction of viable microbial counts seems to be the major mechanism in reducing the actual biofilm formation rate and the overall effect UV provides could indeed render it an effective tool in mitigating biofilm formation in water distribution systems.

To analyze the daytime and phenological variations of canopy O₃ and CO₂ uptake of winter wheat, the canopy fluxes of wheat plants were measured using a chamber system with four different O₃ levels (0, 40, 80, and 120 nmol mol⁻¹) being applied. During the daytime (7:30–18:00 hours), canopy fluxes usually peaked around noon in early growing stages, while a generally decreasing trend from morning to afternoon was observed in the later stages. O₃ and CO₂ fluxes were positively and negatively correlated with O₃ concentration, respectively. Significant differences were observed in O₃ fluxes but CO₂ fluxes among O₃ treatments. Photosynthetically active radiation (PAR) and vapor pressure deficit (VPD) could affect canopy gas uptake in opposite ways. On the phenological timescale, both O₃ and CO₂ fluxes followed the variation of leaf area index (LAI) with the maximum occurring simultaneously at the booting stage. The daytime mean fluxes varied from −10.6 to −17.2 nmol m⁻² s⁻¹ for O₃ and from −5.9 to −19.6 μmol m⁻² s⁻¹ for CO₂. Quantitatively important O₃ deposition (−3.1∼−11.6 nmol m⁻² s⁻¹) was also observed at night with the ratios being about 40∼70 % relative to the daytime O₃ fluxes for most measuring days, which indicates a significant contribution from non-stomatal components to canopy O₃ removal. This study confirms that environmental variables and plant phenology are important factors in regulating canopy O₃ and CO₂ uptake. O₃ exposure (≤120 nmol mol⁻¹) could not significantly affect the CO₂ uptake of wheat canopy in a short time (ca. 10 min).

Synergistic effect of nanosized TiO₂ and impressed magnetic field (MF) was studied by investigating the photocatalytic degradation of phenol at room temperature. The introducing of MF with relatively high intensity (>0.082 T) has obvious promotion effects on phenol degradation rate (C/C ₀), while negative influences of MF on C/C ₀ can be observed under low-intensity MF (<0.044 T). The yield of hydroxyl radicals (·OH) in reaction processes increases with the raising of MF intensity initially and reaches the maximum concentration when the magnetic intensity is 0.082 T. The photoinduced carriers initially decrease until the MF intensity reaches at 0.024 T, and then increase with the increasing of MF intensity. The effects of MF on photoinduced carriers can be explained in terms of the Δg mechanism together with the hyperfine coupling mechanism. Low-intensity MF accelerates the recombination of electrons and holes and suppresses the generation of photoinduced carriers, which further restricts the degradation of phenol. In contrast, the presence of high-intensity MF retards the recombination of hydroxyl radicals and thus enhances the production of ·OH radicals. The generation of hydroxyl radicals is the primary factor in determining the phenol degradation process in the high-intensity MF region. Graphical Abstract Effect of impressed magnetic field on phenol degradation over TiO2 photocatalytic system.

Embryonic and early postembryonic development of the cuttlefish Sepia officinalis (a cephalopod mollusk) occurs in coastal waters, an environment subject to considerable pressure from xenobiotic pollutants such as pharmaceutical residues. Given the role of serotonin in brain development and its interaction with neurodevelopmental functions, this study focused on fluoxetine (FLX), a selective serotonin reuptake inhibitor (SSRI, antidepressant). The goal was to determine the effects of subchronic waterborne FLX exposure (1 and 10 μg L⁻¹) during the last 15 days of embryonic development on neurochemical, neurodevelopmental, behavioral, and immunological endpoints at hatching. Our results showed for the first time that organic contaminants, such as FLX, could pass through the eggshell during embryonic development, leading to a substantial accumulation of this molecule in hatchlings. We also found that FLX embryonic exposure (1 and 10 μg L⁻¹) (1) modulated dopaminergic but not serotonergic neurotransmission, (2) decreased cell proliferation in key brain structures for cognitive and visual processing, (3) did not induce a conspicuous change in camouflage quality, and (4) decreased lysozyme activity. In the long term, these alterations observed during a critical period of development may impair complex behaviors of the juvenile cuttlefish and thus lead to a decrease in their survival. Finally, we suggest a different mode of action by FLX between vertebrate and non-vertebrate species and raise questions regarding the vulnerability of early life stages of cuttlefish to the pharmaceutical contamination found in coastal waters.

This paper has its origin via an inadvertent error wherein a length of rubber hose was added to the sampling line of a sulphur gas analyser at the Australian Baseline Station at Cape Grim. This carbon disulphide (CS₂) contamination source was removed after a period of 10 weeks. In the interim, substantial data was collected and is here compared with the record of ambient station temperatures. CS₂ was found to vary with ambient temperature over both short and monthly time scales. Comparisons of linear, natural log (ln) and log₁₀ correlations yield the conclusion that log₁₀ and ln CS₂ emission vs. temperature (°C) associations provide the best correlations. No significant depletion of CS₂ emission from the rubber over a 10-week period was detected. Implications for regional and global emission inventories of CS₂ and carbonylsulphide (COS) are discussed.