Zebrafish were placed in the upper layer of aquariums to investigate the impacts of anatase and rutile nano-TiO2 on perfluorooctanesulfonate (PFOS) bioaccumulation in zebrafish. Both variations of particle hydrodynamic size and concentration in water column suggest that anatase was better dispersed than rutile. PFOS could be significantly adsorbed on nano-TiO2 to form TiO2-PFOS complexes, leading to reduced concentration of PFOS in upper layer. Due to enhanced exposure to PFOS by ingestion and adhesion of TiO2-PFOS complexes, the whole-body PFOS concentration in zebrafish was enhanced by 59.0% (95% CI: 55.9%, 61.9%) and 25.4% (95% CI: 24.8%, 25.6%) in the presence of anatase and rutile nano-TiO2 after equilibrium compared with the control with PFOS alone. The bioaccumulation of PFOS was much more promoted by anatase, which was attributed by greater adsorption capacity of PFOS to anatase, slower migration of their complex in water column, and slower elimination rate of anatase from fish.

Using enrichment culture technique, three isolates marked as ODB-1, ODB-2 and ODB-3, were selected from oil contaminated seawater. 16S rDNA gene sequencing indicated that ODB-1 affiliated with Pseudomonas sp. while ODB-2 and ODB-3 affiliated with Brevundimonas sp. Subsequently, the bacterial cells were immobilized on the surface of expanded graphite (EG), expanded perlite (EP) and bamboo charcoal (BC). Among the three isolates, ODB-1 showed a strong binding to the bio-carriers through extracellular polysaccharides, while ODB-2 and ODB-3 made the adhesion to bio-carrier through direct physical adsorption. The immobilized bacteria exhibited good salinity tolerance compared with the planktonic bacteria. Their total diesel oil removal rates were more than 85% after 6 days’ incubation. Adsorption–biodegradation process played an important role in the oil-pollution remediation. EG-bacteria system was treated as a promising remediation method, which achieved nearly 100% removal of diesel oil. Thereinto, over 83% removal of diesel oil owed to biodegradation.

Inspired by the adhesion of marine mussels, a kind of superhydrophobic oil sorbent was successfully fabricated by robustly immobilizing the micro/nanostructure layer onto the sponge skeleton. The as-prepared sponges possess excellent hydrophobicity with the water contact angle of 154°, which enables the sponge to selectively absorb various oils floating on water surface. The oil sorption capacities of as-prepared sponge for a series of oils can reach 18.3–46.8g/g. The absorbed oil can be recovered by mechanical squeezing and the resulting sponge can be recycled more than 70 cycles while still keeping high oil sorption capability. More importantly, the obtained sponge has excellent affinity to the high viscosity oils. Therefore, the as-prepared sponge might find practical applications in the large-scale removal of oils especially high viscosity oils from water surface.

The role of chemical interactions in shaping microbial communities has raised increasing interest over the last decade. Many benthic microorganisms are known to develop chemical strategies to overcome competitors, but the real importance of chemical interactions within freshwater biofilm remains unknown. This study focused on the biological and chemical mechanisms of an interaction involving two benthic microorganisms, an allelopathic filamentous green alga, Uronema confervicolum, and a common diatom, Fistulifera saprophila. Our results showed that functions critical for benthic phototrophic microorganisms were inhibited by U. confervicolum extracts. Growth, cell motility, adhesion, and photosynthetic activity were impaired at extract concentrations ranging between 5 and 20 μg ml⁻¹. The adhesion inhibition was mediated by intracellular nitric oxide (NO) induction. A bioassay-guided fractionation of the extract with HPLC helped to identify two C18 fatty acids present in the growth-inhibiting fractions: linoleic (LA) and α-linolenic (LNA) acids. These compounds represented 77 % of the total free fatty acids of U. confervicolum and were present in the culture medium (1.45 μg l⁻¹ in total). Both could inhibit the diatom growth at concentrations higher than 0.25 μg ml⁻¹, but had no effect on cell adhesion. The discrepancy between the effective concentrations of fatty acids and the concentration found in culture medium may be explained by the presence of high-concentration microenvironments. The compounds involved in adhesion inhibition remain to be identified. Though further experiments with complex biofilms are needed, our results suggest that U. confervicolum may participate to the control of biofilm composition by inhibiting diatom adhesion.

Cellulose acetate monoliths (CAM) were used as the substrate for the deposition of TiO₂films to produce honeycombed photoactive structures to fill a tubular photoreactor equipped with a compound parabolic collector. By using such a setup, an efficient single-pass gas-phase conversion was achieved in the degradation of n-decane, a model volatile organic compound. The CAM three-dimensional, gas-permeable transparent structure with a rugged surface enables a good adhesion of the catalytic coating. It also provides a rigid structure for packing the tubular photoreactor, and maximizing the illuminated catalyst surface. The efficiency of the photocatalytic oxidation (PCO) process on n-decane degradation was evaluated under different operating conditions, such as feeding concentration (73 and 146 ppm), gas stream flow rate (73, 150, and 300 mL min⁻¹), relative humidity (3 and 25 %), and UV irradiance (18.9, 29.1, and 38.4 WUVm⁻²). The results show that n-decane degradation by neat photolysis is negligible, but mineralization efficiencies of 86 and 82 % were achieved with P25-CAM and SG-CAM, respectively, for parent pollutant conversions above 95 %, under steady-state conditions. A mass transfer model, considering the mass balance to the plug-flow packed photoreactor, and PCO reaction given by a Langmuir-Hinshelwood bimolecular non-competitive two types of sites equation, was able to predict well the PCO kinetics under steady-state conditions, considering all the operational parameters tested. Overall, the performance of P25-CAM was superior taking into account mineralization efficiency, cost of preparation, surface roughness, and robustness of the deposited film.