Currently HPLC/MS is the state of the art tool for environmental/drinking water perfluorooctane sulfonate (PFOS) monitoring. PFOS can bind to peroxisomal proliferator-activated receptor-alpha (PPARα), which forms heterodimers with retinoid X receptors (RXRs) and binds to PPAR response elements. In this bioassay free PFOS in water samples competes with immobilized PFOS in ELISA plates for a given amount of PPARα–RXRα. It can be determined indirectly by immobilizing PPARα–RXRα–PFOS complex to another plate coated with PPARα antibody and subsequent measuring the level of PPARα–RXRα by using biotin-modified PPARα–RXRα probes–quantum dots–streptavidin detection system. The rapid and high-throughput bioassay demonstrated a detection limit of 2.5 ng L⁻¹ with linear range between 2.5 ng L⁻¹ and 75 ng L⁻¹. Detection results of environmental water samples were highly consistent between the bioassay and HPLC/MS.

The Lenga Estuary is a small brackish wetland located southwest of San Vicente Bay, Region VIII, Chile. Surface sediment from nine sites in the estuary were analysed for PAHs and compared to Sediment Quality Guidelines (SQG). Sediment samples were freeze dried and soxhlet extracted for 16h using DCM. Identification and quantification was carried out by HPLC. Organic carbon was also determined. Results showed total PAH concentrations ranged from 290 to 6118 (2025±1975)ngg⁻¹ d.w. (2025±1975). Results for organic carbon percentages ranged from 1% to 7%. Statistical analysis showed a significant positive correlation (Pearson test) between organic carbon percentage PAHs. Comparison of contaminant levels and international Sediment Quality Guidelines (SQG) (ERL and ER) suggested that sediment of the Lenga estuary did not show any ecotoxicologial risk for benthic organisms where high levels of PAHs were detected. Monitoring of this and other contaminants is recommended in Chile.

Inverted microscopy is widespread employed for the analysis of phytoplankton composition within water quality monitoring networks. However, the analysis at the lowest taxonomical level is not always required for ecological status assessment. In addition, inverted microscopy can underestimate the small phytoplankton, and not always distinguish photoautotrophic from heterotrophic cells. In this study, as alternative tools, epifluorescence microscopy and High Performance Liquid Chromatography (HPLC) were employed to characterize phytoplankton communities within waters of different trophic condition. Epifluorescence microscopy confirmed its effectiveness to count the small phytoplankton. Furthermore, significant correlations between nutrients of anthropogenic origin and nanoplankton abundances were found. However, this technique resulted very time-consuming. HPLC together with the CHEMTAX program was more appropriate than inverted microscopy, in terms of cost-effectiveness. Also, the main variability patterns observed in the phytoplankton community structure by HPLC coincided with previous findings in the study area. Nevertheless, a rapid screening at the inverted microscope is recommended.

The aim of this work was to determine the optimum values for the biodegradation process of six abiotic factors considered very influential in this process. The optimisation of a polycyclic aromatic hydrocarbon (naphthalene, phenanthrene and anthracene) biodegradation process was carried out with a degrading bacterial consortium C2PL05. The optimised factors were the molar ratio of carbon/nitrogen/phosphorus (C/N/P), the nitrogen source, the iron source, the iron concentration, the pH and the carbon source. Each factor was optimised applying three different treatments during 168 h, analysing cell density by spectrophotometric absorbance at 600 nm and PAH depletion by HPLC. To determine the optimum values of the factors, an analysis of variance was performed using the cell density increments and biotic degradation constants, calculated for each treatment. The most effective values of each factor were: a C/N/P molar ratio of 100:21:16, NaNO3 as nitrogen source, Fe2(SO4)3 as iron source using a concentration of 0.1 mmol l−1, a pH of 7.0 and a mixture of glucose and PAHs as carbon source. Therefore, high concentrations of nutrients and soluble forms of nitrogen and iron at neutral pH favour the biodegradation. Also, the addition of glucose to PAHs as carbon source increased the number of total microorganism and enhanced PAH biodegradation due to the augmentation of PAH degrader microorganisms. It is also important to underline that the statistical treatment of data and the combined study of the increments of the cell density and the biotic biodegradation constant have facilitated the accurate interpretation of the optimisation results. For an optimum bioremediation process, it is very important to perform these previous bioassays to decrease the process development time and, therefore, the costs.

Recently, there has been increasing concern about perfluorinated compounds, especially perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) due to their biotic and abiotic persistence and chronic toxicity. To characterize the spatial distribution and seasonal variation of PFOS and PFOA in the aquatic and oceanic environment of Singapore, more than 100 water samples from reservoirs, rivers/canals, coastal waters, and treated effluents of wastewater treatment plants (WWTPs) were collected and analyzed in this study. Solid-phase extraction followed by high-performance liquid chromatography (HPLC) coupled with tandem MS (HPLC/MS/MS) was applied to quantitatively identify PFOS and PFOA. PFOS concentrations in surface waters, wastewaters and coastal waters were in the range of 2.2–87.3 ng/L, 5.8–532 ng/L, and 1.9–8.9 ng/L, respectively, while those of PFOA were 5.7–91.5 ng/L, 7.9–1,060 ng/L, 2.4–17.8 ng/L, respectively. Compared with surface waters and wastewaters, coastal waters had lower concentrations of PFOS and PFOA. Highest concentration of PFOA (532 ng/L) and PFOA (1,060 ng/L) were observed in treated effluents of two WWTPs. Our results suggest that coastal waters in the western area of Singapore are more heavily contaminated than those in the middle and eastern areas. The release of effluents from WWTPs is an important pathway by which perfluorinated compounds enter the oceanic environment. Between dry season and wet season, significant seasonal differences (p = 0.025) were observed in surface waters for PFOS only, while no discernable seasonal differences were found for both PFOS and PFOA in coastal waters and wastewaters.

Comamonas sp. UVS was able to decolorize Reactive Blue HERD (RBHERD) dye (50 mg L−1) within 6 h under static condition. The maximum dye concentration degraded was 1,200 mg L−1 within 210 h. A numerical simulation with the model gives an optimal value of 35.71 ±â€‰0.696 mg dye g−1 cell h−1 for maximum rate (Vmax) and 112.35 ±â€‰0.34 mg L−1 for the Michaelis constant (Km). Comamonas sp. UVS has capability of decolorization of RBHERD in the presence of Mg2+, Ca2+, Cd2+, and Zn2+, whereas decolorization was completely inhibited by Cu2+. Metal ions also affected the levels of biotransformation enzymes during decolorization of RBHERD. Comamonas sp. UVS was also able to decolorize textile effluent with significant reduction in COD. The biodegradation of RBHERD dye was monitored by UV–vis spectroscopy, FTIR spectroscopy, and HPLC.

Purpose This paper analyses the presence of polychlorinated biphenyls (PCBs) in escaped: farmed and wild salmons in southern Chile, analysing their concentrations and congener profiles in two species (Oncorhynchus kisutch and Oncorhynchus mykiss). Methods Muscle samples from both farmed and escaped fish of two species, O. mykiss (rainbow trout) and O. kisutch (coho salmon), were analysed for PCBs (42 congeners). To differentiate between the wild salmon and the salmon that have escaped from fish farms, the astaxanthin content in the muscular tissue was analysed with a high-performance liquid chromatography -diode array detector method. PCBs were measured by gas chromatography with an electron capture detector. Results The levels of astaxanthin can be used to differentiate between farmed, escaped and wild-borne salmons with statistically different concentrations. When comparing the total PCB concentrations for both trout and salmon samples, it can be determined that a separate analysis for farmed, escaped and wild-borne fish more accurately describes the real differences in the concentrations; these differences are hidden when separate analyses are not performed. The congener profiles are similar in both trout and coho salmon, where the tri-, tetra- and penta-CB congeners are the most abundant. Conclusion This study is the first report of PCBs in wild-borne, farmed and escaped salmons for the Southern Hemisphere, considering that Chile is actually one of the principal world producers of salmon.

PURPOSE: The dyes and dye stuffs present in effluents released from textile dyeing industries are potentially mutagenic and carcinogenic. Phytoremediation technology can be used for remediating sites contaminated with such textile dyeing effluents. The purpose of the work was to explore the potential of Glandularia pulchella (Sweet) Tronc. to decolorize different textile dyes, textile dyeing effluent, and synthetic mixture of dyes. METHODS: Enzymatic analysis of the plant roots was performed before and after decolorization of dye Green HE4B. Analysis of the metabolites of Green HE4B degradation was done using UV–Vis spectroscopy, high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR), and gas chromatography–mass spectroscopy (GC-MS). The ability of the plant to decolorize and detoxify a textile dyeing effluent and a synthetic mixture of dyes was studied by a determination of the American Dye Manufacturer’s Institute (ADMI), biological oxygen demand (BOD), and chemical oxygen demand (COD). Phytotoxicity studies were performed. RESULT: Induction of the activities of lignin peroxidase, laccase, tyrosinase, and 2,6-dichlorophenol indophenol reductase was obtained, suggesting their involvement in the dye degradation. UV–Vis spectroscopy, HPLC, and FTIR analysis confirmed the degradation of the dye. Three metabolites of the dye degradation were identified, namely, 1-(4-methylphenyl)-2-{7-[(Z)-phenyldiazenyl] naphthalen-2-yl} diazene; 7,8-diamino-2-(phenyldiazenyl) naphthalen-1-ol; and (Z)-1,1′-naphthalene-2,7-diylbis (phenyldiazene) using GC-MS. ADMI, BOD, and COD values were reduced. The non-toxic nature of the metabolites of Green HE4B degradation was revealed by phytotoxicity studies. CONCLUSION: This study explored the phytoremediation ability of G. pulchella (Sweet) Tronc. in degrading Green HE4B into non-toxic metabolites.

Background Airborne fine particulates (PM 2.5) and its associated polycyclic aromatic hydrocarbons (PAHs) are reportedly hazardous in urban environment due to the presence of multiple emission sources. Methods In this study, fine particulates collected from fourth largest metropolitan city of India, Chennai, were extracted and analyzed for 11 PAHs by high-performance liquid chromatography equipped with a fluorescence detector. Results PM 2.5 values varied between 27.2 and 190.2 μg/m³, while average concentration of particle-associated PAHs determined was in the range from 325.7 to 790.8 ng/m³, which signaled an alarming pollution level in Chennai. Conclusions Factor analysis suggested vehicular emissions inclusive of petrol- and diesel-driven engines as probable sources.

Background and purpose Surfactant-assisted soil washing and photocatalysis are well-known remediation processes of environmental concern. The application of photocatalysis to treat soil washing extracts containing 4-methylphenol, 4-ethylphenol and 4-tert-butylphenol in the presence of nonionic (C₁₂E₈ and C₁₂E₂₃) and anionic (SDS) surfactants and some of their binary mixtures was investigated in this work by studying the pollutants degradation in the presence of TiO₂ dispersions irradiated with simulated solar light. Materials and methods Clean soil samples were spiked with the investigated alkylphenols. Aqueous solutions of the chosen surfactants were placed in contact for some hours with the spiked soil samples in a rotatory mixer. The pollutants recoveries were evaluated via HPLC analysis. Photocatalytic experiments were performed in solarbox on aqueous solutions and on aqueous surfactant solutions containing the pollutants. Results The pollutants removal from the soil was proven effective using the examined surfactant solutions. The photocatalytic treatment of the wastes was faster using Brij 35, but also SDS and C₁₂E₈-SDS mixtures can be applied. After 2-5 h the complete pollutants abatement was obtained, depending on the surfactant chosen and on the amount of TiO₂ employed. On the contrary, the treatment of wastes containing C₁₂E₈ was an extremely slow process. Conclusions The photocatalytic approach can be applied to remove the examined aromatic pollutants from the washing wastes, confirming the viable coupling between this advanced oxidation method and the surfactant-based soil remediation treatments. Surfactant adsorption onto TiO₂ and micelles concentration play a dominant role.