Analysis of phenolic compounds in the dissolved and suspended phases of Lake Balaton water by gas chromatography-tandem mass spectrometry

A sensitive PnpR-based biosensor for p-nitrophenol detection

A common aromatic and phenolic pollutant, p-nitrophenol (PNP), is widely used in various industry and has serious risk to the environmental health. Biosensors have been extensively employed as an alternative technology for pollutants monitoring. By mining the new sensing elements, more specific biosensors could be characterized for highly sensitive detection. Herein, the PnpR transcription factor was identified to activate the transcription of pnpC1 by binding to PpnpC1 promoter region in P. putida DLL-E4, and PNP was recognized as its specific inducer. The PnpR-based biosensor for detection of PNP was developed, demonstrating adequate sensitivity in a liquid solution with satisfactory specificity. The biosensor was optimized by adopting a transcriptional amplifier, which increased the maximum output by 149-fold, and improved the detection limit by 100-fold, from 1 mg/L to 10 μg/L. These biosensors had a linear range of 5-80 mg/L and 0.01-1.0 mg/L for PNP determination, respectively. Then, the agarose gel entrapment-based biosensor was constructed and allowed a good of PNP detection in the range of 5-60 mg/L in M9 solid agar within 70 min, and a detection sensitive of 16.8 mg/kg in soil. The good performance of the biosensor suggested its potential application of high-efficient and on-site detection in environmental matrices.

Synergistic potency of ultrasound and solar energy towards oxidation of 2,4-dichlorophenol: a chemometrics approach

Industrial units based on chemical processes-the textile and paper industries-are major sources of chlorophenols in the environment, and chlorophenolic compounds persist within the environment for a long time with high toxicity levels. The photo-assisted Fenton's and photocatalysis processes were investigated for the degradation of chlorophenols in the present study. Response surface methodology was employed to get optimised conditions for photocatalysis and photo-Fenton process-governing factors, thus, yielding a profound removal efficiency. Under optimised conditions, with a photocatalyst dose of 0.2 g/L, oxidant concentration of 10.0 mM and pH 5.0, complete removal of 2,4-dichlorophenol (2,4-DCP) was observed in 210 minutes in photocatalytic treatment. In the case of the photo-Fenton process, at an H2O2 dose of 5.0 mM and Fe2+ concentration of 0.5 mM, the organic pollutant was eliminated within 5 minutes of reaction time under acidic conditions (pH 3.0). The RSM model reported the perfect fit of experimental data with the predicted response. Among different isotherm models, the Langmuir isotherm was the best fit. The process followed pseudo-first order rate kinetics among various kinetics models. For the obtained optimised conditions, sonication and solar energy-driven processes were incorporated to study enhanced mineralisation. The solar-assisted Fenton process reported maximum mineralisation (90%) and cost-effective ($0.01/litre for 100 mg/L 2,4-DCP) treatment among different hybrid oxidation processes. The work provides insight into harnessing the naturally available solar energy, reducing the overall treatment cost and opting for a sustainable treatment method.

Non-targeted analysis by DLLME-GC-MS for the monitoring of pollutants in the Mar Menor lagoon

Non-targeted analysis for the monitoring of organic pollutants resulting from agricultural and industrial practices, plastics and pharmaceutical products of seawater from the Mar Menor lagoon (SE Spain) is proposed using dispersive liquid-liquid microextraction (DLLME) and gas chromatography-mass spectrometry (GC-MS). Initially, a home-made MS database including 118 environmental organic pollutants, whose presence in different ecosystems has already been reported, was created. The analytical method was applied for the analysis of 42 samples and a total of 18 pollutants were detected and identified. Samples were obtained from different sites around the Mar Menor in three sampling campaigns, enabling the assessment of impact of rain on the input of the detected chemicals and their distribution. In addition, this methodology was validated using a standard mixture containing 54 of the environmental pollutants included in the database, allowing the quantification of the 9 of the identified compounds (dibutyl phthalate, diisobutyl phthalate, diethyl phthalate, bis(2-ethylhexyl) phthalate, anthracene, 2-methylnaphthalene, hexachlorocyclopentadiene, bis(2-ethylhexyl) adipate and oleamide) with concentration between 3 and 271 μg L^-1.

Assessment of anthropogenic pollution by monitoring occurrence and distribution of chemicals in the river Liffey in Dublin

This paper evaluates for the first time the spatial distribution of a wide group of organic (phthalates, nitro, aliphatic, halogen, aromatic, phenol and amino compounds) and inorganic pollutants along the Liffey river in Dublin city. The work takes into account the effect of short-term weather conditions on the occurrence of these contaminants. The results showed that rainfall conditions affect the levels of pollutants along the river in the days following a rainfall event. In addition, the tributaries entering the river Liffey were not found to impact its water quality. In relation to organic pollutants, 2,4,6-trichlorophenol, 2-nitrophenol and phthalate compounds were found in many water samples between concentrations of 0.21 and 2.17 μg L-1. On the other hand, dimethyl phthalate was present in certain samples at levels around 100 μg L-1. The levels of these contaminants in the river were lower than the toxicity values reported in the literature. Regarding inorganic pollutants, nitrates were detected from 0.59 to 6.81 mg L-1 increasing from upstream to downstream. Based on the chemical nature and applications of detected pollutants, the river contamination can be mainly related to agricultural, industrial activities as well as diffuse urban contributions. These vary with location within a short distance and have the potential to impact aquatic biodiversity as the chemical composition changes with rainfall events.

Chlorophenols in textile dyeing sludge: Pollution characteristics and environmental risk control

Chlorophenols (CPs) are toxic contaminants that tend to accumulate in textile dyeing sludge and pose a threat to the environment through the disposal process. To comprehensively evaluate CPs in sludge, the characteristics and risks of CPs from five textile dyeing plants (TDPs) were investigated in this study. The total concentration of 19 CPs (Σ₁₉ CPs) varied from 170.90 to 6290.30 ng g^-1 dry weight (dw), among which high-chlorine phenols accounted for the greatest proportion. The ecological screening level (ESL) of CPs was used to judge their pollution levels, while the risk quotient (RQ) value and dioxin conversion rate were used to analyze their potential risk. The results indicated that CPs may pose a moderate to high risk to the environment. The Fenton process was used to condition the hazardous sludge, and a higher content of CPs was found after conditioning. A lower rate of CP increase was achieved with a reagent dose of 180 mmol/L, H₂O₂:Fe²⁺ = 1:1, pH of 3-4 and reaction time of 30 min. In summary, the work helps to address the general knowledge gap in the textile dyeing industry and provides a reference for further research.

Wastewater-based epidemiology approach to assess population exposure to pesticides: a review of a pesticide pharmacokinetic dataset

Wastewater-based epidemiology is an innovative approach to estimate a population's intentional and unintentional consumption of chemicals based on biomarker assays found in wastewater. This method can provide real-time objective information on the xenobiotics to which a population is directly or indirectly exposed. This approach has already been used to assess the population exposure to four classes of pesticides: organochlorines (chlordecone), triazines, organophosphates, and pyrethroids. This review aims to obtain the data (excretion rates) and characteristics (pesticide and metabolites stability, including in-sewer one) for other pesticides to broaden the scope of this new method. Excretion rates and stability descriptions for 14 pesticides, namely 2,4-D, aldrin, carbaryl, chlorobenzilate, dieldrin, diquat, ethion, glufosinate, glyphosate, folpet, malathion, parathion, penconazole, and tebuconazole, will be discussed in a practical framework.

The state of bisphenol research in the lesser developed countries of the EU: a mini-review

Bisphenol compounds are a class of chemical epoxy resins that are found throughout the world in food packaging, thermal paper products, dental materials, and more. These compounds were deemed to be safe until recently, when some studies noticed adverse effects at very low doses, due to the fact that bisphenol acts as an endocrine disruptor. Over the last ten years, studies have been performed to detect bisphenols (especially BPA) in serum and blood samples throughout the world. Essentially, the majority of the earth's population seems to have significantly measurable levels of bisphenol in their blood plasma or urine. However, the majority of the population is unaware that a potential danger may exist. The purpose of this mini-review is to report upon the state of bisphenol research in the lesser developed member-states of the European Union and to increase awareness of the exposure level and possible adverse health effects of this endocrine disruptor. The results show that only three of the most newly admitted members of the European Union have published research concerning the health effects and/or environmental exposure of EU citizens to bisphenol compounds. Those countries were Slovenia, Poland and the Czech Republic. The rest of the surveyed member-states had little or no published research in relation to bisphenol compounds. Furthermore, even the three nations referred to above still lagged far behind the more advanced EU member-states. The lack of research could translate into a lack of awareness amongst the citizenry of nearly half of the EU, and may be unnecessarily putting those EU citizens at an increased risk of exposure.

β-Estradiol and ethinyl-estradiol contamination in the rivers of the Carpathian Basin

17β-Estradiol (E2) and 17α-ethinyl estradiol (EE2), which are environmental estrogens, have been determined with LC-MS in freshwater. Their sensitive analysis needs derivatization and therefore is very hard to achieve in multiresidue screening. We analyzed samples from all the large and some small rivers (River Danube, Drava, Mur, Sava, Tisza, and Zala) of the Carpathian Basin and from Lake Balaton. Freshwater was extracted on solid phase and derivatized using dansyl chloride. Separation was performed on a Kinetex XB-C18 column. Detection was achieved with a benchtop orbitrap mass spectrometer using targeted MS analysis for quantification. Limits of quantification were 0.05 ng/L (MS1) and 0.1 ng/L (MS/MS) for E2, and 0.001 ng/L (MS1) and 0.2 ng/L (MS/MS) for EE2. River samples contained n.d.-5.2 ng/L E2 and n.d.-0.68 ng/L EE2. Average levels of E2 and EE2 were 0.61 and 0.084 ng/L, respectively, in rivers, water courses, and Lake Balaton together, but not counting city canal water. EE2 was less abundant, but it was still present in almost all of the samples. In beach water samples from Lake Balaton, we measured 0.076-0.233 E2 and n.d.-0.133 EE2. A relative high amount of EE2 was found in river Zala (0.68 ng/L) and in Hévíz-Páhoki canal (0.52 ng/L), which are both in the catchment area of Lake Balaton (Hungary).