Priority Pollutants In Water Research Articles

Potential of cobalt ferrite-graphitic carbon nitride nanocomposite in trace determination of pyrene as one of the priority pollutants in water and food samples

In this research, cobalt ferrite-graphitic carbon nitride (CoFe2O4/GC3N4) nanocomposite with high extraction ability, high sensitivity, and strong magnetic properties was successfully synthesized and evaluated as a sorbent for ultrasound-assisted dispersive magnetic micro-solid phase extraction (UA-DM-μ-SPE) of pyrene (Py) in food and water samples. A successful synthesis of CoFe2O4/GC3N4 was inspected by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray spectrometry (EDXS), and vibrating sample magnetometer (VSM) techniques. The experimental parameters affecting the UA-DM-μ-SPE efficiency, such as the amount of sorbent, pH, adsorption time, desorption time, and temperature, were effectively investigated according to a multivariate optimization approach. Under the optimal conditions, the detection limit, quantification limit, and relative standard deviation (RSD) for the target analyte were achieved at 2.33 ng mL−1, 7.70 ng mL−1, and 3.12%, respectively. The CoFe2O4/GC3N4 based UA-DM-μ-SPE followed by spectrofluorometry confirmed favorable results for the convenient and efficient determination of Py in the samples of vegetable, fruit, tea, and water.

Electrochemical activation of copper oxide decorated graphene oxide modified carbon paste electrode surface for the simultaneous determination of hazardous Di-hydroxybenzene isomers

The construction of a consistent electrochemical sensor is essential for the determination of hazardous pollutants in water and environments. Hydroquinone (HQ), catechol (CT), and resorcinol (RS) frequently coexist as priority pollutants in water and interfere with each other during identification, which poses a challenge for simultaneous and sensitive determination for those di-hydroxybenzene isomers. In this work, copper oxide (CuO) decorated graphene oxide (GO) nanocomposite (CuO/GO) was prepared and used to modify carbon paste electrode (CPE). The as-prepared electrode (CGCPE) was electrochemically activated in the presence of NaOH solution (Et-CGCPE) for the simultaneous determination of di-hydroxybenzene isomers (HQ, CT, and RS), and showed a well-defined oxidation peak with a significantly improved electrochemical response. We ascribe this high performance to the formation of electroactive functional groups on the electrode surface during the electrochemical activation and the synergistic effect between GO and CuO. Under the optimized conditions, the results show a long linear concentration range of HQ (0.2–360 µM), CT (0.3–360 µM), and RS (0.7–250 µM) with the detection limits of 1.0 μM, 1.1 μM, and 1.8 μM, respectively. The Et-CGCPE was effectively applied to detect three di-hydroxybenzene isomers in lake water with good repeatability and stability.

Double-endpoint Genotoxicity Quantification and PAHs Characterization of Drinking Water Source alongside Polluted Yinghe River with High Tumor Mortality.

The etiology for the high tumor mortality in heavy polluted Yinghe river basin is still unclear and polycyclic aromatic hydrocarbons (PAHs) belong to the priority pollutants in water based on the former surveillance data. In order to explore the potential genotoxicants contributing to the double-endpoint genotoxicity of polluted drinking water source, 12 groundwater and 3 surface water samples were collected from 3 villages and the nearby rivers alongside Yinghe river basin, respectively and their comprehensive genotoxicity was estimated with a bioassay group of SOS/umu test and micronucleus (MN) test (MNT). Some groundwater samples showed positive genotoxicity and all surface water samples were highly genotoxic. Eight groundwater samples showed DNA genotoxic effect with the average 4-NQO equivalent concentration (TEQ(4-NQO)) of 0.067 µg/L and 0.089 µg/L in wet and dry season, respectively. The average MN ratios of groundwater samples were 14.19‰ and 17.52‰ in wet and dry season, respectively. Groundwater samples showed different genotoxic effect among 3 villages. The total PAHs concentrations in all water samples ranged from 8.98 to 25.17 ng/L with an average of 14.97±4.85 ng/L. BaA, CHR, BkF, BaP and DBA were the main carcinogenic PAHs contributing to the genotoxicity of water samples. In conclusion, carcinogenic PAHs are possibly related to the high tumor mortality in the target area. Characterization of carcinogenic PAHs to genotoxicity of drinking water source may shed light on the etiology study for high tumor mortality in Yinghe river basin.

Occurrence and sources of aliphatic hydrocarbons in anthropogenic impacted soils from petroleum tank-farms in the Niger Delta, Nigeria

Abstract The occurrence and compositional pattern of priority pollutants are vital in understanding the anthropogenic contributions, origin, and risks of these pollutants to the surrounding environment. Thus, the focus of this study was to determine the concentrations, compositional profiles, and sources of aliphatic hydrocarbons (AHCs) in anthropogenic impacted soils from petroleum tank-farms environment in the Niger Delta, Nigeria. Forty-five soil samples were collected from the vicinity of petroleum tank-farms at the top (0-15 cm), sub (15-30 cm), and bottom (30-45 cm) soil depths. The concentration of AHCs was determined using gas chromatography-mass spectrometer (GC-MS) after extraction by ultrasonication with hexane/dichloromethane and clean-up in silica gel/alumina packed column. The mean concentrations of AHCs in the samples ranged from 0.52 ± 0.90 to 35.26 ± 35.69 mg/kg. The AHCs results show that the equivalent carbon number index (ECn-) ECn-13-35 had the highest concentration when compared to ECn-8-12 and ECn-36-40. The linear regression and ANOVA indicate that there is no significant positive correlation between TOC and the total concentration of AHCs in the soil profiles, and a significant variation in AHCs levels between soil profiles respectively. Results also showed that soils from the tank-farms are moderately contaminated with AHCs when compared to the UNEP recommended limit. However, when compared to other regulatory thresholds, the observed concentrations of AHCs, human and environmental health risks are likely. Source apportionments depict that the principal sources of AHCs were petrogenic and plant diagenesis. Appropriate clean-up and mitigation measures and further study to determine the occurrence, composition, and exposure risks of other priority pollutants in water and sediment samples from the surrounding creeks should be determined.

Priority Pollutants in Water and Sediments of a River for Control Basing on Benthic Macroinvertebrate Community Structure

Understanding the drivers of macroinvertebrate community structure is fundamental for adequately controlling pollutants and managing ecosystems under global change. In this study, the abundance and diversity of benthic macroinvertebrates, as well as their chemical parameters, were investigated quarterly from August 2014 to April 2015 in four reaches of the Huai River basin (HRB). The self-organizing map (SOM) algorithm and canonical correspondence analysis (CCA) were simultaneously applied to identify the main factors structuring the benthic community. The results showed that the benthic community structure was always dominated by gastropoda and insecta over seasons and presented obvious spatial and temporal heterogeneity along different pollution levels. The insects were always the top contributors to number density of the benthic community, except for the summer, and the biomass was mainly characterized by mollusca in all seasons. Statistical analysis indicated that TN and NH3-N in water, as well as Hg, As, Cd, and Zn in sediments, were the dominant factors structuring the community, which determined the importance of sediment heavy metal concentrations in explaining the benthic community composition in comparison with other factors. These major factors should be given priority in the process of river pollutant control, which might be rated as a promising way to scientifically improve river health management and ecological restoration.

BACTERIA AND PARASITIC PATHOGENS IN CONDITIONS OF CHEMICAL POLLUTION OF WATER FROM SURFACE WATER BODIES

There were identified priority pollutants in water of the Moscow river below the city (petroleum products, lead, cadmium, zinc, copper; anionic surfactants), which can affect the natural microbiocenosis of surface water. The presence in surface waters heavy metals - cadmium in a concentration of 4 MPC for fishery purposes, of lead at a concentration of 5 MPC for fishery purposes, oil at a concentration of 49 MPC, zinc at a concentration of 10 MPC for fishery purposes, anionic surfactants at the concentrations below the MPC, and also at excess of MPC by 5 times for chlorides, nitrites and nitrates to a large extent was established to affect the viability of indicator bacteria - coliforms, E. coli, enterococci, while maintaining in the water of pathogenic bacteria - Salmonella and parasitic pathogens living Entamoebae spp. and cystic viable vegetative forms of pathogenic protozoa Flagellata spp. and viable helminth eggs Larvae spp.

A Miniaturized Therapeutic Chromophore for Multiple Metal Pollutant Sensing, Pathological Metal Diagnosis and Logical Computing.

The efficacy of a miniaturized unimolecular analytic system is illustrated. The easily accessible therapeutic chromophore “temoporfin”, which responds differentially to bound metals at multiple wavelengths of Q-band absorption using chemometric analysis, expeditiously detects and discriminates a wide range of metals regarded as priority pollutants in water and hence may also be used for diagnosis of medically relevant metals in human urine. The molecule was further investigated as an electronic logic device, e.g. keypad lock device, to authorize multiple highly secure chemical passwords for information protection.

Determination and Distribution of Polycyclic Aromatic Hydrocarbons in Rivers, Sediments and Wastewater Effluents in Vhembe District, South Africa.

Polycyclic aromatic hydrocarbons are very toxic and persistent environmental contaminants. This study was undertaken to assess the concentrations and possible sources of 16 PAHs (Polycyclic aromatic hydrocarbons) classified by the United State Environmental Protection Agency as priority pollutants in water and sediments of the Mvudi and Nzhelele Rivers. Effluents from Thohoyandou wastewater treatment plant and Siloam waste stabilization ponds were also investigated. Diagnostic ratios were used to evaluate the possible sources of PAHs. PAHs in the water samples were extracted using 1:1 dichloromethane and n-hexane mixtures, while those in the sediment samples were extracted with 1:1 acetone and dichloromethane using an ultrasonication method. The extracts were purified using an SPE technique and reconstituted in n-hexane before analyses with a gas chromatograph time of flight—mass spectrometer. The results obtained indicate the prevalence of high molecular weight PAHs in all the samples. PAHs concentrations in water and sediment samples from all the sampling sites were in the range of 13.174–26.382 mg/L and 27.10–55.93 mg/kg, respectively. Combustion of biomass was identified as the major possible source of PAHs. Effluents from wastewater treatment facilities were also considered as major anthropogenic contributions to the levels of PAHs found in both river water and sediments. Mvudi and Nzhelele Rivers show moderate to high contamination level of PAHs.

A continuous-flow device for photocatalytic degradation and full mineralization of priority pollutants in water

The removal of hazardous pollutants which are harmful, even at very low concentrations, to human health and the environment is a challenging task. Standard techniques used to remove such pollutants from water often produce a polluted sludge that needs to be disposed of as hazardous waste. Photocatalytic degradation is an advanced oxidation process that might allow full mineralization of the pollutant with zero discharge of hazardous waste. However, most current devices performing photocatalytic degradation processes usually suffer from low efficiency due to technical problems that hinder efficient contact between the pollutant, the light and the catalyst. The system presented in this study aims to optimize this contact and allows photodegradation of polluted effluent flowing continuously through it. The system was used to study photodegradation of acetaminophen and picric acid. Under UVC radiation (254 nm), both pollutants underwent non-catalyzed photodegradation that followed zero-order kinetics. However, the addition of TiO2 accelerated the process, reducing half lives to 25% of their respective non-catalyzed values, and completely changing the reaction mechanism: the catalyzed processes obeyed second-order kinetics law. When a relatively low concentration (2 ppm) of pollutant was treated with the device, it was completely removed within about 1 h of irradiation time.

The usefulness of total concentrations and pore water concentrations of pesticides in soil as metrics for the assessment of ecotoxicological effects ‐ Scientific Opinion of the Panel on Plant Protection Products and their Residues (PPR)

The usefulness of total concentrations and pore water concentrations of pesticides in soil as metrics for the assessment of ecotoxicological effects ‐ Scientific Opinion of the Panel on Plant Protection Products and their Residues (PPR)

Modelling and design of thin-film slurry photocatalytic reactors for water purification

Photocatalytic oxidation processes are highly effective clean technologies for the degradation and mineralization of a wide variety of priority pollutants in water and wastewater. However, the application of heterogeneous photocatalysis for wastewater treatment on an industrial scale has been impeded by a lack of mathematical models that can be readily applied to reactor design and scale-up. As a results current photocatalytic reactors in research and development have been designed by empirical or semi-empirical methods only. In this paper, a simple and generic mathematical model for steady-state, continuous flow, thin-film, slurry (TFS) photocatalytic reactors for water purification using solar and UV lamps is presented. The model developed is applicable to TFS flat plate and annular photoreactors of (a) falling film design or (b) double-skin design, operating with three ideal flow conditions: (1) falling film laminar flow, (2) plug flow and (3) slit flow. The model is expressed in dimensionless form and scale-up of TFS photocatalytic reactors can be carried out by dimensional analysis. In addition, the model parameters can be estimated easily from real systems and model solutions can be obtained with little computational effort. Comparison of a number of ideal flow systems shows that both falling film laminar flow and plug flow operation modes give higher performance than the slit flow system. Slit flow operation mode results in lower conversions due to the non-correspondence of fluid-residence time and the transversal radiation field. The effect of optical thickness, on reactor performance and the evolution of radial profiles of a model pollutant with photoreactor length are presented for each of the operation modes. The falling film laminar flow system was found to be more efficient than the plug flow system when the reactor conversion is above 80%. For lower reactor conversion the plug flow system was found to be marginally more efficient than the falling film laminar flow system. A methodology for the optimal geometrical design of a highly efficient configuration of TFS photocatalytic reactors is also presented. The mathematical models presented may be used as a tool for the design, scale-up and optimization of these types of photocatalytic reactors.

Membrane extraction for the determination of halogenated ether priority pollutants in water

A method is described for the solvent‐free extraction, concentration, and determination of the halogenated ether base/neutral priority pollutants in water. Samples are collected by permeation through a silicone polycarbonate membrane followed by trapping onto a Tenax‐TA sampling tube. These samples were thermally desorbed and allowed to directly pass into a gas Chromatograph (GC) equipped with a flame ionization detector (FID) for subsequent separation and quantitation. Concentrations in the parts per billion (μg/L) were found for all the compounds studied. A linear relationship was obtained for concentrations ranging between approximately 8 and 300 parts per billion (ppb). The method can be used as an alternative to current preconcentration methods or for continuous monitoring of wastewater streams. It also offers the advantages of eliminating the need for costly solvents which in turn may contribute to sample contamination, and also lowering the number of analysis steps while still providing acceptable detection limits.

Continuous Permeation Sampler for Monocyclic Aromatic Priority Pollutants in Water

A method for continuous monitoring or off-site analysis of monocyclic aromatic priority pollutants in water is described. The monocyclic aromatics permeate through a polymeric membrane and are purged by an inert gas stream into a sampling tube packed with Tenax-TA. The samples are then thermally desorbed into a capillary column gas chromatograph. This sampler has advantages over conventional methods, such as eliminating time-consuming preconcentration procedures and avoiding the need for an organic solvent. Seven monocyclic aromatics with concentration of from low to mid-μg/L can be detected using one hour sampling time.

Passive Sampling of Monocyclic Aromatic Priority Pollutants in Water

A passive sampling technique based on permeation through a polymeric membrane has been used for collection of eight monocyclic aromatic priority pollutants from aqueous media. Pollutants permeating through the membrane are collected onto a solid adsorbent in the sampling device. Both solvent extraction and thermal desorption techniques were evaluated for the recovery of collected materials with quantification achieved by gas chromatography. Linear relationships between the amount of the pollutants collected and the product of exposure times and pollutant concentrations have been observed. The effects of the exposure temperature, pH, and the potential interferences were investigated. Sample species collected can be stored for three months without significant loss of the species.

Phenolic water pollutants in a Malaysian River basin

Phenolic chemicals with their very low taste and odour thresholds, high persistence and toxicity, are of growing concern as water pollutants. The compounds are known to exist in raw water as well as in treated water. The level of phenolic priority pollutants in water within the catchment area of the Linggi River Treatment Plant in Negeri Sembilan, Malaysia, which includes the Linggi river basin, was monitored. The 4-aminoantipyrin colourimetric method was used to determine total phenols whereas capillary column gas chromatography was used to determine the individual compounds. The results show that at most sampling stations, particularly those within the Seremban municipality, the level of phenols was found to exceed the recommended Malaysian standard of 2.0 μg/L(-1) for raw water. This is seen as the direct impact of industrial and urbanization of the area and clearly indicates the unhealthy state of the Linggi river. The results also indicate the need to improve the water quality if the river is going to be used as a source of raw water.

Determination of phenolic pollutants in water using permeation sampling

Abstract A passive sampling technique for the determination of time‐weighted‐average concentrations of phenolic priority pollutants in water is described. Phenols permeate a silicone polycarbonate membrane and are collected on a polymeric adsorbent. For high concentration ranges, phenols are adsorbed on the XAD‐7 resin and then desorbed with acetonitrile. Low ppb concentrations of phenols are analyzed by collection on Tenax‐TA followed by thermal desorption. Separation and quantification is achieved by capillary column gas chromatography using a flame ionization detector. A linear relationship between the amount of phenols collected and the products of the exposure time and phenolic concentrations over the range of 5 ppb ‐ 20 ppm have been determined. Temperature and solution pH affect permeation rates of the phenols. The sampling method is simple, inexpensive and suitable for multilocation monitoring.

Using Headspace Sampling With Capillary Column GC‐MS to Analyze Trace Volatile Organics in Water and Wastewater

Headspace sampling combined with capillary column gas chromatography–mass spectrometry analysis was evaluated for use in the investigation of priority pollutants in water and wastewater. A 3 mL sample loop and cryogenic trapping at ‐80°C were employed to increase the sensitivity into the nanogram‐per‐litre range, and excellent reproducibility was found in the low microgram‐per‐litre range. Separations were accomplished with a coated 30‐m × 0. 32‐mm fused silica capillary column. Mass spectral data were acquired by selective ion monitoring from 50 to 500 amu. The method was applied to water and wastewater samples with good results.

Determination of volatile priority pollutants in water by purge and trap and capillary column gas chromatography/mass spectrometry.

Two wide-bore capillary columns are evaluated for their applicability to the purge-and-trap technique and GC/MS analysis of 34 volatile organics. Neither column is able to completely resolve all 34 compounds, as is also typical of the packed column; however, the analysis is faster than with the packed column (18 to 21 min compared to 30 min), and the column effluent is introduced directly into the mass spectrometer without requiring an open-split interface. Method precision, as assessed from the instrument response at a concentration of 50 micrograms/L per component, is better than +/- 5% for 41% of the compounds using the VOCOL column (diphenyl dimethyl polysiloxane with crosslinking moieties) and for 53% of the compounds using the 007 column (95% methyl 5% phenyl silicone). The instrument response is linear from 20 to 200 micrograms/L for most compounds, and the amounts loaded to either column without serious distortion of the peak shape or resolution can be as high as 5 micrograms per component. Because the VOCOL column resolved more compounds than the 007 column within approximately the same analysis time, this column is further tested for performance with groundwater samples.

Direct LC analysis of selected priority pollutants in water at ppb levels

AbstractThirty‐two priority pollutants can be analyzed in water with detection limits of 10 ppb by direct liquid chromatography. High sensitivity is obtained by use of an ultra‐violet detector at 202 nm and a reverse phase C18 column with a water‐acetonitrile gradient that is compatible with two milliliter water samples.

The chromatographic and GC/MS analysis of organic priority pollutants in water.

This article is an overview of the proposed EPA methods for the analysis of priority pollutants in water by chromatography and gas chromatography/mass spectrometry (GC/MS). It discusses sampling, storage, apparatus, sample preparation, chromatographic and GC/MS analysis, quality control and quality assurance, and data handling as they apply to the proposed methods. Comments on the legal implications are included to underline the importance of understanding the NPDES permit granting and effluent monitoring system, as it applies to the proposed methods.