Trace Organic Pollutants Research Articles

Correlations between in situ sensor measurements and trace organic pollutants in urban streams

Quantification of organic and microbial pollutant loading is expensive and labor-intensive because collection and analysis of grab samples are needed. Instruments are available, however, for in situ analysis of basic water quality parameters at high temporal resolution. Throughout the late summer and fall of 2008 a two-node water quality monitoring network was deployed to measure turbidity, specific conductance, pH, depth, temperature, dissolved oxygen, and nitrate at high frequencies in two urban streams in the Minneapolis, MN metropolitan area. Grab samples also were collected at 2 h intervals for 22 h during two dry periods and five rain events and analyzed for organic and microbial pollutants. This study investigated the viability of using in situ near real-time sensors to predict fecal coliforms, prometon (a residential herbicide), atrazine (an agricultural herbicide), and caffeine (a wastewater indicator) concentrations. Such pollutants can be used as indicators of sources that contribute to what is often termed "urban stream syndrome." At one stream, linear correlations were observed between nitrate and caffeine (R(2) = 0.66), turbidity and prometon (R(2) = 0.91), and discharge and prometon (R(2) = 0.92). At another location, caffeine linearly correlated with specific conductance (R(2) = 0.64). A lack of correlation with sensed water quality parameters was also observed with some of the pollutants. When one considers that error is estimated to be as high as 200% when using monthly grab samples to estimate pollutant loading in streams, even moderate correlations, such as the ones found in this study, can provide better loading estimates if frequently sensed parameters can be used for load estimation. Therefore, such site-specific relationships can be used to estimate the loading of specific pollutants in near real-time until robust low-cost technologies to analyze these pollutants in situ become available.

Preparation of gallic acid-chitosan complex (eco-brown) and its application for adsorption of mutagens and carcinogens

Gallic acid was reported to suppress the mutagenicity and to inhibit the metabolic activation. Chitosan is a unique polysaccharide derived from chitin and is utlized as adsorbents of organic trace pollutants in environmental water sample. In this study, we have found that chitosan was suitable as a solid support to carry gallic acid. And it was examined that gallic acid could form an insoluble material when mixed with chitosan, and the solid chitosan-gallic acid complex (eco-brown) thus prepared could efficiently trap polycyclic mutagenic compounds. The adsorption of the test compounds was observed using UV/Visible spectrometry. The order of extent of removal by ecobrown was B[a]P (96.1%)>QC (83.0%)>2-AA (80.3%) >2-AF (30.3%)>PhIP (29.6%). From these results, eco-brown may be expected as a useful adsorber for several polycyclic mutagens and carcinogens.

Adsorptive removal and oxidation of organic pollutants from water using a novel membrane

To develop an effective method to remove and mineralize trace organic pollutants, a series of composite functional membranes containing immobilized ACF (activated carbon fibre) powder (<300 mesh) and Ce 3+-TiO 2, a combination of adsorbent and photo-catalyst on terylene (PET) filter cloth, was prepared by using a sol–gel and dip coating method. As high as 93% BPA (bisphenol A) pollutant can be separated successfully by adsorption onto the membrane in a series of batch adsorption tests, 40% removal was achieved in dynamic filtration/adsorption test, which also removed 98% koalinite suspended solids at the same time. The measured adsorption of BPA corresponds to 37.0, 70.6 and 62.2 mg (BPA)/g(ACF) for three membranes A, B and C, where the weight ratio of ACF to ACF + TiO 2 was 29.9%, 17.6% and 11.3% respectively in batch adsorption tests (50 ml solution) and 25.48 mg (BPA)/g(ACF) for membrane A after 2 h adsorption in 200 ml solution. After dynamic filtration, the total adsorption capacity was 81.0 mg (BPA)/g(ACF) for membrane A. It is noteworthy that membrane adsorption can be regenerated by UV/Fenton treatment. Order of BPA adsorption quantity is 1st > 2nd > 3rd time use for membrane C, due to loss of ACF resulted from the supersonic treatment before oxidative regeneration. Introducing TEOS in the preparation of sol–gel solution and subsequent coating to form composite membrane, improved membrane adsorption stability in UV/Fenton regeneration treatment.

Determination of photochemically-generated reactive oxygen species in natural water

Reactive oxygen species (ROS) can be produced by interactions between sunlight and light-absorbing substances in natural water environment. ROS may participate in the indirect photolysis of trace organic pollutants, therefore resulting in changes in their environmental fates and ecological risks in natural water systems. Bisphenol A (BPA), an endocrine-disrupting chemical, exits widely in natural waters. The photodegradation of BPA promoted by ROS (*OH, 1O2, HO2*/O2(*-)), which were produced on the excitation of ubiquitous constituents (such as nitrate ion, humic substances and Fe(III)-oxalate complexes) in natural water under simulated solar radiation was investigated. Both molecular probe method and electron spin resonance (ESR) test were used for the characterization of the generated ROS. It was found that *OH was photochemically produced in the presence of nitrate ions, humic substances and Fe(III)-oxalate complexes and that 102 was produced with the presence of humic substances. The steady-state concentrations of *OH was 1.27x10(-14) mol/L in a nitrate solution, and the second-order rate constant of BPA with *OH was 1.01 x 10(10) L/(mol x s).

Simultaneous determination of pharmaceuticals, endocrine disrupting compounds and hormone in soils by gas chromatography–mass spectrometry

Analytical methods have been developed for simultaneous determination of six different pharmaceuticals and personal care products (PPCPs) (clofibric acid, ibuprofen, naproxen, ketoprofen, diclofenac, and triclosan), three endocrine disrupting compounds (EDCs) (4- tert-octylphenol, 4- n-nonylphenol, and bisphenol A (BPA)) and one estrogenic compound (estrone) in soil matrix. The soils were extracted by different solvents with the help of an ultrasonic treatment at 42 kHz, followed by a solid phase extraction (SPE) as a cleanup procedure. The purified extracts were derivatized with N-methyl- N-( tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA) and then analyzed by GC–MSD (SIM mode). The method was evaluated by testing the following variables: initial spiking levels, extraction solvents, solvent volumes, and soil types (sandy and clay soils). For 5 g of soil, four successive extraction steps with the mixture of acetone–ethyl acetate provided satisfactory recoveries. In the sandy soil, the recoveries of all the compounds were from 63.8 to 110.7% for the spiking level of 100 ng/g dry soil, and from 52.2 to 108.2% for 5 ng/g dry soil, respectively. Result was similar for the clay soil. The precision across all recoveries was high, suggesting that this method has a good reproducibility. The method was successfully employed to soil samples collected from a golf course irrigated with reclaimed wastewater in southern California, and resulted in the detection of clofibric acid, ibuprofen, naproxen, triclosan, bisphenol A, and estrone at ng per gram dry weight concentration levels. The method is robust and simple, and provides straightforward analyses of these current-emerging trace organic pollutants in solid matrices.

How polluted is the Yangtze river? Water quality downstream from the Three Gorges Dam

The concentrations of major anions and cations, nitrogen and phosphorus, dissolved and particulate trace elements, and organic pollutants were determined for the middle and lower reaches of the Yangtze River (Changjiang) from below the Three Gorges Dam (TGD) to the mouth at Shanghai in November 2006. The concentration of dissolved inorganic phosphate (DIP) was constant at a low level of 6–8 µgP/L, but the concentration of nitrate (NO 3 −) approximately doubled downstream and was closely correlated with K +. This translated to a daily load of well over 1000 t of dissolved inorganic nitrogen (DIN) at Datong. The average concentrations of dissolved Pb (0.078 ± 0.023 µg/L), Cd (0.024 ± 0.009 µg/L), Cr (0.57 ± 0.09 µg/L), Cu (1.9 ± 0.7 µg/L), and Ni (0.50 ± 0.49 µg/L) were comparable with those in other major world rivers, while As (3.3 ± 1.3 µg/L) and Zn (1.5 ± 0.6 µg/L) were higher by factors of 5.5 and 2.5, respectively. The trace element contents of suspended particles of As (31 ± 28 µg/g), Pb (83 ± 34 µg/g), and Ni (52 ± 16 µg/g) were close to maximum concentrations recommended for rivers by the European Community (EC). The average concentrations of Cd (2.6 ± 1.6 µg/g), Cr (185 ± 102 µg/g), Cu (115 ± 106 µg/g), and Zn (500 ± 300 µg/g) exceeded the EC standards by a factor of two, and Hg (4.4 ± 4.7 µg/g) by a factor of 4 to 5. Locally occurring peak concentrations exceed these values up to fourfold, among them the notorious elements As, Hg, and Tl. All dissolved and particulate trace element concentrations were higher than estimates made twenty years ago [Zhang, J., Geochemistry of trace metals from Chinese river/estuary systems: an overview. Estuar Coast Shelf Sci 1995; 41: 631–658.]. The enormous loads of anthropogenic pollutants disposed to the river were diluted by the large water discharge of the Yangtze even during the lowest flow resulting in the relatively low concentration levels of trace elements and organic pollutants observed. We estimated loads of e.g. As, Pb and Ni to the East China Sea to be about 4600 kg As d − 1 , 3000 kg Pb d − 1 , and 2000 kg Ni d − 1 . About 6000 t d − 1 of dissolved organic carbon (DOC) was delivered into the sea at the time of our cruise. We tested for 236 organic pollutants, and only the most infamous were found to be barely above detection limits. We estimated that the load of chlorinated compounds, aromatic hydrocarbons, phenols, and PAHs were between 500 and 3500 kg d − 1 . We also detected eight herbicides entering the estuary with loads of 5–350 kg d − 1 . The pollutant load, even when at low concentrations, are considerable and pose an increasing threat to the health of the East China Sea ecosystem.

Rejection of trace organic pollutants with high pressure membranes (NF/RO)

AbstractThis article presents a modeling approach for the rejection of trace organic pollutants in high‐pressure membranes. The rejection values of uncharged organic solutes with a wide range of solute size and hydrophobicity are determined. Sigmoidal rejection curves are constructed and modeled for solutes of different hydrophobicity. The model is based on a log‐normal pore size distribution model. A model is also presented to model the rejection of charged organic solutes, based on the rejection of uncharged solutes and the concept of a “charge concentration polarization.” Moreover, scale‐up issues arising when translating results from bench‐scale units to full‐scale plants are addressed, by assessing the viability of a full‐scale rejection model. The full‐scale model is based on a convection‐diffusion model for the transport of organic solutes through the high‐pressure membranes and the use of mass balances in the system. © 2008 American Institute of Chemical Engineers Environ Prog, 2008

Distribution of persistent toxic substances in benthic bivalves from the inshore areas of the Yellow Sea

A baseline survey of trace metals and organic pollutants in bivalves from the coastal areas of the Yellow Sea (China) showed the the concentrations of Cd and Pb in the bivalves from more than 85 and 73%, respectively, of the total sites (30 sites in all) exceeded the low limits of the national quality standards for marine organisms. At three sites, the contents of Cd in three species were even higher than the median limit, and a similar case with Pb occurred at another site. The tissue concentrations of As at four sites and of Hg at one site were above the low and the median limits, respectively, of the quality standards. At 43% of all sites, the levels of petroleum hydrocarbons were higher than the low limit of the quality standards, and the tissue concentrations at two sites even went beyond the median limit at one site and the high limit at the other. The concentrations of phthalate esters and polycyclic aromatic hydrocarbons (PAHs) in the collected bivalves were not high, as shown by peak values of 305 and 302 ng/g, respectively. The contents of polychlorinated biphenyls for all the species were much lower than the low limit of the quality standards. The compositional properties and isomeric ratios of PAHs indicated various pyrolytic procedures as the dominant origins. The sites with higher tissue contents of DDT and its metabolites (DDTs) over the low or the median quality limit were located mainly in the South Yellow Sea. The fractions and specific ratios of DDTs suggested that new inputs of DDT existed at two sites in the North Yellow Sea, and the potential sources involved technical DDT, technical dicofol, and their mixture.

Historical trends of organic pollutants in sediment cores from Hong Kong

Recent studies have indicated the occurrence of a wide range of trace organic contaminants, including polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the Hong Kong environment. These contaminants are potentially harmful to ecological systems, particularly in coastal areas. In this study, two sediment cores (4 m) were collected from southern waters of Hong Kong in 2004 to study the historical trends, distribution patterns, and potential sources of trace organic contaminants. DDTs ( p,p′-DDT, o,p′ -DDT, p,p′-DDD, o,p′ -DDD and p,p′-DDE), hexachlorohexanes (HCHs) (α and γ), hexachlorobenzene (HCB), and PCBs were detected in the samples, whereas other target compounds were all below detection limits. Many OCPs have not been produced or used for many years due to toxicological or environmental concerns and PCB use is prohibited in Hong Kong. However, some compounds were still detectable in recent years, and were found to be widely distributed in the environment, likely because of pollutant inputs from the highly industrialized Pearl River Delta region. These results provide important information on current and historical contamination in Hong Kong, and help to reconstruct the pollution history of these trace organic pollutants in Hong Kong coastal waters.

Characteristics of dissolved organic matter and trace organic pollutants depending on leachate treatment processes in final disposal site containing incineration residues

Characteristics of dissolved organic matter and trace organic pollutants depending on leachate treatment processes in final disposal site containing incineration residues

The microtopography of manganese dioxide formed in situ and its adsorptive properties for organic micropollutants

The microtopography of manganese dioxide formed in situ was captured by AFM. The adsorptive properties of manganese dioxide formed in situ were evaluated for trace organic pollutants' removal with four different organic pollutants as the model organics which have different functional groups on aromatic ring. Several factors, such as the structure of manganese dioxide formed in situ, the adsorption time, the adsorbent concentration, and the background constituents (Ca 2+, Mg 2+, fulvic acid, etc.) in natural water, were investigated to evaluate their effects on adsorption. Results showed that manganese dioxide formed in situ had smaller particle size and higher adsorption capacity than the coagulated one. Ca 2+ and Mg 2+ added to the aqueous solution decreased the organics' removal significantly by accelerating the coagulation of manganese dioxide formed in situ and competing the adsorption sites with organics. The presence of fulvic acid had little impact on organic removal though it competes for the surface sites of manganese dioxide with organics. The four organics adsorbed on manganese dioxide formed in situ are listed in the order of decreasing reactivity: aniline > phenol > nitrobenzene > benzoic acid. The relative reactivity of organics was discussed in terms of electrostatic interaction between organics and adsorbent.

Effects of calcium-based sorbents on PCDD/F formation from pentachlorophenol combustion process

Calcium-based sorbents are widely employed to reduce the acidic gases emission from combustion processes, and also have effects on trace organic pollutants formation and emission. Batch experiments were conducted to investigate the effects of calcium-based sorbents on pentachlorophenol (PCP) forming PCDDs/Fs during high temperature combustion processes. The results indicated that highly chlorinated PCDD/F homologues were the predominant dioxin products from PCP thermo decomposition, and only minor increasing of PCDDs happened when Ca/Cl ratio was lower than 1, while a major jump occurred when Ca/Cl ratio increased from 1 to 2. The CaO addition clearly promoted the production of all chlorinated dibenzo- p-dioxins homologue and 4–7DFs homologue. Comparison of total PCDD/F emission and its I-TEQ for three different calcium-based sorbents addition (CaO, CaCO 3, basic fly ash) indicated that CaO and fly ash containing CaO had almost the same promotion effects on PCDDs/Fs originated from PCP, while CaCO 3 inhibit PCDD/F formation greatly with inhibition efficiency up to 70%. Such effects may be partly proved by the observed clearly different micro-surface structures of their reaction residues. The mechanism of CaO on condensation and dechlorination reactions for PCP forming PCDDs and acid–base interaction were proposed to speculate the promotion effects of CaO, and the reaction precedence was used to speculate the inhibition effects of CaCO 3 on PCDDs/Fs originated from PCP. The results of the present paper might be useful for the industrial application of calcium-based sorbents to control PCDD/F emission.

Relationships between pesticides and organic carbon fractions in sediments of the Danshui River estuary and adjacent coastal areas of Taiwan

In order to understand the fate of pesticides in marine environments, concentrations of pesticides and different carbonaceous fractions were determined for surface sediments in the Danshui River and nearby coastal areas of Taiwan. The major compounds detected were tetrachlorobenzene, HCHs, chlordane, aldrin, DDDs, DDEs and DDTs. Total concentrations of pesticides in the sediments ranged from not detectable to 23 ng g −1, with the maximum value detected near the discharge point of the marine outfall from the Pali sewage treatment plant. These results confirm that pesticides persist in estuarine and nearby coastal environments of the Danshui River well after their ban. Concentrations of total pesticides significantly correlate with concentrations of total organic carbon and black carbon in these sediments, suggesting that total organic carbon and black carbon regulate the distribution of trace organic pollutants in fluvial and coastal marine sediments.

The kinetics of polycyclic aromatic hydrocarbon (PAH) biodegradation assessed by isothermal titration calorimetry (ITC)

Interest in the biodegradation mechanisms and environmental fate of hydrophobic organic compounds (HOC) such as polycyclic aromatic hydrocarbons (PAHs) is motivated by their ubiquity in the environment, their persistence and their potentially deleterious effect on human health. Due to their high hydrophobicity, PAH tend to interact with non-aqueous phases and natural organic matter and, as a consequence, are poorly bioavailable for microbial degradation. Here, a novel calorimetric approach was developed and successfully tested in order to gain real time information on the kinetics and the physiology of PAH bioconversion in aqueous systems. Anthracene-degrading soil bacterium Mycobacterium frederiksbergense LB501T was exposed to a pulsed titration of dissolved anthracene and the resulting thermal reaction monitored. The heat flux signals of the biodegradation of 180 ng anthracene were interpreted in terms of the Michaelis-Menten kinetics and the parameters K A and r A max of anthracene degradation were derived. The comparison with a conventional method shows the suitability of isothermal titration calorimetry (ITC) to extract kinetic degradation parameters of organic trace pollutants from simple ITC experiments.

Extraction and Concentration of Freshwater – and Seawater – Derived Dissolved Organic Matter for Use in Aquatic Toxicology Studies

Dissolved organic matter (DOM) is defined as the organic matter that passes through a 0.45 μm-mesh filter. Recent studies have shown the DOM importance in mitigating trace metals and organic pollutants toxicity. In general, studies with DOM are performed using commercial organic matter. However, it has been demonstrated that this organic matter has little structural similarity with the aquatic humic acids. Furthermore, a natural DOM is composed by different fractions, which can exhibit different complexing properties with metals. Thus, it is important to evaluate the effect of different sources of natural DOM on pollutants toxicity. To use natural DOM in aquatic toxicity tests, it is necessary to extract and provide suitable storage for samples in the laboratory. The ideal process for DOM isolation from natural waters should be capable of rapidly and effectively extracting large quantities of DOM from water without fractionation, chemical alteration and/or other losses. Therefore, in the present paper we describe the methodological approaches currently in use in our laboratory for extraction and concentration of both freshwater and seawater-derived DOM using reverse osmosis (freshwater) and solid phase extraction (seawater).

Transport of pollutants in two estuarine systems on the coast of Georgia

The aim of the present study was to examine the distribution of pollutants in two coastal systems in Georgia: (1) Kubitskali river which flows into the Black sea through the city of Batumi and is polluted mainly from the effluents of an oil refinery; (2) Paliastomi lake, which is a shallow water body at the south-east of the city of Poti. During 2000–2001, two samplings took place in each system, one in the low-flow period and one in the high-flow period. During these samplings, pH, temperature, dissolved oxygen, and salinity were measured in situ, whereas water samples were collected for the analysis of trace metals, nutrients, and organic pollutants with standard methods. The results of the measurements indicate the significant pollution of both systems by ammonia and in the case of Kubitskali River also by oil products. The need for a sustainable management plan of the activities taking place in the river basin is urgent.

Relationship between carbonaceous materials and polychlorinated biphenyls (PCBs) in the sediments of the Danshui River and adjacent coastal areas, Taiwan

Persistent organic pollutants, POPs (e.g., polychlorinated biphenyls) can seriously and deleteriously affect environmental quality and human health. These organic pollutants are exhibiting high affinities to solid phases and thus, quickly end up in sediments. To better understand the role of carbonaceous materials in the transport and distributions of POPs in terrestrial and near-shore environments, concentrations of PCBs and carbonaceous materials (including total organic carbon, black carbon and total carbohydrates), were determined in surface sediments of the Danshui River and nearby coastal areas, Taiwan. Total concentrations of PCBs in the sediments ranged from non-detectable to 83.9 ng g −1, dry weight, with the maximum value detected near the discharge point of the marine outfall from the Pali Sewage Treatment Plant. These results suggest that the sewage treatment plant has discharged PCBs in the past and the concentrations are still high due to their persistence; alternatively, PCBs are still being discharged in the estuarine and near-shore environment of the Danshui River. Organic carbon and black carbon concentrations correlated well with those of total PCBs in the sediments, suggesting that both organic carbon and black carbon significantly affect the distribution of trace organic pollutants through either post-depositional adsorption, or by co-transport of similar source materials. The field results demonstrate that black carbon and plays an important role in the general distribution of PCBs, while concentrations of some specific PCBs are affected by both black carbon and organic carbon concentrations.

Assesment of Trace Elements and Organic Pollutants from a Marine Oil Complex into the Coral Reef System of Cayo Arcas, Mexico

Possible contaminants produced by the Petroleos Mexicanos (PEMEX) marine oil complex in the vicinity of the Cayo Arcas (Mexico) coral reef ecosystem were evaluated by analyzing sediments and sea water for hydrocarbons and metal elements. We found that the concentrations of aliphatic hydrocarbons in the sea water were generally low, with the highest values detected near the oil station; the concentration of polycyclic aromatic hydrocarbons (PAHs) was generally below the detection limit. The hydrocarbons found in the sediments seem to have a pyrogenic origin, and were probably produced by marine traffic in the study area. The total PAH concentration did not exceed the NOAA criteria, although levels of some individual PAHs did. The only metal detected in the sea water at high concentrations was nickel. The Ni/V ratio in the sediments indicates the contribution of crude oil to the system. The high content of Ni and Zn was attributed to the ballast waters from the oil tankers that load at the station's monobuoys. The presence of fine sediments that commonly originate from terrestrial ecosystems supported this assumption.

Water quality of rooftop rainwater harvesting systems: a review

There has been a growing interest, especially in developing countries, in rooftop rainwater harvesting as an alternative source of drinking water. This paper reviews the available information on the water quality of rooftop rainwater harvesting systems. Various factors that affect the physico-chemical and microbiological quality of harvested water are discussed. Different contaminants including heavy metals and trace organic pollutants in the roof runoff reported from different parts of the world are compared. The review shows that the quality of harvested water from roof catchments often does not meet the drinking-water guideline values. Most of the studies reveal that harvested water is heavily contaminated microbiologically by a variety of indicator and pathogenic organisms unless special care is taken during collection and storage of rainwater. Heavy metals and trace organics could also pose problems in some cases. The review thus indicates that the purity of rainwater harvested from rooftops should not be taken for granted, and analysis of the harvested water especially for microbiological contamination should be undertaken. Appropriate treatment of collected rainwater would be necessary to make the harvested rainwater fit for drinking. The review also shows the need for further research on proper design and maintenance strategies to minimise contamination of roof-collected rainwater supplies.

Sampling of water, soil and sediment to trace organic pollutants at a river-basin scale

Sampling is considered a crucial step in the analysis of organic compounds in the environment. This review describes field sampling techniques and provides detailed step-by-step procedures for collection and preservation of all major environmental matrices (water, sediment and soil) integrated as part of the river-basin water cycle. Attention is given to the prerequisites for obtaining reliable samples, and the practical issues of sample collection (planning, field sampling, sampling strategies and equipment and data quality assessment) are considered. Considering the heterogeneity of environmental matrices, special considerations for each matrix are given to solve typical problems and to find the most appropriate solutions to ensure the quality of the sample. The procedures described in the next sections are commonly used protocols that reflect true field conditions and current state-of-the-art techniques used in the sampling of organic compounds. The aim is to signify the importance of sampling to the overall analytical procedure. Finally, quality control issues to be considered in environmental sampling are given.