Search

The distribution and fate of organic pollutants within different compartments of a river system are determined by several key effects and drivers. Within the scope of this study, the aqueous and sedimentary compartments have been analyzed complementary to understand transport and accumulation pathways and to determine temporospatial effects. The bi-annual campaigns allow general statements to be made about relevant processes and effects on pollutant distribution. GC/MS non-target screenings revealed that there is only a minor group of contaminants that occur both in the water and in the riverbed. Nevertheless, for both phases, the main contamination with organic compounds occurred in the anthropogenic, middle to lower course of the river with loads up to 18.3 kg/d (2,4,7,9-tetramethyl-5-decyne-4,7-diol, TMDD) in the water and amounts up to 3.3 mg/gTOC (ƩEPA16 polycyclic aromatic hydrocarbons, PAHs) in the riverbed. Main emission sources were comparable, resulting in a high, almost constant contamination level which also contributes to the pollution of the superior, receiving river. Indeed, the pollution transport of the aqueous and sedimentary phases was closely connected, but with slight temporal and spatial heterogeneities. For the aqueous compartment, seasonal effects were identified while a remarkable change in riverbed contamination occurred due to an extreme flood event. However, dams within the catchment system cause a disconnection of the transport of lipophilic and hydrophilic substances. Overall, the combined investigation of different phases is an important aspect for a comprehensive view of river and environmental contamination. [ABSTRACT FROM AUTHOR]

Fast growing coastal population centers face an increasing vulnerability to several emission sources of anthropogenic and industrial pollutants. The ongoing industrialization in emerging countries increases the environmental and human risk for people living in coastal megacities, especially in the global south of Asia. Extreme weather events, such as heavy rainfalls and resulting flood events, are projected to increase in frequency in the foreseen future, facing an increasing vulnerability to monsoon-induced floods and the release and distribution of xenobiotics causing harm to communities and the environment along a river's pathway. To endeavor the unknown risks posed by these toxic floods and to assess the associated contamination distribution, the preserved organic geochemical signature from floodplain sediments is studied. This investigation evaluates the inorganic and organic pollutant assemblage in ten surface sediments along the Adyar and Cooum river in the urban areas of Chennai (southern India). Potentially toxic elements (Cr, Ni, Cu, Zn, Pb) show a continuous concentration decrease downstream. Four main groups of persistent organic pollutants have been detected: petrogenic pollutants (hopanes, PAHs), urban wastewater pollutants (LABs, DEHA, methyl-triclosan, octocrylene), technical compounds (Mesamoll®, DPE, NBFA), and pesticides (DDX). While most organic compounds show source specific properties, the definite sources for others remain vague based on the multitude of potential sources and diffusiveness of anthropogenic emissions. The chosen approaches have shown that urban wastewater pollutants and several technical compounds are suitable to assess the anthropogenic-induced contamination in floodplain sediments. However, sedimentary archives in fast-growing, urbanized environments are influenced and superimposed by anthropogenic alterations. [ABSTRACT FROM AUTHOR]

Due to intensive anthropogenic usage, a complex mixture of inorganic and organic contaminants entered and still enters freshwater systems, released by various activities and emission sources. However, because of the highly dynamic nature of rivers, the individual occurrence, fate, and behavior, especially of organic contaminants, are highly complex and not fully understood. Here, a GC/MS non-target screening was applied to identify and determine the chemical diversity in the aqueous phase of the meso-scaled Rur river and to categorize indicative and relevant contaminants according to their load profiles for a distinct emission characteristic. Besides very well-known or widespread lipophilic to semi-polar contaminants, also so far unknown or only sporadically identified substances have been detected. In particular, wastewater treatment plants and the paper industry have been identified as major emission sources. Additionally, temporal variations in organic contamination were investigated over three sampling campaigns (2004, 2015, and 2020). Within this timespan, the overall composition of the contamination in the Rur has changed slightly, but nevertheless, the high chemical diversity remained. A detailed consideration such as that undertaken in this study is necessary as the occurrence of substances in a river system depends on many different factors. For a holistic assessment of environmental behavior, not only the sampling locations and associated development of emission profiles must be considered but also temporal variations and mitigation measures. Such a multi-parameter scenario provides an important basis for the mitigation and reduction of organic pollutants in our environment. [ABSTRACT FROM AUTHOR]

The original version of this article unfortunately contained an error. [ABSTRACT FROM AUTHOR]

Environmental compartments of riverine systems are polluted by organic contaminants in particular as a result of industrial activity. Sediments and soils of conjunct floodplains can act as archives for long-term anthropogenic pollution. While some chemicals are prevalent, several compounds show source specificity. Compounds closely related to industrial chemical processes comprise precursors, intermediates, and by- and side-products. To better understand the environmental fate of such contamination in aquatic systems, we examined historic sediments of the Mulde River, a riverine system adjacent to the former industrial area Bitterfeld-Wolfen, Germany. This industrial complex produced a variety of chemical compounds between 1950 and the late 1980s. Comparison with related, more recent soil samples from floodplains revealed the presence of these organic indicators (e.g., halogenated naphthalenes, tetrachlorothiophene, dichlorodiphenylsulfone, 1,1,1,2,2-pentachloroethylbenzene, chlorinated diphenylethers) in the uppermost soil layers even over 20 years after the general shutdown of industrial production. Concentrations of numerous non-source-specific pollutants such as DDT metabolites, chlorinated benzenes, and dinaphthyl sulfones were also elevated in most recent wetland soil layers. Generally, concentration profiles showed the highest concentration of compounds in the uppermost soil layer. With increasing soil depth, concentrations decreased. Therefore, the results suggest a continuous input of source and non-source specific contaminations over secondary pollution pathways. This long-term pollution of the environment poses a threat to the quality of riverine systems. [ABSTRACT FROM AUTHOR]

The detailed characterization of the organic composition of industrial effluents discharged from various industrial branches and the distribution of the emitted pollutants in the surface waters in North Rhine-Westphalia have been done with the use of non-target screening analyses. Based on the characterization of molecular structures of wastewater constituents, their quantification as well as the available information on their origin and industrial applications, the identification of typical organic representatives for petrochemical and food effluents has been performed. Among a wide range of hydrocarbons detected in the petrochemical effluents, several novel organic wastewater constituents have been found for the first time. In the effluents from paper production plant, potential industrial indicators were distinguished, such as resin acids (abietic and dehydroabietic acids) and photoinitiators (Irgacure 184). The monitoring of the behaviour of certain environmentally relevant and newly described pollutants in the contaminated river systems allowed the identification of several industrial site-specific markers. Particularly, 2-(chloromethyl)-1,3-dioxolane, an unknown contaminant, exclusively found in the effluents from a chemical production complex, was present in the river under discharge at high concentrations downstream the contamination source. The comprehensive and detailed evaluation of the anthropogenic markers in the industrial effluents is a promising tool for the environmental assessment of industrial emissions, especially if accompanied with toxicological and ecotoxicological investigations of novel environmental contaminants. [ABSTRACT FROM AUTHOR]

This paper presents transformations of saturated hydrocarbons of petroleum type pollutants during ex situ bioremediation of soil on the pilot heap (halde), during a period of 6 months, within the grounds of Petroleum Refinery Pančevo (Serbia). Samples for analysis were taken in time intervals of 2 weeks (P1–P12 samples). Organic substance was extracted by Soxhlet’s method and quantified. Isoprenoid aliphatics, in particular pristane and phytane, and polycyclic aliphatics of sterane and triterpane types in saturated hydrocarbon fractions were analysed by GC-MS (SIM method). Significant amounts of n-alkanes have not been detected. The MS-chromatogram revealed only marginal amounts of pristane and phytane in sample P1. Pristane and phytane occurred in sample P8, and in even higher quantities in the final sample P12. The proceeding bioremediation process was accompanied by the decrease of the relative amounts of pentacyclic terpanes of hopane type, compared to tri- and tetracyclic terpanes. In the initial sample P1 the distribution of steranes and hopanes follows a pattern, which is characteristic for crude oils. However, their identification by SIM method was not possible in samples P8 and P12 because of the reduced concentration. The observed changes in the alkane fractions’ compositions may be considered as atypical, referring to the fact that during oil biodegradation under natural conditions, decomposition of isoprenoids occurs much easier and faster than decomposition of polycyclic alkanes of tri-, tetra- and pentacyclic terpane, sterane and diasterane types, after the decomposition of n-alkanes has been almost completed. [ABSTRACT FROM AUTHOR]

A review is given in this paper of the up-to-date results observed in differentiation and transformation studies on petroleum-type pollutants in underground and surface waters. Water and particulate matter derived from the locality of Pančevo Petroleum Refinery, Serbia (River Danube alluvial formations). It was shown that distributions of n-alkanes, steranes and triterpanes, and δ13CPDB values of n-alkanes may successfully be used for qualitatively differentiating the petroleum-type pollutants from native organic matter in recent sedimentary formations. In underground waters, a petroleum-type pollutant is exposed to microbiological degradation which is manifested through relatively fast degradation of n-alkanes. Following an almost complete degradation of crude oil n-alkanes in underground water, the biosynthesis of novel, even carbon-number C16–C30 n-alkanes may be observed. It is shown that the n-alkane distribution observed in a petroleum-type pollutant may depend on the intensity of its previous interaction with water. The fate of petroleum-type pollutants in environmental waters may be predicted through laboratory simulative microbiological degradation experiments by using microorganism consortiums similar to those observed under relevant natural conditions, as well as on corresponding nutrient base. [ABSTRACT FROM AUTHOR]

Analysis of limnic sediments can serve as a tool to assess sedimentary pollution for both the status quo as well as changes over time. However, in environmental studies, often only a small number of established well-studied contaminants are considered. This study focused on a more comprehensive investigation of sedimentary pollution of Djerdap Reservoir. Therefore, complementary analytical approaches were applied covering lipophilic organic contaminants and heavy metals. Investigations were performed on limnic sediment layers representing a period of 43 years of reservoir functioning. The core was sectioned on 11 samples and analyzed for, loss on ignition (LOI), and organic compounds (gas chromatography-mass spectrometry). Here, we report the quantitative data of 43 lipophilic organic compounds indicating both domestic and industrial emissions. Measured concentrations are generally low. Surprisingly, no polychlorinated biphenyls have been detected. Data concerning grain size, sedimentological, and inorganic composition were measured and published by in Kasanin-Grubin et al. (Kasanin-Grubin et al. 2019). [ABSTRACT FROM AUTHOR]

Fluvial sediments can act as archives for long-term pollution. However, in environmental studies, often only preselected contaminants and, therefore, only a limited part of the pollution are considered. Herein, geochemical investigations of riverbank samples of the Wurm River (catchment < 400 km2) depict the anthropogenic impact of the city Aachen (250,000 inhabitants) to its main outlet resulting in an exhaustive list of present pollutants including their concentrations. The study is based on 14 riverbank sediment samples at eight sampling sites on a 7.6-km-long segment of the Wurm River. The sediment samples were analyzed for grain size composition (laser diffraction particle size analyzer), total organic carbon (TOC), trace element inventory (X-ray fluorescence), and organic compounds (chromatography-mass spectrometry). Here, we report quantitative data for 71 persistent organic substances as well as six trace elements (Cu, Zn, As, Ba, Hg, and Pb) entering the Wurm River due to domestic and industrial emissions. In general, a slight decline of, e.g., PTEs, DDX, and PCB concentrations with decreasing sampling depth points to a steady improvement of conditions. Whereas no clear trends can be seen for organic pollutants along the investigated reach with increasing distance to the main source of pollution (Aachen city). As obtained concentrations for organic pollutants indicate a rather low level of pollution, trace element values exceed geogenic background values by far. Furthermore, we used selected compounds as time markers for a rough estimation of sedimentation rates. Obtained values point to a highly complex morphodynamic regime with changing sedimentation rates (0.6 to 3.0 cm a−1) within barely 100 m of river course. [ABSTRACT FROM AUTHOR]