Journal articles: 'Pollutants Structure-activity relationships'

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Mani, S. V., D. W. Connell, and R. D. Braddock. "Structure activity relationships for the prediction of biodegradability of environmental pollutants." Critical Reviews in Environmental Control 21, no. 3-4 (January 1991): 217–36. http://dx.doi.org/10.1080/10643389109388416.

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Gorinchoy, N. N., I. Ya Ogurtsov, A. Tihonovschi, I. Balan, I. B. Bersuker, A. Marenich, and J. Boggs. "Toxicophores and Quantitative Structure -Toxicity Relationships for Some Environmental Pollutants." Chemistry Journal of Moldova 3, no. 1 (June 2008): 94–104. http://dx.doi.org/10.19261/cjm.2008.03(1).13.

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The electron-conformational (EC) method is employed to reveal the toxicophore and to predict aquatic toxicity quantitatively using as a training set a series of 51 compounds that have aquatic toxicity to fish. By performing conformational analysis (optimization of geometries of the low-energy conformers by the PM3 method) and electronic structure calculations (by ab initio method corrected within the SM54/PM3 solvatation model), the Electron-Conformational Matrix of Congruity (ECMC) was constructed for each conformation of these compounds. The toxicophore defined as the EC sub-matrix of activity (ECSA), a sub-matrix with matrix elements common to all the active compounds under consideration within minimal tolerances, is determined by an iterative procedure of comparison of their ECMC’s, gradually minimizing the tolerances. Starting with only the four most toxic compounds, their ECSA (toxicophore) was found to consists of a 4x4 matrix (four sites with certain electronic and topologic characteristics) which was shown to be present in 17 most active compounds. A structure-toxicity correlation between three toxicophore parameters and the activities of these 17 compounds with R2=0.94 was found. It is shown that the same toxicophore with larger tolerances satisfies the compounds with les activity, thus explicitly demonstrating how the activity is controlled by the tolerances quantitatively and which atoms (sites) are most flexible in this respect. This allows for getting slightly different toxicophores for different levels of activity. For some active compounds that have no toxicophore a bimolecular mechanism of activity is suggested. Distinguished from other QSAR methods, no arbitrary descriptors and no statistics are involved in this EC structure-activity investigation.

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Urrestarazu Ramos, Eñaut, Wouter H. J. Vaes, Henk J. M. Verhaar, and Joop L. M. Hermens. "Quantitative Structure−Activity Relationships for the Aquatic Toxicity of Polar and Nonpolar Narcotic Pollutants." Journal of Chemical Information and Computer Sciences 38, no. 5 (September 1998): 845–52. http://dx.doi.org/10.1021/ci980027q.

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Öberg, Tomas. "VIRTUAL SCREENING FOR ENVIRONMENTAL POLLUTANTS: STRUCTURE–ACTIVITY RELATIONSHIPS APPLIED TO A DATABASE OF INDUSTRIAL CHEMICALS." Environmental Toxicology and Chemistry 25, no. 4 (2006): 1178. http://dx.doi.org/10.1897/05-326r.1.

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URRESTARAZU RAMOS, E., W. H. J. VAES, H. J. M. VERHAAR, and J. L. M. HERMES. "ChemInform Abstract: Quantitative Structure-Activity Relationships for the Aquatic Toxicity of Polar and Nonpolar Narcotic Pollutants." ChemInform 30, no. 3 (June 18, 2010): no. http://dx.doi.org/10.1002/chin.199903236.

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Folawewo, Abayomi D., and Muhammad D. Bala. "Nanocomposite Zinc Oxide-Based Photocatalysts: Recent Developments in Their Use for the Treatment of Dye-Polluted Wastewater." Water 14, no. 23 (November 30, 2022): 3899. http://dx.doi.org/10.3390/w14233899.

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This review highlights current developments in utilising zinc oxide (ZnO) composite materials as photocatalysts. Systematic analyses of the various synthetic methods for producing ZnO-based hetero-structured materials, the variety of methods for their characterisation, their mechanisms of action, and widespread applications for the degradation of pollutants are discussed. Structure/activity relationships and methods of improving on some of the recognised shortcomings of ZnO-based nanomaterial catalysts are also presented.

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Wols, B. A., and D. Vries. "On a QSAR approach for the prediction of priority compound degradation by water treatment processes." Water Science and Technology 66, no. 7 (October 1, 2012): 1446–53. http://dx.doi.org/10.2166/wst.2012.328.

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Emerging (chemical) substances are increasingly found in water sources and must be removed by water treatment systems. However, the treatment efficiency regarding these substances is often unknown. A promising approach is using QSARs (quantitative structure activity relationships) or QSPRs (quantitative structure property relationships) to correlate the existing knowledge of a compound's chemical structure to water treatment process properties, such as a biological activity or physico-chemical property. As UV/H2O2 treatment of water is an important barrier against priority pollutants, a QSAR model has been developed for the prediction of a typical physico-chemical property: i.e. hydroxyl radical reaction constants. Hydroxyl radicals are highly reactive and therefore largely responsible for a compound's degradation during UV/H2O2 treatment. A good correlation is found for the training data set. Chemical parameters that were related to charge on C atoms and topology of the compound were found to be important for the hydroxyl radical rate constants. So far, these results look promising, but further research is still required to increase the predictability of the model and to develop QSAR models for other physico-chemical properties.

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Ivshina, Irina, Elena Tyumina, and Elena Vikhareva. "Biodegradation of emerging pollutants: focus on pharmaceuticals." Microbiology Australia 39, no. 3 (2018): 117. http://dx.doi.org/10.1071/ma18037.

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A priority environmental problem is pollution and disturbance of natural environments by emerging pollutants ‒ substances of various origins and structures and with known and/or potential ecotoxic effects. One of the most dangerous groups of emerging pollutants is pharmaceutical substances due to their highly stable chemical structure and pronounced biological activity. They are found in soil, bottom sediments, surface, sewage, groundwater and drinking water. Uncontrolled release of pharmaceuticals in open ecosystems is potentially dangerous, entailing environmental consequences. Their negative impacts on living organisms are evident. This has driven the search for effective ways to neutralise persistent pollutants. In Russia, pharmaceutical pollution of the environment has commenced recently and is still presented as research with a local focus. In particular, the dynamics and metabolic mechanisms of pharma pollutants by Rhodococcus actinobacteria, outstanding among other microorganisms for their capacity to degrade a great diversity of degradable pollutants, are most intensively investigated. These studies are implemented at the junction of organic chemistry, molecular biology, biotechnology, and pharmacology. They include a set of interrelated fundamental tasks, such as developing drug detection methods in the cultivation media of microorganisms, elucidating the relationships between the systematic affiliation of microorganisms and their ability to degrade chemically different drug substances, as well as studying the degree of biodegradability and toxic effects of new compounds on the degrading microorganisms, and also the features of their decomposition and co-metabolism. Solving these tasks is important to enable understanding of the environmental fate of pharmaceuticals and to create prerequisites for innovative technical solutions in the advanced treatment of pharmaceutical wastewater. It is also essential for the development of environmentally safe approaches to hazardous pharmaceutical waste management.

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Mydy, Lisa S., Zahra Mashhadi, T. William Knight, Tyler Fenske, Trevor Hagemann, Robert W. Hoppe, Lanlan Han, Todd R. Miller, Alan W. Schwabacher, and Nicholas R. Silvaggi. "Swit_4259, an acetoacetate decarboxylase-like enzyme from Sphingomonas wittichii RW1." Acta Crystallographica Section F Structural Biology Communications 73, no. 12 (November 14, 2017): 672–81. http://dx.doi.org/10.1107/s2053230x17015862.

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The Gram-negative bacterium Sphingomonas wittichii RW1 is notable for its ability to metabolize a variety of aromatic hydrocarbons. Not surprisingly, the S. wittichii genome contains a number of putative aromatic hydrocarbon-degrading gene clusters. One of these includes an enzyme of unknown function, Swit_4259, which belongs to the acetoacetate decarboxylase-like superfamily (ADCSF). Here, it is reported that Swit_4259 is a small (28.8 kDa) tetrameric ADCSF enzyme that, unlike the prototypical members of the superfamily, does not have acetoacetate decarboxylase activity. Structural characterization shows that the tertiary structure of Swit_4259 is nearly identical to that of the true decarboxylases, but there are important differences in the fine structure of the Swit_4259 active site that lead to a divergence in function. In addition, it is shown that while it is a poor substrate, Swit_4259 can catalyze the hydration of 2-oxo-hex-3-enedioate to yield 2-oxo-4-hydroxyhexanedioate. It is also demonstrated that Swit_4259 has pyruvate aldolase-dehydratase activity, a feature that is common to all of the family V ADCSF enzymes studied to date. The enzymatic activity, together with the genomic context, suggests that Swit_4259 may be a hydratase with a role in the metabolism of an as-yet-unknown hydrocarbon. These data have implications for engineering bioremediation pathways to degrade specific pollutants, as well as structure–function relationships within the ADCSF in general.

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Abe, T., H. Saito, Y. Niikura, T. Shigeoka, and Y. Nakano. "Embryonic development assay with Daphnia magna: application to toxicity of chlorophenols." Water Science and Technology 42, no. 7-8 (October 1, 2000): 297–304. http://dx.doi.org/10.2166/wst.2000.0582.

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Cladoceran embryos, derived from Daphnia magna, were used for the developmental toxicity assay system of chlorophenols (CPs) and the quantitative structure-activity relationships (QSAR) studies. As the toxicity end point, the median effective concentration (EC50s) to reduce hatchability was estimated. The EC50s for embryo hatchabilities were found to be significantly correlated to acute immobilization toxicity (24-h EC50s) with juveniles, and the embryo assay appeared to be more sensitive to CPs with higher water solubility than the juveniles assay. The EC50s for embryos were correlated with six physicochemical parameters, and the Pow (n-octanol/water partition coefficient) gave a good correlation in simple linear regression analysis, as is frequently stated in toxicity studies with aquatic organisms. These results suggest that in vitro hatchability assay using D. magna embryos are useful for ecotoxicity screening of aquatic pollutants.

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Pandey, Vandana. "Comparative Study of Depuration Rate Prediction against Mussel (Elliptio complanata) using Different Chemometric Approaches." Trends in Sciences 19, no. 10 (May 1, 2022): 3976. http://dx.doi.org/10.48048/tis.2022.3976.

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Different chemometric approaches were applied to a heterogeneous dataset of persistent organic pollutants(POPs), which included polybrominated diphenyl ethers(PBDEs), polychlorinated biphenyls(PCBs) and polycyclic aromatic hydrocarbons(PAHs) with associated depuration rate constant in Mussel (Elliptio complanata), to develop robust quantitative structure-activity relationship(QSAR) models. These models were further validated for statistical significance and predictive ability by internal and external validation. Out of various methods available, genetic algorithm and principal component analysis (PCA) approaches were used to identify relevant molecular descriptors from a large descriptor pool that exhibited a strong correlation with the depuration rate constant values of the diverse dataset. Then, multiple linear regression(MLR) and artificial neural network (ANN) methods were applied to the selected descriptors to create good predictive models. Statistical comparison of 3 hybrid approaches namely, GA-MLR, GA-ANN and PCA-ANN have shown that the genetic algorithm coupled with ANN model is superior to the other 2 models (R2train= 0.961, R2test= 0.947, mapetest= 7.939 and rmsetest=0.128). The applicability domain of the selected models was analyzed using the Euclidean distance and leverage approach signifies that all test set compounds fall within the applicability domain of the developed regression-based models. HIGHLIGHTS Evaluation of toxicokinetic parameters in aquatic ecosystem from the molecular structure satisfies the growing demand of theoretical methods for sustainable chemistry Three different chemometric approaches namely GA-MLR, GA-ANN and PCA-ANN are applied to establish quantitative-structure-activity relationships for the prediction of depuration rate constant values (logkd) of a dataset containing POPs in mussel Elliptio complanata OECD guidelines are used to evaluate and validate the presented models

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Kodavanti, Prasada Rao S. "Neurotoxicity of Persistent Organic Pollutants: Possible Mode(S) of Action and Further Considerations." Dose-Response 3, no. 3 (May 1, 2005): dose—response.0. http://dx.doi.org/10.2203/dose-response.003.03.002.

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Persistent organic pollutants (POPs) are long-lived toxic organic compounds and are of major concern for human and ecosystem health. Although the use of most POPs is banned in most countries, some organochlorine pesticides are still being used in several parts of the world. Although environmental levels of some POPs such as polychlorinated biphenyls (PCBs) have declined, newly emerging POPs such as polybrominated diphenyl ethers (PBDEs) have been increasing considerably. Exposure to POPs has been associated with a wide spectrum of effects including reproductive, developmental, immunologic, carcinogenic, and neurotoxic effects. It is of particular concern that neurotoxic effects of some POPs have been observed in humans at low environmental concentrations. This review focuses on PCBs as a representative chemical class of POPs and discusses the possible mode(s) of action for the neurotoxic effects with emphasis on comparing dose-response and structure-activity relationships (SAR) with other structurally related chemicals. There is sufficient epidemiological and experimental evidence showing that PCB exposure is associated with motor and cognitive deficits in humans and animal models. Although several potential mode(s) of actions were postulated for PCB-induced neurotoxic effects, changes in neurotransmitter systems, altered intracellular signalling processes, and thyroid hormone imbalance are predominant ones. These three potential mechanisms are discussed in detail in vitro and in vivo. In addition, SAR was conducted on other structurally similar chemicals to see if they have a common mode(s) of action. Relative potency factors for several of these POPs were calculated based on their effects on intracellular signalling processes. This is a comprehensive review comparing molecular effects at the cellular level to the neurotoxic effects seen in the whole animal for environmentally relevant POPs.

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Miliukiene, Valė, and Narimantas Čėnas. "Cytotoxicity of Nitroaromatic Explosives and their Biodegradation Products in Mice Splenocytes: Implications for their Immunotoxicity." Zeitschrift für Naturforschung C 63, no. 7-8 (August 1, 2008): 519–25. http://dx.doi.org/10.1515/znc-2008-7-809.

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Nitroaromatic explosives like 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitrophenyl-Nmethyl- nitramine (tetryl) comprise an important group of toxic environmental pollutants, whose toxicity is mainly attributed to the flavoenzyme electrontransferase-catalyzed redox cycling of their free radicals (oxidative stress) and DT-diaphorase [NAD(P)H:quinone oxidoreductase, NQO1, EC 1. 6.99.2]-catalyzed formation of alkylating nitroso and/or hydroxylamine metabolites. Because of the incomprehensive data on the immunotoxic effects of nitroaromatic explosives, we have studied the structure-cytotoxicity relationships in the action of tetryl, TNT as well as its amino and hydroxylamino metabolites, and related nitroaromatic compounds towards mouse splenocyte cells. The protective effects of desferrioxamine and the antioxidant N,N′-diphenyl-p-phenylene diamine against the cytotoxicity of TNT and other nitroaromatics showed that the oxidative stress-type cytotoxicity mechanism takes place. In addition, the cytotoxicity of nitroaromatics is also partly prevented by an inhibitor of NQO1, dicumarol. The cytotoxicity of the amino metabolites of TNT is also partly prevented by α- naphthoflavone and isoniazide, which points to the involvement of cytochromes P-450 in their activation. In general the cytotoxicity of nitroaromatics in splenocytes increases with an increase in their single-electron reduction potential, Eζ . This points to the prevailing mechanism of the oxidative stress-type cytotoxicity. The obtained structure-activity relationship and the studies of other mammalian cell lines showed that the immunotoxic potential of nitroaromatic explosives may decrease in the order tetryl ≥TNT ≥ hydroxylamino metabolites of TNT > amino and diamino metabolites of TNT.

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Ducey, T. F., P. R. Johnson, A. D. Shriner, T. A. Matheny, and P. G. Hunt. "Microbial Community Structure Across a Wastewater-Impacted Riparian Buffer Zone in the Southeastern Coastal Plain." Open Microbiology Journal 7, no. 1 (June 28, 2013): 99–117. http://dx.doi.org/10.2174/1874285801307010099.

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Riparian buffer zones are important for both natural and developed ecosystems throughout the world because of their ability to retain nutrients, prevent soil erosion, protect aquatic environments from excessive sedimentation, and filter pollutants. Despite their importance, the microbial community structures of riparian buffer zones remains poorly defined. Our objectives for this study were twofold: first, to characterize the microbial populations found in riparian buffer zone soils; and second, to determine if microbial community structure could be linked to denitrification enzyme activity (DEA). To achieve these objectives, we investigated the microbial populations of a riparian buffer zone located downslope of a pasture irrigated with swine lagoon effluent, utilizing DNA sequencing of the 16S rDNA, DEA, and quantitative PCR (qPCR) of the denitrification genes nirK, nirS, and nosZ. Clone libraries of the 16S rDNA gene were generated from each of twelve sites across the riparian buffer with a total of 986 partial sequences grouped into 654 operational taxonomic units (OTUs). The Proteobacteria were the dominant group (49.8% of all OTUs), with the Acidobacteria also well represented (19.57% of all OTUs). Analysis of qPCR results identified spatial relationships between soil series, site location, and gene abundance, which could be used to infer both incomplete and total DEA rates.

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Lasocha, Wieslaw, Anna Szymanska, Marcin Oszajca, Graham Appleby, Katarzyna Pamin, and Jan Poltowicz. "Polymolybdates and Peroxomolybdates: Candidates for Catalysts in Industry." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C589. http://dx.doi.org/10.1107/s2053273314094108.

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Progress in catalysis depends on a full understanding of the role of the individual components of catalytic materials. Crystallographic studies offer insight into crystal structure, which enables the rational selection of reagents and better planning of the syntheses of novel materials and catalysts. In this paper we have studied the process of the oxidation of hydrocarbons and terpenes with oxygen from the air. Processes of this type are important in so-called "Green Chemistry." Their application can reduce the amount of environmentally harmful pollutants formed through conventional oxidation based on nitric acid. While investigating the catalytic activity of peroxo- and polymolybdates(VI) in the oxidation of cycloalkanes, we found a number of intriguing relationships. To explain them, we designed, synthesized and solved the crystal structures of the family of new peroxomolybdates, tri-, octa- and pentamolybdates of amines. Both single crystal and polycrystalline materials were investigated using laboratory as well as synchrotron radiation. Next, we used these compounds as catalysts in certain interesting for industry processes (e.g. oxidation of cyclic hydrocarbons). We have concluded that: – The activity of peroxocompounds is enhanced by the coordination of N-oxide groups to Mo atoms. – The activity of anionic polymeric trimolybdates decreases when `surface of polymeric fiber' is blocked by cations. – The anionic layers of pentamolybdates are separated by cations of variable size. The distance between layers plays a role similar to that of the size of channels in zeolites. Summary: Peroxomolybdates and polyoxomolybdates show great prospects for new industrial uses (besides cracking and desulfurization).

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Rabea, Entsar I., Mohamed E. I. Badawy, and Ahmed F. El-Aswad. "Biochemical Characterization and Kinetics of Carboxylesterase Isolated from Rabbit Liver and Lung in order to Application in the Detoxification of Environmental Pollutants." Current Enzyme Inhibition 13, no. 1 (February 2, 2017): 56–66. http://dx.doi.org/10.2174/1573408012666160801151753.

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Objective: A carboxylesterase (CbE) or carboxylic-ester hydrolase (EC 3.1.1.1) is an enzyme that catalyzes the hydrolysis of carboxylesters to alcohol and carboxylate. The objective of this study is to obtain this enzyme from liver and lung of rabbit with a comparison between the effects of two specific substrates, α-naphthyl acetate (α-NA) and p-nitrophenyl acetate (p-NPA) on the enzymes activity. The kinetic characteristics of the enzymes have been also investigated in details. Methods: CbE was obtained from rabbit liver and lung with Tris/HCl buffer (pH 7.4) extraction, ammonium sulfate precipitation, dialysis, and lyophilized. Results: The lyophilized enzyme appeared to be homogeneous on native polyacrylamide gel electrophoresis and its molecular mass was estimated to be 30 kDa suggesting a monomeric structure for the obtained enzyme. The enzyme exhibited a broad activity at different pH and temperature. The pH optimum was 7.5 and optimum temperature was 35ºC. The enzyme showed specific activities of 1.36 and 1.04 μmol α-naphthol hydrolyzed/mg protein/min for liver and lung CbEs, respectively using α-naphthyl acetate (α-NA). However, the specific activities of the liver and lung CbE were 0.44 and 0.23 μmol p-nitrophenol hydrolyzed/mg protein/min, respectively using p-nitrophenyl acetate (p- NPA). The relationships between estimates of Km and Vmax calculated from the Michaelis-Menten equation have been explored. The Km values of liver and lung CbEs were 59.28 and 28.10 μM with α-NA, respectively however, the values were 86.39 and 90.05 μM with p-NPA. The Vmax values of liver and lung CbEs were 2.32 and 1.05 with α-NA, respectively however, the values were 0.55 and 0.19 with p- NPA. The enzyme showed residual activity when incubated at wide range of pesticides chlorpyrifos and methomyl however it was totally inhibited by concentrations higher than 200 μM. The extent of the inhibition was different, as estimated by the values of the inhibition constant Ki that were found to be 2.14 and 5.14 for chlorpyrifos and methomyl, respectively. Conclusion: Conclusion: This enzyme may play an important role in the detoxification of organophosphorous and carbamate pesticides at low levels.

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Masunaga, S., N. L. Wolfe, and L. Carriera. "Transformation of para-Substituted Benzonitriles in Sediment and in Sediment Extract." Water Science and Technology 28, no. 8-9 (October 1, 1993): 123–32. http://dx.doi.org/10.2166/wst.1993.0610.

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Degradation mechanisms of chemicals in sediment must be known in order to permit more accurate assessment of aquatic pollutants. One possible degradation mechanism -- abiotic transformation -- has received little attention, however. In this study, the abiotic transformation of para- substituted benzonitriles in an extract prepared by protein extraction from sediment was compared with that in raw sediment and in water. In water, the benzonitriles were hydrolyzed to benzoic acid through benzamides at elevated temperature. In anaerobic river sediment, the benzonitriles were transformed to the corresponding benzoic acids, except for iodo- and methoxy-derivatives. In the sediment extract, the benzonitriles, including iodo- and methoxy-derivatives, were transformed to benzoic acids. Benzonitrile transformation did not produce benzamides as intermediates in the latter two media. Transformation in sediment and in sediment extract must have been mediated by an enzyme whose activity is similar to that of nitrilase. Analyses using quantitative structure activity relationships (QSAR) were carried out with the three sets of rate constants measured in the three media. The rate constants in sediment and sediment extract were correlated mainly with the hydrophobicity substituent parameter π. Rate constants for purely chemical hydrolysis in water were correlated with the electronic substituent parameter Hammett σp. These results showed that the reaction mechanisms in sediment and sediment extract resembled each other and indicate that the abiotic reaction mediated by the extracted sediment protein fraction was responsible for at least part of the reaction occurring in raw sediment.

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Mumtaz, M. M., and P. R. Durkin. "A Weight-of-Evidence Approach for Assessing Interactions in Chemical Mixtures." Toxicology and Industrial Health 8, no. 6 (November 1992): 377–406. http://dx.doi.org/10.1177/074823379200800604.

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The risk assessment process must encompass all available toxicological data and scientific evidence on the plausible toxicities of a chemical or chemical mixture. As an extension to the approaches used to conduct risk assessments on chemical mixtures, a preliminary scheme, analogous to the IARC classification of carcinogens, is proposed to express the weight of evidence for the interactions in binary mixtures. This scheme is based on composite representation of all the toxicological evidence from animal bioassays and human data, pharmacokinetics studies, metabolism studies, and structure activity relationships. In addition, factors such as the relevance of route, duration and sequence of exposure, toxicological significance of interactions and the quality of in vivo and in vitro data are taken into consideration. The scheme yields an alphanumeric classification that can be used for qualitative risk assessment, and has the potential, as demonstrated in this paper, for quantitative application to site-specific risk assessments. Furthermore, the scheme can be used to estimate interactions or form hypotheses concerning binary interactions. It is flexible and allows all pertinent information to be incorporated in a methodical and consistent manner. Research is needed to identify interaction patterns for simultaneous and sequential exposure scenarios of chemical pollutants in order that this scheme may be developed further and its usefulness and limitations may be tested.

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Klösener, J., D. C. Swenson, L. W. Robertson, and G. Luthe. "Effects of fluoro substitution on 4-bromodiphenyl ether (PBDE 3)." Acta Crystallographica Section B Structural Science 64, no. 1 (January 17, 2008): 108–19. http://dx.doi.org/10.1107/s0108768107067079.

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It is our hypothesis that fluoro substitution provides a powerful tool to modulate the desired characteristics and to increase the specificity of studies of structure–activity relationships. 4-Bromodiphenyl ether (PBDE 3) and its five corresponding monofluorinated analogues (F-PBDEs 3) have been synthesized and fully characterized (using 1H, 13C and 19F NMR spectroscopy, and mass spectrometry). The accurate structure from X-ray crystal analysis was compared with iterative calculations using semi-empirical self-consistent field molecular-orbital (SCF-MO) models. The compounds studied were 4-bromodiphenyl ether (PBDE 3), the 13C6-isotopically labeled PBDE 3 (13C6-PBDE 3) and 2-fluoro-4-bromodiphenyl ether (3-2F), 2′-fluoro-4-bromodiphenyl ether (3-2′F), 3-fluoro-4-bromodiphenyl ether (3-3F), 3′-fluoro-4-bromodiphenyl ether (3-3′F), and 4′-fluoro-4-bromodiphenyl ether (3-4′F). Solid-state intermolecular interactions for PBDE 3 and the F-PBDEs 3 isomers are dominated by weak C—H(F,Br)...π and C—H...F interactions. The C—F bond lengths varied between 1.347 (2) and 1.362 (2) Å, and the C4—Br bond length between 1.880 (3) and 1.904 (2) Å. These bond lengths are correlated with electron-density differences, as determined by 13C shifts, but not with the strength of the C—F couplings. The interior ring angles of ipso-fluoro substitution increased (121.9–124.0°) as a result of hyperconjugation, a phenomenon also predicted by the calculation models. An attraction between the vicinal fluoro and halo substituents (observed in fluoro substituted chlorobiphenyls) was not observed for the bromo substituted F-PBDEs. The influence of a fluoro substituent on the conformation was only observable in PBDEs with di-ortho substitution. Calculated and observed torsion angles showed a positive correlation with increasing van der Waals radii and/or the degree of substitution for mono- to tetra-fluoro, chloro, bromo and methyl substitutions in the ortho positions of diphenyl ether. These findings utilizing F-tagged analogues presented here may prove fundamental to the interpretation of the biological effects and toxicities of these persistent environmental pollutants.

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Satpathy, Raghunath. "Quantitative structure–activity relationship methods for the prediction of the toxicity of pollutants." Environmental Chemistry Letters 17, no. 1 (July 20, 2018): 123–28. http://dx.doi.org/10.1007/s10311-018-0780-1.

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Wang, Ya, Weihao Tang, Yue Peng, Zhongfang Chen, Jingwen Chen, Zijun Xiao, Xiaoguang Zhao, Yakun Qu, and Junhua Li. "Predicting the adsorption of organic pollutants on boron nitride nanosheets via in silico techniques: DFT computations and QSAR modeling." Environmental Science: Nano 8, no. 3 (2021): 795–805. http://dx.doi.org/10.1039/d0en01145b.

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Four quantitative structure–activity relationship (QSAR) models were developed for predicting the log K values of organic pollutants adsorbed onto boron nitride nanosheets in gaseous and aqueous environments.

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Lončarević, D., J. Dostanić, V. Radonjić, A. Radosavljević-Mihajlović, and D. M. Jovanović. "Structure–activity relationship of nanosized porous PEG-modified TiO2 powders in degradation of organic pollutants." Advanced Powder Technology 26, no. 4 (July 2015): 1162–70. http://dx.doi.org/10.1016/j.apt.2015.05.012.

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Qin, Hong, JingWen Chen, Ying Wang, Bin Wang, XueHua Li, Fei Li, and YaNan Wang. "Development and assessment of quantitative structure-activity relationship models for bioconcentration factors of organic pollutants." Chinese Science Bulletin 54, no. 4 (February 2009): 628–34. http://dx.doi.org/10.1007/s11434-009-0053-2.

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Huang, Zhe, Yinning Chen, Riming Huang, and Zhengang Zhao. "Identification and Structure–Activity Relationship of Recovered Phenolics with Antioxidant and Antihyperglycemic Potential from Sugarcane Molasses Vinasse." Foods 11, no. 19 (October 8, 2022): 3131. http://dx.doi.org/10.3390/foods11193131.

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Sugarcane molasses vinasse is the residue of the fermentation of molasses and the water and soil environmental pollutants from distilleries. However, its recycling value has been neglected. The chemical analysis of the molasses vinasse led to the isolation of a new benzoyl chloride called 2,3,4-trihydroxy-5-methoxy benzoyl chloride, as well as thirteen known compounds, including six benzoic acids. The structure of the new benzoyl chloride was elucidated on the basis of extensive spectroscopic analysis. The antioxidant activity of all isolated compounds was measured using the ORAC assay. Moreover, we compared the cellular antioxidant activity (CAA) and inhibitory activity against α-amylase and α-glucosidase for structure–activity analysis. The results showed that only vanillic acid had CAA (8.64 μmol QE/100 μmol in the no PBS wash protocol and 6.18 μmol QE/100 μmol in the PBS wash protocol), although other benzoic acid derivatives had high ORAC values ranging between 1879.9 and 32,648.1 μmol TE/g. Additional methoxy groups at the ortho-positions of the p-hydroxy group of benzoic acids enhanced the inhibition of α-glucosidase but reduced the ORAC activity unless at the para-position. This work indicated that phenolics, especially phenolic acids in the sugarcane molasses vinasse, possessed potential antioxidant and antihyperglycemic activity, which improved the utilization rate of resources and reduced the discharge of pollutants.

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Fatemi, Mohammad Hossein, and Elham Baher. "A novel quantitative structure–activity relationship model for prediction of biomagnification factor of some organochlorine pollutants." Molecular Diversity 13, no. 3 (February 14, 2009): 343–52. http://dx.doi.org/10.1007/s11030-009-9121-4.

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Jin, Qianqian, Zhonglin Chen, Qian Chen, Pengwei Yan, Shengxin Zhao, Jimin Shen, Li Li, Fang Guo, and Jing Kang. "Structure activity relationship study of N-doped ligand modified Fe(III)/H2O2 for degrading organic pollutants." Journal of Hazardous Materials 404 (February 2021): 124142. http://dx.doi.org/10.1016/j.jhazmat.2020.124142.

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Yu, Chao, Tianliang Zhao, Yongqing Bai, Lei Zhang, Shaofei Kong, Xingna Yu, Jinhai He, et al. "Heavy air pollution with a unique “non-stagnant” atmospheric boundary layer in the Yangtze River middle basin aggravated by regional transport of PM<sub>2.5</sub> over China." Atmospheric Chemistry and Physics 20, no. 12 (June 23, 2020): 7217–30. http://dx.doi.org/10.5194/acp-20-7217-2020.

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Abstract. The regional transport of air pollutants, controlled by emission sources and meteorological factors, results in a complex source–receptor relationship of air pollution change. Wuhan, a metropolis in the Yangtze River middle basin (YRMB) of central China, experienced heavy air pollution characterized by hourly PM2.5 concentrations reaching 471.1 µg m−3 in January 2016. To investigate the regional transport of PM2.5 over central eastern China (CEC) and the meteorological impact on wintertime air pollution in the YRMB area, observed meteorological and other relevant environmental data from January 2016 were analyzed. Our analysis presented noteworthy cases of heavy PM2.5 pollution in the YRMB area with unique “non-stagnant” meteorological conditions of strong northerly winds, no temperature inversion, and additional unstable structures in the atmospheric boundary layer. This unique set of conditions differed from the stagnant meteorological conditions characterized by near-surface weak winds, air temperature inversion, and stable structure in the boundary layer that are typically observed in heavy air pollution over most regions in China. The regional transport of PM2.5 over CEC aggravated PM2.5 levels, thus creating heavy air pollution in the YRMB area. This demonstrates a source–receptor relationship between the originating air pollution regions in CEC and the receiving YRMB region. Furthermore, a backward trajectory simulation using a Flexible Particle dispersion (FLEXPART) Weather Research and Forecasting (WRF) model to integrate the air pollutant emission inventory over China was used to explore the patterns of regional transport of PM2.5 governed by the strong northerly winds in the cold air activity of the East Asian winter monsoon season. It was estimated that the regional transport of PM2.5 from non-local air pollutant emissions contributes more than 65 % of the PM2.5 concentrations to the heavy air pollution in the YRMB region during the study period, revealing the importance of the regional transport of air pollutants over China as a causative factor of heavy air pollution over the YRMB area.

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Zhao, Rui, Han Wang, Dan Zhao, Rui Liu, Shejiang Liu, Jianfeng Fu, Yuxin Zhang, and Hui Ding. "Review on Catalytic Oxidation of VOCs at Ambient Temperature." International Journal of Molecular Sciences 23, no. 22 (November 8, 2022): 13739. http://dx.doi.org/10.3390/ijms232213739.

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As an important air pollutant, volatile organic compounds (VOCs) pose a serious threat to the ecological environment and human health. To achieve energy saving, carbon reduction, and safe and efficient degradation of VOCs, ambient temperature catalytic oxidation has become a hot topic for researchers. Firstly, this review systematically summarizes recent progress on the catalytic oxidation of VOCs with different types. Secondly, based on nanoparticle catalysts, cluster catalysts, and single-atom catalysts, we discuss the influence of structural regulation, such as adjustment of size and configuration, metal doping, defect engineering, and acid/base modification, on the structure–activity relationship in the process of catalytic oxidation at ambient temperature. Then, the effects of process conditions, such as initial concentration, space velocity, oxidation atmosphere, and humidity adjustment on catalytic activity, are summarized. It is further found that nanoparticle catalysts are most commonly used in ambient temperature catalytic oxidation. Additionally, ambient temperature catalytic oxidation is mainly applied in the removal of easily degradable pollutants, and focuses on ambient temperature catalytic ozonation. The activity, selectivity, and stability of catalysts need to be improved. Finally, according to the existing problems and limitations in the application of ambient temperature catalytic oxidation technology, new prospects and challenges are proposed.

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Egemen, E., and N. Nirmalakhandak. "Use of Quantitative Structure Activity Relationship Methods in Predicting Activated Carbon Adsorption Isotherms for Hazardous Air Pollutants." SAR and QSAR in Environmental Research 5, no. 4 (October 1996): 281–98. http://dx.doi.org/10.1080/10629369608031717.

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Aydogdu, S., and Arzu Hatipoglu. "QUANTUM CHEMICAL STUDY FOR THE TOXICITY PREDICTION OF SULFONAMIDE ANTIBIOTICS WITH QUANTITATIVE STRUCTURE – ACTIVITY RELATIONSHIP." Latin American Applied Research - An international journal 51, no. 1 (September 30, 2020): 7–13. http://dx.doi.org/10.52292/j.laar.2021.66.

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Sulfonamides are one of the most important classes of chemicals found in the aquatic environment as a pollutant due to excessive consumption. The DFT- B3LYP method with the basis set 6-311++G (d,p) was employed to calculate various quantum chemical descriptors of sulfonamide molecules. A quantitative structure activity relationship (QSAR) study was performed for the toxicity value LD50 of sulfonamides with their quantum chemical descriptors by multi linear regression. The QSAR models were validated by internally and externally. The best multilinear equation with correlation coefficient, R and the cross-validation leave-one-out correlation coefficient, Q2 values were 0.9528 ,0.8556 respectively The results show that the QSAR models have both favourable estimation stability and good prediction power.

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Hosoya, Junichi, Kumiko Tamura, Naomi Muraki, Hiroki Okumura, Tsuyoshi Ito, and Mitsugu Maeno. "A Novel Approach for a Toxicity Prediction Model of Environmental Pollutants by Using a Quantitative Structure-Activity Relationship Method Based on Toxicogenomics." ISRN Toxicology 2011 (July 2, 2011): 1–9. http://dx.doi.org/10.5402/2011/515724.

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The development of automobile emission reduction technologies has decreased dramatically the particle concentration in emissions; however, there is a possibility that unexpected harmful chemicals are formed in emissions due to new technologies and fuels. Therefore, we attempted to develop new and efficient toxicity prediction models for the myriad environmental pollutants including those in automobile emissions. We chose 54 compounds related to engine exhaust and, by use of the DNA microarray, examined their effect on gene expression in human lung cells. We focused on IL-8 as a proinflammatory cytokine and developed a prediction model with quantitative structure-activity relationship (QSAR) for the IL-8 gene expression by using an in silico system. Our results demonstrate that this model showed high accuracy in predicting upregulation of the IL-8 gene. These results suggest that the prediction model with QSAR based on the gene expression from toxicogenomics may have great potential in predictive toxicology of environmental pollutants.

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Shoji, Ryo, Takanori Miyazaki, and Tatsuaki Nishimiya. "Estimation of Cytotoxicity to HEP-G2 Cells of 255 Environmental Pollutants and Water Using QSAR (Quantitative Structure-Activity Relationship)." Journal of Environmental Science and Health, Part A 38, no. 12 (December 2003): 2807–23. http://dx.doi.org/10.1081/ese-120025832.

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van der Zandt, Peter T. J., Floor Heinis, and Arjen Kikkert. "Effects of narcotic industrial pollutants on behaviour of midge larvae (Chironomus riparius (Meigen), Diptera): a quantitative structure-activity relationship." Aquatic Toxicology 28, no. 3-4 (April 1994): 209–21. http://dx.doi.org/10.1016/0166-445x(94)90034-5.

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Cocci, Paolo, Gilberto Mosconi, and Francesco A. Palermo. "An In Silico and In Vitro study for Investigating Estrogenic Endocrine Effects of Emerging Persistent Pollutants using Primary Hepatocytes from Grey Mullet (Mugil Cephalus)." Environments 8, no. 6 (June 18, 2021): 58. http://dx.doi.org/10.3390/environments8060058.

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There is growing concern about the environmentally relevant concentrations of new emerging persistent organic pollutants, such as perfluorinated compounds and pharmaceuticals, which are found to bioaccumulate in aquatic organisms at concentrations suspected to cause reproductive toxicity due to the activation of estrogen receptor (ER) α and β subtypes. Here, we use a combined in silico and in vitro approach to evaluate the impact of perfluorononanoic acid (PFNA) and Enalapril (ENA) on grey mullet (Mugil cephalus) hepatic estrogen signaling pathway. ENA had weak agonist activity on ERα while PFNA showed moderate to high agonist binding to both ERs. According to these effects, hepatocytes incubation for 48 h to PFNA resulted in a concentration-dependent upregulation of ER and vitellogenin gene expression profiles, whereas only a small increase was observed in ERα mRNA levels for the highest ENA concentration. These data suggest a structure–activity relationship between hepatic ERs and these emerging pollutants.

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Ding, Han, and Jiangyong Hu. "Prediction of Second-Order Rate Constants of Sulfate Radical with Aromatic Contaminants Using Quantitative Structure-Activity Relationship Model." Water 14, no. 5 (February 28, 2022): 766. http://dx.doi.org/10.3390/w14050766.

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Predicting the second-order rate constants between aromatic contaminants and a sulfate radical (kSO4•−) is vital for the screening of pollutants resistant to sulfate radical-based advanced oxidation processes. In this study, a quantitative structure-activity relationship (QSAR) model was developed to predict the values for aromatic contaminants. The relationship between logkSO4•− and three molecular descriptors (electron density, steric energy, and ratio between oxygen atoms and carbon atoms) was built through multiple linear regression. The goodness-of-fit, robustness, and predictive ability of the model were characterized statistically with indicators showing that the model was reliable and applicable. Electron density was found to be the most influential descriptor that contributed the most to logkSO4•−. All data points fell within the applicability domain, and no outliers existed in the training set. The comparison with other models indicates that the QSAR model performs well in elucidating the mechanism of the reaction between aromatic compounds and sulfate radicals.

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Qian, Jiahong, Yuying Qiu, Xiang Ji, Yiduo Yang, and Laili Wang. "Ecotoxicological Impact Assessment of the Production of Cotton Fabric." AATCC Journal of Research 7, no. 6 (November 1, 2020): 23–32. http://dx.doi.org/10.14504/ajr.7.6.4.

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Textiles and garments are increasingly being included in life cycle assessment (LCA) studies because the use of chemicals in industrial production of these items has potential environmental impacts. The USEtox model, characterized by ecotoxicity characterization factors based on abundant data, is a useful tool for assessing the toxicity of chemical pollutants. The objectives of this study were to estimate characterization factors of cotton fabric-related chemicals based on data from a quantitative structure–activity relationship (QSAR) model and assess the ecotoxicological impact of cotton woven fabric. The research boundary ranged from fabric production to wet treatment. Wet treatment was found to contribute more to ecotoxicity than fabric production did, with primary alcohol ethoxylate and sodium hydroxide being the main pollutants.

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Tonooka, Y., and Y. Fujii. "Developing Air Pollutant Emission Structure Database in Japan—For Analysis of Relationships Between Emission, Energy Consumption, and Urban Activity." IFAC Proceedings Volumes 22, no. 17 (October 1989): 109–14. http://dx.doi.org/10.1016/s1474-6670(17)52913-4.

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Hao, Pengcheng, Gang Wang, Jiantong Wen, Xiang Li, Yanli Suo, Haijuan Zhan, Shuxian Bi, and Wanyi Liu. "Efficient photocatalytic-fenton oxidation performance of Fe3+/g-C3N4/NCDs nanorods: Structure-activity relationship of photocatalytic degradation of water pollutants." Journal of Environmental Chemical Engineering 10, no. 3 (June 2022): 107728. http://dx.doi.org/10.1016/j.jece.2022.107728.

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Zhu, Benzhan, Chen Shen, Huiying Gao, Liya Zhu, Jie Shao, and Li Mao. "Intrinsic chemiluminescence production from the degradation of haloaromatic pollutants during environmentally-friendly advanced oxidation processes: Mechanism, structure–activity relationship and potential applications." Journal of Environmental Sciences 62 (December 2017): 68–83. http://dx.doi.org/10.1016/j.jes.2017.06.035.

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Sudhakar. C, Sudhakar C., Devi R. Devi. R, Nikhil S. Nikhil. S, Kalyani P. Kalyani. P, Suganthi A. Suganthi. A, and Rajarajan M. Rajarajan. M. "Visible Light Degradation of Rose Bengal Dye with a Novel WO2/ZnMoO4 Nanocomposite as Photocatalyst." Oriental Journal Of Chemistry 38, no. 1 (February 28, 2022): 144–50. http://dx.doi.org/10.13005/ojc/380118.

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The fabrication of WO2/α-ZnMoO4 nanocomposite using a novel chemical aqueous technique is described in this research. This treatment is mild, easy to use, affordable, and successful. The samples were described using XRD, FT-IR, SEM, EDX, and UV-DRS as they were created. The WO2/α-ZnMoO4 is seen in the visible portion of the DRS (Diffuse Reflectance Spectroscopy). The structural and morphological features of the generated WO2/α-ZnMoO4 nanocomposite were examined using SEM. The photocatalytic activity of WO2/α-ZnMoO4 nanocomposite for the Rose Bengal degradation was investigated in depth under visible light. The WO2/α-ZnMoO4 nanocomposite had the best photodynamic performance (59 percent to 96 percent of RB degradation). Adsorption of Rose Bengal came next. Using a kinetic pseudo-first order kinetics, the samples' exceptional stability was tested four times under visible light using photodegradation RB. The relationship between structure of the WO2/α-ZnMoO4 nanocomposite and photocatalytic activity, are investigated. As a result, the method of preparation throws light on the photocatalytic destruction of organic pollutants using WO2/α-ZnMoO4 nanocomposite.

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Sherwood, Graham D., Jennifer Kovecses, Alice Hontela, and Joseph B. Rasmussen. "Simplified food webs lead to energetic bottlenecks in polluted lakes." Canadian Journal of Fisheries and Aquatic Sciences 59, no. 1 (January 1, 2002): 1–5. http://dx.doi.org/10.1139/f01-213.

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Very little is known about the consequence of human activities on the flow of energy through natural ecosystems. Here, we present a trophic-based approach to describing energy relationships in pollutant-disturbed lakes, emphasizing the importance of prey diversity in maintaining energy transfer to growing fish. Both diet and community analysis indicated that the food web leading to yellow perch (Perca flavescens) in metal-polluted lakes was extremely simplified compared with reference lakes. Through the application of an in situ marker for fish activity costs (muscle lactate dehydrogenase activity) and through bioenergetic modelling, we show how this has severe consequences on the efficiency of energy transfer to perch from their prey; premature energetic bottlenecks (zero conversion efficiency) occur when successively larger prey types are not available to growing perch. These observations provide a much needed ecological and physiological framework for assessing how energy transfer can be affected in polluted systems. Our approach need not be limited therein but should be applicable to any aquatic system where food web structure is variable and (or) disrupted.

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Chen, Yuting, Yuying Dong, Le Li, Jian Jiao, Sitong Liu, and Xuejun Zou. "Toxicity Rank Order (TRO) As a New Approach for Toxicity Prediction by QSAR Models." International Journal of Environmental Research and Public Health 20, no. 1 (December 30, 2022): 701. http://dx.doi.org/10.3390/ijerph20010701.

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Quantitative Structure–Activity Relationship (QSAR) models are commonly used for risk assessment of emerging contaminants. The objective of this study was to use a toxicity rank order (TRO) as an integrating parameter to improve the toxicity prediction by QSAR models. TRO for each contaminant was calculated from collected toxicity data including acute toxicity concentration and no observed effect concentration. TRO values associated with toxicity mechanisms were used to classify pollutants into three modes of action consisting of narcosis, transition and reactivity. The selection principle of parameters for QSAR models was established and verified. It showed a reasonable prediction of toxicities caused by organophosphates and benzene derivatives, especially. Compared with traditional procedures, incorporating TRO showed an improved correlation coefficient of QSAR models by approximately 10%. Our study indicated that the proposed procedure can be used for screening modeling parameter data and improve the toxicity prediction by QSAR models, and this could facilitate prediction and evaluation of environmental contaminant toxicity.

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Santonastaso, Marianna, Filomena Mottola, Concetta Iovine, Fulvio Cesaroni, Nicola Colacurci, and Lucia Rocco. "In Vitro Effects of Titanium Dioxide Nanoparticles (TiO2NPs) on Cadmium Chloride (CdCl2) Genotoxicity in Human Sperm Cells." Nanomaterials 10, no. 6 (June 5, 2020): 1118. http://dx.doi.org/10.3390/nano10061118.

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The environmental release of titanium dioxide nanoparticles (TiO2NPs) associated with their intensive use has been reported to have a genotoxic effect on male fertility. TiO2NP is able to bind and transport environmental pollutants, such as cadmium (Cd), modifying their availability and/or toxicity. The aim of this work is to assess the in vitro effect of TiO2NPs and cadmium interaction in human sperm cells. Semen parameters, apoptotic cells, sperm DNA fragmentation, genomic stability and oxidative stress were investigated after sperm incubation in cadmium alone and in combination with TiO2NPs at different times (15, 30, 45 and 90 min). Our results showed that cadmium reduced sperm DNA integrity, and increased sperm DNA fragmentation and oxidative stress. The genotoxicity induced by TiO2NPs-cadmium co-exposure was lower compared to single cadmium exposure, suggesting an interaction of the substances to modulate their reactivity. The Quantitative Structure-Activity Relationship (QSAR) computational method showed that the interaction between TiO2NPs and cadmium leads to the formation of a sandwich-like structure, with cadmium in the middle, which results in the inhibition of its genotoxicity by TiO2NPs in human sperm cells.

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Lei, Hong Jun, Chang Jia Li, Xun Feng Xia, and Bei Dou Xi. "Decomposing the Influencing Factors of China’s Industrial Wastewater Discharges Using LMDI I Method." Advanced Materials Research 518-523 (May 2012): 2089–98. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.2089.

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China’s industry accounts for 46.8% of the national gross domestic product (GDP) and plays an important strategic role to its economic growth, but it is also the main water pollution sources. In order to identify the relationship between the underlying driving forces and various environmental indicators, two critical industrial wastewater pollutant discharges over 2001-2009, including Chemical Oxygen Demand (COD) and ammonia nitrogen (NH4-N), were decomposed into three factors, i.e., production effect (caused by change in the scale of economic activity), structural effect (caused by change in economic structure) and intensity effect (caused by change in technological level of the sector), using a logarithmic mean Divisia index I (LMDI I) decomposition method. Results showed that: (1) the average annual effect changes of industrial wastewater changes of COD discharges in China is -2.99% with the production effect, structural effect, and intensity effect as 14.64%, -1.39%, and -16.24%, respectively. Similarly, the average effect changes of industrial wastewater changes of NH4-N discharges is -4.03% with production effect, structural effect, and intensity effect as 16.18%, -2.88%, and -17.33%, respectively. (2) production effect was the major factor responsible for the rise of COD and NH4-N discharges, accounting for 45% and 44% of the total contribution. (3) structural effect contributed to the decrease of COD and NH4-N discharges with a small effect of 4% and 8% in total contribution. (4) intensity effect had an dominant decremental effect in COD and NH4-N discharges, accounting for 50% and 48% of the total contribution; intensity effect could be further decomposed in cleaner production effect and pollution abatement effect, and cleaner production effect of COD and NH4-N accounts for 60% and 55% in pollution reduction. (5) the main contributors to incremental COD and NH4-N discharges among industrial sub-sectors were manufacture of paper and paper products, processing of food from agricultural products, manufacture of textile and so on. These sectors should be the top priorities for policy makers to reduce pollutants discharges, and the potential measures are industrial restructuring and related regulation.

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Bao, Yiqiong, Mengrong Li, Yanjie Xie, and Jingjing Guo. "Investigating the Permeation Mechanism of Typical Phthalic Acid Esters (PAEs) and Membrane Response Using Molecular Dynamics Simulations." Membranes 12, no. 6 (June 6, 2022): 596. http://dx.doi.org/10.3390/membranes12060596.

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Phthalic acid esters (PAEs) are typical environmental endocrine disrupters, interfering with the endocrine system of organisms at very low concentrations. The plasma membrane is the first barrier for organic pollutants to enter the organism, so membrane permeability is a key factor affecting their biological toxicity. In this study, based on computational approaches, we investigated the permeation and intramembrane aggregation of typical PAEs (dimethyl phthalate, DMP; dibutyl phthalate, DBP; di-2-ethyl hexyl phthalate, DEHP), as well as their effects on membrane properties, and related molecular mechanisms were uncovered. Our results suggested that PAEs could enter the membrane spontaneously, preferring the headgroup-acyl chain interface of the bilayer, and the longer the side chain (DEHP > DBP > DMP), the deeper the insertion. Compared with the shortest DMP, DEHP apparently increased membrane thickness, order, and rigidity, which might be due to its stronger hydrophobicity. Potential of means force (PMF) analysis revealed the presence of an energy barrier located at the water-membrane interface, with a maximum value of 2.14 kcal mol−1 obtained in the DEHP-system. Therefore, the difficulty of membrane insertion is also positively correlated with the side-chain length or hydrophobicity of PAE molecules. These findings will inspire our understanding of structure-activity relationship between PAEs and their effects on membrane properties, and provide a scientific basis for the formulation of environmental pollution standards and the prevention and control of small molecule pollutants.

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Xue, Yongtao, Zhansheng Wu, Xiufang He, Xia Yang, Xiaoqing Chen, and Zhenzhen Gao. "Constructing a Z-scheme Heterojunction of Egg-Like Core@shell CdS@TiO2 Photocatalyst via a Facile Reflux Method for Enhanced Photocatalytic Performance." Nanomaterials 9, no. 2 (February 7, 2019): 222. http://dx.doi.org/10.3390/nano9020222.

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A well designed and accurate method of control of different shell thickness and electronic transmission in a Z-scheme core@shell system is conducive to obtaining an optimum photocatalytic performance. Herein, the Z-scheme heterojunction of egg-like core@shell CdS@TiO2photocatalysts with controlled shell thickness (13 nm, 15 nm, 17 nm, 22 nm) were synthesized by a facile reflux method, and the CdS@TiO2 structure was proved by a series of characterizations. The photodegradation ratio on methylene blue and tetracycline hydrochloride over the 0.10CdS@TiO2 composites with TiO2 shell thickness of 17 nm reached 90% in 250 min and 91% in 5 min, respectively, which was almost 9.8 times and 2.6 times than that of TiO2 and CdS on rhodamine B respectively under visible light. Besides, the higher total organic carbon removal ratio indicated that most of the pollutants were degraded to CO2 and H2O. The Z-scheme electronic transfer pathway was studied through radical species trapping experiments and electron spin resonance spectroscopy. Moreover, the relationship between shell thickness and photocatalytic activity demonstrated that different shell thickness affects the separation of the electron and holes, and therefore affected the photocatalytic performance. In addition, the effects of pollutants concentration, pH, and inorganic anions on photocatalytic performance were also investigated. This work can provide a novel idea for a well designed Z-scheme heterojunction of core@shell photocatalysts, and the study of photocatalytic performance under different factors has guiding significance for the treatment of actual wastewater.

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Song, Liqiong, Wei Xia, Zhao Zhou, Yuanyuan Li, Yi Lin, Jie Wei, Zhengzheng Wei, et al. "Low-level phenolic estrogen pollutants impair islet morphology and β-cell function in isolated rat islets." Journal of Endocrinology 215, no. 2 (September 3, 2012): 303–11. http://dx.doi.org/10.1530/joe-12-0219.

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Phenolic estrogen pollutants, a class of typical endocrine-disrupting chemicals, have attracted public attention due to their estrogenic activities of imitating steroid hormone 17β-estradiol (E2) effects. Exposure to these pollutants may disrupt insulin secretion and be a risk factor for type 2 diabetes. In this study, we investigated the direct effects of phenolic estrogen diethylstilbestrol (DES), octylphenol (OP), nonylphenol (NP), and bisphenol A (BPA) on rat pancreatic isletsin vitro, whose estrogenic activities were DES>NP>OP>BPA. Isolated β-cells were exposed to E2, DES, OP, NP, or BPA (0, 0.1, 0.5, 2.5, 25, and 250 μg/l) for 24 h. Parameters of insulin secretion, content, and morphology of β-cells were measured. In the glucose-stimulated insulin secretion test, E2and DES increased insulin secretion in a dose-dependent manner in a 16.7 mM glucose condition. However, for BPA, NP, or OP with lower estrogenic activity, the relationship between the doses and insulin secretion was an inverted U-shape. Moreover, OP, NP, or BPA (25 μg/l) impaired mitochondrial function in β-cells and induced remarkable swelling of mitochondria with loss of distinct cristae structure within the membrane, which was accompanied by disruption of mRNA expression of genes playing a key role in β-cell function (Glut2(Slc2a2),Gck,Pdx1,Hnf1α,Rab27a, andSnap25), and mitochondrial function (Ucp2andOgdh). Therefore, these phenolic estrogens can disrupt islet morphology and β-cell function, and mitochondrial dysfunction is suggested to play an important role in the impairment of β-cell function.

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Eddy, Diana Rakhmawaty, Soraya Nur Ishmah, Muhamad Diki Permana, and M. Lutfi Firdaus. "Synthesis of Titanium Dioxide/Silicon Dioxide from Beach Sand as Photocatalyst for Cr and Pb Remediation." Catalysts 10, no. 11 (October 29, 2020): 1248. http://dx.doi.org/10.3390/catal10111248.

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Heavy metals are non-biodegradable and have a high toxicity effect on microorganisms which makes their presence in the environment extremely dangerous. The method of handling heavy metal waste by photocatalysis techniques using TiO2/SiO2 composite showed a good performance in reducing harmful pollutants. In this study, SiO2 from Bengkulu beach sand, Indonesia, was used as a support material for TiO2 photocatalyst to remove Cr(VI) and Pb(II). SiO2 was obtained through leaching techniques using NaOH as a solvent. The TiO2/SiO2 composite photocatalyst was synthesized using a solvothermal method at 130 °C and then characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and a particle size analyzer (PSA). Based on the XRD diffractogram, the synthesized TiO2 showed the anatase structure while the SiO2 showed the amorphous structure. The Ti–O–Si bond is defined in the infrared (IR) spectra, which indicates that the relationship between TiO2 and SiO2 is a chemical interaction. The results of SEM and PSA characterizations show agglomerated spherical (round) particles with a mean particle size of 616.9 nm. The TiO2/SiO2 composite of 7:1 ratio showed the highest photocatalytic activity after 180 min of ultraviolet (UV) irradiation, with a concentration-decrease percentage of 93.77% and 93.55% for Cr(VI) and Pb(II), respectively.

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Zhang, Haigang, Chengji Zhao, and Hui Na. "Enhanced Biodegradation of Phthalic Acid Esters’ Derivatives by Plasticizer-Degrading Bacteria (Burkholderia cepacia, Archaeoglobus fulgidus, Pseudomonas aeruginosa) Using a Correction 3D-QSAR Model." International Journal of Environmental Research and Public Health 17, no. 15 (July 23, 2020): 5299. http://dx.doi.org/10.3390/ijerph17155299.

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A phthalic acid ester’s (PAEs) comprehensive biodegradability three-dimensional structure-activity relationship (3D-QSAR) model was established, to design environmentally friendly PAE derivatives, which could be simultaneously degraded by plasticizer-degrading bacteria, such as Burkholderia cepacia, Archaeoglobus fulgidus, and Pseudomonas aeruginosa. Only three derivatives of diethyl phthalate (DEP (DEP-27, DEP-28 and DEP-29)) were suited for their functionality and environmental friendliness, which had an improved stability in the environment and improved the characteristics (bio-toxicity, bioaccumulation, persistence, and long-range migration) of the persistent organic pollutants (POPs). The simulation inference of the microbial degradation path before and after DEP modification and the calculation of the reaction energy barrier exhibited the energy barrier for degradation being reduced after DEP modification and was consistent with the increased ratio of comprehensive biodegradability. This confirmed the effectiveness of the comparative molecular similarity index analysis (CoMSIA) model of the PAE’s comprehensive biodegradability. In addition, a molecular dynamics simulation revealed that the binding of the DEP-29 derivative with the three plasticizer-degradation enzymes increased significantly. DEP-29 could be used as a methyl phthalate derivative that synergistically degrades with microplastics, providing directional selection and theoretical designing for plasticizer replacement.

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Cheng, Yan, Hui-ming Chen, Wen-lian Yu, Yuan Cui, Li-li Zhou, and Xin Zhou. "3D-QSAR study of the endocrine disrupting effect of perfluorooctane sulfonates (PFOS) and perfluorooctanoic acid (PFOA) on human estrogen, androgen and thyroid receptors." Collection of Czechoslovak Chemical Communications 75, no. 4 (2010): 471–92. http://dx.doi.org/10.1135/cccc2009547.

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Abstract:

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) have become emerging persistent organic pollutants (POPs), but their health effects on humans remain controversial because of contradictory experimental and epidemiological studies. In this study, we used three-dimensional quantitative structure–activity relationship (3D-QSAR) method by applying Surflex-dock to study and compare the binding modes between PFOS, PFOA and eight other endocrine disrupting chemicals, and human estrogen receptor (hERα), human androgen receptor (hAR) and human thyroid receptor (hTRβ). Molecular docking and hydrogen bond studies indicated that PFOS and PFOA had high affinity potency toward hERα, hAR and hTRβ due to low free binding energies, while the highest value was obtained toward hTRβ. This means that PFOS and PFOA might have more disrupting effects on thyroid than on estrogen and androgen receptors. Hydrogen bonding interactions revealed that Met313 in hTRβ might act as the critical amino acid residue in the binding of ligand–receptor complex, which would provide an explanation for the interaction mechanisms. Our results provide an important reference and direction for the interaction mode and mechanism study between PFOS/PFOA and human endocrine systems.

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