scholarly journals Uncommon Sorption Mechanism of Aromatic Compounds onto Poly(Vinyl Alcohol)/Chitosan/Maleic Anhydride-β-Cyclodextrin Hydrogels

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 877 ◽  
Author(s):  
Cesar M. C. Filho ◽  
Pedro V. A. Bueno ◽  
Alan F. Y. Matsushita ◽  
Bruno H. Vilsinski ◽  
Adley F. Rubira ◽  
...  

Aromatic hydrocarbons are extensive environmental pollutants occurring in both water and air media, and their removal is a priority effort for a healthy environment. The use of adsorbents is among the several strategies used for the remediation of these compounds. In this paper, we aim the synthesis of an amphiphilic hydrogel with the potential for the simultaneous sorption of a set of monocyclic and polycyclic aromatic hydrocarbons associated with toxicity effects in humans. Thus, we start by the synthesis of a copolymer-based in chitosan and β-cyclodextrin previously functionalized with the maleic anhydride. The presence of β-cyclodextrin will confer the ability to interact with hydrophobic compounds. The resulting material is posteriorly incorporated in a cryogel of poly(vinyl alcohol) matrix. We aim to improve the amphiphilic ability of the hydrogel matrix. The obtained hydrogel was characterized by swelling water kinetics, thermogravimetric analysis, rheological measurements, and scanning electron microscopy. The sorption of aromatic hydrocarbons onto the gel is characterized by pseudo-first-order kinetics and Henry isotherm, suggesting a physisorption mechanism. The results show that the presence of maleic anhydride-β-cyclodextrin and chitosan into hydrogels leads to an increase in the removal efficiency of the aromatic compounds. Additionally, the capacity of this hydrogel for removing these pollutants from a fossil fuel sample has also been tested.

2012 ◽  
Vol 60 (2) ◽  
pp. 117-126 ◽  
Author(s):  
Juliana Souza Azevedo ◽  
Belisandra Lopes ◽  
Alberto Katsumiti ◽  
Elisabete Santis Braga ◽  
Helené Roche ◽  
...  

Different components of the mixed function oxidase (MFO) system and the levels of fluorescent aromatic compounds in bile (FACs) were measured in Cathorops spixii in order to assess the impact of polycyclic aromatic hydrocarbons (PAHs). Fish were sampled in an estuary (Santos/São Vicente) with a history of contamination by PAHs, mainly due to the presence of the industrial complex of Cubatão city and of another of low anthropogenic influence (Cananéia) on the Brazilian coast. FACs were higher in fish from the polluted site, and the PAH 5 and 6-ring metabolites were the most frequent - with 14% and 15%, respectively. Levels of the different components of the MFO system showed the same variation profile as the FACs for both estuaries. Therefore, the values found for somatic indexes and biomarkers with data of bile PAH metabolites indicate the presence of organic contaminants, especially in the area subject to the influence of the industrial complex on the Santos/São Vicente estuary.


Author(s):  
Natela Khetsuriani ◽  
Vladimer Tsitsishvili ◽  
Elza Topuria ◽  
Irina Mchedlishvili ◽  
Zaza Molodinashvili

The individual composition of polycyclic aromatic hydrocarbons has been studied in high boiling (340–590°) fractions of Norio oil (wells 200, 201) which are characterized by high content of aromatic hydrocarbons and high intensity fluorescence. The eluates obtained by adsorption fractionation of aromatic hydrocarbons separated by aniline and concentrates of their crystalline components have been studied by GC, MS and GC-MS methods. For analysis of the obtained data an automated system of mass deconvolution and identification (AMDIS) was used. In the eluates under investigation the following structures were identified: indenes, tetralines, dinaphtilbenzenes, naphthalenes, fluorenes, phenantrenes, antracenes, mono- and polyalkyl derivatives ofnaphtofluorene and phenantrene, and terpeniles. In crystal samples of the eluates the banzantracene, chrizene, their methyl-, dimethyl and trymethylanaloges, phenantrene derivatives, antracenes and pyrenes were identified. The heterocyclic analogues of polycyclic aromatic hydrocarbons likemethylbenzoanthracenes, benzonaphthothiophenes, benzocarbazoles and dibenzthiophene were identified in Georgian oils for the first time.


2019 ◽  
Vol 23 (10) ◽  
pp. 1861-1866
Author(s):  
A.A. Enuneku ◽  
B. Kubeyinje

Polycyclic aromatic hydrocarbons (PAHs) are emerging ubiquitous environmental pollutants with reported carcinogenic, mutagenic and teratogenic potentials on living organisms and humans. The objective of this study was to assess the concentrations of PAHs in agricultural soils of Tsekelewu Community and environs (Egbema Kingdom) in Warri North Local Government Area of Delta State, Nigeria impacted by gas flaring using gas chromatograph system Agilent 5890 Series 11 gas chromatograph equipped with Flame ionization detector (GC-FID). The results revealed that station 1 and 2 were fairly contaminated; with mean total PAH concentration of 236.40 μg/kg and 279.75 μg/kg respectively. Stations 3, 4, 6, 7 and 9 having mean total PAH concentration of 692.45μg/kg, 726.22 μg/kg, 739.82 μg/kg, 609.38 μg/kg, and 772.99 μg/kg were moderately contaminated. Heavy contamination was recorded in station 5 and station 8 with mean PAH concentrations of 1231.08μg/kg and 1224.33 μg/kg. The dominant PAHs in soil samples were benzo(a)anthracene, phananthrene and chrysene with benzo(a)anthracene having the highest concentration across all sample stations. The PAH concentration observed in this study is thus a serious cause for concern since soil contamination from gas flaring will likely continue. Measures that will attenuate PAHs concentrations in soil should be adopted as farmers are likely exposed by largely inhalation.Keywords: Hydrocarbons; Contamination; Agricultural soils; Gas flaring 


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