Photocatalytic Degradation of Polycyclic Aromatic Hydrocarbons on Soil Surfaces Using Fe2O3 under UV Light

2011 ◽  
Vol 189-193 ◽  
pp. 420-423 ◽  
Author(s):  
Li Hong Zhang ◽  
Nan Jia ◽  
Cheng Bin Xu ◽  
Xue Mei Li

The photocatalytic degradation of phenanthrene (PHE), pyrene (PYRE) and benzo[a]pyrene (BaP) on soil surfaces in the presence of Fe2O3 using ultraviolet (UV) light source was investigated. The effects of various factors, namely Fe2O3, soil pH, and humic acid, on the degradation performance of polycyclic aromatic hydrocarbons (PAHs) were studied. The results show that photocatalytic degradation of PAHs follows the pseudo-first-order kinetics. Catalyst Fe2O3 accelerated the photodegradation of PHE, PYRE and BaP significantly. In acidic or alkaline conditions, the photocatalytic degradation rates of the PAHs were greater than those in neutral conditions. Humic acid significantly enhanced the PAH photocatalytic degradation by sensitizing radicals capable of oxidizing PAHs.

2011 ◽  
Vol 233-235 ◽  
pp. 466-469
Author(s):  
Li Hong Zhang ◽  
Cheng Bin Xu ◽  
Zhong Lin Chen ◽  
Xue Mei Li

The photocatalytic degradation of pyrene (PYRE) and benzo[a]pyrene (BaP) on soil surfaces in the presence of Fe2O3 using ultraviolet (UV) light source was investigated in a photo chamber, in which the temperature was maintained 30 . The effects of UV irradiation intensity and UV wavelength on the degradation performance of polycyclic aromatic hydrocarbons (PAHs) were studied. The results show that with the intensity of UV irradiation being enhanced, the photocatalytic degradation rates of PAHs were increased. Photocatalytic degradation rates of PYRE and BaP on soil surfaces with 5% Fe2O3 were different at UV irradiation wavelengths of 254, 310 and 365 nm, respectively.


2021 ◽  
Author(s):  
Zhao Wang ◽  
Xiangzi Jin ◽  
Han Yeong Kaw ◽  
Zakia Fatima ◽  
Maurizio Quinto ◽  
...  

Abstract Due to their wide distribution and availability, plant leaves can be considered interesting candidates as biomonitoring substrates for the evaluation of atmospheric pollution. In addition, some species can also retain historical information, for example, related to environmental pollution, due to their leaf class age. In this study, the content of polycyclic aromatic hydrocarbons (PAHs) in Abies holophylla and Pinus tabuliformis needle samples in function of their class age has been investigated to obtain information regarding the degradation constant for each PAH under investigation (α values ranging from 0.173 to 1.870) and to evaluate the possibility to correlate the presence of PAHs in needles with some important pollution environmental factors. Considering air pollutant variables registered in Jilin Province, significant correlations (at 95% confidence level) have been found between coal consumption per year and anthracene contents in needles, while fluorene, phenanthrene, and anthracene resulted correlated with coal consumption. Furthermore, it has been demonstrated that the total PAH concentration in needles, for both species, increased with their age (from 804 to 3604 ng g− 1 dry weight), showing a general tendency to accumulate these substances through years. PAH degradation rates increased instead with molecular complexity. This study could be considered a first trial to obtain historical environmental information by pine needles biomonitoring.


2016 ◽  
Vol 70 (9) ◽  
pp. 1520-1528 ◽  
Author(s):  
Ruifang Yang ◽  
Nanjing Zhao ◽  
Xue Xiao ◽  
Shaohui Yu ◽  
Jianguo Liu ◽  
...  

The presence of humic acid (HA) makes it extremely difficult to determine and quantify accurately polycyclic aromatic hydrocarbons (PAHs) in aquatic environment because of their complex and strong interaction. To solve this problem, a new method was developed in this work through the combination of PARAFAC and fluorescence spectroscopy, which mainly includes: (1) the fluorescence quantum yield acquisition of PAHs with and without HA by PARAFAC; (2) the  concentration score correction of PAHs in validation and test sets using the fluorescence quantum yields; and (3) the prediction of PAHs concentration in the validation and test sets in the presence of HA by corrected concentration. Using this method, the PAHs concentration on the level of µg L−1 in the test samples with HA of 2.5 mg/L and 5.0 mg/L can be successfully predicted with the root mean square error below 0.15 µg L−1, relative error of prediction below 4% for validation samples, recoveries of each PAH between 82.5% and 102.6% for test samples.


2021 ◽  
Vol 50 (1) ◽  
pp. 123-133
Author(s):  
Siti Nurul Umira Mohd Sabari ◽  
Saw Hong Loh ◽  
Sazlinda Kamaruzaman ◽  
Noorfatimah Yahaya ◽  
Wan Mohd Afiq Wan Mohd Khalik

Sample pre-treatment is often the bottleneck in an analytical process. Due to the drawbacks of conventional sample pre-treatment methods, microextraction utilizing lower amounts of adsorbents and organic solvents are therefore favoured. A micro-solid phase extraction (μ-SPE) technique coupled with gas chromatography-flame ionization detection (GC-FID) was successfully developed for the analysis of selected polycyclic aromatic hydrocarbons (PA Hs), namely phenanthrene, fluoranthene, and pyrene, in environmental water. In this study, μ-SPE techniques using C18 and molecularly imprinted polymer (MIP) membranes were optimized, validated, and applied to the analysis of selected PA Hs in environmental water samples. The analytical merits were compared, and the two methods were evaluated in terms of linearity, repeatability, and relative recovery. Under the optimal extraction conditions, both μ-SPE techniques using either C18 or MIP membranes as the adsorbents offered comparable ultratrace analysis of the selected PA Hs in the range of 0.003 to 0.01 μg L–1. The extraction strength of C18 membranes was superior to that of MIP membranes for the extraction of low molecular weights PA Hs from water in the presence of humic acid as a matrix factor. The C18membranes overcome the non-covalence interaction between PA Hs and humic acid and thus achieve better recovery.


2021 ◽  
Author(s):  
Zhao Wang ◽  
Xiangzi Jin ◽  
Han Yeong Kaw ◽  
Zakia Fatima ◽  
Maurizio Quinto ◽  
...  

Abstract Due to their wide distribution and availability, plant leaves can be considered interesting candidates as biomonitoring substrates for the evaluation of atmospheric pollution. In addition, some species can also retain historical information, for example, related to environmental pollution, due to their leaf class age. In this study, the content of polycyclic aromatic hydrocarbons (PAHs) in Abies holophylla and Pinus tabuliformis needle samples in function of their class age has been investigated to obtain information regarding the degradation constant for each PAH under investigation (α values ranging from 0.173 to 1.870) and to evaluate the possibility to correlate the presence of PAHs in needles with some important pollution environmental factors. Considering air pollutant variables registered in Jilin Province, significant correlations (at 95% confidence level) have been found between coal consumption per year and anthracene contents in needles, while fluorene, phenanthrene, and anthracene resulted correlated with coal consumption. Furthermore, it has been demonstrated that the total PAH concentration in needles, for both species, increased with their age (from 804 to 3604 ng g− 1 dry weight), showing a general tendency to accumulate these substances through years. PAH degradation rates increased instead with molecular complexity. This study could be considered a first trial to obtain historical environmental information by pine needles biomonitoring.


2018 ◽  
Vol 83 (5) ◽  
pp. 549-559 ◽  
Author(s):  
Xin Wang ◽  
Yu Shi ◽  
Zi Ni ◽  
Zhao Li ◽  
Jia Bao

The biodegradation of polycyclic aromatic hydrocarbons (PAHs) in soils by laccase is reported. However, the low laccase activities of free laccase have limited its applications in environmental bioremediation. In this study, polluted soil was made with 3:1 volume ratio of soil to PAH solution. Subsequently, the adsorption?cross-link composite immobilization method was applied to immobilize laccase derived from fungi onto nylon net and chitosan, respectively. These two kinds of immobilized laccase were used in the degradation of pyrene (Pyr) and benzo[a]pyrene (BaP), and their degradation efficiencies under different temperature and pH conditions were investigated. Consequently, the optimal laboratory experimental parameters were determined as follows: first, compared with free laccase, the degradation rates of Pyr and BaP by immobilized laccase increased by around 10?30 %; second, the degradation efficiency of chitosan as a carrier of immobilized laccase was much better than that of nylon net as a carrier of the immobilized laccase; finally, when the temperature was set at 40?C and the pH was set at 4, the degradation efficiency achieved by immobilized laccase was the best.


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