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ABSTRACT: Using submerged aquatic plants is a cheap and clean technique to remediate heavy metal water pollution at low concentrations.
Biosorption of Cu(II) ions by fresh tissues of Myriophyllum spicatum, a submerged aquatic plant, was characterized in an artificial solution system under different values of contact time, temperature
and pH in this paper. Cu(II) biosorption was fast and equilibrium was attained within 20 min. The equilibrium biosorption
data were analyzed using three widely applied isotherm models: Langmuir, Freundlich and Redlich-Peterson isotherm. Langmuir
isotherm parameters obtained from the three Langmuir linear equations by using linear method were dissimilar, except when
the non-linear method was used. Best fits were yielded with Langmuir and Redlich-Peterson isotherms (R2=0.961–0.992 and 0.990–0.998, respectively). The saturated monolayer biosorption capacity of M. spicatum for Cu(II) at 298 K was calculated to be 0.19 mmol/g. The biosorption capacity of M. spicatum for Cu(II) increased with increasing pH, and the resulting isotherms were well described by Langmuir and extended Langmuir
models (R2=0.931–0.993 and 0.961, respectively). The comparison of calculated q
e
and experimental q
e
values showed that the extended Langmuir model had a better simulation for Cu(II) biosorption by M. spicatum than the Langmuir isotherm model. FT-IR was used to characterize the interaction between M. spicatum and Cu(II), with the results indicating that carboxyl groups played an important role in Cu(II) binding.
Key wordsAquatic Plant-Copper-Biosorption-Langmuir Isotherm Forms-pH
Korean Journal of Chemical Engineering 04/2012; 27(4):1239-1245. · 0.99 Impact Factor
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ABSTRACT: Xiamen Bay (XMB) has received substantial loadings of pollutants from industrial and municipal wastewater discharged since
the 1980s. To assess ecological risks and the current spatial changes of metal contaminants in bottom surface sediments, 12
samples were collected. Samples were subjected to a total digestion technique and analyzed by ICP–OES for Cu, Pb, Zn, Cr,
and Cd, and by AFS for Hg and As. Among these metals, Zn had the highest values (68–268mgkg−1), followed by Pb (27–71mgkg−1), and lower concentrations were found for Cd (42–1,913μgkg−1) and Hg (0–442μgkg−1). In comparison with the average crustal abundance values, the results indicated that nearly half of the sediment samples
of XMB and its adjacent areas were contaminated by Cd, Pb, Zn, and As. Furthermore, based on the modified BCR sequential extraction
procedure, the chemical speciation of heavy metals (Cd, Cr, Cu, Pb, Zn, Hg, and As) in selected sediment samples were evaluated
in this study. Data from BCR sequential extractions indicated that Cd posed a medium ecological risk, whereas, Cr posed low
risk since its exchangeable and carbonate fractions were below 4%, and the mobility of heavy metals in XMB decreased in the
order Cd>Pb>Cu>Zn>Hg>As>Cr. By applying mean effects range median quotients (mERMQ), the results showed that Yuandang
Lagoon with mERMQ value >0.5 would be expected to have the greatest potential toxic risk in amphipod within XMB and its adjacent
areas.
KeywordsXiamen Bay-Surface sediment-Heavy metals-Risk assessment code (RAC)-Mean effects range median quotients (mERMQ)-Yuandang Lagoon
Environmental earth sciences 04/2012; 60(7):1469-1479. · 1.06 Impact Factor
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ABSTRACT: Seven estrogenic compounds--estrone (E1), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), diethylstilbestrol (DES), nonylphenol (NP), octylphenol (OP), and bisphenol A (BPA)--in sediments, surface water, pore water, and organisms were investigated and estrogenic activities were estimated by examining estradiol equivalent (EEQ) concentrations in Yundang Lagoon of Xiamen. The results showed that estrogenic compounds were present in all matrixes of interest: in surface water, ranging from 609.61 to 711.31 ng/l; in pore water, ranging from 562.12 to 1038.15 ng/l; in sediments, ranging from 1433.12 to 2060.41 ng/g; and in biota samples, ranging from 1373.76 to 3199.09 ng/g (lipid weight). NP was the predominant component in all collected samples and the highest concentration was 1964.80 ng/g in sediment. Total EEQ ranged from 4.56 to 13.79 ng/l in surface water, from 2.40 to 17.16 ng/l in pore water, and from 8.66 to 23.95 ng/g in sediments. However, major contributors to total EEQ concentrations were E2, E1, and DES. The EEQ concentrations in surface water samples were at a higher level in comparison to that reported in European countries. To biological sample, the highest level of total estrogenic compounds was found in the short-necked clam. Higher values of the biota-sediment accumulation factor (BSAF) were found in short-necked clam and black seabream, indicating that the living habits of organism and physical-chemical properties of estrogenic compounds might influence the bioavailability of estrogenic compounds in organisms.
Archives of Environmental Contamination and Toxicology 07/2011; 61(1):93-100. · 1.93 Impact Factor
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ABSTRACT: Batch experiments were conducted to assess the effects of Cu(II) and Zn(II) on the biosorption of Pb(II) ions by fresh tissues of Myriophyllum spicatum. The biosorption of Pb(II) was examined for single, binary and ternary solutions at different initial concentrations and different pH values. The experimental results showed that the biosorption capacity increased with increasing pH from 2.0 to 6.0. Both Cu(II) and Zn(II) ions were found to have an adverse effect on the biosorption of Pb(II). The biosorption equilibrium data for single-metal solution were fitted to three isotherm models: Langmuir, Freundlich and Sips, and the Sips isotherm model gave the best fit for the experimental data. The maximum biosorption of Pb(II) in Pb-Cu binary system decreased with increasing concentration of copper ions, and the biosorption equilibrium data for the binary metal solution fitted the Langmuir competitive model well. Comparison between biosorption of Pb(II) and Cu(II) by M. spicatum in the binary solution could lead to the conclusion that the biosorbent (M. spicatum) has no preference of Pb(II) over Cu(II). Fourier transform infrared (FT-IR) spectroscopy was used to characterize the interaction between M. spicatum and Pb(II) ions. The results revealed that the carboxyl, hydroxyl and carbonyl groups are the main binding sites for Pb(II).
Journal of hazardous materials 03/2010; 179(1-3):721-8. · 4.14 Impact Factor
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ABSTRACT: Concentrations of seven estrogenic compounds, i.e., estrone (E1), 17beta-estradiol (E2), 17 alpha-ethynylestradiol(EE2), diethylstilbestrol (DES), nonylphenol (NP), octylphenol (OP) and bisphenol A (BPA), were determined in sediments and pore water from Xiamen Bay in China, and their distributions and potential risks in the Bay were assessed. Total estrogenic compounds concentrations varied from 49.20 to 1230.69 ng/g dw in sediments and from 102.33 to 4376.60 ng/L in pore water. The highest levels of these compounds were found at Yundang Lagoon. The results showed that estrogenic compounds in Xiamen Bay originated mainly from municipal wastewaters. Compared with other areas, Xiamen Bay was contaminated with high levels of estrogen hormones. This contamination poses a potential threat to benthic organisms. Although a good relationship (r=0.94) was observed between the estrogenic compounds concentrations and total organic carbon (TOC) contents in sediments, which did not indicate that the sediment organic matter favors the accumulation of the detected estrogenic compounds.
Marine pollution bulletin 05/2009; 58(8):1210-6. · 2.63 Impact Factor
