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Cai Y.,Agro Environmental Protection Institute | Cai Y.,Key Laboratory of Production Environment and Agro product Safety | Lv J.,East China Institute of Technology | Feng J.,East China Institute of Technology | And 5 more authors.
Spectroscopy Letters | Year: 2012

The analysis of plastics and fibers is of importance to forensic scientists, especially in the investigation of trace evidence. In this study, we use Fourier transform infrared microscope and confocal Raman spectroscope to investigate two kinds of polymers: poly(butylenes adipate-co-terephthalate) and poly(ethylene terephthalate), which are very similar in structure and cannot be discriminated easily with other instruments. Infrared and Raman spectra were tentatively interpreted. The indicative peaks (937cm -1, 1121cm -1 in Infrared spectra; 996cm -1, 1396cm -1 in Raman spectra) to distinguish the two polymers were also summarized. The data in this study can help forensic scientists identify these two polymers accurately and avoid wrong certificate of authenticity. The data also offer the producer and researchers an effective and fast method to characterize and identify the poly(butylenes adipate-co-terephthalate). Copyright © Taylor & Francis Group, LLC.

Zhou Q.,Nankai University | Zhou Q.,CAS Shenyang Institute of Applied Ecology | Diao C.,Nankai University | Sun Y.,CAS Shenyang Institute of Applied Ecology | And 3 more authors.
Chemosphere | Year: 2012

The growth, photosynthesis rate, and ultrastructure of Mirabilis jalapa L. as a newly-found remediation species under stress of nitrobenzene (NB) and its uptake and removal of NB by the plants were investigated. The results showed that M. jalapa plants could endure contaminated soils by lower than 10.0mgNBkg -1 because there was no decrease in the total length of the plant roots, the maximum length of the hypocotyle, the length of the first seminal root, the height of the shoots and the dry biomass of the seedlings as well as the photosynthesis rate of the plants compared with those in the control. In particular, the growth of the plants could be significantly (P<0.01) enhanced by 0.1mgNBkg -1 under unautoclaved and autoclaved soils. Ultrastructural observations on leaf cells of the plants found that these cells had smooth, clean and continuous cell membranes and cell walls, indicating that there was no obvious damage by NB in comparison with those in the control. Although the absorption of NB in shoots and roots of M. jalapa was weak, plant-promoted biodegradation of NB was considerable and the dominant contribution in the removal of NB from contaminated soils, suggesting the feasibility of M. jalapa applied to phytoremediation of NB contaminated soils. © 2011 Elsevier Ltd.

Zheng S.,Zhejiang University | Zheng S.,Agro Environmental Protection Institute | Zheng S.,Key Laboratory of Production Environment and Agro product Safety | Zheng S.,Tianjin Key Laboratory of Agro environment and Agro product Safety | Zhang M.,Zhejiang University
Journal of Environmental Sciences | Year: 2011

Sequential extraction procedure was applied to assess the dynamics of solid-phase transformation of added Cu, Pb, Cd, and Hg in a typical Chinese paddy soil incubated under three moisture regimes (75% field capacity, wetting-drying cycle, and flooding). The heavy metals spiked in the soil were time-dependently transferred from the easily extractable fraction (the exchangeable fraction) into less labile fractions (Fe-Mn oxide- and organic matter-bound fractions), and thus reduced lability of the metals. No significant changes were found for the carbonate-bound and residual fractions of the heavy metals in the soil during the whole incubation. Change rate of the mobility factor (MF), a proportion of weakly bound fractions (exchangeable and carbonate-bound) in the total metal of soil, reflected the transformation rate of metal speciation from the labile fractions toward stable fractions. It was found that soil moisture regime did not change the direction and pathways of transformation of metal speciation, but it significantly affected the transformation rate. In general, the paddy soil under flooding regime had higher metal reactivity compared with 75% field capacity and wetting-drying cycle regimes, resulting in the more complete movement of metals toward stable fractions. This might be related to the increased pH, precipitation of the metals with sulfides and higher concentration of amorphous Fe oxides under submerged condition. © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.

Zhang K.,Agro Environmental Protection Institute | Zhang K.,Key Laboratory of Production Environment and Agro Product Safety | Zhang K.,Tianjin Key Laboratory of Agro Environment and Agro Product Safety | An Y.,Agro Environmental Protection Institute | And 6 more authors.
Chemosphere | Year: 2012

Nano-MgO is a good bactericide but with strong alkalinity in water due to its rapid hydrolysis. To control its hydrolysis rate and keep its bactericidal properties, we synthesized nano-MgO microspheres using chitosan-alginate system in this study. The synthesized nano-MgO release-controlled microspheres (nMgO-RCM) were with 0.98-1.20mm of particle sizes. Also, their embedding ratio and loading percentage was 63.52% and 12.27%, respectively. Based on the characterization results, nano-MgO was only observed on surface of the nMgO-RCM. Its release rate from the nMgO-RCM could be controlled by the chitosan-alginate system, and the observed rate constant (kobs) increased from 0.0289h-1 to 0.0358h-1 with the increment of the dosage from 10mgL-1 to 80mgL-1. Furthermore, the nMgO-RCM could maintain pH value lower than 8.5 and colony counts less than 20CFUmL-1 for at least 120h. © 2012 Elsevier Ltd.

Zheng S.-a.,Agro Environmental Protection Institute | Zheng S.-a.,Key Laboratory of Production Environment and Agro Product Safety | Zheng S.-a.,Tianjin Key Laboratory of Agro Environment and Agro Product Safety | Zheng X.,Agro Environmental Protection Institute | And 5 more authors.
PLoS ONE | Year: 2012

Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their speciation in the artificially contaminated soil columns. Results showed that the maximum leachate concentrations of Cu, Pb, Cd, and Zn were less than those specified in the Chinese Quality Standards for Groundwater (Grade IV), thereby suggesting that the heavy metals that leached from the polluted purple soil receiving acid rain may not pose as risks to water quality. Most of the Pb and Cd leachate concentrations were below their detection limits. By contrast, higher Cu and Zn leachate concentrations were found because they were released by the soil in larger amounts as compared with those of Pb and Cd. The differences in the Cu and Zn leachate concentrations between the controls (SAR at pH 5.6) and the treatments (SAR at pH 3.0 and 4.5) were significant. Similar trends were observed in the total leached amounts of Cu and Zn. The proportions of Cu, Pb, Cd, and Zn in the EXC and OX fractions were generally increased after the leaching experiment at three pH levels, whereas those of the RES, OM, and CAR fractions were slightly decreased. Acid rain favors the leaching of heavy metals from the contaminated purple soil and makes the heavy metal fractions become more labile. Moreover, a pH decrease from 5.6 to 3.0 significantly enhanced such effects. © 2012 Zheng et al.

Ding Y.Z.,Agro Environmental Protection Institute | Ding Y.Z.,Key Laboratory of Production Environment and Agro product Safety | Ding Y.Z.,Tianjin Key Laboratory of Agro environment and Food Safety | Song Z.G.,Agro Environmental Protection Institute | And 8 more authors.
International Journal of Environmental Science and Technology | Year: 2014

Vegetation at mining sites can produce increased heavy metal leaching by the organic acids and protons originating from root secretion and litter degradation. Batch experiments were conducted to investigate the effects of organic acids and pH on the extraction of Pb, Cd, Zn and Cu from an alkaline mine soil (sampled from a mining site of Chenzhou City, Hunan Province) and an acid mine soil (sampled from a mining site of Daxin county, Guangxi Province). The results showed that in the presence of organic acids (acetic, oxalic, malic, fumaric, tartaric and citric acids) at pH 7, the extraction of Pb, Cd, Zn and Cu from the acid mine soil was much higher than that from the alkaline mine soil, in which only citric acid with higher concentration was capable of extracting some heavy metals. Citric acid had the strongest ability in extracting heavy metals, followed by oxalic acid. Heavy metal extraction dramatically decreased with increasing pH. Moreover, at low pH, oxalic acid promoted the risk of Cu leaching; at high pH, the leaching of Pb, Zn, Cd and Cu was enhanced by both oxalic and citric acids. This indicated that those plants, which can produce substantial citric acid or oxalic acid by root secretion and litter degradation, should not be selected for the revegetation of mining sites. © 2013 Islamic Azad University (IAU).

An Y.,Agro Environmental Protection Institute | An Y.,Key Laboratory of Production Environment and Agro product Safety | An Y.,Tianjin Key Laboratory of Agro environment and Agro product Safety | Dong Q.,Agro Environmental Protection Institute | And 5 more authors.
Chemosphere | Year: 2014

Hydrogenotrophic bacteria (HTB) were introduced into a nitrate removal system, which used nanoscale zero-valent iron (nZVI) as reductant, to investigate its bioinhibitory effect. Based on the results, it was noted that addition of HTB culture (10-50mL) led to 58.9-91.4% decrease in the first observed rate constant (kobs1), which represented the nitrate removal rate by nZVI, and a reduction in the generated poisonous by-products from 94.9% to 38.5%. In other words, HTB had a significant inhibitory effect on nitrate reduction by nZVI. However, the pathway of this bioinhibition only prevented the occurrence of chemical reduction, but not competition for nitrate. Furthermore, FeOOH coating was observed on the surface of nZVI, instead of Fe3O4 or Fe2O3, which could prevent electron transmission from nZVI to nitrate. Considering that FeOOH was the product of iron corrosion, the result indicated that HTB could inhibit chemical reduction by enhancing the reaction between nZVI and water. © 2013 Elsevier Ltd.

An Y.,Agro Environmental Protection Institute | Zhang K.,Key Laboratory of Production Environment and Agro product Safety | Dong Q.,Tianjin Key Laboratory of Agro environment and Agro product Safety | Zhang L.,Tianjin University
Water Science and Technology | Year: 2013

An integrated nitrate treatment using passivated iron powder (PIP) and Alcaligenes eutrophus, which is a kind of hydrogenotrophic denitrifying bacteria, was conducted to investigate the effect of iron oxide coating on final-product distribution in hydrogenotrophic denitrification. Based on the results, the autotrophic denitrification supported by PIP could completely remove about 50 mg·L1 of nitrate within 4 days, and almost 80% of nitrate was changed into N2O (under acetylene blocking) without residual nitrite or ammonium. While only 53% of the nitrate was removed using acid-washed iron (AWI) instead of PIP, about 70% was converted into ammonium. Furthermore, a layer of FeOOH converted from hematite (α-Fe2O3) and magnetite (Fe3O4), which may block direct chemical nitrate reduction, was observed on the iron surface when PIP was used to support hydrogenotrophic denitrification. In addition, increasing pH from 5 to 8 increased nitrite generation from 1.19 to 4.91%, and decreased ammonium formation from 4.23 to 0%. Copyright © IWA Publishing 2013 Water Science and Technology.

Liang X.,Agro Environmental Protection Institute | Liang X.,Key Laboratory of Production Environment and Agro product Safety | Xu Y.,Agro Environmental Protection Institute | Xu Y.,Key Laboratory of Production Environment and Agro product Safety | And 7 more authors.
Chemical Engineering Journal | Year: 2011

In order to improve the sorption performance of sepiolite for heavy metals, sepiolite was functionalized by nanotexturization in aqueous sepiolite gel and surface grafting in toluene with mercaptopropyltrimethoxysilane. The pristine sepiolite and mercapto functionalized samples were characterized through XRD, FT-IR, SEM, TEM, TG, surface area analysis, solid state 29Si CP/MAS NMR. The chemical bonding took place between the silanol group within sepiolite and the methoxy group of mercaptopropyltrimethoxysilane. The reaction in aqueous gel produced a continuous coating of individual fibers of sepiolite compared with part grafting on the external surface in toluene. After surface modification, the surface areas decreased due to the bulk size of the mercapto ligand, but the crystal structure did not change obviously, and the stretching of mercapto could be detected by FT-IR. The sorption of Pb(II) and Cd(II) on the samples were studied in batch experiments and it was found that the surface modification can obviously increase the sorption capacities for Pb(II) and Cd(II). The mercapto functionalized sepiolite could provide a potential remedy for heavy metal contamination in soils and water. © 2011 Elsevier B.V.

Ju X.H.,Agro Environmental Protection Institute | Ju X.H.,Key Laboratory of Production Environment and Agro product Safety | Tang S.,Agro Environmental Protection Institute | Tang S.,Key Laboratory of Production Environment and Agro product Safety | And 10 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2011

Metal-binding thiols, involved in detoxification mechanisms in plant and other organism under heavy metal stress, are receiving more and more attentions, and various methods have been developed to determine related thiols such as cysteine (Cys), glutathione (GSH) and phytochelatins (PCs). In present study, an HPLC method was established for simultaneous determination of Cys GSH and PC2-6 after treatment with disulfide reductant of tris (2-carboxyethyl) phosphine hydrochloride (TCEP) and thiolyte reagent of monobromobimane (mBBr). The separation of thiol derivatives was performed on an Agilent Zorbax Eclipse XDB-C18 column (4.6mm×30mm, 1.8μm) with a linear gradient elution of 0.1% (v/v) trifluoroacetic acid (TFA)-acetonitrile (ACN) at 0.8mLmin-1. The temperature of the column was maintained at 25°C. The excitation and emission wavelengths were set at 380 and 470nm, respectively. The thiol derivatives were well separated in 19min, and the total analysis time was 30min. The established method was proved selective, specific and reproducible, and could be applicable to determine Cys, GSH and PC2-6 and to evaluate their roles in detoxification mechanisms in Cd-treated Lolium perenne L. under ambient and elevated carbon dioxide (CO2). It was found that the total SH contents and proportions of thiols in roots and shoots were dependent on Cd concentration, whereas the total SH contents decreased and the proportions of thiols altered without significance at elevated CO2 level. © 2011 Elsevier B.V.

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