Hu X.,Nankai University |
Wei Z.,Nankai University |
Mu L.,Agro Environmental Protection Institute
Carbon | Year: 2017
Studies of the environmental and health risks of graphene oxide (GO, a carbon nanosheet of broad concern) have focused on direct exposure. In contrast, the effects of GO on offspring through parental exposure at trace concentrations remain largely unknown, particularly in sensitive neurological systems. Thus, parental zebrafish were exposed to GO nanosheets at concentrations of 0.01–1 μg/L. GO translocated from the water to the brains of parental and offspring fish with a significant loss of claudin5a (a core component of the neuroepithelial barrier system). GO did not trigger obvious neurotoxicity in parental zebrafish, whereas remarkable neurotoxicity occurred in the offspring, which exhibited a loss of dopaminergic neurons and reductions in acetylcholinesterase activity. In the offspring, ER damage, autophagy promotion, ubiquitin downregulation and increased β-galactosidase activity were observed. Orthogonal partial least squares discriminant analysis revealed that the failures of carbohydrate and fatty acid metabolisms positively contributed to the loss of offspring dopaminergic neurons. The above results support the need for offspring to be examined in nanotoxicology, even for environmentally relevant concentrations. © 2017 Elsevier Ltd
Li J.,China Institute of Technology |
Xu Y.,Agro Environmental Protection Institute
Ecotoxicology and Environmental Safety | Year: 2017
We examined in situ remediation of sepiolite on cadmium-polluted soils with diverse water regimes, and several variables including brown rice Cd, exchangeable Cd, pH, and available Fe/P. pH, available Fe/P in soils increased gradually during continuous flooding, which contributed to Cd absorption on colloids. In control group (untreated soils), compared to conventional irrigation, brown rice Cd in continuous flooding reduced by 37.9%, and that in wetting irrigation increased by 31.0% (p<0.05). In contrast to corresponding controls, brown rice Cd in sepiolite treated soils reduced by 44.4%, 34.5% and 36.8% under continuous flooding, conventional irrigation and wetting irrigation (p<0.05), and exchangeable Cd in amended soils reduced by 27.5–49.0%, 14.3–40.5%, and 24.9–32.8% under three water management regimes (p<0.05). Compared to corresponding controls, decreasing amplitudes of exchangeable Cd and brown rice Cd in sepiolite treated soils were higher in continuous flooding than in conventional irrigation and wetting irrigation. Continuous flooding management promoted soil Cd immobilization by sepiolite. © 2017
Hu X.,Nankai University |
Kang J.,Nankai University |
Lu K.,Nankai University |
Zhou R.,Nankai University |
And 2 more authors.
Scientific Reports | Year: 2014
Graphene oxide (GO) is widely used in various fields and is considered to be relatively biocompatible. Herein, "indirect" nanotoxicity is first defined as toxic amplification of toxicants or pollutants by nanomaterials. This work revealed that GO greatly amplifies the phytotoxicity of arsenic (As), a widespread contaminant, in wheat, for example, causing a decrease in biomass and root numbers and increasing oxidative stress, which are thought to be regulated by its metabolisms. Compared with As or GO alone, GO combined with As inhibited the metabolism of carbohydrates, enhanced amino acid and secondary metabolism and disrupted fatty acid metabolism and the urea cycle. GO also triggered damage to cellular structures and electrolyte leakage and enhanced the uptake of GO and As. Co-transport of GO-loading As and transformation of As(V) to high-toxicity As(III) by GO were observed. The generation of dimethylarsinate, produced from the detoxification of inorganic As, was inhibited by GO in plants. GO also regulated phosphate transporter gene expression and arsenate reductase activity to influence the uptake and transformation of As, respectively. Moreover, the above effects of GO were concentration dependent. Given the widespread exposure to As in agriculture, the indirect nanotoxicity of GO should be carefully considered in food safety.
Li H.,Shandong University |
Liu J.,Shandong University |
Liang X.,Agro Environmental Protection Institute |
Hou W.,Shandong University |
Tao X.,Shandong University
Journal of Materials Chemistry A | Year: 2014
BiOBr lamellas were synthesized at different reaction pH values via a hydrothermal process. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy and N2 sorption measurements were used to characterize the BiOBr samples. BiOBr samples have the same lamella structures and band gaps but different lamella sizes and thicknesses. Adjusting the pH of the reaction system tunes the BiOBr lamella thickness from 42 to 21 nm. The photodegradation efficiencies of the BiOBr lamellas for rhodamine B (RhB) and methylene blue (MB) in aqueous solution were examined. The degradation efficiency for RhB is much higher than that for MB. The decrease in BiOBr lamella thickness significantly enhances the photocatalytic activity for dye degradation, despite the decrease in exposed photoactive (001) facet percentage. Decreasing the lamella thickness from 42 to 21 nm yields a more than fourfold enhancement in photodegradation efficiency of BiOBr samples for RhB. The most important factor influencing the photocatalytic activity of the BiOBr samples is their lamella thickness, rather than the exposed (001) facet percentage. Thus, even for flaky semiconductors with high exposed photoactive facet contents, the influence of lamella thickness on photocatalytic activity should be preferentially considered. This journal is © the Partner Organisations 2014.
Mu L.,Agro Environmental Protection Institute |
Gao Y.,Nankai University |
Hu X.,Nankai University
Biomaterials | Year: 2015
Graphene oxide (GO) has been employed in various fields, and its ecological and health risks have attracted much attention. A small and inexpensive biomolecule, l-cysteine, was covalently immobilized onto GO to form l-cysteine-GO (CysGO) as a thio-functionalized nanosheet of 1.4nm in thickness. Both the d-spacing and crystallinity of CysGO were observed to be lower than those of GO, whereas the D and G peaks remained similar to those of GO. CysGO exhibited remarkable uptake invivo: no tissue defects, malformation, death or significant hatching delay were observed in zebrafish embryos. Significant DNA damage, decreased Na+/K+-ATPase activity and decreased mitochondrial membrane potential were not observed for CysGO. As a nonspecific activity linked to nanotoxicology, the unpaired electron spinning intensity of CysGO was approximately two orders of magnitude lower than that of GO. Oxygen microsensor analysis showed that the hypoxic and normoxic environments resulting from the presence of GO and CysGO envelopment, respectively, contributed to the difference in biocompatibility. CysGO also protected embryos from arsenic poisoning. Thus, CysGO has the advantageous properties of GO, exhibits excellent biocompatibility, acts as a breathable coating and antidote, and is suitable for various applications. © 2015 Elsevier Ltd.
Feng R.W.,Agro Environmental Protection Institute |
Feng R.W.,Open Key Laboratory of Agro environment and Food Safety |
Wei C.Y.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research
Plant, Soil and Environment | Year: 2012
Selenium (Se) contamination due to industrial activities has received increasing concerns. Phytoremediation has been suggested to be an efficient and feasible way to remove Se from Se-contaminated environment. Recently, an arsenic (As) hyperaccumulator Pteris vittata L. (Chinese Brake fern) was found to be a Se accumulator. This study was carried out to investigate Se accumulation mechanisms concentrating on antioxidant responses of this plant to six levels of selenite (0, 1, 2, 5, 10, and 20 mg/L). The results showed that Chinese Brake fern can accumulate a large amount of Se without any visible toxic symptoms and significant decreases in its biomass. However, the root took up more Se than the fronds. The highest concentration of Se in the roots and fronds was 1.536 mg/kg and 242 mg/kg, respectively, demonstrating a typical accumulation character to Se. Addition of 2 mg/L Se decreased, but ≥ 5 mg/L Se enhanced the production of malondialdehyde (MDA), suggesting an antioxidant role of low dosages of Se. The enzymes of catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) contributed their anti-oxidative functions only under low dosages of Se, as shown by their increased activities at Se levels ≤ 5 mg/L and lowered activities at Se levels > 5 mg/L. The concentration of glutathione (GSH) and enzyme activity of glutathione reductase (GR) were stimulated by ≥ 5 mg/L Se. Superoxide dismutase (SOD) activity was also enhanced by 20 mg/L Se. Our results suggest that SOD, GSH and GR were likely responsible for, but enzymes of POD, APX, and CAT have limited roles in Se accumulation in Chinese Brake fern.
Feng R.,Agro Environmental Protection Institute |
Feng R.,Open Key Laboratory of Agro environment and Food Safety of Ministry of Agriculture |
Wei C.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research |
Tu S.,Huazhong Agricultural University
Environmental and Experimental Botany | Year: 2013
Selenium (Se), an essential element for animals and humans, has also been found to be beneficial to plants. In some countries around the world, such as China and Egypt, Se deficiency in the diet is a common problem. To counteract this problem, Se compounds have been used to increase the Se content in the edible parts of crops, through foliar sprays or base application of fertilizers. Se has also been shown to counteract various abiotic stresses induced in plants by cold, drought, high light, water, salinity and heavy metals (metalloids) (HMs), but the associated mechanisms are rather complicated and still remain to be fully elucidated. In this paper, we have focused on reviewing the effects of Se on HM-induced stress in plants, with an emphasis on the potential roles of Se compounds (e.g., selenite and selenate) in conferring tolerance against abiotic stresses. Numerous studies have implicated Se in the following mechanisms: the regulation of reactive oxygen species (ROS) and antioxidants, the inhibition of uptake and translocation of HM, changes in the speciation of HM and finally, rebuilding of the cell membrane and chloroplast structures and recovery of the photosynthetic system. In addition, two other mechanisms may be involved along with the established ones described above. Firstly, it may affect by regulating the uptake and redistribution of elements essential in the antioxidative systems or in maintaining the ion balance and structural integrity of the cell. Secondly, it may interfere with electron transport by affecting the assembly of the photosynthesis complexes. Future relevant studies should be increasingly focused on the changes in the cellular distribution of HM, the formation of Se-HM complexes, the substitution of S by the incorporation of Se into Se-Fe clusters and the relationships between Se, Fe, S and lipid peroxidation. © 2012 Elsevier B.V.
Zhi S.-L.,Agro Environmental Protection Institute |
Zhang K.-Q.,Agro Environmental Protection Institute
Desalination | Year: 2016
A novel electrochemical system was proposed to remove hardness species, which has synergistic effect of the conventional electrocoagulation (EC) and electrochemical precipitation (EP). The synergistic removal rate and the sum removal rate of two conventional methods were compared, and the difference value of the two removal rates was used to determine the optimum operating conditions. The results showed that the optimum synergistic effect was obtained when the current density of EC cell was 20A/m2, the current density of EP cell was 250A/m2, the consistent flow rate was 120ml/min, the pH value was 7.2, the water temperature was 60°C, the recycle time was 130min, and the initial hardness concentration lower was better. The order must be EC and then EP to have the synergistic effect after comparing the removal rates of different processes. The total cost of the novel system was divided into three parts: Al cost of 11.02%, power cost of 85.33% and DSA cost of 3.65% under the optimum conditions. Then the variations of power cost, Al cost and Dimensionally Stable Anodes (DSA) cost with current density, were analyzed to provide a reference for industrial operators. © 2015 Elsevier B.V.
Guo J.,Tianjin University |
Guo J.,Agro Environmental Protection Institute |
Chi J.,Tianjin University
Plant and Soil | Year: 2014
Background and aims: Plant growth-promoting rhizobacteria (PGPR) have been widely studied for agricultural applications. One aim of this study was to isolate cadmium (Cd)-tolerant bacteria from nodules of Glycine max (L.) Merr. grown in heavy metal-contaminated soil in southwest of China. The plant growth-promoting (PGP) traits and the effects of the isolate on plant growth and Cd uptake by legume and non-legume plants in Cd-polluted soil were investigated. Methods: Cd-tolerant bacteria were isolated by selective media. The isolates were identified by 16S rRNA gene and phylogenetic analysis. The PGR traits of the isolates were evaluated in vitro. Cd in soil and plant samples was determined by ICP-MS. Results: One of the most Cd-tolerant bacteria simultaneously exhibited several PGP traits. Inoculation with the PGPR strain had positive impacts on contents of photosynthesis pigments and mineral nutrients (Fe or Mg) in plant leaves. The shoot dry weights of Lolium multiflorum Lam. increased significantly compared to uninoculated control. Furthermore, inoculation with the PGPR strain increased the Cd concentrations in root of L. multiflorum Lam. and extractable Cd concentrations in the rhizosphere, while the Cd concentrations in root and shoot of G. max (L.) Merr. significantly decreased. Conclusions: This study indicates that inoculation with Cd-tolerant PGPR can alleviate Cd toxicity to the plants, increase Cd accumulation in L. multiflorum Lam. by enhancing Cd availability in soils and plant biomass, but decrease Cd accumulation in G. max (L.) Merr. by increasing Fe availability, thus highlighting new insight into the exploration of PGPR on Cd-contaminated soil. © 2013 Springer Science+Business Media Dordrecht.
Zhou D.,Wuhan University |
Chen L.,Hubei University |
Zhang C.,Agro Environmental Protection Institute |
Yu Y.,Hubei University |
And 2 more authors.
Water Research | Year: 2014
We previously reported the decolorization of the azo dye Acid Orange 7 (AO7) by sulfate radical (SO4-) in the presence of iron(II) sulfite complex and oxygen under UV-vis irradiation (photo-iron(II) sulfite system). This system, however, achieves very limited mineralization of AO7 (in terms of total organic carbon (TOC) removal), which is not in accordance with literature reports on the oxidation of organic contaminants by SO4 In the present work, kinetics and products under irradiation of xenon lamp (350W) were analyzed to reveal the reaction pathway of decolorization of AO7. Steady-state approximation (SSA) of SO4- radicals and apparent kinetics of AO7 were examined. The reaction between AO7 and SO4- was found to proceed in two steps, namely, electron transfer and SO4- addition. The second-order rate constant for the reaction between AO7 and SO4- was found to be 8.07±1.07×109M-1s-1 by SSA and 6.80±0.68×109M-1s-1 by competition kinetics method. The apparent kinetics of the decolorization of AO7 under irradiation closely fits the mechanism of radical chain reactions of various reactive sulfur species. By liquid chromatography coupled with mass spectrometry, we identified the sulfate adduct AO7-SO4 and confirmed the two-step reaction between AO7 and SO4 This stable sulfate adduct provides a good explanation of the poor TOC removal during decolorization of AO7 by the photo-iron(II) sulfite system. © 2014 Elsevier Ltd.