Qiu-jin Xu

Chinese Research Academy of Environmental Sciences, Peping, Beijing, China

Are you Qiu-jin Xu?

Claim your profile

Publications (9)9.45 Total impact

  • Bei-Dou Xi, Ya-Li Zhang, Qiu-Jin Xu
    [Show abstract] [Hide abstract]
    ABSTRACT: The temporal changes of total dissolved solid concentrations were analyzed according to the investigations and regular monitoring data in the Inner Mongolia-Xinjiang plateau. The result showed that the salinization process in the Inner Mongolia-Xinjiang plateau became strong. Integrated regression equation indicated that, the environmental physical and chemical factors affecting chlorophyll-a were total phosphorus and TDS. The relationship between the nutrient and biological variables was analyzed in typical examples in the Inner Mongolia-Xinjiang plateau. The results showed that, dissolved oxygen, pH, total nitrogen, chlorophyll-a, transparency were significant factors that affected TDS of the Inner Mongolia-Xinjiang plateau. It presented a significantly negative relationship (P<0.01) between dissolved oxygen, pH and TDS, whereas it presented a significantly positive relationship (P<0.01) between total nitrogen, chlorophyll-a, and TDS, and a positive relationship (P<0.05) between transparency and TDS was observed. The linear relationship between TDS, eutrophication response variables (i. e., chlorophyll-a and transparency) and reasonable variables (i. e., total phosphorus and total nitrogen) was investigated as well in this paper. The result suggested that TDS should be classified into the nutrient criteria of the Inner Mongolia-Xinjiang plateau, which provides a theoretical basis to determine the candidate variables and indicator for lake nutrient criteria in the Inner Mongolia-Xinjiang plateau.
    Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.] 10/2012; 33(10):3308-13.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In order to clarify the distribution characteristics and risk levels of heavy metals in typical drinking water sources of towns in Dongjiang River Basin, several regular water quality indexes as well as concentrations of Fe, Cu, Mn, Zn, As, Cr, Hg, Pb and Cd were analyzed in the 45 random water samples of 9 towns in the study area. The risk assessment was conducted according to different drinking water types using the environmental health risk assessment model recommended by U. S. EPA. The results indicated that the metal carcinogenic risk is relatively high in this area. The highest carcinogenic risk was from Cr in reservoir water, with the risk for adult people reaching 1.14 x 10(-4) x(-1) and the risk of children reaching 2.14 x 10(-4) x a(-1). Total carcinogenic risk of reservoir, river and underground water exceeded the accepted level of 5.0 x 10(5) x a(-1) as suggested by ICRP while all the non-carcinogenic risk levels were within the acceptable range. The primary control sequence of metal pollution in this area was Cr > As > Pb > Fe > Zn; the risk value of different drinking water sources descended in this order: reservoir > river > underground water > mountain spring.
    Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.] 09/2012; 33(9):3083-8.
  • [Show abstract] [Hide abstract]
    ABSTRACT: To explore a method for rapid restoration and artificial regulation of submerged macrophytes in large-scale restoration of eutrophic lakes, the succession and the biodiversity changes of four communities composed of four native, common submerged macrophytes, Hydrilla verticillata, Potamogeton malaianus, Vallisneria spiralis and Najas marina, on two kinds of sediments were investigated. Under low light intensity (reduced by 99%), the plant biomass changed with seasonal changes, plant competition, and environmental stress. The competitive capability for light differed in the four species due to different shoot height and tiller number. After 405 days of transplantation, H. verticillata became dominant in all communities. The biomass of H. verticillata, with strong ability to endure low water light environment, accounted for more than 90% of the total community biomass, and P. malaianus had only weak growth, while V. spiralis and N. marina almost disappeared. Based on livability and biomass of submerged macrophytes on two sediment types, brown clay sediment appeared to be more favorable for the settlement of the plants, while fertile sludge sediment was suitable for vegetative growth. In conclusion, the improvement of habitats and the selection of appropriate plant species are of the greatest importance for ecological restoration of the aquatic ecosystem.
    Ecological Engineering 11/2009; 35(11-35):1656-1663. DOI:10.1016/j.ecoleng.2008.05.008 · 3.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, submersed plant Hydrilla verticillata was cultivated in a 1/10 Hoagland culture medium added with different concentration NH4 + -N (0, 0. 5, 2. 0, 4. 0 mg x L(-1)) and 10 mg x L(-1) cadmium to study the effects of NH4 + -N on H. verticillata growth and its antioxidant enzyme system under Cd stress, and approach the degradation mechanism of submersed macrophyte in eutrophic and polluted water bodies. The results showed that under 10 mg x L(-1) Cd stress, the chlorophyll content of H. verticillata decreased obviously, and SOD and POD activities increased first but declined then. NH4 + -N accelerated the stress effect of Cd. Under 0. 5 h joint stress of Cd and NH4 + -N, SOD activity increased significantly, while such an increase needed 3 hours under single Cd stress. Relative to chlorophyll and protein, antioxidant enzyme system was an early sensitive index, and SOD was more sensitive than POD. After two days exposure to Cd plus NH4 -N, H. verticillata was mainly stressed by Cd, and NH4+ -N stress could be neglected.
    Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban 03/2007; 18(2):420-4.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. verticillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.
    Journal of Environmental Sciences 02/2007; 19(2):217-21. DOI:10.1016/S1001-0742(07)60035-7 · 1.92 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Combined pollution is more ubiquitous than the single pollution in water and soil environment. Iodine method was used to study the effects of both single and combined pollution of Cd and NH4+ on Hydrilla verticillata and Myriophyllurn spicatum. Results came out that H. verticillata was distinctly stressed at 4.0 mg x L(-1) concentration of NHI4+, oxygen production of photosynthesis and oxygen depletion of respiration all declined, but for M. spicatum ,it was not be stressed. If treated with 0.2 mg x L(-1) Cd, H. verticillata and M. spicatum all were stressed, and H. verticillata was stressed more seriously. Combined pollution of Cd and NH4+ produced cooperative adverse effects on H. verticillata. But for M. spicatum, the stress was less severe comparatively. The main reason was that M. spicatum made of less crude cellulose. So it had less combined pathway with heavy mental than H. wvrticillata. It demonstrated that M. spicatum is suit for pioneer plant comparatively during the process of lake restoration.
    Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.] 11/2006; 27(10):1974-8.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Equilibrium sorption isotherms for Cu2+ onto Hydrilla verticillata Royle and Myriophyllum spicatum were studied. Both methods of linear and non-linear fitting were applied to describe the sorption isotherms, and their applicability were analyzed and compared. The results were: (1) The applicability of simulated equation can't be compared only by R2 and chi2 when equilibrium sorption model was used to quantify and contrast the performance of different biosorbents. Both methods of linear and non-linear fitting can be applied in different fitting equations to describe the equilibrium sorption isotherms respectively in order to obtain the actual and credible fitting results, and the fitting equation best accorded with experimental data can be selected; (2) In this experiment, the Langmuir model is more suitable to describe the sorption isotherm of Cu2+ biosorption by H. verticillata and M. spicatum, and there is greater difference between the experimental data and the calculated value of Freundlich model, especially for the linear form of Freundlich model; (3) The content of crude cellulose in dry matter is one of the main factor affecting the biosorption capacity of a submerged aquatic plant, and -OH and -CONH2 groups of polysaccharides on cell wall maybe are active center of biosorption; (4) According to the coefficients qm of the linear form of Langmuir model, the maximum sorption capacity of Cu2+ was found to be 21.55 mg/g and 10.80mg/g for H. verticillata and M. spicatum, respectively. The maximum specific surface area for H. verticillata for binding Cu2+ was 3.23m2/g, and it was 1.62m2/g for M. spicatum.
    Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.] 07/2006; 27(6):1068-72.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In recent years cyanobacteria blooms have become a severe problem in Taihu Lake, a large shallow eutrophic lake in China. Microcystins produced by certain genera of cyanobacteria can affect public health in this area because of their acute and chronic toxic effects. In this study, samples of cyanobacteria were collected and extracted by two solvent systems. The extracts were tested with three short-term genotoxicity assays, the ara test, the Ames test, and the SOS/umu test. In addition, temporal variation in the concentrations of microcystin-LR in the water samples was determined and monitored by an ELISA assay. Then the concentration of microcystin-LR in the drinking water was estimated. The risk of microcystin-LR exposure by drinking water was assessed according to tolerable daily intake (TDI). The three genotoxicity assays showed negative results regardless of the solvent system used, and there were clear inconsistencies in the spatiotemporal profiles of genotoxic potential and microcystin concentrations in Taihu Lake. Risk assessment showed that the drinking water from Taihu Lake was not safe from the end of July to the beginning of November because of a high concentration of microcystin-LR. Our study indicated the drinking water from Taihu Lake posed a risk because of the microcystin-LR, although it was neither genotoxic nor associated with genotoxicity of the lake water.
    Environmental Toxicology 06/2006; 21(3):250-5. DOI:10.1002/tox.20178 · 2.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The potential use of Myriophyllum spicatum L. biomass as a biosorbent for the removal of copper(II) from aqueous solution was investigated in laboratory condition. The sorption experiments were undertaken to obtain copper(II) biosorption properties of M. spicatum L., i.e. equilibrium time, the maximum capacity, and rate constants. Copper(II) biosorption was fast and equilibrium was attained within 35 min at initial copper(II) concentration of 6 mg/L. Different isotherm models including the Langmuir, Freundlich, Temkin and Redlich-Peterson model, were used to investigate the sorption capacity and isotherm. These models showed an excellent match with the experimental data except for the Freundlich model. According to the Langmuir coefficients, the maximum sorption capacity of copper onto M. spicatum L. was 10.80 mg/g. The kinetics of copper(II) sorption was also analysed and rate constants were derived. It was found that the overall sorption process was best described by the pseudo second-order equation, and that intraparticle diffusion was not the rate determining step. The results of this study showed that M. spicatum L. can be considered as useful vehicles for the removal and recovery of copper(II) from aqueous solutions.
    Journal of Environmental Sciences 02/2005; 17(6):1025-9. · 1.92 Impact Factor