Biomedical subjects

Qixing Zhou

Publications and source records attributed to Qixing Zhou.

At least 37 records · Page 2Linked to original sources

PubMed2005

Effects of methamidophos and glyphosate on copper sorption-desorption behavior in soils.

A batch-equilibration technique was employed to study the impact of two organophosphorus pesticides methamidophos (MDP) and glyphosate (GPS) on copper (Cu2+) sorption-desorption for phaeozem and burozem collected from Northeastern China. The addition of the two pesticides decreased Cu2+ sorption, increased Cu2+ desorption and prolonged the equilibrium time of Cu2+ sorption-desorption. But GPS appeared to exert a stronger influence on Cu2+ sorption-desorption due to its stronger complexion with Cu2+. When MDP was added, Cu2+ sorption-desorption was linearly correlated with MDP treatment concentrations. But in the presence of GPS, Cu2+ sorption first underwent a rapid decrease period, and then slowly tended towards a steady period. The reverse pattern could be found for Cu2+ desorption in the presence of GPS. Without pesticides and with the existence of MDP, Cu2+ sorption-desorption kinetics was well conformed to two-constant equation and Elovich equation. But that was not the case for Cu2+ desorption kinetics in the presence of GPS although its sorption could be also described by these two equations.

Adsorption↗

PubMed2005

Single and joint toxicity of chlorimuron-ethyl, cadmium, and copper acting on wheat Triticum aestivum.

Investigation of the toxicological effects of some agricultural pollutants on germination rate and on shoot and root elongation of wheat (Triticum aestivum) was carried out. Seeds of wheat were exposed to various concentrations of chlorimuron-ethyl with or without cadmium and copper addition. The inhibitory rates of seed germination and shoot and root elongation of wheat were calculated. Significant linear relationships between the root and shoot elongation and the concentration of chlorimuron-ethyl with or without copper or cadmium addition were observed. The interactive effects of the three pollutants on seed germination were not significant (P > 0.05), but on shoot and root elongation they were markedly significant (P < 0.01). When concentrations of added Cd2+ or Cu2+ reached the concentration under which the inhibitory rate of wheat root elongation was about 20%, cadmium (or copper) and chlorimuron-ethyl had an antagonistic effect on the inhibition of shoot and root elongation, although the interactive effects of copper were not significant (P > 0.05). However, cadmium (or copper) and chlorimuron-ethyl had significantly synergic effects on the inhibition of shoot and root elongation (P < 0.05) when concentrations of added Cd2+ and Cu2+ reached the concentrations under which the inhibitory rate of root elongation was about 70%. At the high concentration of added cadmium or copper, joint toxicity of chlorimuron-ethyl and the heavy metals was more dependent on the concentrations of the latter. The sensitivity of wheat to the toxicity of the three pollutants was in the following sequence: root elongation>shoot elongation>germination rate.

Cadmium↗

PubMed2005

Joint chemical flushing of soils contaminated with petroleum hydrocarbons.

How to increase the efficiency of chemical flushing and decrease the remediation expenses of contaminated soils are two key scientific and technological issues to be solved. Joint chemical flushing was tested and compared with the water-flushing. The joint acid-flushing could effectively remove petroleum hydrocarbons in contaminated aquorizem and the dosage of washing powder as a flushing agent was greatly reduced, thereby, saving approximately 1200 US dollars of expenses relative to the water-flushing. The joint salt-flushing could be an optimal method for the cleanup of meadow burozem contaminated with petroleum hydrocarbons under the experimental conditions. Moreover, the amount of surfactant remained in the two washed soils after the joint acid-flushing and the joint-salt-flushing was minimal.

Acetates↗

PubMed2005

Identification of weed plants excluding the uptake of heavy metals.

Using the field pot-culture and sample-analysis method, 54 weed species belonging to 20 families and 31 weed species belonging to 17 families were systematically examined as to whether they can exclude the uptake of heavy metals. After a systematic identification, it was determined that Oenothera biennis and Commelina communis were Cd-excluders and Taraxacum mongolicum was a Zn-excluder. O. biennis is a potential Cd-excluder, but also a potential Cu-excluder. The research raises the possibility of making a major breakthrough in the application of metal excluders for safe agro-production in the future.

Cadmium↗

PubMed2005

[Research advance on environmental exposure and ecotoxicological effects of polybrominated diphenyl ethers (PBDEs)].

Polybrominated diphenyl ethers (PBDEs) are a group of new type organic pollutants with significant ecological risk. As flame retardants, they have been increasingly added to industrial products, and thus, resulted in more and more extensive pollution of air, water, sediment and soil as well as their relevant ecosystems. In view of the new environmental problem and based on limited available data, this paper approached the anthropogenic sources of PBDEs and their pathways of environmental exposure, and gave the possible occurrence and concentration of PBDEs in several living organisms and different human tissues. The toxic effects and ecological influences of PBDEs acting on animals and human beings, and their potential biological accumulation and magnification in ecosystems were analyzed in the aspects of hypothyroid, neurotoxicity, and reproductive and developmental toxicity, and the pivots of further researches on environmental exposure, ecological effects and human health influences of PBDEs were thus suggested.

Environmental Exposure↗

PubMed2005

[Eco-toxicity diagnosis on sediments of petroleum wastewater irrigation channel].

Sediment samples were collected from several sites in the upper, mid and lower reaches of the petroleum wastewater irrigation channel in eastern Shenyang of China, and the concentrations of their Cu, Zn, Pb, Cd and mineral oil were analyzed. The results showed that the pollutants were accumulated in all of sediment samples, with 408-118,300 mg x kg(-1) mineral oil, 17.83-78.53 mg x kg(-1) Cu, 35.76-155.16 mg x kg(-1) Zn, 8.50-31.03 mg x kg(-1) Pb and 0.1-1.0 mg x kg(-1) Cd. The sediments showed an inhibition or stimulation effect on plant root elongation and a lethal and sub-lethal effect on earthworm. The inhibition rate of root elongation based on germination test was -29.81 to 93.8%. During 14 d exposure, the maximum mortality rate of earworm was 100%, and during 14d and 28d exposure, the inhibition rate of its body weight growth was -36.6%-(-)6.08% and -40.4%-6.1%, respectively. The study indicated that a long-term irrigation with petroleum wastewater resulted in the accumulation of pollutants in channel sediments and enhanced eco-toxicity.

Crops, Agricultural↗

PubMed2005

[Ecological effects of land-use changes in a small town of Zhejiang Province, China].

By the methods of systematic ecology, and that of Simpson's biodiversity indices in particular, this paper quantitatively analyzed the ecological effects of ten years land use changes in a small town with rapid rural urbanization of Shaoxing County, Zhejiang Province, aimed to provide a scientific basis for healthy development of towns and small cities in China. The results showed that owing to the changes of land use functions, the biodiversity of green plants and soil microorganisms was obviously decreased, and the local climate conditions deteriorated, which was represented by the increase of annual mean air temperature and the decrease of annual mean relative humidity in this town. It was suggested that the long-term ecological changes in biodiversity should be considered in land use with rural urbanization.

Biodiversity↗

PubMed2005

[Pollution-ecological problems of old industrial and mining areas and future research prospects].

Environmental pollution and its solicitation in ecological problems of old industrial and mining areas have become a worldwide technological puzzle restricting sustainable economic and social development. But, the definition and category of old industrial and mining areas is still disputed as an important concept. In this paper, the concept of old industrial and mining area was discussed in theory, and, proceeded with analyzing the complexity of current situation and environmental pollution problems of old industrial and mining areas in China, more keystone attention was paid to the secondary pollution problems from old industrial and mining areas as an important frontier of science. On the basis of expounding the complexity and characters of environmental pollution in old industrial and mining areas, it was suggested that as two key scientific problems in environmental sciences and ecology, the formation mechanisms and control technology of secondary pollution in old industrial and mining areas and the responses of new-type diseases to environmental pollution based on molecular ecotoxicology should be systematically studied on the national scale, and be an important component of environmental protection strategy in China in the future.

China↗

PubMed2005

[Research advances on eco-chemical behaviors and toxicological effects of cadmium in root-soil interface].

Many active substances such as organic acids and enzymes excreted by living plant roots could induce a great difference of Eh and pH values between root-soil interface and non-rhizosphere soil, forming a special root-soil interface miniature environment. As a mini-type ecological area with most frequent exchanges of substances, root-soil interface plays a crucial role in their absorption, transformation, migration and eco-toxicological effects. In this paper, the eco-chemical behaviors of Cd in root-soil interface affected by the change of pH, Eh and root secretion, and its eco-toxicological effects on microorganisms and enzymes in root-soil interface were reviewed, based on the related research advances in recent decade. The shortages in relevant fields were pointed out, and the scientific problems to be researched in the future were suggested.

Cadmium↗

PubMed2005

[Advances in research and application of water-treatment flocculants].

Water-treatment flocculants are being developed from traditional to inorganic, from inorganic to organic, from natural organic to synthetic organic, from synthetic organic to modified natural organic, from inorganic or organic to inorganic-organic, and from chemical to biological with ecological safety. In order to promote the rapid development and practical application of water-treatment flocculants, the research progress and application situation of flocculants for water treatment at home and abroad were reviewed. In particular, the characteristics of two important flocculant types, chemical and microbiological flocculants, as well as their application processes in water treatment were summarized, their development orientations were analyzed and evaluated, and the future research directions aimed to overcome the current shortages in developing and applying flocculants in China were put forward.

Ecosystem↗

PubMed2005

[Degradation-detoxification behavior of methamidophos in phaiozem and burozem rhizosphere].

With plastic rhizobox system, this paper studied the degradation behavior of methamidophos in the rhizosphere and non-rhizosphere of phaiozem and burozem planted with soybean. The results suggested that methamidophos could be rapidly decomposed in soil environment despite its higher acute toxicity, and its residual amount in phaiozem was generally below the level in burozem under same condition. In the absence of soybean (control), the residual amount of methamidophos at the 2nd day of incubation was about 33% in burozem, whereas only about 26% in phaiozem. An accelerated degradation of methamidophos in soybean rhizospheric soil was observed, especially in phaiozem. At the 9th day of incubation, the insecticide residue in the middle rhizobox phaiozem and burozem with soybean was decreased by 87.5% and 76.0%, respectively, compared with that of the control. The degradation process of methamidophos in soil environment followed the first-order equation, and its half-life was about 2 days.

Biodegradation, Environmental↗

PubMed2005

[Ecological toxicity of aluminum-based coagulant on representative corps in neutral environment].

By the terrestrial ecotoxicological methods of seed germination and root elongation, and with aluminum-based coagulant AlCl3 which was widely used in wastewater- and water treatment as an example, this work studied the toxicological effects of aluminum-based coagulants on representative crops, including radish Raphanus sativus, cabbage Brassica chinensis and wheat Triticum aestivum, over a range of exposure concentrations under the neutral condition (pH= 7.0), with contrast to an acid condition (pH= 4.00). The results indicated that there was a significantly positive correlation between the concentration of AlCl3 and the inhibitory rate of root elongation and seed germination either under pH 7.0 or 4.0 (P < 0.01). Cabbage and wheat was more susceptive to AlCl3 toxicity under acid than under neutral condition, while radish was in adverse. The minimum inhibitory concentration of AlCl3 (< 2.0 mg x L(-1)) was lower under neutral than under acid condition.

Aluminum Chloride↗

PubMed2005

[Adsorption behavior of cadmium in phaeozem and burozem].

The study on the thermodynamics and kinetics of Cd2+ adsorption in phaeozem and burozem showed that within the test range, Cd2+ adsorption was increased with its increasing initial concentration, and phaeozem had a much higher Cd2+ adsorption capacity than burozem. When the Cd2+ concentration in adsorption equilibrium was 20 mg x kg(-1), the amount of adsorbed Cd2+ was 1 485.2 mg x kg(-1) in phaeozem, but 700.6 mg x kg(-1) in burozem. The adsorption isotherm of Cd2+ in the two soils could significantly conform to Langmuir, Freundlich and Henry equations, while Temkin equation was not applicable to describe the isothermal adsorption process of Cd2+ in phaeozem and burozem. The maximum adsorption of Cd2+ in phaeozem and burozem was 5939.3 and 2 790 mg x kg(-1), respectively, according to Langmuir formulation. The Cd2+ adsorption in test soils was a rapid reaction, with 90% of Cd2+ adsorption in the first 2 min and reached equilibrium in 15-30 min. First-order dynamic equation was the optimal model to describe the kinetics of Cd2+ adsorption, while the other models in point were Elovich and Two-constant equations. The adsorption rate of Cd2+ in test soils was increased with its increasing initial concentration, but decreased with its increasing adsorbed amount. Under low concentrations of Cd2+, the decrease of its adsorption rate with time was more quickly in phaeozem than in burozem.

Adsorption↗

PubMed2004

Quantitative analyses of relationships between ecotoxicological effects and combined pollution.

The responses of wheat Triticum aestivum, rice Oryza sativa, earthworms Eisenia foetida, and prawns Penaeus japonicus to combined acetochlor-Cu, Cd-Zn were studied in hydroponic and soil-culturing systems using the methods of ecotoxicology. In particular, systematically quantitative analyses were documented by field experiments. Results showed that ecotoxicological effects under the combined pollution were not only related to chemical properties of pollutants but also dependent on the concentration level of pollutants, in particular on the combination of concentrations of pollutants in ecosystems. Additionally, species of organisms, especially the type of ecosystem, determined the influences. To some extent, biological tissue targets attacked by pollutants were an important factor.

Animals↗

PubMed2004

[Methodology of enacting standards for remediation of contaminated soils].

Remediation technology for contaminated soils is being developed rapidly in recent years. However, there is a hysteresis in enacting remediation standards for contaminated soils. In particular, no corresponding research has been done in China. Methodology of enacting standards for the remediation of contaminated soils is discussed in order to promote the work in this field. It is emphasized that technological cleanup levels including limits of detection, environmental background levels and regulatory cleanup levels should be fully considered in the enactment of remediation standards.

Biodegradation, Environmental↗

PubMed2004

[Revulsive response of protein and enzyme activity of degradative Bacilluss strains by phenanthrene].

Three strains of Bacillus sp. BAll, BA19 and BA27, which can grow when phenanthrene is taken as the sole source of carbon and energy, were isolated from an oil-contaminated soil. Their crude extract was used to test the activities of polyphenol oxidase and catalase. The results demonstrated that all the three strains did not show a significant change in the activity of both enzymes when phenanthrene was lower than 200 mg x L(-1). Under different phenanthrene concentration, the enzyme activities of strains BA19, BA27 showed a higher stabilization than BA11. Using the SDS-PAGE contrasted the difference of proteins between the strains in normal medium and the strains growing on phenanthrene, the results showed that BA27 growing on phenanthrene synthesized a new protein with 27000 dal of molecular weight. At the same time, the synthesis of some proteins was cancelled. We conjecture that the new protein induced by phenanthrene may be related to the ability of phenanthrene degradation and the stabilization of enzyme activity by the strain.

Bacillus↗

PubMed2004

[Designing cruxes and ecological issues of constructed wetland systems for wastewater treatment].

Constructed wetland system for wastewater treatment is an important technological mode of economical and high-effective ecological treatment of wastewater, but it is still necessary to develop and perfect in its performance, and in particular, to make a continuous improvement and systematic optimization in its technical parameters. In this paper, the designing cruxes of constructed wetland systems for wastewater treatment at home and abroad were summarily discussed, and the optimal models and most adaptable values for constructed wetland systems were given on the basis of technological parameters such as hydraulic residence time, hydraulic conduction factors, surface loading rate, and engineering-construct design. In the meantime, some ecological methods were recommended to solve the management of wild animals and mosquito problems resulted from the operation of constructed wetland systems for wastewater treatment.

Ecosystem↗

PubMed2004

[Wastewater treatment efficiency of combined aluminum-starch flocculant].

This paper examined the efficiency of a combined flocculants synthesized by aluminum and starch (noted as CAS) in treating kaolin suspension, domestic wastewater, municipal effluent and pulp-making wastewater. Jar test results showed that the flocculent performance of CAS was prior to polyaluminum-chloride (PAC) in treating different concentration kaolin suspension samples (100, 400 and 2000 mg x L(-1)). The optimal dose of CAS to each sample was 3.0, 2.0 and 2.0 mg x L(-1), being 60%, 50% and 50% of PAC, respectively. CAS also showed a priority to PAC in removing the COD and turbidity of domestic and municipal effluents. When treating pulp-making wastewater, the optimal dose of CAS was 70% of PAC. The removal rate of COD was enhanced 10%, the sludge was reduced 40%, and the sediment time was greatly shortened. It was also identified that the optimal concentration required to affect flocculation depended on the concentration and the character of the wastewater within the range examined. CAS was more effective in treating high turbidity wastewater.

Aluminum↗