[Distribution of Micro-plastics in the Soil Covered by Different Vegetation in Yellow River Delta Wetland].

Micro-plastics (MPs) pollution has been a hotspot in soil environment. To explore the correlation of the vegetation cover and the distribution of MPs in Yellow River Delta wetland, the characters of MPs in the soil sampled at 16 sites where reed (Phragmites communis, a low-salt dominant species) and Suaeda salsa (a high-salt dominant species) covered were investigated. The abundance of MPs here ranged to 80-4640 n·kg-1, and the particle size ranged to 13 µm-5 mm. The main components of MPs with large size were polyethylene (PE), polyethylene terephthalate (PET) and polystyrene (PS), and the content of PET ranged to 0.22-1.16 µg·kg-1. The barrier effect of reed on MPs was higher than that of Suaeda salsa. The average abundance of MPs and PET contents at the sites where reed covered were 1423 n·kg-1 and 0.62 µg·kg-1, and they mainly consisted of small particles with a size less than 50 µm. The average abundance of MPs and PET contents at the site Suaeda salsa covered were 584 n·kg-1 and 0.33 µg·kg-1, and they mainly consisted of fragments and fibers with a size ranged to 100-1000 µm. The abundance of MPs in the soil was significantly correlated with the growth statues of the vegetations (P=0.001). Therefore, the distribution of MPs in the soil in the same area covered by different vegetation might be spatial different.

[Changes of Microbial Community Structure in Activated Sludge Bulking at Low Temperature].

The mechanism of activated sludge bulking in Zhengzhou wastewater treatment plant was studied by measurement of water quality parameters and high-throughput sequencing technology. The change of SVI value was significantly negatively correlated with the seasonal temperature variation, and sludge bulking was easy to occur during December to the next April, but the water quality was not affected. The result verified by high-throughput sequencing technology analysis showed that the microbial community structure of bulking sludge was significantly different from that of the non-bulking one. The dominant filamentous bacteria in the bulking sludge in this plant were Saprospiraceae and Flavobacterium. Therefore, the activated sludge bulking in this wastewater treatment plant was caused by the propagation of filamentous bacteria at low temperature.

[Application of zebrafish microarray on the toxicity mechanism study of bisphenol A].

The toxicity mechanism of bisphenol A (BPA) to zebrafish (Danio rerio) was studied in the molecular level,by the method of zebrafish microarray and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Zebrafish embryos were exposed to 0.5, 1.5 and 4.5 mg/L BPA for 8 days since fertilization. The results from microarray and validated by qRT-PCR showed that, 50 specific genes were up-or down-regulated, and dose-responses for them were significant (p < 0.05). This study demonstrates the genotoxicity of BPA. Moreover,according to their function and pathway analysis,it could support the mechanisms for the morphological toxicity and metabolize turbulence observed in prophase study.

[Bioaccumulation and toxicity test of diethylstilbestrol to zebrafish (Danio rerio) embryo].

The bioaccumulation regulation and the toxicity of diethylstilbestrol (DES) were studied on zebrafish (Danio rerio) embryos with the methods of HPLC and early life stage test, and the toxic mechanisms were also discussed with the techniques of quantitative structure-activity relationship (QSAR) and gene chips. After the zebrafish embryos exposed at 0.2 mg x L(-1) DES for 24, 48 and 72 h, the body levels of DES in zebrafish embryo were (25.78 +/- 4.95), (54.88 +/- 7.10) and (71.93 +/- 10.55) microg/g, respectively. Even exposure started at different time (0 hpf and 8 hpf), the most sensitive sub lethal endpoints were both 72 h delayed hatch, and the EC50 values for them were (0.14 +/- 0.09) and (0.33 +/- 0.14) mg/L, so that zebrafish embryo was more sensitive to the exposure of DES before the stage of gastrula (8 h after fertilization). QSAR studies found when compared with other phenol-endocrine disrupts, DES was much more toxic, and this related to its higher TE value (52.1217 eV). Meanwhile, when adult zebrafish exposed at 5 microg/L DES for 21 d, it was found by the gene chips that parts of gene expressions would be changed and the genetic toxicity of DES was approved. DES was concluded to be developmental and genetic toxic to zebrafish, and the biochemical reaction-associated process might be the key parameter in determining the toxicity level.

[Oxidative damages of long-term exposure to low level fullerenes (C60) in Carassius auratus].

To determine the potential effects of fullerenes (C60) on aquatic organism, larval Carassius auratus was exposed to low level C60 (0.04-1.0 mg x L(-1)) for 32 days. Then the oxidative damages in brain, liver and gill tissue of larval Carassius auratus were measured. The results showed that: compared to the control, the reduced glutathione (GSH) contents in all different tissues decreased significantly (p < 0.05), and the most serious inhibition of GSH with a 14.3% inhibition rate was found in the gill tissue of larval crucian exposed to 1 mg x L(-1) C60 aqueous suspension; whereas the superoxide dismutase (SOD) and catalase (CAT) activities in liver tissue, Na+ -K+ -ATPase activities in gill tissue were stimulated significantly (p < 0.05), and the maximal activity of them were 121.34% (exposed to 0.04 mg x L(-1) C60 aqueous suspension), 114.80% (exposed to 0.04 mg x L(-1) C60 aqueous suspension) and 348.59% (exposed to 0.20 mg x L(-1) C60 aqueous suspension) respectively than that of control. The experiment results indicated that oxidative damages induced by long-term exposure might play a role in the bio-toxicity of C60 to larval crucian.