[Driving Factors Analyze of Phytoplankton Community by Comparison of Population and Functional Groups and Water Quality Evaluation in Dongting Lake].

Phytoplankton is the most important component of water ecosystems, which could indicate the state of the water environment owing to its sensitivity to water environment variation. However, its response to the environment is influenced by classification methods. To understand the phytoplankton population(phyla and genera) and functional groups(FG) for driving response characteristics and applicability to the environment in Dongting Lake, a total of four samples were collected from the lake from March to December 2019, and the distribution characteristics of the phytoplankton population and functional groups and their responses to environmental factors were compared and analyzed.

Coagulation-flocculation: a potential application for mosquito Larval Source Management (LSM).

Larval mosquitoes have a more limited home range and lower resistance to adverse environment than adults, thus can be ideal targets for vector control in some cases. Coagulation-flocculation technology, which could be used for water treatment in breeding sites of several vector mosquito species, can significantly change both the distribution of organic particles and surface sediment characteristics in water environment. The aim of this study was to explore the effect, principle and possibility of using coagulation-flocculation technology in immature mosquitoes killing.

[Research on Remediation of Heavy Metals in Sediment with Lotus and Water Lily].

The aquatic landscape plants lotus and water lily were selected to repair the heavy metal in black odorous river sediments. With ICP-AES inductively coupled full spectrum of direct reading plasma emission spectrometry, the total and forms of content of heavy metals Cd, Cr, Cu, Ni, Pb in sediment and plants, the distribution of heavy metals in plants to were determined .The results showed that the average removal rate of the lotus in terms of the removal of heavy metals in the sediments was 20.

[Optical signatures of chromophoric dissolved organic matter in water body of Tien Lake].

The water samples of the Tien Lake were collected for the three-dimensional fluorescence spectrum detected. And parallel factor analysis (PARAFAC) and principal component analysis (PCA) were used for the spectra analyzing to know the main factor and relative contribution of the chromophoric dissolved organic matter (CDOM). PARAFAC decomposed CDOM into four components, the humic-like: C1 (240, 415), C3 (265, 525), C4 (255, 505) and the protein-like: C2(230/280, 330).

Toxicity bioassays for water from black-odor rivers in Wenzhou, China.

Following urbanization, a large number of urban rivers were contaminated and turned to black-odor rivers. The traditional approach for detecting water quality is based on chemical or physical analysis. However, biological toxicity of black-odor water has been less addressed.

Molecular phylogenetic analysis of dominant microbial populations in aged refuse.

The phylogenetic analysis of dominant microbial populations in 8-year-old refuse samples was done in terms of the whole Bacterial and Archaeal domains. The results indicated that the Bacterial 16S rRNA genes sequences from the aged refuse were largely affiliated with the genus Bacillus, and that more than 60 % of the Archaeal sequences were closely related to the methanogenic archaeon. Some inferentially identified extremophilic organisms, particularly alkaliphiles and/or halophiles, were noted to be present in the aged refuse.

Seasonal variations and aeration effects on water quality improvements and physiological responses of Nymphaea tetragona Georgi.

Seasonal variations and aeration effects on water quality improvements and the physiological responses of Nymphaea tetragona Georgi were investigated with mesocosm experiments. Plants were hydroponically cultivated in six purifying tanks (aerated, non-aerated) and the characteristics of the plants were measured. Water quality improvements in purifying tanks were evaluated by comparing to the control tanks.

[Spatial distribution and contamination assessments of heavy metals in sediments of Wenzhou River network].

In order to investigate the spatial distribution pattern and degree of heavy metal pollution in river network sediments of Wenzhou, 29 sediment samples were collected, and using atomic fluorescence spectrometry (AFS) and inductively coupled plasma-optical emission spectrometry (ICP-OES) heavy metal concentration in the samples were analyzed. The Kriging interpolation map reflected the spatial distribution of heavy metal. Comprehensive geo-accumulation index based on the Nemerow index method was established to assess the pollution degree.

[Influence of disturbance intensity on nitrogen, phosphorus and permanganate index release of Potamogeton crispus during soaking in water].

Influence of various disturbance intensities on nitrogen, phosphorus and permanganate index (PI) release of Potamogeton crispus were investigated during the plant soaking in water, and the plant materials were collected in an urban lake of Beijing. Results showed that more rapid release of TP and PI from Potamogeton crispus were caused by disturbance, NH4(+) -N and TN in water were significantly increased (ANOVA, p < 0.05) under the condition of high disturbance (120 r/min) for 240 h.

[Exploration of relationships between phytoplankton and related environmental factors in the Daning River during sensitive period of algal blooms].

To elucidate relationships between phytoplankton and related environmental factors, phytoplankton and environmental parameters of water quality in the Daning River were conducted using multivariate statistical analysis. Most of the investigated physico chemical parameters [water temperature, total nitrogen, nitrate-N (NO3(-) -N), pH and dissolved oxygen concentration (DO)] in Daning River are significantly different among those sampling sites (ANOVA, p < 0.05).

[Diurnal variations in purifying-tanks when use Pontederia cordata treating the Malodorous River water].

Aquatic plants (Ponsederie cordaza) were waked in two purifying-tanks to investigate the effects of illumination intensity and aeration on diurnal variations of Chla, SP, POD of Ponsederia cordaza and pH, DO, COD, NH4+ -N, TP of water from purifying-tanks when treating the malodorous river water at seven different times, another blank purifying-tank was set as a control. Comparative studies and correlation analysis of these different indicators were carried out to improve the plants working efficiency and provide scientific basis for optimal operation of plant purifying-tanks. Results showed that all indicators affected by changes of light, TP shows best correlation coefficient Cr = 0.

[Systematic investigation into winter and spring algal blooms in Daning River of Three Gorges Reservoir].

According to the survey conducted from winter and spring algal blooms, the changes of water quality and characteristics of Daning River of Three Gorges Reservoir (TGR) were studied. The results suggested that during the period of winter algal blooms centered on Tangjia bay in Daning river, chlorophyll a (Chl-a) had a wide range (the rates of (Chl-a)max and (Chl-a)min is 260). The contents of total nitrogen (TN), total phosphorus (TP) and potassium permanganate index were at very high levels because of bioaccumulation from algal blooms, but the values of dissolved oxygen (DO) and pH were very low.

[Analysis of algal blooms in Da-Ning River of Three Gorges Reservoir].

According to the survey conducted from Apr. to Jun. 2007 and from Apr.

[TTC-ETS activity monitoring of A2/O process for combined sewage treatment].

The influences of variations of temperature and F/M on the TTC-ETS activity have been experimentally studied. The correlation between TTC-ETS activity and COD degradation was also analyzed. Comparing TTC-ETS activities with physical and chemical indexes when high C/N ratio impacted A2/O process, the advantages and disadvantages of using TTC-ETS activity to characterize the status of A2/O process were illustrated.

[Relation analysis of phosphorus removal and BOD5 loading using PHB monitoring in A2/O process].

In a pilot-scale anaerobic-anoxic-oxic experimental system for municipal wastewater treatment, PHB consumption in an oxic tank and PHB production in an anaerobic tank had been monitored overtime, and relations among PHB consumption/production, phosphorus removal/release and BOD5 loading had been analyzed. The results indicated that the consumption of PHB was positively related with phosphorus removal, and about 140 mg PHB consumption could result in 1 mg P removal. In the anaerobic tank, about 1.

[Evaluation of the damaging effect of dyestuff on Phanerochaete chrysosporium with amplified fragment length polymorphism (AFLP) analysis].

The AFLP analysis was carried out in order to evaluate the DNA damaging effects of dyestuff of different concentrations on Phanerochaete chrysosporium. The DNA similarity and UPGMA cluster analysis were conducted to determine the relationships between the concentrations of dyestuff and DNA damaging effects. The results showed that the AFLP analysis could reflect the polymorphisms of DNA well, and the primer pairs E-AAC/M-CAA could give more amplified DNA fragments than others primers.

[Analysis of phosphorus distribution characters and their sources of the major input rivers of Three Gorges Reservoir].

The seasonal characters of the water flux and suspended substance, phosphorus in the water of input rivers of Three Gorges Reservoir (TGR) were discussed, and the their distributions among three major input rivers (Changjiang river, Jialingjiang river and Wujiang river) were studied, according to the survey conducted from Jan. 2004 to Dec. 2005.

[Research of aeration with bio-film technology to treat urban landscape water].

Research of the aeration with bio-film technology was carried out to treat scenic water of a sanatorium in Beijing. The aim of the research was improving the water habitat by increasing the transparency and reducing the concentration of N and P. The equipments were set in a 5,000 m2 water area, which combined the plug flow jet aerator with the elastic biological filler.

[Analysis of nitrogen distribution characters and their sources of the major input rivers of Three Gorges Reservoir].

According to the survey conducted from Jan. 2004 to Dec. 2005, the seasonal characters of nitrogen in the water of input rivers of Three Gorges Reservoir (TGR) were discussed, and the forms and distributions of nitrogen among three major input rivers (Changjiang river, Jialingjiang river and Wujiang river) were studied.

[Experimental study on the processes and mechanism of enhanced denitrification by addition zeolite in wastewater treatment].

Aim to enhance nitrogen removal from wastewater, addition zeolite to aeration tank was preformed. The result showed that addition of zeolite could improve the nitrification/denitrification efficiencies by comparing two phase experiment of 25 mg/L with blank and 25 mg/L with 50 mg/L, and the population of nitrifying bacteria in activated sludge increased obviously. When 25 mg/L zeolite was added into aeration tank, NH4(+) -N and TN removal increased 10% - 13% and 13% respectively, endogenous respiration rate of nitrification increased about 138%, and the population of nitrification bacteria increased about 2.

[Impact of dissolved oxygen on the activity of anaerobic granular sludges].

The effect of dissolved oxygen (DO) on the methanogenic activity of anaerobic granular sludges introduced into the expanded granular sludge bed (EGSB) reactor was measured in serum flasks. Results show that the specific methanogenic activity (SMA) decreases with DO increases. At 22 degrees C, the SMA drops from 75.

Antibacterial effects of resinous retrograde root filling materials.

The effect of three resinous retrograde root filling materials on the growth of four obligate anaerobic bacteria associated with endodontic infections was determined by using the agar diffusion inhibitory test. Samples of the following resinous materials (resin-modified, glass-ionomer cement, Fuji II LC; compomer, Dyract; and composite resin, Spectrum) were incubated for 1 week with the following anaerobic bacteria: Fusobacterium nucleatum, Porphyromonas gingivalis, P. endodontalis, and Prevotella intermedia.

Assessment of the genotoxicity of resin and zinc-oxide eugenol-based root canal sealers using an in vitro mammalian test system.

Endodontic sealers frequently are placed in direct contact with living tissues. Thus root canal sealers should have good biocompatibility. However, the pathobiologic effects, especially genotoxicity, of various root canal sealers widely used in dentistry have not been studied systematically on eukaryotic cells.