Papers by Author: Yin Lu

Abstract: A lot of plants have been confirmed to be capable of purifying water. To screen for plants for water purification in the Xixi wetland, water was sampled from the Xixi wetland for indoor experiment. Four kinds of aquatic plants of different growth type (Eichhornia crassipe, Ceratophyllum demersum, Acorus calamus and Lemna minor) were selected for culture using the water under test. After 45 days of culture, obvious water quality improvement was observed for all of the plants. The BOD₅, COD, TN and TP value of the water was decreased by 64.80%, 58.73%, 87.52% and 90.06%, respectively by the plants in the experiment. Based on a comprehensive analysis, Eichhornia crassipe and Ceratophyllum demersum showed high efficiency in water purification. Therefore, these two kinds of aquatic plants are suggested to be planted more in Xixi wetland.

Abstract: In order to achieve a good correlation between toxicology and Artemia salina lethality test, several chemical pollutants were examined in A. salina test, with the purpose to use the latter as convenient preliminary protocol for toxic activity. During the test, it was observed the effect of a particular lethal dose or only a knockdown in the arthropod of HgCl₂, KCN, K₂Cr₂O₇, C₆H₆ and C₆H₆Cl₆. The 24h LC₅₀ of these five chemical pollutants to the artemia nauplius was 0.12±0.09, 0.06±0.12, 0.72±0.21, 1.57±0.58 and 0.44±0.10 mg/L, respectively. The results of the A. salina lethality test for the chemical substances are essentially in agreement with those described in literature for toxic activity.

Abstract: Perfluorinated compounds (PFCs) are man-made fluorinated hydrocarbons, which are very persistent in the environment. Being the most important PFC, perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) have received much attention. According to the large production volume and wide usage in industrial and commercial products in the past, PFOS and PFOA can be detected in various environmental media and matrix, even in human tissues. This paper attempts to review the current status of PFOS and PFOA contaminations in Asia, focusing on a variety of water systems, including surface waters, drinking water, coastal water and sea water. The current information suggests that PFOS and PFOA were replacement compounds identified, although PFC species detected were not completely the same in different water systems. The information also suggests that drinking water might be an important source of exposure to PFOS and PFOA, and continued human exposure to even relatively low concentrations of PFOS and PFOA in drinking water may result in elevated body burdens that may increase the risk of health effects.

Abstract: An aerobic denitrifying bacterium isolated from sludge was evaluated for water treatment application. The denitrification reaction condition was optimized using orthogonal experiment as temperature 30°C,pH7.0 and shaking speed 250rpm. The highest denitrification rate observed at 24h in the optimization experiment was 94.8%. Temperature was confirmed to be the most significant one in the four factors affecting the denitrification efficiency. In a comprehensive evaluation experiment for printing-dying wastewater treatment, the bacterium showed a satisfying water purification effects with obvious decreasing of COD, total phosphorous concentration and nitrate. The highest NO3--N removal rate occurred on day 3, which reached 94.2%.

Abstract: An aerobic denitrifying bacterium was isolated from sludge in wastewater pool. The isolate was identified by Microbial Identification System as Pseudomonas stutzeri. The bacterium isolated could degradate nitrate nitrogen, nitrite nitrogen and amonium salt nitrogen. The bacterium resulted in 82.4% NO3 – -N removal rate, 40.1% NO2 – -N removal rate and 87.9% NH4+-N removal rate respectively at 24 h in a characterization experiment. The isolate preferred to utilize sodium citrate as carbon source. Temperature was confirmed to be an important factor effecting the denitrification reaction. Optimization of reaction condition resulted in over 96% NO3 – -N removal rate after 48 h of treatment.

Abstract: The petroleum ether, chloroform, ethyl acetate, n-hexane and aqueous successive extracts from the stems of Actinidia macrosperma C. F. Liang have been screened for antibacterial and antifungal activities in vitro using the disc diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC). General toxicity of these extracts has also been assessed by brine shrimp lethality assay. The chloroform extract exhibited the most significant antimicrobial (MIC in the range of 60–500μg/ml, MBC in the range of 150–1000μg/ml, MFC in the range of 170–600μg/ml) and cytotoxic activities (LC₅₀=16.82μg/ml at 24 hours).

Abstract: A medicinal wild kiwi in China, Actinidia valvata Dunn, has been well known for its activities against leprosy and cancers. The compositions and the antimicrobial activity of its leaf oil were reported for the first time. The oil obtained by hydrodistillation and analyzed by GC and GC-MS, was characterized by the high content of monoterpenes. Linalool (48.14%) is the major component identified, followed by 1,2-dimethyl-lindoline (7.94%), linolenic acid methylester (6.57%) and (E)-phytol (5.29%). The antimicrobial activity of the oil was evaluated against four bacterial and three fungal species. The results showed that it exhibited a mild antibacterial activity against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), a significant activity against Gram-negative bacteria (Escherichia coli), and no activity on Pseudomonas aeruginosa. The test fungi were more sensitive to the oil, with a MIC range of 0.78~1.56 μL/mL than bacteria in the range which were significantly higher from 0.78 to 25.50 μL/mL.