Advanced Materials Research Vols. 864-867

Abstract: An aerobic bacterial strain Q1 capable of utilizing quinoline as sole source of carbon, nitrogen and energy was isolated from activated sludge of a coke plant wastewater treatment process. The morphological properties and the phylogenetic analysis based on 16S rDNA sequences showed strain Q1 belonged to the Pseudomonas sp.. Another strain Q2 was unable to utilize quinoline as sole source of energy alone can coexist with Q1 when quinoline was sole energy. The coexistence of Q1 and Q2 has synergistic effect to quinoline degradation. The biodegradation tests suggested that the kinetics of quinoline biodegradation by Q1 or the combaination of Q1and Q2 strain can be described by Haldane equation kinetically.

Abstract: Supercritical CO₂ extraction of Plumula nelumbinis oil rich in γ-sitosterol was investigated with a 4² full factorial design and response surface analysis. At optimal conditions (P=35 MPa, T=55 C, d_p=0.22 mm, Q=2.0 L/min), the yield of the extracted oil was up to 12.2%, in which the concentration of γ-sitosterol was 7.38%, indicating that the γ-sitosterol contents in Plumula nelumbinis and its oil were much higher than that in other vegetables.

Abstract: The organic complex chelators (OCC) were synthesized and applied to stabilization of heavy metals in fly ash according to the municipal solid waste landfill pollution control standard. The influences of different chelators, amount of chelator, pH value of leaching, solidification time were investigated and optimized. Comparing to the traditional inorganic chelator, this OCC has more powerful performance of stabilization. Under the optimized conditions, the leaching concentrations for typical heavy metals Pb and Cd were less than 0.19 and 0.11 mg/L, respectively, which could meet the demand of landfill. The organic complex chelators could react with heavy metals to form stable complexes, which would be embedded in fly ash particles and have the strong ability to prohibit leaching from acidic environment.

Abstract: A full-length sequence coding for a betaine aldehyde dehydrogenase gene from S. portulacastrum was cloned into expression vector pGEX-4T-1, and named pGEX-4T-SpBADH. The GST-SpBADH fusion protein was expressed and the expression conditions were optimized. Through the research on optimization of expression the concentration of IPTG, concentration of bacterium, induction time and temperature and so on, the results showed, the expression of GST-SpBADH increased accompany with the induction time. The expression level of GST-SpBADH fusion protein reached the highest for 5 h cultured and for OD₆₀₀ is about 0.6 at 37°C, 0.2 mmol/L IPTG can effectively induce the expression of GST-SpBADH in Escherichia coli expression system.

Abstract: A continuous stirred-tank reactor (CSTR) was used to produce biohydrogen gas from organic wastewater. The hydrogen producing reactor was operated under high organic loading rate of 21 kgCOD/m³·d, and molasses wastewater was used as substrate. Hydrogen production rate, pH value, sugar utilizing rate and fermentative products in effluent were investigated in continuous fermentation. When Organic Loading Rate was controlled at 21 kgCOD/m³·d, the average concentrations of acetic acid, ethanol, propionic acid, butyric acid and valeric acid in liquid fermentative products were 833, 748, 482, 484 and 256mg/L respectively. There is not any fermentation product playing dominant role absolutely in hydrogen production fermentation. The pH value in effluent was about 4.7~4.9, the average utilizing rate of sugar reached 92.1%, most of the sugar in molasses wastewater was utilized. The biogas production rate in hydrogen producing fermentation was from 21.2 to 27.1L/d, and the average biogas production rate was about 25.1L/d. The hydrogen content was about 37%.

Abstract: In order to reveal the composite contaminations characteristic of dimethoate adsorption onto the surficial sediments, the competitive adsorption of dimethoate in pesticide (dimethoate, metalaxyl, atrazine, malathion, and prometryn)/heavy metals (copper, zinc, lead, cadmium and nickel) system is investigated. A 2^10-5 fractional factorial design method at resolution IV and a multiple linear regression adsorption model are used to identify the main effects and interactions of above ten pollutions. The adsorption amount of dimethoate surficial sediments is set as the dependent variable, and the main effects and second-order interactions of ten pollutions are set as independent variables. Thus, a multiple linear regression model of dimethoate adsorption is screened and established. The results of model show that the main effects of Cd, malathion and prometryn performed a significant antagonistic effect (α=0.05) on the adsorption of dimethoate onto the sediment (competitive adsorption effects), and the order is: prometryn (-0.0925) > Cd (-0.0878) > malathion (-0.0827); while heavy metal Zn performed a significant synergy effect on the adsorption of dimethoate. The second-order interaction effects of Zn*prometryne, Pb*atrazine and Pb*atrazine has a significant antagonistic impact on the adsorption of dimethoate in sediments, which is in a sequence of Zn*prometryne (-0.0967) > Pb*atrazine (-0.0945) > Cd*atrazine (-0.0922). Moreover, according to the rate of contributions of main effects and second-order interaction effects in composite contaminations system, we can also estimate and definite the pollution levels of target pollutant.

Abstract: In order to understand the pollution status of mercury in fish and shellfish products from the Jiaozhou Bay and its health mercury risk for the population, a total of 86 samples for 13 kinds of seafood products from Shuangbu, Hongdao, Yinghai and Huangdao in Jiaozhou Bay were collected from April to May 2009. The mercury content in samples was determined by the method of cold atomic absorption method used F732-V mercury detector. The result of this experiment showed that the range of mercury contents in the collected fish and shellfish samples were 0.0044-0.4895 mg/kg. The mercury content in Psetta maxima had the highest value in all fish samples collected, and Clinocardium californiense had the highest mercury content in shellfish samples gathered. The fish and shellfish samples from Hongdao had the highest average mercury contents in all the four origin regions, and that in Huangdao had the lowest average mercury content. There were 16.67% of Ruditapes philippinarum samples over the national standard of China, and the data was 33.33%, 50%, and 50% for Clinocardium californiense, Psetta maxima, and Mylopharyngodon piceus, repectively. Population has a certain health risk for mercury exposure from the consumption of fish and shellfish in Jiaozhou Bay.

Abstract: This study examined the effects of submergence and nitrogen concentration on biomass allocation and nutrients utilization of an invasive plant Alternanthera philoxeroides. In the experiment, A. philoxeroides was applied to two water level treatments (0 and 25cm above the surface) across with two nitrogen concentrations (0 and 10 mg/l N). The results showed that submergence decreased leaf fraction and increased stem fraction, but high N changed this situation. In submergence, high N increased leaf fraction but decreased stem fraction due to leaves survival and maintenance. Submergence decreased root fraction and the content of soluble sugar in stem. The results suggested that high N concentration could counteract the negative effects of submergence. Therefore, the risk of A. philoxeroides invasion might be enhanced by nitrogen pollution in fluctuating water bodies, and should be attention intensely.

Abstract: Cadmium (Cd) is an environmental pollutant extremely toxic to plants and other living organisms including humans. To assess Cd phytotoxicity, the seedling growth, mineral (K, Fe, Zn) and carbohydrate contents and hydrolase activities in the endosperm and seedlings during rice seed germination subjected to Cd stress were investigated. The results showed that Cd caused a reduction in seedling growth and distribution of biomass, mineral contents, compared to the control. Cd accumulation in seedlings increased in the duration of treatment. Cd exposure caused a deleterious fall in mineral nutrient supply in seedlings. Moreover, Cd decreased the content of starch and sustained a higher level of soluble sugar in the endosperm of rice seeds. Activities of α-amylase and acid invertase were inhibited in Cd-treated seeds during the germination. The results suggest that Cd inhibits early seedling growth due to restriction of mineral and carbohydrate reserves mobilization.

Abstract: Indoor simulation method was applied to study the characteristics of nitrogen and phosphorus release from sediments in small freshwater lake Huangjia Lake. Meanwhile, the grading determination method of inorganic phosphate was applied to study the existing form of inorganic phosphate in sediments. The results showed that sedimentary environment in various areas of Huangjia Lake would have influence on release of nitrogen and phosphorus. At the same time, the temperature and pH value were proved to have obvious influence on release of nitrogen and phosphorus.