Advanced Materials Research Vols. 113-116

Abstract: Treatment of xenobiotic compounds such as textile dyes with bacterial laccases is limited to the acid pH range and moderate temperatures. A bacterial strain, designated as WD23, was isolated from forest soil using Luria-Bertani medium supplemented with 0.4 mmol/L Cu2+. The isolated strain was identified as Bacillus subtilis by physiological and biochemical tests and 16S rDNA sequence analysis. Here we charactered the spore-bound laccase of B. subtilis WD23 and used the laccase to decolorize dyes. The spores of the strain showed laccase-like activity, oxidizing syringaldazine, 2,6-dimethoxyphenol and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonate acid)(ABTS). The optimum pH and temperature for the spore-bound laccase were 6.8 and 60°C, respectively. It also showed higher stabilities over a broad pH range, the pH half-life was more than 6 months at pH 6.8. The spore laccase could efficiently decolorize 50~90% of anthraquinone and azo dyes in 24 h. The spore laccase can play an important role in bioremediation.

Abstract: During oil production from several wells in Daqing, significant productivity decline was noticed. One of the reasons behind the productivity decline might be scale precipitation. The corrosion is very serious for scaling of the fifth injection wells. It brings enormous damage to oilfield and seriously influences the oilfield production and development. Based on the research of scaling of three different sections of injection wells, we clear the distribution of injection wells scaled and the source of injection water. Choose the representative scaling wells of three blocks and injection water sample, use modern instrument analysis method to analysis the composition of water and scale sample. According to the data analysis, to certain the components of the sample scale, put forward the main form of scaling mechanism, and provide a dependable basis for making effective measures of scale removal and prevention.

Abstract: With the rapid urbanization, medium-small-size cities have become essential to urban system in China. However, due to limited financial and technology conditions, development has lead to serious water pollution. This study statistically analyzed the socioeconomic development and water pollution situations of 10 typical medium-small-size cities in southern China with factor analysis and find that: 1) industry development is the major contributor to water pollution, so it should be well planned; 2) pollution in rural area is mainly caused by high concentration of pollutant discharged, and the control should emphasize on the disposal of pollutant; 3) in urban areas, the large quantum of sewage emission has a greater contribution to water pollution, and water conservation will bring a great improvement in the level of pollution control. The results propose some ways more effective to control water pollution for medium-small-size cities in southern China.

Abstract: Since wood is porous it also is a good heat and sound insulating material. Puffing the cell wall may lose certain level of mechanical properties but would increase its insulation properties. In this study, Trema orientalis wood was first treated with nitric acid aqueous solution to damage the S3 layer of cell walls, followed by puffing the cell wall inward with saturated urea and ZnCl2 solutions. Results indicated that treating Trema orientalis with 10% nitric acid at 100 oC for 20 minute damaged the S3 layer of cell walls, and the subsequent treatment with urea and ZnCl2 saturated solutions caused the fiber tracheid walls to swell up to 76%. Then, the swollen material was dried with critical CO2 fluid to obtain puffed wood. SEM examinations of nitric acid-treated samples showed that lignin were removed from the S3 layer surfaces and S3 mirofibrils were ruptured causing the entire secondary walls to swell inward.

Abstract: Hydrogenophaga palleronii LHJ38 can grow on naphthalene as sole carbon and energy source. The growth and naphthalene degradation curve of the strain were determined in biphase and monophase system respectively. The growth and naphthalene degradation capacity of cells obtained from oil phase and aqueous phase were compared carefully. The maximum biomass of 4.248g/L was obtained after cultivating 72h under the optimum conditions of 30 mL paraffin oil and 2g naphthalene in 1L mineral salt medium. In the biphase system, the naphthalene degradation capacity of Hydrogenophaga palleronii LHJ38 was higher more than 2 times than that in the monophase system. The naphthalene (2g/L) can be degraded completely in 132h when the concentration of cell was 2 mg dry weight cell/mL. The naphthalene degradation rate of cells obtained from oil phase was 2.7 fold as fast as that of cells obtained from aqueous phase.

Abstract: The cascade correlation algorithm that is cascade-correlation(CC) algorithms, CC network structure and CC network weights learning algorithm are introduced, based on the real data in hydropower station, considering the cavitation characteristics, the network model is established based on CC algorithm, and the applications of CC and BP algorithm of turbine are compared. The results show that the CC algorithm is better than BP neural network, the results can be used in the optimal operation of hydropower, and it has a practical significance.

Abstract: With peanut shells as raw material of activated carbon adsorbent, the adsorption property of wastewater containing phenol was studied. The effection of the amount of adsorbent, adsorption time, temperature, pH and other factors on absorbing effect were investigatied. It also made the preliminary research on adsorption mode. The results determined in acidic or neutral condition are as follows: the amount of absorbent 0.8g, the adsorption time 1.5h, temperature 30°C, Under which, the optimum absorbing effect of peanut shells activated carbon (PSAC) on the 100mL concentration of 50mg/L of wastewater containing phenol is achieved. The maximum maximum phenol removal rate can be up to 94.6%. PSAC performance curve of phenol adsorption is in line with Freundlich isotherm adsorption equation. PSAC as a adsorbent of wastewater containing phenol has good development prospect.

Abstract: In this paper a stepwise adsorption purification bed was introduced to be used for overflow wastewater treatment. According to the principle of natural purification of soil and paddy fields on sewage, the stepwise adsorption purification bed imitated the self-purification function of natural materials, such as defoliation，rotten wood, charcoal and the stone were processed as filler. The removal rate of the parameters, such as COD, NH3-N and TP was invested to show the treatment effect of this system. The result showed that the system had a high removal rate of the contamination in the sewage. The COD, NH3-N and TP removal rates can reach up to 80%, 85.8% and 84% respectively.

Abstract: This paper mainly discuss the negative externality problems involved in environmental logistics and the necessity of government regulation, and the government’s role in resolving negative externality. In the process of environmental logistics, around the interest distribution after the internalization of external cost, it exists a series of games among parties of logistics systems, including game between enterprises and environment, game between enterprises and game between government and enterprises. Through the analysis of game model, we conclude that environmental logistics cannot only rely on the market forces, the government should play a greater role. The economic incentives based on market are the most effective way to resolve negative externality and at the same time we should avoid rent-seeking behavior. The government should accelerate the process of environmental logistics in China by increasing the intensity of propaganda of environmental logistics, making evaluation standard of environmental logistics, carrying out financial subsidies on environmental logistics, and guiding enterprises participating the technology development of environmental logistics.

Abstract: Amine collectors are widely used as oxidized ore collectors.Based on OECD 301B testing method, the biodegradability of amine collectors were analyzed and evaluated, and the values of IB of lauryl amine, octadecylamine, laurtrimonium chloride, lauryl trimethyl ammonium bromide, decane-propyl ether amine and dodecyl propyl ether amine were 173.4, 162.2, 164.6, 171.2, 160.8 and 149.4, respectively. The biodegradation of six test substances all exceeded 10% in 10 days, and all up to over 50% within 28 days. Considering comprehensively the two evaluation standards, the six amine collectors are all biodegradable. Evaluation of the biodegradability of amine collectors provides information that the chemical structure influences the biodegradability of amine collectors. It seems that the existence of ester group decreases the biodegradability of ether amine, and the shorter the carbon chain, the greater the biodegradation occurred.