Advanced Materials Research Vols. 396-398

Abstract: This paper reports a study on the distribution characteristics of bacteria, ammonifiers, ammonium-oxidizing bacteria, nitrite-oxidizing bacteria, denitrifiers, sulfatereducting bacteria, actinomycetes, and fungi in ten sediment samples from Baihua Lake (a man-made deep plateau canyon reservoir in Guizhou Province, China). In the present research, sampling site of Yueliangwan had the highest population of bacteria and sulfatereducting bacteria. Ammonifiers had the highest population at sampling site Yapengzhai while the other sampling sites showed a slight difference in the population number. Ammonium-oxidizing bacteria had the highest populaton number at sampling site Pingpu. The population number of nitrite-oxidizing bacteria in sediment at Longtan was higher than that at the other sampling sites. The highest population number of denitrifiers was at sampling site Jiangjiapu. Actionmycetes and fungi had the highest numbers at sampling sites Dachong and Laojiutu, respectively.

Abstract: This paper studied the effect of temperature, single surface-active agent and anionic/non-ionic surface-active agents to the viscosity of sludge-sump oil, and ditermined the optimum process conditions by orthogonal experiment. The result showed that the viscosity of sludge-sump iol reduced with the increase of temperature when below 50°C, then the viscosity decreased slowly when the temperature is above 50°C. The optimum conditions obtained by orthogonal experiment were: OP-10 0.6%, sodium dodecyl benzene sulfonate (SDBS) 0.3% and water content 35%. The viscosity reduction rate was about 98.80%.

Abstract: In order to study the reducing and reusing of residual sludge from municipal wastewater treatment plant and solve the technical limit for traditional anaerobic digestion, the contrast research was carried out between the mesophilic(33 °C) and thermophilic(57 °C) anaerobic digestion. The results show that the thermophilic digestive efficiency is one time bigger than mesophilic. When sludge dosage rate increased, volatile fatty acid concentration rises sharply and pH drooped; When the reaction becomes stable, the volatile fatty acid concentration begins to be lowered, the corresponding pH rise gradually. At each sludge dosage rate, the alkalinity drops firstly and then increases with the reaction carried on. Furthermore, the fluctuation of pH values, VFA and the alkalinity of thermophilic are less than that of mesophilic for different sludge dosage.

Abstract: The aldehydes and ketones can be reduced readily by NaBH4 without any modification. NaBH4 can not reduce esters and their derivatives under ambient conditions, reflux and standing overn ight are necessary. However, the activity of NaBH4 can be enhanced by CeCl3.7H2O. In this article, a general, highly efficient and mild methodology for obtaining alcohol compounds by reduction of the corresponding esters with NaBH4 in the presence of a catalytic amount of CeCl3.7H2O in water is described.

Abstract: A series of inorganic-organic hybrid flocculants were synthesized by using aluminum chloride, ferric chloride, polyacrylamide (neutral & cationic) and polydimethyldiallyl ammonium chloride as raw materials. Effect of mass ratio of inorganic and organic polymeric flocculant, basicity, categories of inorganic and organic polymeric flocculant on the regeneration of coking wastewater was investigated. The results showed that the optimum conditions of preparation the title hybrid flocculant were: mass ratio 100, basicity 1.5, inorganic polymeric flocculant PAFC and organic polymeric flocculant CPAM. The removals of CODCr and chroma were 43.48% and 71.88%, respectively, when the pH of raw water was approximately 7 and the dose of flocculant was 360 mg•L–1.

Abstract: Aiming at the problem of lower removal efficiency of ammonia nitrogen in the activated sludge process for wastewater treatment plant of Jilin Chemical Company, a few tests were studied such as filler selection, biological hydrolysis-acidification process, nitrobacteria cultivation, activated sludge process and biofilm process, the feasibility of simultaneous nitrification and denitrification(SND) was developed with biofilm treatment for chemical poor-biological wastewater. The results showed that: SND occurred in the aerobic section, effluent total basicity (TB) in biofilm process was 2mmol / L or more, and was higher than activated sludge process, while the effluent TB in activated sludge process was about 0.1mmol / L,and nitrate produced by activated sludge process was 30mg/L higher than that of biofilm process. Nitrogen removal efficiency using SJ-1-type filler made in Jiangsu Suzhou Purification Group Co., Ltd was 15.01% more than that using combined filler.

Abstract: Although water saving irrigation (WSI) has been widely used in China, there is limited understanding on the effect of such a practice on the CH₄ emission in rice fields. Consequently it is difficult to estimate the region_{Subscript text}al distribution of CH₄ emissions in space and time from rice fields across China. Two water treatments (controlled irrigation (CI), a routine WSI practice in China, and a traditional continuous flooded irrigation (FI)) were used to examine diurnal and seasonal variations of CH₄ emissions in field experiments in Kunshan, east China. The heavy loams in the site have organic matter content of 30.3 g/kg while percolation rates in the shallow groundwater range from 2 to 10 mm per day. Gas samples were collected and analyzed using a static chamber technique and a Gas Chromatograph system respectively. The results show that under WSI conditions, the diurnal variation of CH4 emissions presented regular afternoon-maximum mode during the initial and middle tillering stage, which mainly depends on air temperature. Only one peak of CH4 emission occurred in initial/middle tillering growth stage of rice season under CI conditions, which is mainly regulated by drainage or water layer receding. For CI, seasonal CH₄ emission is 2.4 g•m^-2~24.5g•m^-2, and the seasonal average flux is 0.8 mg•m^-2•h^-1~8.15 mg•m^-2•h^-1, which is 39-85% lower than that for FI. CI has more mitigation potential than midseason drainage. Furthermore, CI significantly reduces irrigation water use while maintains rice yields, even increases yields under atrocious weather conditions. A hydrologic characterization and spatial distribution of rice field in China is needed to assess the extent and magnitude of potential emission reduction in the region.

Abstract: According to the experimental conditions of ASP scene, the indoor simulation experiments were designed to measure the equilibrium concentrations of soluble silicon ion, calcium and magnesium ions under different conditions, then to determine the main scaling influence factors of ASP flooding. The results showed that silicon ion scale was seriously affected by pH value and temperature in a single silicon ion system. Under the polyacrylamide and surfactant single role, the influence to scale was not obvious, and with the higher concentrations of polyacrylamide, surfactant, calcium and magnesium ions,it was easier to form the scale.

Abstract: The growth and the corrosion behaviors of thermophilic sulfate reducing bacteria (SRB), desulfotomaulum thermocisternum strain ST90, were studied in this work. It was found that the growth curves and the main reduction products were influenced greatly by the growth temperatures. The time of the exponential phase and the stable phase decreased with the increase of growth temperatures. The reduction product of this kind of SRB was mainly H2S when it grew at 60°C. With the decrease of growth temperatures, thiosulfate came up as an internal reduction product. The thiosulfate was re-reduced by SRB at the growth temperatures of 40 and 50°C. When the growth temperature came to 30°C, no H2S was generated. The regulation of corrosion rate changed was coincident with the changes of the main reduction products of the SRB. This kind of SRB could accelerate the corrosion rate of carbon steel when grew at higher temperature. But the corrosion rate of carbon steel could be inhibited when it grew at 30°C.

Abstract: Three novel brønsted-acidic ionic liquids based on benzothiazolium cations ([HBth][CH3SO3], [HBth][CF3SO3] and [HBth][p-Tsa]) were prepared and served as effective and environmentally friendly catalysts for the acetalization reactions. Highly catalytic properties and the temperature-sensitive characteristic of the ionic liquid catalysts were exhibited during the process. The temperature-sensitive characteristic made the catalysts homogeneous in higher temperature during the reaction and precipitated from the reaction medium in lower temperature after the reaction, which was conducive to the isolation of the ionic liquids by simple filtration. Furthermore, a recycling study was executed and confirmed that the ionic liquids could be used multiple times affording without noticeable decrease in efficiency.