Advanced Materials Research Vols. 1092-1093

Abstract: In this study, the variation of Zeta potentials and distribution of molecular weight in Extracellular Polymeric Substances (EPS) and soluble microbial products (SMP) were investigated. It is indicated that the salinity is effect on Zeta potentials significantly. When the salinity increased from 0 g/L to 35 g/L, the Zeta potentials decreased gradually. The average molecular weight is mainly over 30 KDa in EPS and SMP at 0 g/L salinity, and is mainly below 10 KDa at 10 g/L and 35 g/L salinity. This result is evident that the variation of molecular weight is contributed to high salinity.

Abstract: In this study, high salinity wastewater was treated by an intermittently aerated membrane bioreactor (IAMBR) and the salinity loadings were set at 35g/L. The activated sludge was inoculated from the municipal wastewater treatment plant. The influent salinity level gradually increased from 0 to 35 g/L with every 5 g/L. With the salt concentration increased to 35 g/L, the performance of IAMBR was significantly affected by higher salinity. The removal efficiencies of the total organic carbon (TOC), ammonia nitrogen (NH₄⁺-N) and total nitrogen (TN) were about 83%, 70% and 51%, respectively. It is indicated that the domestication of activated sludge from municipal wastewater treatment cannot obtain a better performance at high salinity.

Abstract: This paper covers the results of the research devoted to characterize of silica dioxide samples obtained from alkaline hydrolysate or black liquor produced from pulping of rice husk. The paper discusses amorphous silica of various quality. Silica samples are characterized: crude (air-dried); burnt (no preliminary water treatment); washed in distilled water; washed in distilled water and burnt.

Abstract: Based on Shandong Renping Bayer red mud as the raw material, analyzing its basic characteristics, the result is that the content of total iron in red mud is 29.55%. Gas-based high-temperature direct reduction experiments are made by using a gas mixture of CO and H₂O as a reducing agent. And then the reduction effect was investigated by magnetic separation experiments, to realize that separation of iron minerals from red mud. The results show that the consequent of the magnetic separation is improved obviously with the temperature rising. Under these conditions, namely, the roasting temperature being 1050°C, the roasting time lasting 90 minutes, the reduction gas rate being 0.7 m³/min, the magnetic field being 2.2A, and three magnetic separations, the iron recovery ratio in red mud is over 97%.

Abstract: This article describes the research on the preparation of the catalyst which is used to deal with Acid Red 88 by catalytic wet oxidation. The experiment investigated the effect of catalyst carrier, impregnation and roast temperature etc on the catalytic activity. Found the optimal conditions to make catalyst finally, it can be described as follows: take lithium silicon powder as a carrier; 0.1mol /L iron nitrate as active ingredients to dip 20 hours; and then, calcined 90 minutes under the condition of 500°C. The removal rate of Acid Red 88 can reach up to 97.2% by the use of these catalysts after 60 minutes reaction.

Abstract: The characteristics of raw pharmaceutical wastewater was as follows: COD_Cr 30000~32000 mg/L, BOD₅ 4050~4360 mg/L, B/C: 0.12~0.14, Fe-C micro-electrolysis with Fenton reagent was adopted to pretreat this wastewater. Through static experiments analysis, optimal parameters of iron-carbon microelectrolysis Fenton pretreatment process are listed as follows: raw water pH, iron-carbon mass ratio (i.e. 2:3), the mass of iron-carbon (i.e. 500 g/L) and reaction time (i.e. 2 h). The optimal operation conditions (i.e. H₂O₂ dosage is12 mg/L, pH is 3.5, reaction time is 80 min) of Fenton reagent oxidation were confirmed.

Abstract: In order to solve the problems of uneven mixing and aerating in municipal solid waste composting, we present a structural design of mechanical agitation biological reactor. The biological reactor system is composed of cylinder tank, agitator, motivation and drive device. The agitator shaft of reactor is hollow and has 24 holes under agitator blade. The article not only introduces the structural design and check of main body, and rack of reactor, but also the selection of type of arranger. The design of agitator gives consideration to both agitation and aeration, which makes air and materials mixed sufficiently during agitation and the fermentation is more fully.

Abstract: Invasive aquatic species discharged through ship ballast water is one of the most serious problems posed nowadays in the marine environment. The effect of inactivation of phytoplankton by pulsed electric field and thermal treatment was studied. Effect factors such as pulsed voltage, electrode gap, pulse width and preheating temperature were explored, and its mechanism of inactivation was analyzed. The combined effect of mild thermal and PEF treatments was shown to give more effective damage of phytoplankton than application of PEF treatment alone. The untreated ballast water sample pretreated at moderate temperature (323 K) and moderate PEF (E ≈10kV/cm) showed a noticeable enhancing of inactivation.

Abstract: A novel PAHs (polycyclic aromatic hydrocarbons)-degrading strain, TAYx3 was isolated from mineral oil and heavy metal contaminated soil. Strain identification and characterization showed that TAYx3 was Yarrowia lipolytica. Tests for Yarrowia lipolytica TAYx3 growth on different substances are also described. The strain could use all PAHs tasted as sole carbon source, and showed synergistic interaction with humic acid (HA). With the existence of HA, the degradation rate of TAYx3 was naphthalene 90.7%, phenanthrene91.0%, fluoranthene74.7%, pyrene 86.9%, benzanthracene 84.7%, benzopyrene 74.7%, respectively.

Abstract: By zeolite column adsorption test process of nitrate pollution of groundwater, the research of three different inlet velocity of nitrate nitrogen removal, and the roles of nitrite nitrogen accumulation, zeolite adsorption of ammonia nitrogen and the influence of pH value changes, the results show that when the flow rate of 70 mL/h, the nitrate nitrogen concentration in the reaction column rising velocity under concentration less than before, but nitrate nitrogen concentration in the zeolite column has remained at about 3 mg/L, removal rate has remained at more than 95%; Nitrite nitrogen accumulation showed a trend of gradual decline, within the scope of flow rate of 90 mL/h, not affected by the late response, nitrite nitrogen concentration of 0.2 mg/L; As the reaction progresses, pH value gradually rose slightly, but still within the range of 6.0 to 8.0; Flow rate of 50 mL/h, zeolite adsorption of ammonia nitrogen effect is best.