Advanced Materials Research Vols. 356-360

Abstract: The flow field behind non-planar porous fence of geometric porosity ε=0.273 with various bottom gaps (G) has been investigated by hot-wire anemometer velocity field measurement technique in a wind tunnel experiment. Seven gap ratios G/H=0.000, 0.025, 0.075, 0.125, 0.150, 0.175, 0.200 of non-planar porous fence were tested in this study with the free-stream velocity fixed at 10m/s. The experimental data were analyzed and the turbulence intensity and wind reduction ratios for different gaps of the porous fence were calculated to estimate the shelter effect of a non-planar porous fence model. The results show that the gap ratio G/H=0.150 gives the best shelter effect among the seven gaps of the non-planar porous fence tested in this study, having a better mean velocity and turbulence intensity as well as wind reduction ratio in a large area behind the non-planar porous fence.

Abstract: In order to solve the problem of ventilation systems and pollution control systems where exist pollutants, taking into account the traditional sealed enclosures or partial enclosures, and other pollutants in exhaust hood to control the collection rate is very low. As the collection rate of the Traditional closed cover and local cover which control pollutants is poor, besides that, the energy consumption is Large, based on The actual needs of field and laboratory, the Prototypes and experimental models of Convergent air curtain generator have been set up. And with them univariate and multivariate orthogonal experiments have also been made. Through a large number of experimental analyses, the most Optimal parameters has been got, and the Theoretical model of Convergent jet air curtain. Based on the experimental and theoretical analysis, with the Case studies and Under the conditions of heat radiation of the convergent flow air curtain jet, Comparing with the static test, it has been found that Convergent air curtain makes the room temperature, dust and pollutant concentration, the concentration of air pollutants and energy consumption have been greatly reduced. The theoretical model and experimental results has some reference value and significance on environmental protection, labor protection and health protection related to protection design.

Abstract: The process parameters and running effect of baffled-submerged bio-film process applied in the treatment of sewage wastewater were introduced, aiming to improve the broad application of baffled-submerged bio-film process in the wastewater treatment in small towns. An engineering case was taken as an example to describe the process flow, process parameters and sizes of the structures. The character of the designing was explained along with the discussion of the running effect. The running effect shows that sewage wastewater treated by baffled-submerged bio-film process can meet the requirements of Grand B of Primary standard of Discharge standard of pollutants for municipal wastewater treatment plant (GB18918).

Abstract: Using X-ray diffraction to analyze the scaling samples to discuss the scaling causes. The results show that the main ingredients of scaling are CaCO3, CaSiO3 and non-crystal SiO2 in ASP flooding. Taking "heating concentration state", "scaling ions change" and "inhibition rate" as the evaluation indexes, evaluate the British net yuan scale removal instrument, Germany scale-buster and Korea magnetic antiscale apparatus which are all advanced foreign physical instruments online, and search for the suited antiscaling instruments for oilfield. Results show that the antiscaling effect of British net yuan scale removal instrument on the ASP flooding is better, the inhibition rate reach 69.3 %.

Abstract: Four main ingredients of the dust and four material corona electrodes were selected from sintering machine electrostatic precipitator (ESP) in this paper, affinity differences of the corona electrode with the four kinds of dusts can be concluded from the experiment on the condition of low voltage. According to the composition of dust to be processed in actual production, corresponding corona electrode and collecting plate materials should be selected to improve the phenomenon of corona electrode surface mast and tip balling and to improve collection efficiency.

Abstract: The start-up characteristics of internal circulation anaerobic reactor were studied using anaerobic sludge of UASB as vicinal sludge. The concentration of influent COD was kept at 2500mg/L initially, then the influent flow increased from 1L/h to 2.5L/h gradually, and the removal rate retained around 85.0% to 93.5%. During the middle-period of the experiment, the influent flow was maintained at 2.5L/h, and the influent COD concentration was gradually increased from 2500mg/L to 10500mg/L, the removal rate of 91.2%~94.6% was obtained now. At the end period of the experiment, the influent COD concentration was kept at 10500mg/L, and the influent flow was increased from 2.5L/h to 3L/h gradually. When the volume loading was improved to 55.04kg COD/ (m3 • d), the COD removal rate reached 88.3%.

Abstract: The electrochemical treatment of wastewater containing 2, 4, 6-trichlorophenol has been carried out experimentally with synthetic boron-doped diamond (BDD) thin film electrodes. Removal rate of COD, instant current efficiency (ICE) and energy consumption were investigated under different current density. The influence of supporting media is reported, which plays an important role in determining the global oxidation rate. The oxidative chloride is stronger than peroxodisulphate. The electrochemical characteristics of boron-doped diamond electrodes were investigated in comparison with active coating Ti substrate anode (ACT). The experimental results show that BDD is markedly superior to ACT due to its different absorption properties.

Abstract: Power plants that emit great amounts of nitrogen oxides are the key total mass control part of the “Twelfth Five-Year Plan”. SCR is widely used because the technology is mature and the denitrification efficiency is high. According to the problems of the application of SCR, this paper puts forward relevant suggestions: 1) Combine different flue gas denitrification technologies to raise the denitrification efficiency. 2) Urea is recommended as the reductant considering the safety factors. 3) Issue relevant policies and strictly control the emission of sulfur trioxide.

Abstract: The leachate from the Zixiaguan landfill of Wuhan City contains a lot of undesirable or toxic chemicals, among which arsenic may have the most serious threat to environment and human health. Lowering the arsenic concentration in the leachate is therefore of extreme importance. In this study, natural sediments obtained from Wuhan City, including clay, silty soil and silty sand, were used as low-cost sorbents to remove arsenic from solution. The results of the batch sorption experiments indicate that the sorption processes of clay and silty sand match well with linear isothermal sorption model, while that of silty soil is in good accordance with Langmuir isothermal sorption model. Among the three sorbents, clay has the best ability for arsenic removal from solution. Further experiments were carried out to determine the optimum sorption conditions for clay sorbent, the results showing that as the ratio of sorbent dosage to solution volume is 25.0 g/L, the reaction time is 120 min, and the pH of solution equals 7.0, the removal rate of arsenic from the leachate by clay sorbent reaches the highest value of 99.3 %.

Abstract: Based on the existing methods of dust reduction in blasting demolition, a new method of dust reduction, which has the characteristics of cleanliness and environmental protection, is put forward. The new method is an integrative one which combines physical and chemical methods of dust reduction. The new method was applied to blasting engineering at busy district and the dust reduction effect is satisfactory. The new method with foaming agent is a good means of dust reduction in blasting demolition, it will give a beneficial reference to other analogical blasting engineering and has an extensive application prospect.