Advanced Materials Research Vols. 690-693

Abstract: Operating for 1.5 years, part of filtering bags for bag dedusters in a coal-fired power plant had severely decreased intensity and were generally broken. These disabled bags were mainly at the middle and tail of dedusters. By analysis, the reason of the ineffectual filtering bags is oxidation corrosion and more flue gas passing through, owing to the nonuniform distribution of gas. As an improvement measure, such methods are needed as operation optimization, installing de-nitrification system and adding gas uniform plate in dedusters.

Abstract: The effect of coexisting sulfate [(SO4)2-], pH, and conversion rate on arsenic (As) removal from groundwater through nanofiltration, reverse osmosis (RO) membrane, and membrane fouling was studied. The results show that As concentration in permeate water was less than 10 μg/L when the feed As concentration was less than 135 μg/L, whereas As concentration after RO was less than 10 μg/L in all cases even if feed As concentration was more than 199 μg/L; these values in permeate water nearly meet the arsenic content level prescribed by China’s drinking water standards. The As rejection rate decreased with the increase in feed As and coexisting ion concentration, whereas the opposite occurred with regard to pH and conversion ratio. The decreasing percentage of the As rejection rate remained the same when arsenic concentration increased by 1 μmol or when (SO4)2- increased by 0.5 mol. The As rejection rate did not change significantly when the feed As concentration exceeded 200 μg/L. The As rejection rate increased when pH increased, and an ideal rejection rate was achieved at pH 6.5. Transmission electron microscopy and X-ray diffraction analysis showed that the main fouling component was CaCO3 which was deposited in the membrane pores and decreased the As rejection rate.

Abstract: The paper investigates the feasibility to reduce Cr (VI) from the aqueous solution by sulfate-modified titanium-bearing blast furnace slag (STBBFS) prepared with the different preparation method. The different photocatalysts were examined by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra and scanning electronic microscopy (SEM). The photocatalytic activities of the different catalysts were evaluated by the photocatalytic reduction of Cr (VI) under UV-vis light irradiation. For the photocatalytic reduction of Cr (VI), the photocatalytic activities of STBBFS catalysts were found to be strongly dependent of absorbance in UV-visible region, adsorption capacity and surface acidity, and STBBFS prepared by dry-process showed a higher photocatalytic activity compared to that prepared by hydro-chemistry method.

Abstract: Aluminous rocks from Xiuwen County, Guizhou are the main raw materials, mixed some kaolin mineral. Water glass and alkaline activators are used to product polymer materials, the main experimental indicators are the compressive strength. Here, the studies on amount of water glass and alkaline activator, solid-liquid ratio, amount of kaolin and effects on compressive strength of Geopolymer have been proceeded respectively. The result shows that: the highest compressive strength of geopolymers is17.94 Mpa, with aluminous rock 40g, solid-liquid ratio 2.2, water glass12g and alkali activator 2.01g, as well as kaolin 18.02g.

Abstract: The use of environmentally friendly or green concrete to enable worldwide infrastructural development without increase in carbon dioxide (CO2) emission is at the focal point of the global issues concerning sustainability. Aside from the concerted efforts by the key players in the construction industry to successfully replace in part or in whole, the conventional Portland cement with green or eco-friendly cementitious materials, the challenges of ensuring that the so called green or eco-friendly concrete performs up to the required expectation has been the focus of many researches. This study therefore, provides an overview of the various processing techniques for the industrial waste materials as well as the determination of the physical and chemical characteristics of the powders prepared from the respective waste materials. The materials were characterized using BET surface area analysis, X-ray diffraction (XRD), Chemical analysis by X-ray fluorescence (XRF), 45-μm wet sieving, 75-μm and 150-μm dry sieving, Specific gravity using density bottle and reactivity index (RI). The results show that FA and PBC are very similar in terms of their physical and chemical characteristic in comparism with POFA. Notwithstanding, all the materials satisfy the basic requirements of the relevant ASTM specifications and also falls within the limit specified by ASTM C 618 for class F fly ash.

Abstract: Long Dong oil field located in the arid and semi-arid climate environment,as the oil extraction has been lasting for a long period,large amount of wellsite wastewater is produced without proper treatment and stored at the wellsite on long-term basis,which endangered the oil field environment.Focusing on the characteristic of Long Dong wellsite wastewater,conducting the experimental evaluation on treated wellsite wastewater reinjection based on the scaling prediction method,photo-extinction method and scale mass analysis.The evaluation process is standardized by scaling prediction,photo-extinction analysis and scale mass, meanwhile the removal effect of the key controlling factors like the medium particle size and SS of the treated water is detected as the research result shows.Wellsite wastewater treated by coagulation and filtration then supported by the advanced oxidation and membrane separation technology to intensify the size of tiny particles in wastewater.After the above process,the outflow may meet the "Recommended Clastic Rock Reservoir Water Injection Water Quality Index and Analysis Method "(SY/T5329-94 A1 standard) with good compatibility,and its ratio of treated water and reservoir water is 6:4 or8:2

Abstract: The refining is the important stage in the APMP pulping process, and high temperature pulses generated in this stage make pulp fibers stiff and ankylosis, which can reduce the strength properties of the pulp. Latency removal is the best way to modify pulp fibers properties and improve their strength. This study focused on the effect of latency removal on the properties of the poplar APMP pulp. atency removal can improve effectively the physical properties of the APMP pulp,the breaking length of the latency removal pulp increased 3.06%, burst index increased 1.97%, tear index decreased 6.07%, and brightness increased by 0.38%ISO.in the 60°C. the breaking length of the latency removal pulp increased 11.80%, burst index increased 14.30%, tear index decreased 6.63%, and brightness increased by 0.77%ISO in the 80°C.

Abstract: The existing coal slurry drying process efficiency is low and discharge waste gas and water. So a green and efficient coal slurry drying process was putted forward in this paper. A technical support was provided for construction of resource-saving and environment friendly mining area.

Abstract: In this paper, the method of orthogonal experiment was adopted to investigate the influence of seed dosage, stirring time, calcium concentration and sodium carbonate dosage on strontium removal in granulation method. And continuous operation was studied. The order of influence factor was stirring time> seed dosage> sodium carbonate dosage amount> calcium concentration. In the operation experiment, the strontium and calcium removal efficiencies were both more than 90%, while the magnesium removal was less than 5%. The precipitate particles formed gradually became larger.

Abstract: The treatment of dyeing wastewater is a problem of great difficulty and a focus of public owing to its high color intensity, varying water quality and poor biodegradability. The optimal pH values of iron trichloride in treating three kinds of direct sun-proof dyeing wastewater were studied. Experimental results show when the concentration of iron trichloride was 2g/L, the optimum pH value were 8,6 and 7 for three kinds of simulated dye wastewater of direct sun-proof light green, yellow and scarlet.Under these conditions, the removal rate of turbidity were 88.7%, 89.5% and 92.9%, and the removal rate of color were 83.6%, 62.3% and 79.6%.