Advanced Materials Research Vols. 726-731

Abstract: With the improvement of environmental protection requirements, paper-making enterprises are imperative to eliminate pollution directly in production. This paper aims to adopt environment-friendly bleaching method, yield good quality pulp products. Op-Pa-P bleaching process of reed displacement cooking pulp is studied in this paper (O-oxygen, P-hydrogen peroxide, Pa-peracetic acid ). The experimental conditions of Op and Pa stage were optimized respectively. It included oxygen pressure, temperature, time in Op stage and charge of peracetic acid, temperature, time in Pa stage. The results show that the optimal technological conditions of Op are: 0.9Mpa, 100°C, 70min, Op stage can make brightness increase by 57.3%, viscosity decrease by 25% and KMnO₄ number reduce to 2.6. Pa stage optimal conditions are Pa charge 1.5%, 70°C, 75min, brightness reached to 79.1 %ISO, KMnO₄ number to 1.0, viscosity to 631mL.g^-1. The brightness of P bleached pulp reached to 84.8%ISO, viscosity 601 mL.g^-1, KMnO₄ number 0.8.

Abstract: Before oxygen bleaching and hydrogen peroxide bleaching, wheat straw pulp was bleached using xylanase. The effect of enzymatic stage on pulp properties and bleachability has been studied and compared with reference (control) pulps, processed without enzyme addition. Experimental results showed that, the optimal concentration of wheat straw pulp was 10%, the optimal treatment time and dose of enzyme was 60 min and 1.25AXU/g respectively. Oxygen pressure decreased from 0.6MPa to 0.5MPa when conditions of hydrogen peroxide bleachingremained unchanged and wheat straw pulp achieved the same whiteness. Hydrogen peroxide consumption decreased from 2% to 1.8% when oxygen bleaching has the same conditions and achieved the same white degree.

Abstract: This paper concerns with two brominated bacteriostatic agents, using the condition-test to research the inhibitory effect of the microorganisms in the waste paper pulp white water. Using the coated plate culture method of adding different amounts of antibacterial agents in Whitewater, the bacteria and mold in nutrient agar and potato medium experiments were used to observe the inhibitory effect. The results showed that the chosen brominated bacteriostatic agents (PS-2890, GB-3612) in this paper have a better antibacterial effect and 1#is better than 2#,the bacteriostatic agent can be chosen according to the actual situation of the plant .The bacteriostatic agent will achieve a higher rate of bacteriostasis when it is added to 5ppm, and this added amount can also meet the requirements of the factory on the prevention and treatment of microbial. The rate of bacteriostasis generally reached 40% -80% ,the highest 92.8%,when the antibacterial dosage is 3ppm-7ppm.

Abstract: The fate of oil spilled on seawater is an important issue for marine environment. This paper studied the dissolution of two crude oils and the photodegradation of their water-soluble fraction (WSF). The relationship between the solubility and the component of the crude oils was studied by gas chromatograph, UV absorption and synchronous fluorescence spectrum, and the result indicated that the aromatic hydrocarbon was liable to dissolve in water and the dissolved organic matter (DOM) in seawater enhanced the dissolution of crude oils. Moreover, the photodegradation of WSF accorded with the pseudo-first order reaction, and the reaction rate constants for WSF 1 and 2 were 0.088 and 0.121 h^-1, respectively. This investigation is helpful for better understanding the transformation of crude oil spilled on the sea.

Abstract: Palygorskite is widely used as an adsorbent for all kinds of pollutants in wastewater. The effect of hydrothermal treatment parameters including temperature and time on palygorskite's structural character and its adsorption of methylene blue were studied. The structures of the prepared palygorskite adsorbent were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (IR), and Brunauer-Emmett-Teller (BET) analysis. The results illustrate that the palygorskite fibers become shorter evidenced by TEM analysis, but there is no obvious destruction of crystal structure in XRD patterns. The BET specific surface area of palygorskite gets the largest after hydrothermal treatment at 110 °C, and then gradually reduces. Correspondingly, the adsorption capacity of methylene blue (MB) on palygorskite increases at 110 °C and then decreases till 250 °C.

Abstract: This paper reports the effects of wheat stalk anaerobic extract and wheat stalk powder on the inhibition of Microcystis aeruginosa in the laboratory, and the broken wheat stalk on the growth of the phytoplankton and zooplankton in natural water. The results show that: (1) the Wheat stalk Anaerobic extract has inhibitory effect on the Microcystis aeruginosa, the average inhibiting rate was 59%; (2) the Wheat stalk powder has obvious inhibitory effect on the Microcystis aeruginosa, the average inhibitory rate was 74% and the effect increased with the passage of time. The inhibitory rate remained the range of 75%~96% from the 3rd day to 13th day after adding the Wheat stalk powder; (3) In natural water, the addition of broken wheat stalk can cause change of the dominant phytoplankton species in which cyanophyte is not obvious dominant species anymore, and the broken wheat stalk has inhibitory effect on the growth of phytoplankton cells; (4) The addition of broken wheat stalk can promote the growth of poor-middle nutrition species zooplankton in natural water, and make their abundance soars rapidly.

Abstract: Three commercial resins (NDA150, NDA88 and NDA77) with different physicochemical properties were selected to investigate the adsorption behavior and primary factors controlling the adsorption of oxytetracycline (OTC) onto the resins. The adsorption kinetics of OTC onto all resins were fitted well to pseudo-second-order model. NDA150 had the largest adsorption capacity due to its higher surface area and larger total pore volume. Moreover, all of the three resins exhibited nearly the same equilibrium time because of their nearly the same particle size. The suitable pH for the effective adsorption of NDA150 and NDA77 is from 4 to 7, while the ideal pH for NDA88 is 10. OTC adsorption on all of the three resins increased with the increasing ionic concentration.

Abstract: The composite CdSe/K₂La₂Ti₃O₁₀ photocatalyst was synthesized via a precipitation method. The structure of the photocatalyst was determined by powder X-ray diffraction. The photocatalytic properties for organic matter degradation of the photocatalyst were examined under visible light irradiation, using rhodamine B as the goal degradation content and halogen lamp (λ > 420 nm) for the light source. The results show that when the pH of the rhodanmine B at 7, initial concentration of 10 mg/L and every 250 mL solution catalyst dosage is 0.25 g, and the degradation rate of rhodamine B for 4 hours was 50%.

Abstract: This research studied the effects of the water environment on the mechanical, chemical and morphological changes of environmental degradation polyethylene mulching film. The mechanical characteristics of the environmental degradation polyethylene mulching film immersed in water environment or exposed in air declined. The elongation at break retention of the sample immersed in water reached minimum value for 70 days while 40 days for sample exposed in air. FTIR showed new hydroxyl absorption band appeared at 1717cm^-1 after exposed for 60 days. The relative intensity of absorption band of sample exposed in air is higher than sample immersed in water. AFM images showed large fluctuation on the surface after immersed in water or exposed in air for 60days.

Abstract: This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. Iodine adsorption method is used as a valuation means, the study was carried out on the co-carbonization of coal and biomass by the analysis of Iodine adsorption value. The research results show that the straw and cow dung has important effects on carbonization process; According to change rule of the Ignition loss rate and the iodine adsorption value, the iodine adsorption value of straw-coal co-carbonization product is higher than cow dung; Dashing treatment has significant effects on the iodine adsorption value carbonized product; the catalytic carbonization Biomass is the result of KOH effecting.