Advanced Materials Research Vols. 726-731

Abstract: Abstract. The copper in plateau red soil was extracted by ultrasonic-assisted oxalic acid. Tessier fractional extraction method was used to evalute copper speciation. The result showed that the biggest extraction rate was 69%. Compared with oscillation extraction, the extraction rate of ultrasonic extraction was increased by 7.18% under the condition of 0.1 mol/L oxalic acid, 20:1 of liquid-solid ratio and 30 min of extraction time. Ultrasound could promote the oxalic acid extraction of copper from plateau red soil effectively, which could be attributed the success to the activation effect of ultrasound on bound to carbonates speciation and bound to iron and manganese speciation.

Abstract: Under visible light irradiation, the photocatalytic degradation of Br-THMs was successfully achieved. It suggested that Br-THMs were de-bromized in a stepwise manner. The more bromine substituted in Br-THMs, the more easily it can be degraded, due to C-Br bond is easier destroyed than C-Cl. A proposed degradation pathway through a series of free radical reactions was also discussed.

Abstract: The exhaust from diesel engines consists of a large quantity of toxic substances, including NO_x,CO₂, CO, SO_x, particulate matter (PM), and HC compounds from incomplete combustion. In this study, enzyme fuel additive was added to Class A fishing vessel fuel in different proportions in an experiment to measure the changes in the content of air pollutants emitted from the combustion of fuel in a single-cylinder diesel engine power generator. The specimen used in this study was a Class A fishing vessel fuel under the national policy of subsidizing fishermen in fuel consumption blended with enzyme fuel additive. In this experiment, a Class A fishing vessel fuel was used as the controlled specimen to compare three different types of diesel additive available from the market and the fuels blended with enzyme. A diesel engine power generator was used in the experiment to observe the emission of gas pollutants from the engine operated with different formulas of fuels under the same loading conditions. A gas pollutant analyzer was used to observe the content of gas pollutants and their influence on air pollution.

Abstract: Modified bentonite was used as adsorbent for the methylene blue adsorption in a batch process. Experimental results show that the adsorption kinetics is well described by pseudo-second-order model and the equilibrium data was better represented by the Freundlich isotherm model. The results revealed that the modified bentonite has the potential to be used as a good adsorbent for the removal of methylene blue from aqueous solutions.

Abstract: In order to understanding of the fate and transport of TiO₂ nanoparticles (Nps) in the water treatment process, this study focused on the impact of humic acid (HA) on the aggregation and charge behavior of TiO₂ Nps, and investigated the removability of TiO₂ Nps stabilized by HA during the coagulation process. Malvern Zetasizer nanoZS measured the changes of size and zeta potential of HA capped TiO₂ Nps (HA-TiO₂). Uv-vis spectrometer examined the aggregation behavior of TiO₂ and HA-TiO₂ NPs at different pH value. Jar tests were conducted to evaluate the removal efficiency of TiO₂ NPs. HA adsorbed on the surface of TiO₂ Nps could decrease the zeta potential values and enhance the stability of TiO₂ Nps. TiO₂ Nps could be effectively removed by aluminum sulfate (AS) under favorable condition. HA could influence the removal of TiO₂ Nps during the coagulation processes. Low concentration of HA rejected the removal efficiency of TiO₂ Nps, however, high concentration of HA promoted removing effectiveness.

Abstract: Introduction is given to the content of activated sludge model No.3 (ASM3). The simulation program which based on the integration of ASM3 and Anaerobic Digestion Model was used to simulate A²/O with AquaMats Process. The predicted results of effluent COD, NH₃-N and NO₃-N accorded with the actuality. The removal efficiency of TP was quite low when sludge return rate was 100%. Based on this condition, the improved scheme which adjusts sludge reflux ratio to 60% was put forward and simulated. Process was optimized depending on the simulation results and the removal efficiencies of COD, NH₃-N and TP reached to 83.1%, 98.75 and 24.01%. It is verified that ASM3 can be used as the platform of activated sludge process design.

Abstract: The cell dissolved effect of acid and alkali lysis on excess sludge, as well as the influence factors including pH, temperature, time and other factors were examined in this work. Under the optimal experimental conditions of pH=12, T=60°C, t=2h, the results showed that the contents of soluble protein, soluble total sugar, soluble chemical oxigen demand (SCOD) in the organic material dissolved out increased obviously. Therefore, the sludge reduction efficiency was remarkable.

Abstract: Oxidative degradation of ethylenediaminetetraacetic acid(EDTA) in aqueous solution at normal temperature and pressure by the novel bimetallic Al-Fe was investigated. The results showed that the removal efficiency of EDTA, TOC and TN could be about 98%, 75% and 47% respectively after 3h reaction. The effects of initial pH, concentration of EDTA, mass ratio of Al⁰ and Fe⁰ and Al-Fe loading were also investigated. Significantly, the bimetallic Al-Fe process exhibited higher reactivity than monometallic Fe⁰/Al⁰ process for the degradation of EDTA.

Abstract: A strain of Pseudomonas stutzeri named LH42 was isolated from the petroleum-contaminated soil collected from Liaohe Oil Field, Liaoning, China. The strain was capable of degrading dibenzothiophene (DBT). The bacterium was motile, rod-shaped, and grew optimally at 30°C and initial pH of 7.0. The morphological, physiological characterizations and analysis based on 16S rRNA sequence indicated that this strain was most closely related to Pseudomonas stutzeri (>99% similarity in gene sequence). Coal biodesulfurization of this strain was processed. And a total sulfur removal of 41.5% and organic sulfur removal of 92.9% was obtained within 25 days. Scanning electron microscope (SEM) analysis revealed that the strain was closely attached on the coal surface and the coal was markedly etched.

Abstract: Amino-functionalized mesoporous silica (AFMS) with high amino loading, high surface area, and large pore size was synthesized using the anionic surfactant N-lauroylsarcosine sodium (Sar-Na) as template and 3-aminopropyltriethoxysilane (APTES) as co-structure directing agent (CSDA). The synthesized AFMS was characterized by N₂ adsorption-desorption, TEM and elemental analyzer. The results of the removal of Cd²⁺ from aqueous solution showed that the pH value of aqueous solution affected the removal efficiency of Cd²⁺ greatly, and that unary adsorption isotherm of Cd²⁺ on the AFMS was well described by the Sips isotherm model, in which the adsorption capacity was 2.43 mmol/g for Cd²⁺, much higher than the literature data.