Advanced Materials Research Vols. 781-784

Abstract: The research examines the phosphorus removal efficiency of modified fly ash on landscape water and its influencing factors, and also study the actual eutrophication landscape water . Results show that when the solution pH is controlled in the range of 5 ~ 9, agitation speed is 150r. min ^-1and the additive amount modified fly ash is 1.2 g·L^-1, the oscillation adsorption time and adsorption temperature are respectively 60 min and at room temperature, for the raw water whose initial concentration of total phosphorus is 10.0 mg·L^-1 , the adsorption rate is 98.4%,which has a good adsorption effect. The test about Real urban landscape water shows total phosphorus is 0.35 mg·L^-1 , when the additive quantity of modified fly ash is 200 mg·L^-1, the concentration of the water reduce to the level of 0.01 mg·L^-1 ,which is up to the first class of landscape water quality standard (GB18921-2002)

Abstract: The adsorption of freshwater fish scales were used to remove Hg²⁺ in industrial wastewater. The effects of pH, shaking time, initial concentration on the adsorption Hg²⁺ onto freshwater fish scale were investigated. In these conditions, by varying the pH of the mercury (II) solutions from 2 to 8, the removal efficiency remained higher than 96%. Optimal adsorption capacity was 117.2 mg g^-1 at pH 6.0. Characterization of the biosorbent fish scales was performed using scanning electron microscope (SEM), and Fourier transform-infrared (FTIR) spectroscopy. The mechanism for the adsorption was studied. The adsorption of Hg²⁺on to freshwater fish scale could be described by Langmuir isotherm model.

Abstract: According to the structural characteristics of cuprous chloride ions in the wastewater, we use respectively rhodamine-B and 8-hydroxyquinoline as extractant to perform an extraction experimental research for cuprous chloride wastewater. We examine the influence of extraction time, extractant concentration, phase ratio, and pH on the disposal efficiency. We obtain the following observations: The usage of 8-hydroxyquinoline and rhodamine-B as the extractant can extract copper from cuprous chloride wastewater to some extent. Reducing pH of cuprous chloride wastewater solution with concentrated sulfuric acid is not conducive to 8-hydroxyquinoline extraction, which is conducive to rhodamine-B extraction but the effect is not obvious. Increasing temperature is conducive to 8-hydroxyquinoline extraction but not conducive to rhodamine-B.

Abstract: Hydrolysis of corn residue, one of major by-products after the extraction of starch, in sub-critical water to produce amino acids was conducted in this paper. The quality and quantity analysis of amino acids in hydrolysate were carried out by Amino Acid Analyzer (Biological Liquid Chromatography), and the main amino acid of arginine were obtained. The effects of Solid-water ratio, reaction temperature and time on the yield of the arginine were investigated. It was found that the optimum hydrolysis conditions for arginine preparation from the corn residue in sub-critical water are as follows: solid-water ratio 0.05, reaction temperature 473K and reaction time 1h, and the yield of arginine 10.23%. The results show that the sub-critical water hydrolysis process has the advantages of high efficiency, simple process and friendly to environment.

Abstract: Banana fusarium wilt is one of the soil-borne diseases of seriously threat to banana production in the world. However, there is no effective method for prevention. The objective was providing theoretical basis for field diagnosis of banana fusarium wilt. Thirty rhizosphere and non-rhizosphere soil samples were collected from three typical banana plots (Jianfeng, Shiyuetian, Chongpo) infected by banana fusarium wilt. Applying dilution plate method to estimate the pathogenic number, fourteen soil physicochemical properties and nutrient concentrations were chemically determined. Results showed that pathogenic number and nutrient concentrations in rhizosphere soil were higher than non-rhizosphere soil, the pathogenic number and pH in rhizosphere soils significantly increased with increasing of plant infection grades, while the concentrations of available P and B decreased with increasing of plant infection grades. It was concluded that infection degree of banana plants was mainly determined by pathogenic number, pH and the concentrations of available P and B.

Abstract: A micro-electrolysis reactor combined with the technology of impinging stream-cavitations drum was designed. Then it was used in the treatment of high concentration wastewater. Under the conditions of reaction time is 60 min, ratio of iron to carbon is 1 and the pressure of the air compressor is 8Mpa, the COD and chromaticity could remove 95.7% and 85.9% respectively. The biodegradability was improved obviously with 0.55 of BOD5/COD. The determinations of kinetics under the best conditions show that, the mode of COD removal basically conforms to the rule of first order kinetics. The reaction rate in our reactor was faster than only micro-electrolysis or only cavitations obviously. The conjunction of impinging stream-cavitations and micro-electrolysis has good synergism and facilitation.

Abstract: As a kind of particular hazardous materials, waste or expired gun propellants must be properly disposed. The applications of reusing waste gun propellants in the industry of china were summarized. Some disposal technologies were also introduced. Waste gun propellants were not only transformed into some chemical products and civil special energies, but also they were reused as ingredients in different kinds of industrial explosives. Among those the incorporation of propellants into industry explosives offers the most economically effective, safe and environmentally friendly method. This paper also suggests that the trend for disposing energetic materials is resource, recovery and reuse (R³) technology.

Abstract: Based on the actual operation of Wuhan Shanhu WWTP, and combined with the actual feature of A2/O process and reversed A2/O process, this text analyzed the practical effect of which the CODcr is only 48% of the design value and the sludge load is 15.2% of the design value, and the reason for the aged-sludge and the high effluent value of NH³-N, proposed corresponding adjustment and optimized operation program. The result of optimal operation mode shows that the biodegradable organic matter content in activated sludge increases from 49% to 78%. The effluent quality is superior to the first level B criteria specified in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002). The electric consumption saves 0.09kWh/m.

Abstract: The pyrolysis characteristics of pine powder and polyvinyl chloride (PVC), respectively representing the biomass and plastics components of municipal solid waste, were studied in a thermogravimetric analyzer, and the influence of heating rate on pyrolysis characteristics was also investigated. The pyrolysis temperature was heated from ambient up to 900 °C at different heating rates including 10, 20 and 40 °Cžmin^-1. The pyrolysis of pine powder was composed of two obvious weight loss phases, which were dehydration and the decomposition of cellulose and hemicellulose. The lignin in pine powder decomposed over a broad temperature range until 900°C. The pyrolysis of PVC was complicated, and included the release of hydrogen chloride (HCl), the formation of hydrocarbons. Besides, the additives in PVC decomposed at about 600 °C. The TG and DTG curves of pyrolysis for pine powder and PVC were similar at different heating rates, however, each weight loss phase of pyrolysis was shifted to high temperature with increasing the heating rate.

Abstract: Rural domestic refuse treatment technology is a complex uncertainty problem, which should consider not only the technical performance of rural domestic refuse treatment technology, but also its suitability for the social, economic and environmental situation of particular rural region. In this paper, Set pair analysis theory and information entropy method is used to evaluate rural domestic refuse treatment technology option.A case study was conducted in Wanxing Village in Chengdu City, and the evaluation results matched the local conditions. The method can serve as the decision analysis tool for sewage treatment technology demonstration and promotion in rural areas.