Applied Mechanics and Materials Vols. 675-677

Abstract: Gasification slag is one of the solid wastes forming by water-granulation for molten liquid and residual carbon. In this paper, the basic characteristics of gasification slags from Texaco and Shell gasifier (termed as WH and QP, respectively) were studied. X-ray fluorescence (XRF), X-ray diffraction (XRD), optical microscope (OM), and scanning electron microscopy (SEM) were carried to investigate the chemical composition, phase constituents, petrographical structure and microstructure of the slag, respectively. The results showed that: (1) The main chemical composition of WH and QP is SiO₂, Al₂O₃ and CaO. In addition, a large amount of residual carbon is also existed in WH. (2) The main phases of WH and QP are vitreous glass and quartz. In addition, calcite is also detected in WH; (3) The microstructural features of the two slags are nearly the same. Residual carbon in WH is existed with laminar structure.

Abstract: Soybean wastewater is a kind of nutrients wastewater. Using yeast to treat this kind of wastewater can not only degrade high concentration organic pollutants, but the yeast cell itself also can be harvest and realize the resources recycling. In this work, the feasibility and the optimal conditions of using yeast to treat soybean wastewater were investigated. Results showed that the initial COD and hydraulic retention time were the critical factors influencing COD degradation. Under 28 °C and with the initial soybean wastewater of 4800 mg/L, using Candida utilis with 20% of inoculums dosage could realize the higher reduction of the concentration of COD. And after 18 h’s treatment with rotating speed of 160 rpm, the COD removal could reach to 90%. The yeast wastewater treatment technology has the prospect of resources recycling. Besides, the pH value is very important for yeast to treat soybean wastewater.

Abstract: The aim of the work was to analysis effects of biogas residue continuous application on soil fertility improvment. The results showed that biogas residue addtion to peach orchard improved soil quality. Biogas residue application reduced soil bulk density quickly in a short term, improved soil TP, effctive N and available P contents significantly, as well as promoted soil TOC and humus acid accumulations to imoprove soil fertility. The results provide technical support for biogas utilization.

Abstract: By using positive forced aeration with different ventilation, sewage sludge was tested in sewage sludge composting. Temperature, moisture, organic matter, pH, ammonium and Germination Index (GI) were investigated. The ratio of sewage sludge and additives was 1:2 and the aeration rates of two composting piles were 1.2m³/ (h·t) and 2.4m³/ (h·t). After the composting, the moisture descended to 50% or so and the organic matter was under 45%. In addition, the pH was acidic and the ammonium was 0.4mg/g or so. The GI was more than 80%. The parameters tested during composting met the maturity requirements of Disposal of sludge from municipal wastewater treatment plant-Control standard for agricultural use.

Abstract: With acceleration of urbanization, BOT project on waste incineration in China has been developing rapidly in recent years. Starting from present situation of waste disposal, and combining generating electricity through refuse incineration in a city, this paper analyzes content and characteristics of social risk assessment on waste incineration project and further draws the frame of social risk assessment on waste incineration BOT project. Accordingly, put forward risk response suggestions on generating electricity project through refuse incineration of urban solid waste.

Abstract: By examining the compressive and flexural strength of composite and using scanning electron microscopy (SEM), we analyzed the influence of sodium hydroxide on the properties of FGD gypsum and slag composite materials and discussed the influence of sodium hydroxide on the setting time and mechanical strength of the composite materials and presented the action mechanism of sodium hydroxide as a stimulator. The results show that when the content of sodium hydroxide was percent of 0.25, the maximal strength of FGD gypsum-slag composite materials was reached.

Abstract: The accumulation of industrial waste residues is a serious problem with the continuous development of industrial productions during the recent years, how to use reasonably the industrial waste residues has gradually turned into an important research field in the world. Therefore, the research and development of porous ceramics synthesized by the industrial waste residues of fly ash, coal gangue and red mud etc as the raw materials were introduced, the present preparation technique and characteristics of the porous ceramics synthesized by the industrial waste residues were analyzed, and its further investigation was discussed.

Abstract: In the last decade the problem of household hazardous waste (HHW) is becoming increasingly important, in connection with expansion of the assortment and increase of the total number. The household hazardous waste include: mercury-containing fluorescent lamps and other devices, batteries, electrical and electronic devices (waste electrical and electronic equipment), remnants of household chemicals and medicines, and others.Such waste contains in its chemical composition of hazardous substances, which have negative impact on the environment and human health. If dangerous components are not allocated from the overall flow of low-hazardous municipal solid waste (MSW), in the processing or disposal in landfills, they begin to have a negative impact on the environment, which tends to accumulate.The article presents the assessment of the hazard class of solid waste, containing a specified number of HHW (according to various data about their morphological composition), using calculation methods approved in the Russian Federation. The analysis of the impact of HHW in the composition of MSW on the environment during the implementation of the main ways of MSW treatment is performed. A brief review of modern technologies of collection and processing of HHW in Russia and other countries is presented and recommendations are given.

Abstract: A Plackett–Burman design was employed to investigate the effect of various parameters on the denitrification effect of high salinity wastewater treated by biofortification SBR.The purposes of this study were to investigate the significance of pH, DO, C/N, the initial ammonia concentration, salinity, the amount of bacteria and sludge concentration (MLSS).Factors which have significant influence on the denitrification effect of biofortification SBR treatment are quickly screened and used to establish a mathematical model.The results of quick screening provide critical factors for the optimization of operating parameters.

Abstract: For a long time, a large number of residential laundry wastewater emissions increased heavy burden to the city sewage treatment plant and brought serious pollution to the surface water. This study uses industrial waste (slag, fly ash) as substrate, mixed with some binder and pore forming agent to produce spherical composite materials for the study on adsorption of washing wastewater. Experiments show that the main pollutants of the laundry wastewater with sodium n-alkyl benzene sulfonate (LAS) are obviously removed.