Advanced Materials Research Vols. 610-613

Abstract: At present, in the geological disposal domain of high-level radioactive waste, little is known about microorganisms in deep underground geological environment in our country. This paper introduces some interactions between microbiological and geological disposal of high-level radioactive waste. There is a huge biosphere in the deep underground, mainly held by extremophiles. Microorganisms can influence the waste geological disposal environment in two aspects. On the one hand, the storehouse security will be confronted with serious problems of microorganisms because of their material corrosion capability. The main species of corrosion microorganisms include sulfate reducing bacteria, sulfur-oxidizing bacteria, saprophytic bacteria, iron bacteria and fungi. About research development on interactions between microbiological and geological disposal of high-level radioactive waste in China and abroad, foreign countries started early. Specialized research field has been formed and many achievements has been made by a series of research in Sweden, US, France, Canada, and so on. But relevant study is very few in our country. Therefore, there are special necessity and urgency to carry out this research.

Abstract: This paper reports the application of Taguchi optimization technique in determining process condition for synthetic lightweight aggregates by incorporating waste liquid crystal displays (LCD) glass with reservoir sediments. In the study the waste LCD glass cullet was used as an additive. It was incorporated with reservoir sediments to produce lightweight aggregates. Taguchi method with an L₁₆(4⁵) orthogonal array and five controllable 4-level factors (i.e., cullet content, preheat temperature, preheat time, sintering temperature, and sintering time) was adopted. Then, in order to optimize the selected parameters, the analysis of variance method was used to explore the effects of the experimental factors on the performances (particle density and water absorption) of the produced lightweight aggregates. The results showed that it is possible to produce high performance lightweight aggregates by incorporating waste LCD glass cullet with reservoir sediments.

Abstract: Chrome shavings were dechromed by methods of oxidation and the extracts were obtained in acidic or basic condition. The blended solutions were obtained by blending chrome shavings extract with polyvinyl alcohol (PVA). The optimal proportion was determined after comparing the properties which included viscosity of the mixture, mechanical properties of the blended membranes and degradation. The optimal proportion of PVA: extract (prepared with acid method) is 2:8 while solid content is 10 percent. The results of degradation test indicated that the membranes developed with the extract and PVS could be degraded in soil, trypsin solution and AS1.398 solution.

Abstract: With the deeply surveys and interviewing with some students in Shanghai Nanhui University Town, the status of recycling waste materials and its problems are analyzed. By forming a good recycling system, the waste materials can be fully utilized. Combining with the status of Shanghai Nanhui University Town, it is helpful to build a new system of recycling waste materials and operated with a scores-accumulation system.

Abstract: Microwave pyrolysis of sewage sludge was conducted in a single-mode microwave oven. The influencing effects of experimental factors, including particle size and moisture content of sewage sludge, pyrolysis temperature, and shape of microwave adsorber, on concentration of pyrolysis gas products were studied. The results indicated that with the decrease of particle size, the H2 concentration increased from 31 vol.% to 34 vol.%, and CO concentration increased from 17 vol.% to 22 vol.%. When the moisture content of sewage sludge increased from 0 to 83 wt.%, the H2 concentration increased from 32 vol.% to 42 vol.%, and the CO concentration increased from 20 vol.% to 31 vol.%. Compared with microwave adsorber in powder phase, the microwave adsorber in fixed structure can transform more volatile compounds to uncondensable gas, and the concentrations of H2 and CO were also slightly increased.

Abstract: An effective combined process of aeration micro-electrolysis and flocculation was utilized to treat arsenic that incoming contaminate level was 153 mgL-1 from the metallurgical effluent. Treatment mechanisms and operation conditions were discussed which influenced the removal efficiency of arsenic. Under the optimal technological conditions, it was found that the removal efficiencies of COD and As were 92.5% and 99.7% respectively. The remain arsenic concentration in the treated wastewater was only 0.43mgL-1 and met National Wastewater Discharge Standard(GB8978-1996) in China. Analysis by SEM and EDS revealed that using combined process, most of As(III) could be oxidized to As(V), which led to the high efficiency of arsenic removal. In the meantime, most of other heavy metals, such as Cu, Pb and Ni, had been removed. Therefore, the combined process is regarded as a promising technology in the treatment of arsenic from copper smelting effluent. It has bright future in application.

Abstract: As the enhancement of the economic level in our country, the quantity of motor vehicles and the end-of-life vehicles grows fast. The recycling of the end-of-life vehicle is the basic element for the sustainable development in automobile industry. At the same time, the disassembling of the end-of-life vehicle is an important link in the development of the automobile recycle economy and also an important mean to the resource recycling. So, a scientific and rational management system in vehicle disassembling can have a positive effect in building a resource conservation and environment friendly society. At present, many problems in motor vehicle recycling and disassembling have already restricted the development of the industry. Through the investigation of the present status of the end-of-life vehicle recycling and disassembling enterprise in Jiangsu province, the reason of those problems is analyzed, the method to solve those problems is discussed and put forward, and a new management system in motor vehicle recycling and disassembling is built. The research can provide instruction meaning and reference value to all the end-of-life vehicle recycling and disassembling enterprises.

Abstract: In the present work, acrylonitrile removal from analogue wastewater was investigated using the combined Fe/C microelectrolysis–electro-Fenton. The optimization parameters such as ratio of Fe/C, pH value, the reaction time, the dose of H₂O₂, the voltage, and the stir time on the acrylonitrile removal efficiency were determined by measuring the percentage removal of Chemical Oxygen Demand (CODcr) in the acrylonitrile analogue wastewater. In the Microelectrolysis section, the ratio of Fe/C was 1:1, the pH value was 3.0, and reaction time was 1h. In the electrolyzing Fenton, the optimal conditions of process parameters were the dose of H₂O₂ oxidant (5ml/L), the voltage (2.0 V), electrochemical reaction time (40min), and stir time (20min).Under the optimal conditions, the percentage removal of was 69% in first section and about 35% in the second section. Also, the dose of oxidant (H₂O₂) decreased from 11ml/L to 5ml/L compared with the using single active carbon method.

Abstract: Biphasic calcium phosphate bioceramics were fabricated from the recycling of bone ash which is mostly used as raw materials of bone china. Precursor calcium phosphate powders were prepared by soaking the commercial bone ash in 0.1 M of NaOH solution at 80°C for 4 h. Calcium phosphate powders was obtained by calcination at 800°C for 1 h to completely remove residual organics. Biphasic calcium phosphate bioceramics which is composed of hydroxyapatite and tricalcium phosphate was fabricated by the sintering of pressed compacts at 1200°C for 1 h under moisture protection. The bone ash derived-biphasic calcium phosphate ceramics consists of mostly HA and small amounts of α-tricalcium phosphate, magnesium oxide and calcium oxide. After polishing the HA ceramics, they were immersed in buffered water at 37°C for 3 and 7 days. The bone ash derived- biphasic calcium phosphate ceramics show high biostability in liquid environment with immersion time compared with commercial calcium phosphate ceramics.

Abstract: A pilot scale biochemical treatment system containing three isolated biological aerated filters, one oil-separation pool and one secondary sedimentation tank was set up and used for high concentration organic waste water treatment. Effect of different operating conditions on Chemical Oxygen Demand (CODCr), sulphides, hydroxybenzene and oil degradation was investigated. And the ways of sulphides removal were also explored. While CODCr, the concentrations of sulphides, hydroxybenzene and oil in the waste water are no more than 1500 mg/L, 800 mg/L, 15 mg/L and 150mg/L, respectively, the system can run stably and the total removal of these pollutants is 88.8%, 98.8%, 96.8% and 91.0% accordingly though hydraulic retention time (HRT) varies from 7.95 hr to 15.90 hr and the air/water volume ratio (AWVR) varies from 12 to 8. Most of the sulphides are removed by Biodegradation with Isolated Biological Aerated Filters. Most of the pollutants are removed in the 1st BAF and about 96.5% by mean value of sulphides transforme into elemental sulfur and only about 2.7% by mean value of sulphides transforme into sulphates.