Advanced Materials Research Vols. 1010-1012

Abstract: Co-pyrolysis of polyethylene plastic and cellulose as models for medical waste had been studied on a supercritical water batch reactor. The results show that temperature, reaction time, pressure and the mass ratio of water to organic matter have some degree impact on the conversion rate, oil yield and gasification efficiency. Conversion and gasification efficiency reached the maximum values at 440 °C. The content of H₂ in the gaseous products rose significantly between 25 MPa~27 MPa. As reaction time increased, conversion and gasification efficiency increased, but oil yield decreased. The composition of gaseous products was affected greatly by the mass ratio of water to organic matter. Adding K₂CO₃ and Ca (OH)₂ as catalyst, the reaction was promoted obviously.

Abstract: We studied the changes of physicochemical and biological properties in order to evaluate the stability and maturity of the composting process during the forced-aeration composting process of tobacco industry wastes. Composting was carried out using two methods, i.e. waste tobacco leaves mixed with 15% waste tobacco stems (bioreactor A) and the addition of 30% waste tobacco stems (bioreactor B). The results showed that two composting all maintained the temperature exceeding 55°C for more than 3days. Compared with treatment B, the time of reach high temperature in the treatment A was shorted by 1 day and the sustaining time of high temperature extended by 3 days. The final electrical conductivity in compost A did not exceed the limit value of 3.00ms/cm^-1 for stable compost. The final germination index in composting A and B were 111% and 85% respectively, which suggested a higher stability in composting A than B.

Abstract: Bauxite waste sludge as a raw material, the use of reverse chemical coprecipitation synthesize Fe₃O₄. Researching temperature, precipitation concentration, aging time and Fe²⁺/Fe³⁺ molar ratio effect on the particle size, morphology. Optimal experimental conditions: temperature 70 °C, the precipitant NaOH mass ratio of 10%, aging time 3h, Fe²⁺/Fe³⁺ molar ratio of 2:3. Test methods using a laser particle size analyzer, XRD analysis of the products were characterized, the product is Fe₃O₄, the average particle size of 0.11mm.

Abstract: It is urgent for agricultural and forestry wastes (AFWS) to be handled efficiently as the generations of them are increasing rapidly in China. The paper studied the bacterial community variations in composting of AFWS with different three microbial agents by PCR-DGGE. Three microbial agents in the research were Phanerochaete chrysosporium(PC) , Coriolus versicolor (CV) and GP (agent developed from laboratory with high lignocellulose degradation ability). DGGE profiles indicated that the populations of bacteria reduced from warming period to high-temperature phase fistly, then increased till cooling period, and finally descended during maturity period for all the composting treatments. The populations of bacteria in composting with GP innoculation keeped on a high level during high-temperature phase, cooling period and maturity period. In the early phase of the high temperature composting, Bacillus sp., Uncultured Bacillus sp., Pseudomonas sp., Uncultured Pseudomonas sp., Micrococcus sp., Brevibacterium, Sphingomonas sp., Aminobacter aminovorans and Uncultured Acinetobacter sp.were rich, and became the dominant flora of the period. The number of the same dominant flora in AFWS composting with GP and CV innoculations was the most during the high-temperature phase. Simultaneously, the number of the same dominant flora in AFWS composting with GP and PC innoculations was the most during cooling period. Therefore, GP has a good prospect in AFWS composting process for resource utilization.

Abstract: This Thesis introduces the principle and structure of vehicular pyrolysis treatment furnace for medical waste and analyzes two flue gas purification structures of direct purification and coil purification and the effects, existing problems and forming reasons of flue gas emission of aftertreatment underwater aeration quenching structure; purification structure and quenching structure designed based on 3T control theory can control flue gas emission quality effectively and greatly reduce the influence on the environment due to the secondary synthesis of Dioxin and these structures have met national safety and emission standards; flue gas emission technology is a key technology for miniaturization and light-weight trend of pyrolysis treatment equipment for medical waste and a significant technological base for development of pyrolysis treatment car for medical waste.

Abstract: Nowadays, being confronted with the decreasingly nature resource and environment polluted, effectively mining the potential economic benefits of retired or scrap equipment, studying on planning retired or scrap equipment recycling system, is a very important matter. This paper puts forward an ideology of the recycling of retired or scrap weaponry and equipment based on 3R, by introducing 3R principle which is the core ideology of circular economy. This paper presents a retired or scrap equipment recycling system planning thought, analyzes the system framework which consists of recycling targets, recycling objects, functional elements and participating subject. The preliminary structural Model is established, as well as the concrete operation processes are studied.

Abstract: The US Army’s disposal situations about the retired or scrap equipment are discussed. Primary methods are as follow, establishing the Defense Reutilization and Marketing Service (DRMS), setting up Aeronautical Maintenance and Recycle Center, founding a “Shadow Fleet” by retired fleet and ships, carrying on equipment remanufacture program, implementing contractor support. And then, the essay analyzes its characteristics such as paying close attention, perfecting mechanism, integrated management, disposing in time, classifying, using modern techniques, civil-military integration, etc. Finally, its enlightenments are mainly discussed, in current circumstance, paying more attention to dispose the retired or scrap equipment, whole-system whole-life and whole-goal optimization design especially considering the disposal at the designing phase, developing and innovating the technologies of reutilization, taking the development path of civil-military integration type are the inevitable trends.

Abstract: As a low-rank coal, the high moisture content of lignite need to be dehydrated and refined before combustion. To alleviate the water shortage situation of lignite region, this paper put forward a way of microwave dehydration to recycling the water out of lignite. By detecting the chemical oxygen demand, ammonia nitrogen, total phosphorus, hardness, ions, organic compounds of lignite, it can be concluded that the dehydration ratio of lignite reaches 70~80%, and the water quality as ammonia nitrogen, total phosphorus was close to industrial standard. While the chemical oxygen demand exceeded the standard scope as well as trace amount of poisonous metal elements and organic compounds causing cancer, this will become the main task of subsequent purification process.

Abstract: Development of recyclable resources industry makes a positive effect to alleviate the shortage of resources and control environmental pollution. At present, China's recyclable resources industry still has some problems. The Government should vigorously develop recyclable resources industry and participate in global recyclable resources circulation in the future.

Abstract: To reduce the route length of MSW collection without intermediate facilities, A Waste Collection Vehicle Arc Routing Problem with turn constraints (WCVARPTC) model was proposed, which considers the actual traffic regulations: some streets can be traversed in only one direction; some turns will be forbidden when the common angle is too narrow. An asymmetric vehicle node routing problem (AVNRP) model was formulated to reduce the scale of the WCVARPTC. And a MULTI-ACS algorithm was designed for solving such an asymmetric one. The results of 2 benchmark instances for CVARP indicate that the best solutions has approached the best known solutions with deviation 0.28% and 0.16% respectively.