旅客列车真空集便器便盆冲洗排空影响因素及相关技术研究

旅客列车真空集便器便盆污物冲洗排空效果受诸多因素影响,各影响因素间相互作用.为实现以较低冲洗水量达到良好冲洗排空效果、提高系统洁净性能,对便盆曲面、冲洗流型进行分析设计,对旋流和扇面2种不同冲洗流型特点进行比较,分析不同设计参数及安装位置对冲洗排空效果的影响,最终通过试验研究验证冲洗喷嘴的安装位置、旋流喷嘴的射流方向等...     

高水分蔬菜和花卉废物序批式进料联合堆肥的中试

以滇池流域典型蔬菜废物(西芹、白菜)和花卉废物(石竹)为原料,进行了序批式联合堆肥的试验研究.以西芹和石竹作为初始物料,控制初始混合物料的含水率在60%～70%,每隔4d添加一次白菜;采用温度反馈通气量控制的好氧静态堆肥技术,在堆体温度40℃左右时停止通风.试验分析了堆肥过程中堆体温度、通风速率、水分、pH值、有机质、灰分、体积、NH₄⁺-N,NO₃^--N等指标随时间的变化特征.结果表明:采用序批式进料、温度反馈通气量控制的静态好氧堆肥技术进行蔬菜和花卉废物联合堆肥可以有效控制堆肥过程,实现有机物料的快速稳定和去除水分,解决了滇池流域蔬菜废物量远大于花卉废物量时堆肥难以有效进行的技术难题.     

Deep stacking poultry litter as feed ingredient in livestock production

The compelling need to harness the potentials of the numerous agro-industrial by-products and the so-called “wastes” as part replacement for the more expensive conventional feed ingredients have been seriously expressed. This need has arisen mainly from the increasing demand and supply deficit of conventional feed resources with a concomitant sharp rise in their cost prices. The net effect of increased unit cost of the conventional feed resources is increased cost of the compounded rations, which by extension gives rise to increased cost of meat and animal products. It then becomes highly imperative that other sources for rapid livestock output to meet the growing human demands for animal protein foods are sourced. Such other sources should be cheap and nutritionally adequate for feeding animals with the aim of lowering the cost of producing meat. One of such measure is the recycling of poultry litter as part replacement for soya bean in livestock nutrition. Poultry litter is the by-product of poultry production, which should be managed in an environmentally friendly manner. As observed in this study, poultry litter contains 20% crude protein, 621.41 ME kcal kg^?1, and substantial amounts of minerals that could be exploited in feeding livestock. This study has explored the possibility of including poultry litter in diets in view of its contents.     

Metal binding capacity of soft acid,organic‐rich waters

Organic carbon from one stream and two ponds in South Carolina was fractionated into five nominal molecular diameter fractions by ultrafiltration. The concentrations associated with and binding capacity for Ca, Cd, Cu and Pb were determined for each fraction. The distribution of organic carbon among ultrafilter fractions varied from water to water, with the largest percentage occurring in the smaller fractions. Calcium was associated with each of the fractions isolated from each of the three waters, indicating Ca is bound to organics in all fractions, however, more than 99% of the Ca which passed the smallest ultrafilter was removed by cationic exchange resin. Each fraction bound more Ca than Cd, Cu or Pb except in a few cases where Pb binding was greater. All of the organic fractions had their Ca++ binding sites saturated. Calcium was not an effective competitive ion against Cd, Cu or Pb for organic binding sites. The total Cu binding capacity was less than that of Ca or Pb but similar to that of Cd. Naturally occurring organics bound more Pb than Cd or Cu but less than Ca. Saturation of Cu binding sites was less than 20% in most ultrafilter fractions except that with a nominal molecular weight of between 10,000 and 300,000 where the percent of saturation was as much as 60%. Approximately 50% of the Cu was removed onto anionic exchange resin in two waters while more than 90% was removed from water with a high organic content. Percent saturation of Cd and Pb binding sites ranged from 0.091% to 5.4% and 0.059% to 1.5%, respectively. All ions tested effectively competed with Cd, Cu or Pb for some but not all binding sites, indicating that organic binding sites were heterogeneous. A generalized order of metal‐organic stabilities based on competition for binding sites is Al>Cd>Pb>Cu>Ni = Mg=Zn = Mn>Ca. Both Cd+2 and Al+3 effectively out competed Pb++ and Cd and Pb out competed Cu for most organic binding sites.     

Overview of Radioactive Waste Disposal at Sea

For hundreds of years, the seas have been used as a place to dispose of wastes from human activities. Although no high level radioactive waste has been disposed of into the sea, variable amounts of packaged low level radioactive wastes have been dumped at 47 sites in the northern part of the Atlantic and Pacific Oceans. in 1946 the first sea dumping operation took place at a site in the North-East Pacific Ocean. the last dumping operation was in 1982, at a site off the European continental shelf in the Atlantic Ocean. Between these two dates, an estimated 46 PBq (1.24 MCi) of radioactive waste coming from research, medical, military and industrial activities have been disposed of at sea. the present trend, through the Convention for the Prevention of Marine Pollution by Dumping of Wastes and other Matter and other Regional Conventions, points towards the prohibition of the dumping of any radioactive waste into the marine environment.     

Fabrication,characterization and evaluation of mesoporous activated carbons from agricultural waste: Jerusalem artichoke stalk as an example

This work explores the feasibility of Jerusalem artichoke stem (JAS), an agricultural waste, as an alternative precursor for fabrication of mesoporous activated carbon (MAC) via conventional ZnCl₂ activation. The as-prepared JAS-MACs were characterized by thermogravimetric, nitrogen gas adsorption isotherm and high resolution scanning electron microscopy analysis. The interacting effects of chemical dosage, activation temperature and time on the mesoporosity, mesopore volume and carbon yield were investigated, and further optimized by response surface methodology (RSM). The Brunauer-Emmett-Teller surface area, mesoporosity and mesopore volume of the JAS-MAC prepared under optimum condition were identified to be 1631 m²·g^-1, 90.16% and 1.11 cm³·g^-1, respectively. Compared with commercial activated carbons, this carbon exhibited a comparable monolayer adsorption capacity of 374.5 mg·g^-1 for Methylene Blue dye. The findings suggest that RSM could be an effective approach for optimizing the pore structure of fabricated activated carbons.     

Hydrothermal treatment of MSWI fly ash for simultaneous dioxins decomposition and heavy metal stabilization

Researches on the hydrothermal treatment of municipal solid waste incineration (MSWI) fly ash were conducted to eliminate dioxins and stabilize heavy metals. In order to enhance decomposing polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs) during hydrothermal process, a strong reductant carbohydrazide (CHZ) is introduced. A hydrothermal reactor was set up by mixing raw MSWI fly ash or the pre-treated fly ash with water and then heated to a pre-set temperature; CHZ was spiked into solution according to specially defined dosage. Experimental results showed that under the temperatures of 518 K and 533 K, the decomposition rates of PCDDs/PCDFs were over 80% and 90%, respectively, by total concentration. However, their toxic equivalent (TEQ) decreased only slightly or even increased due to the rising in concentration of congeners 2, 3, 7, 8-TCDD/TCDF, which might be resulted from the highly chlorinated congeners losing their chlorine atoms and being degraded during the hydrothermal process. Better results of TEQ reduction were also obtained under the higher tested temperature of 533 K and reactor with addition of 0.1%wt CHZ was corresponded to the best results. Good stabilization of heavy metals was also obtained in the same hydrothermal process especially when ferrous sulphate was added as auxiliary agent.     

宁东能源化工基地固体废物中汞含量分布及对环境影响

通过分析宁东能源化工基地各大燃煤电厂以及煤化工厂固体废物样品,研究了固体废物中的汞分布规律及环境影响。结果表明:汞易在脱硫石膏、粉煤灰和气化粗渣中富集,汞浓度分别为0.16、0.24、0.15 mg/kg,而炉渣和气化细渣中的汞含量则相对较低,分别为0.05、0.03 mg/kg。通过化学组成及汞含量数据分析发现,出现这种情况的原因与汞本身易挥发的性质和固体废物的物化性质有关。此外,通过固体废物浸出毒性实验发现,脱硫石膏、粉煤灰、气化粗渣的浸出汞浓度小于浓度限值(0.1 mg/L),而气化细渣因锅炉回用,不参与填埋,汞又不易在炉渣中富集,故总体上宁东能源化工基地的固体废物无汞环境污染倾向。     

Avian Mortality at Oil Pits in the United States: A Review of the Problem and Efforts for Its Solution

Oil production operations produce waste fluids that may be stored in pits, open tanks, and other sites accessible to wildlife. Birds visit these fluid-filled pits and tanks (“oil pits”), which often resemble water sources, and may become trapped and die. The US Fish and Wildlife Service (USFWS) has a program to reduce these impacts by locating problem pits, documenting mortality of protected wildlife species, and seeking cleanup or corrective action at problem pits with the help of state and federal agencies regulating the oil industry. Species identification and verification of protected status for birds recovered from oil pits are performed at the USFWS National Fish and Wildlife Forensics Laboratory. From 1992 to 2005, a minimum of 2060 individual birds were identified from remains recovered from oil pits, representing 172 species from 44 families. The taxonomic and ecological diversity of these birds indicates that oil pits pose a threat to virtually all species of birds that encounter them. Ninety-two percent of identified bird remains belonged to protected species. Most remains identified at the Forensics Laboratory were from passerines, particularly ground-foraging species. Based on Forensics Laboratory and USFWS field data, oil pits currently cause the deaths of 500,000–1 million birds per year. Although law enforcement and industry efforts have produced genuine progress on this issue, oil pits remain a significant source of mortality for birds in the United States.     

猪场废弃物强制通风静态仓堆肥系统的试验研究

通过组织5个猪场废弃物堆肥试验,度量温度、表观性状、体积、重量损失、全氮、全磷、大肠杆菌值、蛔虫卵杀灭率和发芽指数等指标,检验了开发的强制通风静态仓堆肥系统的性能.结果表明,除起始含水率为80%试验堆体因起始含水率过高导致发生厌氧反应外,其余4个堆体均实现堆肥无害化、减量化、稳定化和资源化的处理目标;堆肥温度维持50℃以上5～7 d,或55℃以上3 d是大肠杆菌值达到国家粪便无害化卫生标准的必要条件;堆肥过程能有效脱除堆料的生物毒性,后腐熟阶段是必需阶段;氮、磷、钾等主要营养元素在堆肥前后呈现"浓缩效应".因此,堆肥化能提高猪场废弃物肥效和利用价值.