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51.
52.
以硫化钠为硫化剂,机械化学硫化荧光灯管芯柱玻璃中金属铅,实现金属铅向硫化铅快速转化.通过单因素实验,考察了不同机械化学硫化条件,即球磨时间、球磨转速和球料比对硫化率的影响,并通过XRD、SEM和粒度对硫化产物进行表征.结果表明,硫化率随球磨时间和球磨转速的增大而增大,随球料比的增大先增大后减小,当球磨转速为750r/min、球磨时间为120min、球料比为50:1g/g时,荧光灯管芯柱玻璃中金属铅的硫化率可达96.18%.XRD结果表明,荧光灯管芯柱玻璃中金属铅的机械化学硫化产物为PbS、SEM和粒度结果表明,荧光灯管芯柱玻璃的粒径随球磨转速和球磨时间的增加而减小. 相似文献
53.
Ajay Kumar Kaviti Akhilesh Yadav Amit Shukla 《International Journal of Green Energy》2019,16(6):442-449
Developing a compact, simple, and productive solar still is a main challenge. This paper describes a simple modification of the solar still that significantly enhances its productivity. A laboratory scale of modified single effect double slope glass solar still with the opaque triangular north wall has been developed and tested for enhancement of productivity in sunny days of the summer season in the month of April. The experiments on still have been carried out under three levels of water depths from 1 to 3 cm and compared it with the performance of conventional still of double slope single effect solar still of the same size. It is clear from the observations that opaque type still gave maximum distillate of 1793 ml at 1 cm depth of water while conventional still could produce only 1519 ml for the same depth of water. Also, for 2 and 3 cm depth of water, the opaque type still found to be more productive than conventional double slope solar still. As the former produced 1532 and 1464 ml while the latter produced 1328 and 1235 ml, for 2 and 3 cm depth of water, respectively. 相似文献
54.
混凝沉淀工艺处理玻璃纤维生产废水试验研究 总被引:2,自引:0,他引:2
通过多种混凝剂对玻璃纤维生产废水进行混凝沉淀处理试验,结果表明,FeSO4.7H2O对玻纤废水具有较好的处理效果,并且探索了其处理的最佳工艺条件,在FeSO4.7H2O投加量为500-800mg/L,PH为6-11时,出水各项指标均达到国家排标准。 相似文献
55.
The synthesis of carboxymethylcellulose was investigated using effluents containing short cellulose fibers. Carboxymethylcellulose was synthesized according to the slurry process using different amount of sodium hydroxide and different incubation times at 30 °C after the etherification reaction as variables. Characterization of the product was conducted by Fourier transformed infrared spectroscopy, X-ray diffraction, degree of substitution, average degree of polymerization, water imbibing capacity, color, rheological properties, apparent viscosity and trace elements content. Incubation time slightly increased the yield of the reaction and the degree of substitution during the first 12 h. The reaction yield and degree of substitution both decreased when the initially concentration of NaOH was increased from 7.0 g/mL to 10.5 g/mL. The carboxymethylcellulose obtained was darker and had lower hydration properties than commercial samples. Trace elements content suggests that the product could be only used in paint factories or building materials industries. 相似文献
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Aggregate is used in road and building construction to provide bulk, strength, support, and wear resistance. Reclaimed asphalt pavement (RAP) and reclaimed Portland cement concrete (RPCC) are abundant and available sources of recycled aggregate. In this paper, current aggregate production operations in Virginia, Maryland, and the District of Columbia are used to develop spatial association models for the recycled aggregate industry with regional transportation network and population density features.The cost of construction aggregate to the end user is strongly influenced by the cost of transporting processed aggregate from the production site to the construction site. More than 60% of operations recycling aggregate in the mid-Atlantic study area are located within 4.8 km (3 miles) of an interstate highway. Transportation corridors provide both sites of likely road construction where aggregate is used and an efficient means to move both materials and on-site processing equipment back and forth from various work sites to the recycling operations.Urban and developing areas provide a high market demand for aggregate and a ready source of construction debris that may be processed into recycled aggregate. Most aggregate recycling operators in the study area are sited in counties with population densities exceeding 77 people/km2 (200 people/mile2). No aggregate recycling operations are sited in counties with less than 19 people/km2 (50 people/mile2), reflecting the lack of sufficient long-term sources of construction debris to be used as an aggregate source, as well as the lack of a sufficient market demand for aggregate in most rural areas to locate a recycling operation there or justify the required investment in the equipment to process and produce recycled aggregate.Weights of evidence analyses (WofE), measuring correlation on an area-normalized basis, and weighted logistic regression (WLR), are used to model the distribution of RAP and RPCC operations relative to transportation network and population distribution data. The models can be used on a regional scale to quickly map the relative site suitability for a RAP or RPCC aggregate recycling operation in a particular area based on transportation network and population parameters. The results can be used to identify general areas to be further evaluated on a site-specific basis using more detailed marketplace information. As transportation or population features change due to planning or actual development, the models can be easily revised to reflect these changes. 相似文献
58.
利用GC-MS对上海市玻璃表面有机膜中PAHs浓度进行了定量分析。结果表明随着楼层的增加,10层居民楼玻璃表面PAHs浓度出现先增加后减少的趋势,最高浓度出现在3层(736 ng/m~2),最低在9层(346 ng/m2);17层公寓楼PAHs浓度则是先减少后增加再减少的趋势,最高浓度出现在9层(2 338 ng/m~2),最低在16层(564 ng/m~2)。TOC与PAHs相关性分析暗示除TOC外,玻璃表面PAHs富集可能还受控于其他因素。10层居民楼主要以3环和4环PAHs为主;而17层公寓楼则以4环为主。玻璃外表面PAHs浓度(555 ng/m~2)远高于内表面(308 ng/m~2);外表面主要以Phe、Pyr、Chry、Fluo和Fl为主;内外表面低环PAHs比值接近于1,高环比值基本上低于0.6。TEQ值虽然较低,但生态风险仍不能忽视。 相似文献
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60.
The sperm cell toxicity test with Paracentrotus lividus is widely used in Italy to assess the quality of complex aqueous matrices, but at present there is a shortage of standardized methodologies for the bioassay performance. In this work several critical points were considered, in order to verify the reliability of this bioassay and to improve its standardization.In particular, we have studied the differences in EC50 values at different sperm: egg ratios and with different quantities of gametes; the influence of sperm and eggs on fertilization rate and the influence of different recipients materials (plastic or glass). At the same time, it was evaluated if the obtained EC50 values were in accordance with those reported in literature.Experiments performed yielded EC50 values for copper ranging from 16.54 μ g/l to 69.59 μ g/l, with a total mean value ± SD of 39.79 μ g/l ± 11.17. These data fit with those found in literature for other echinoid species. According to the same authors, poor fertilization was probably due to the effects on sperm and not on eggs, and moreover the linear regression analysis performed on each experiment suggested that the best amount of eggs to use in the test was 1000.Results from the comparison between the performance of the test in plastic or glass tubes showed an higher success in fertilization rate using borosilicate glass tubes. 相似文献