废聚苯乙烯泡沫塑料制备水泥助磨剂的研究

以废聚苯乙烯泡沫塑料为原料合成了聚苯乙烯磺酸钠,研究了其助磨性能及对水泥性能的影响。研究结果表明:聚苯乙烯磺酸钠(SPS)对水泥具有较好的助磨性能,显著降低80μm及45μm筛余量,有效改善颗粒分布;SPS可显著改善水泥各龄期强度,掺入0.04%的SPS试样的3 d、28 d抗压强度较空白样分别增加了19%和8%,优于三乙醇胺和三异丙醇胺;其对水泥净浆流动性的影响也更小。     

尿素/三乙醇胺吸收烟气NOx的实验研究

以尿素作为吸收液，与NO_x反应生成N₂和CO₂，脱除烟气中的氮氧化物。以一套双级串连的填料塔为主体反应器，分别对气速、液气比、反应物浓度、添加剂浓度和反应温度等参数对尿素溶液吸收NO_x反应的影响进行了实验研究，获得了优化实验工况，研究结果显示，在气速为0.1 m/s、液气比为16 L/m³、三乙醇胺为0.01%(质量比)、尿素浓度为13%（质量比）工况下, 反应温度为30~70℃，脱硝总效率可达50％以上，且随着NO_x体积分数增加而提高。     

尿素/三乙醇胺吸收烟气NO_x的实验研究

以尿素作为吸收液,与NOx反应生成N2和CO2,脱除烟气中的氮氧化物。以一套双级串连的填料塔为主体反应器,分别对气速、液气比、反应物浓度、添加剂浓度和反应温度等参数对尿素溶液吸收NOx反应的影响进行了实验研究,获得了优化实验工况,研究结果显示,在气速为0.1 m/s、液气比为16 L/m3、三乙醇胺为0.01%（质量比）、尿素浓度为13%（质量比）工况下,反应温度为30~70℃,脱硝总效率可达50%以上,且随着NOx体积分数增加而提高。     

Analytical Investigations on a Releasing Agent Application in Aluminium Diecasting (6 pp)

Background, Aims and Scope Releasing agents, applied in the aluminium diecasting process, usually consist of water, oils, waxes, polysiloxanes, as well as of a set of additives like emulsifiers, corrosion inhibitors, and biocides. During spray application and part release, gases and aerosols are emitted into workplace air. The chemical compositions of these emissions are determined by the components of the releasing agents and their reaction products formed during thermal stress of more than 700 °C. In the frame of the joint project, the analytical tasks were to develop an appropriate sampling strategy for this production environment, to draw conclusions about the occurrence of hazardous chemicals from production plant studies and from laboratory-scale thermolysis experiments, and to determine the biodegradability of customary releasing agents. Methods During realistic test production, active air sampling was performed in a production hall using different adsorption materials. Cotton fabric sheets were positioned in the production area as passive samplers. Thermolysis experiments were performed at 600 °C with sealed quartz ampoules. The biodegradability of different releasing agents was determined according to German industry standard DIN 51828 (2000). For analyses, GC/MS (headspace), FTIR, HPLC, IC, and ICP-OES techniques were applied. Results and Discussion The substance spectrum, which was found in workplace air, was dominated by saturated and non-saturated aliphatic hydrocarbons. Besides these, alcohols, alkyl phenols, xylenes and other benzene derivatives, aldehydes, glycols, carboxylic acid esters, and amides were present. The German limiting value of 40 mg/m3 of complex hydrocarbon mixtures in a diecasting workplace atmosphere was clearly under-run. Total hydrocarbon contents ranged between 2.7 and 6.3 mg/m3. Five different PAH were found in the air close to the diecasting machine, with maximum concentrations between 0.05 and 3.06 μg/m3. Concentrations of nonylphenols ranged from 10 to 200 μg/m3, and those of triethanolamine from 20 to 30 μg/m3. From 17 elements analyzed, only B, Fe, P, S, Si, and Ti were emitted in small amounts. It was striking that the PAH patterns resulting from thermolysis experiments were quite the same compared to those determined during the diecasting process. An influence of water and of Fe/Al on the composition of the thermolysis products could mostly be shown. The degrees of biodegradation of three releasing agent extracts after 21 days were 21%, 29%, and 55%, respectively. Conclusion A sampling strategy was developed, which allows an emission assessment for the industrial process of aluminium diecasting. It enabled one to control limiting values, to characterise a wide variety of compounds emitted, and to identify and quantify relevant pollutants. Only a few hazardous substances could be detected during the exemplary use of one releasing agent within the compounds emitted into workplace air. Indications were found, that the prediction of the formation of harmful substances from releasing agent components should be possible via thermolysis experiments. The biodegradability test can serve to assess the expenditure of disposal of the usual leakage run-off of excess agent during production. Recommendation and Outlook Investigations on further differently composed releasing agents, e.g. powders, would be desirable. A substitution of nonylphenol ethoxylates by less harmful components would surely be an improvement of a releasing agent with regard to work safety and health care, because of avoiding the emission of toxic and endocrine active nonylphenols. The surprisingly wide range of biodegradability of the investigated releasing agents points to an optimization potential, that has obviously not yet been considered.