侯马市环境空气状况探析

根据2006年以来的环境空气质量监测数据,对侯马市空气质量状况进行了月际浓度趋势和年际浓度趋势分析评价,指出了燃料燃烧、交通运输、城市建设、气象因素、外来污染等大气污染物的来源及特征,提出了深入治理煤烟污染、积极推广新能源使用、控制机动车尾气污染、加大治理城市扬尘污染、强化工业污染源治理等改善大气环境质量的对策建议。     

空气置换装置在产品温度试验中凝露预防方面的应用研究

本文提出了一种基于空气置换原理来预防产品在温度试验中凝露的装置,以干燥的惰性气体不断替换试验箱内湿热空气,降低试验箱内的相对湿度,保持空气干燥,从而避免在进行模拟环境试验时,由于试验箱环境的局限性而在试验过程中发生凝露现象对产品造成非必要损伤。获得的结果表明,此装置有效预防了产品在温度试验中凝露的产生。     

碳酸氢钠及其固态分解产物对玉米淀粉爆炸抑制实验研究*

为研究NaHCO3对玉米淀粉爆炸的抑制效果,采用20 L球形爆炸装置测试玉米淀粉在添加不同抑制比NaHCO3及其固态分解产物Na2CO3后爆炸参数变化规律,并分析NaHCO3抑制淀粉爆炸过程。结果表明:NaHCO3及Na2CO3对玉米淀粉爆炸均有抑制作用,NaHCO3抑制效果优于Na2CO3;混合粉尘的最大爆炸压力、最大爆炸压力上升速率与爆炸指数随抑制比增大而逐渐减小,爆炸时间随抑制比增大而逐渐延长。随着NaHCO3浓度增加,物理抑制效果逐渐增加,化学抑制效果基本保持不变。NaHCO3浓度不同时,其抑制主导过程不同,当抑制比为0.1~0.5时,NaHCO3抑制效果以化学抑制为主,物理抑制为辅;抑制比为0.8和1.2时,NaHCO3抑制效果以物理抑制为主,化学抑制为辅;当抑制比为1.2时,玉米淀粉爆炸完全被NaHCO3抑制,此时物理抑制起主导作用。     

地铁区间隧道竖井送风有效风量研究*

为得到地铁区间隧道竖井送风有效风量的无量纲计算模型,通过推导地铁区间隧道竖井送风有效风量的无量纲公式,并采用数值模拟方法明确竖井送风有效风量与火源功率、火源距离、阻塞比和竖井送风量之间的量化关系。结果表明:火源功率、火源距离与竖井送风有效风量之间不存在函数关系;阻塞比对竖井送风有效风量影响显著,随着阻塞比的增大,有效风量逐渐减小,单侧列车停靠时,无量纲有效风量Qe*与阻塞比β呈-1.08次方减小关系,两侧列车停靠时,无量纲有效风量Qe*与阻塞比β呈-0.22次方减小关系;有效风量随竖井送风风量的增大逐渐增大,且有效风量增大比例高于送风风量,单侧列车停靠时,无量纲有效风量与无量纲送风风量呈1.11次方增大关系,两侧列车停靠时,无量纲有效风量与无量纲送风风量呈1.07次方增大关系。     

室内空气污染预测方法的实证研究

在大型(30m3)、小型(1m3)环境箱实验获得数据的基础上构建释放模型,并将模拟结果和现场监测得到的浓度水平进行对比,对开发的室内空气污染预测方法进行了实证研究.以一新装修房间为例,分别利用大型和小型环境箱实验,研究了复杂整装材料和简单层状材料的释放规律,建立了相应材料的污染物释放模型;依据单元内物质守恒理论和污染物充分混合的假设将释放模型组合,建立了室内空气污染预测方法,并预测了该房间甲醛和TVOC(total volatile organic compounds)浓度的变化过程.在考虑了0.03ACH(air change per hour)的换气率之后,模型预测与现场监测的污染物浓度变化趋势基本吻合,甲醛和TVOC污染预测误差(正则化标准差)分别为2.8%和1.6%.模型分析表明,各污染源对于甲醛污染的贡献,家具＞涂料＞地板;对于TVOC污染的贡献,涂料＞地板＞家具.结论表明,该预测方法可以真实反映现场污染物浓度变化趋势,可以用来分析各污染源对于整体污染的贡献、指导装修材料的选择和作为室内污染评估和控制的有效工具.     

核级高效空气过滤器的结构与阻力关系探讨

探讨了核级高效空气过滤器的结构形式与过滤阻力之间的关系.分别采用进口的和国产的过滤材料,制作了一批不同褶间距(2.5～8.2mm)、褶深(33～275 mm)和褶形状的高效空气过滤器,并对其过滤阻力进行了测试,研究了高效空气过滤器的结构与阻力之间的关系.实验结果表明,对于进口过滤材料.当褶深为33 mm、52 mm和73 mm时,过滤阻力最低时相应的褶间距分别为2.7 mm、3.4 mm和4.0 mm;对于国产过滤材料,当褶深为33 mm、52 mm、73 mm、105 mm和245 mm时,过滤阻力最低时,相应的褶间距分别为2.5 mm,3.1 mm、3.7 mm、4.8 mm和5.4 mm.因此,不同的过滤材料.应该有不同的过滤器最佳结构参数.此外,V形过滤材料褶过滤器比矩形过滤材料褶过滤器的阻力低.     

动力学调控实现单一反应器内亚硝化与硝化过程的互相转化

通过动力学调控在单一反应器内实现了亚硝化到硝化再到亚硝化过程的转化.在小试曝气上流式污泥床(Aerated Upflow Sludge Bed,AUSB)反应器中,在20℃、DO为2～4mg·L-1的条件下,主要通过调节反应器内的pH值调控氨氧化细菌(AOB)和亚硝酸盐氧化细菌(NOB)比生长速率的相对大小,以无机自配水为进水时,分别在20d和25d内将反应器的亚硝化率(出水中亚硝氮与总硝态氮之比)从95%降低至15%再恢复至95%以上,期间反应器的氨氮去除率基本维持在90%以上;当以实际高氨氮废水为进水时,同样主要通过调节反应器的pH值,分别在30d和23d内实现了反应器的亚硝化率从90%降低至10%再恢复至90%的过程.     

主动脉动气流分选处理废弃催化剂

废弃催化剂重整后含有富集贵金属的海绵体和烧结磁珠,二者的有效分选是提纯贵金属富集体的重要环节。主动脉动气流分选装置能够对此物料进行干法分选,避免了湿法分选对物料的改性,有利于贵金属富集体的后续提纯。介绍了主动脉动气流分选装置的结构,分析主动脉动气流分选机理及其动力学模型。通过实际物料进行分选试验。结果表明,在脉动频率为7/3 Hz,气流流速为2.50~6.00 m/s时,总分选效率Ef高于94.50%;在气流流速为3.33 m/s时,分选效率最高,总分选效率Ef可达97.63%。     

Performance of a water hyacinth （Eichhornia crassipes） system in the treatment of wastewater from a duck farm and the effects of using water hyacinth as duck feed

Nowadays, intensive breeding of poultry and livestock of large scale has made the treatment of its waste and wastewater an urgent environmental issue, which motivated this study. A wetland of 688 m2 was constructed on an egg duck farm, and water hyacinth (Eichhornia crassipes) was chosen as an aquatic plant for the wetland and used as food for duck production. The objectives of this study were to test the role of water hyacinth in purifying nutrient-rich wastewater and its effects on the ducks’ feed intake, egg laying performance and egg quality. This paper shows that the constructed wetland removed as much as 64.44% of chemical oxygen demand (COD), 21.78% of total nitrogen (TN) and 23.02% of total phosphorus (TP). Both dissolved oxygen (DO) and the transparency of the wastewater were remarkably improved, with its transparency 2.5 times higher than that of the untreated wastewater. After the ducks were fed with water hyacinth, the average daily feed intake and the egg-laying ratio in the test group were 5.86% and 9.79% higher, respectively, than in the control group; the di erences were both significant at the 0.01 probability level. The egg weight in the test group was 2.36% higher than in the control group (P < 0.05), but the feed conversion ratios were almost the same. The eggshell thickness and strength were among the egg qualities significantly increased in ducks fed with water hyacinth.We concluded that a water hyacinth system was e ective for purifying wastewater from an intensive duck farm during the water hyacinth growing season, as harvested water hyacinth had an excellent performance as duck feed. We also discussed the limitations of the experiment.     

Indoor and outdoor BTX levels in Barcelona City metropolitan area and Catalan rural areas

Five aromatic hydrocarbons (benzene, toluene, and three isomeric xylenes) were monitored in indoor and outdoor air of 7 public buildings and 54 private homes, located in Barcelona City metropolitan area and in several rural areas of Catalonia. The sampling was carried out over four periods: spring-summer and winter of 2000, and summer and winter of 2001. Passive ORSA 5 Dra¨ger samplers were used for benzene, toluene, and xylenes (BTX) adsorption. BTX were extracted with carbon disulphide and analysed using ...