排序方式: 共有27条查询结果,搜索用时 109 毫秒
1.
2.
建立了吹扫捕集-气相色谱法测定水样中乙醛和丙烯醛的方法,并对吹扫捕集测试条件进行优化,考察了吹扫温度和吹扫时间对吹扫捕集效率和方法检出限的影响。在50℃下,吹扫时间为20 min时,该方法乙醛和丙烯醛的检出限分别为0.001 2 mg/L、0.000 6 mg/L,相对标准偏差分别为3.5%~6.9%、2.9%~5.8%,加标回收率分别为91.6%~108%、92.0%~105%。与GB3838-2002推荐使用的分析方法相比较,该方法具有操作简便、灵敏度高、重复性好、基本上不消耗有机溶剂等特点,可满足地表水和废水中乙醛和丙烯醛的测定要求。 相似文献
3.
4.
Polyethylene terephthalate bottles containing natural spring water were used to study the leaching effect of carbonyl compounds after one year storage under real conditions of exposure. Ultraviolet-B and ultraviolet-A spectra of direct sunlight were acquired during the experiment. Leaching of acetone, acetaldehyde, and formaldehyde reached steady state after 210 days of outdoor storage, with the following concentrations: 434 ± 22, 345 ± 18, and 94 ± 5 µg/L, respectively. The increase due to sunlight exposure in comparison with laboratory storage in the dark was around 10%, 16%, and 36%. The leaching process of all three carbonyl compounds was found to follow the first-order kinetics. Photo-degradation of Polyethylene terephthalate bottles and the appearance of carboxyl end-groups were followed by attenuated total reflectance infrared spectra. After 313 days of storage under direct sunlight, new peaks appeared in the regions of 1770–1920 cm?1 and 1685–1490 cm?1. Cations, anions, total dissolved solids, pH, and conductivity were also measured during the storage period. Additionally, microbiological measurements as well as statistical analyses were also carefully discussed. 相似文献
5.
乙醛废水处理的工程实例 总被引:2,自引:0,他引:2
溧阳市某化工厂以乙醇氧化法生产乙醛,该厂原有一套污水处理站,但系统出水难以达标.在改造过程中,利用原有污水处理系统,在调节池后新建多级内循环厌氧(MIC)反应器.该废水经过冷却到35~39℃、在调节池加营养和碱调节pH为7左右,MIC反应器进水CODCr约为3200mg/L、HRT为24h时,CODCr去除率为85%以上,MIC出水进入推流式好氧池,采用微孔曝气器曝气,HRT为36h,好氧出水CODCr小于100mg/L.该工艺运行稳定,为乙醛化工企业处理该废水提供一条新途径. 相似文献
6.
通过对仪化涤纶厂乙醛废气污染源的调查及监测,分析了其源强、生产车间及厂区内外的分布规律,并进一步作了该厂乙醛废气对环境影响的预测评价。结果表明,周边地区乙醛废气的质量浓度分布均达到《工业企业设汁卫生标准》的要求。 相似文献
7.
研究多点电喷汽油机燃用不同掺混比的乙醇/汽油混合燃料时的排放及催化器的转化性能.结果表明,在汽油机参数未做任何调整的情况下,与汽油机相比,乙醇/汽油混合燃料汽油机催化器之前的CO排放降低,降幅接近15%;HC排放在大负荷时略有升高;NOx排放基本相同;乙醇对排放物催化转换效率的影响与电喷汽油机的转速、负荷和空燃比控制策略有关.用气相色谱分析仪测录的未燃乙醇排放在大负荷时略有升高,甲醇排放量变化不大,乙醛排放量随乙醇含量增大而增大,经三效催化转化器后,可以被控制在接近零排放的水平.在怠速工况,随乙醇含量增加,CO、HC和NOx的排放与汽油机相比略有降低. 相似文献
8.
建立了环境大气中乙醛的气相色谱测定方法。采样效率在995以上,回收率为92.8%-99.5%,变异系数为2.56%-3.24%。当采样体积为10L时,最低检出浓度为0.14mg/m^3。 相似文献
9.
10.