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431.
CO2的过量排放对全球的气候变暖有着不可推卸的责任,同时CO2又是一种重要的碳资源,对它的回收和利用将具有很大的经济效益和社会效益。CO2回收的方法主要是膜吸收法、变压吸附法、化学吸收法和低温分离法,特别是离子液体对CO2的吸收,为CO2的减排提供了良好的手段。 相似文献
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在流化床膜生物反应器中引用在线超声技术来控制膜污染,考察了在线超声对污泥混合液特性的影响,探讨了在线超声作用下的膜污染机制。结果表明:在线超声流化床膜生物反应器的跨膜压差(TMP)增长速度明显慢于普通流化床膜生物反应器,可延长膜清洗周期约51%。在线超声作用下,污泥平均粒径降低约70μm,污泥胞外聚合物(EPS)含量增加(14±5)mg/g,混合液溶解性微生物产物(SMP)有所降低;同时,在线超声使得污泥浓度和混合液粘度降低,从而改善了混合液的过滤性,有助于膜污染的控制。分析表明,在线超声能够减少膜表面不可逆污染的发生,膜的主要污染机制为泥饼层污染。 相似文献
434.
Effects of UV-B radiation on the growth interaction of Ulva pertusa and Alexandrium tamarense 总被引:7,自引:0,他引:7
Enhanced UV-B(280-320nm) radiation resulting from ozone depletion is one of global environmental problems. Not only marine organisms but also marine ecosystems can be affected by enhanced UV-B radiation. The effects of UV-B radiation on interaction of macro-algae and micro-algae were investigated using Ulva pertusa Kjellman and Alexandrium tamarense as the materials in this study. The results demonstrated that UV-B radiation could inhibit the growth of Ulva pertusa and Alexandrium tamarense when they were both mono-cultured, and the growth inhibition of algae was more significant with increasing doses of UV-B radiation. Alexandrium tamarense could inhibit the growth of Ulva pertusa in mixed culture, and the growth inhibition was more significant when increasing the initial cell density. However, Ulva pertusa could inhibit the growth of Alexandrium tamarense in early phase and stimulate the growth in latter phase when they were grown in mixed culture. Lower initial cell density(10^2 cell/ml) of Alexandrium tamarense could inhibit the growth of Ulva pertusa under UV-B radiation treatment,however, with the initial cell density increasing( 10^3 and 10^4 cell/ml), the growth of Ulva pertusa was stimulated under lower dose of UV-B radiation and inhibited under higher dose of UV-B radiation by Alexandrium tamarense. Compared with that in mixed culture, Ulva pertusa showed more positive inhibition to the growth of Alexandrium tamarense under UV-B radiation treatment. 相似文献
435.
为探索西北地区颗粒物(PM)短期暴露对人群血压(BP)水平的影响,基于金昌队列研究平台,收集甘肃省金昌市2011~2017年颗粒物污染数据及队列人群血压测量数据,在调整相关混杂因素基础上,采用线性混合效应模型分析PM2.5和PM10短期暴露对收缩压(SBP)、舒张压(DBP)、平均动脉压(MAP)、脉压(PP)和Mid-BP (SBP和DBP的均值)的影响.结果显示,随着PM2.5浓度的增加,人群SBP,MAP,PP和Mid-BP均呈上升趋势,该效应值分别在累积滞后05,03,07和05d最大.随着PM10浓度的增加,5种BP指标也均呈上升趋势,效应最大值均出现在累积滞后07d.PM2.5和PM10对BP产生的影响分别在吸烟和男性人群中更为显著.此外,沙尘天气和气态污染物(SO2和NO2)对PM-BP效应存在一定的修饰作用.因此,在该队列人群中,PM2.5和PM10短期暴露对人群血压具有一定影响,吸烟者和男性人群可能是颗粒物影响血压效应的易感人群. 相似文献
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An acclimatized mixed microbial culture, predominantly Pseudomonas sp., was enriched from a sewage treatment plant, and its potential to simultaneously degrade mixtures of phenol and m-cresol was investigated during its growth in batch shake flasks. A 22 full factorial design with the two substrates at two different levels and different initial concentration ranges (low and high), was employed to carry out the biodegradation experiments. The substrates phenol and m-cresol were completely utilized within 21 h when present at low concentrations of 100 mg/L for each, and at high concentration of 600 mg/L for each, a maximum time of 187 h was observed for their removal. The biodegradation results also showed that the presence of phenol in low concentration range (100–300 mg/L) did not inhibit m-cresol biodegradation. Whereas the presence of m-cresol inhibited phenol biodegradation by the culture. Moreover, irrespective of the concentrations used, phenol was degraded preferentially and earlier than m-cresol. A sum kinetics model was used to describe the variation in the substrate specific degradation rates, which gave a high coefficient of determination value (R2 > 0.98) at the low concentration range of the substrates. From the estimated interaction parameter values obtained from this model, the inhibitory effect of phenol on m-cresol degradation by the culture was found to be more pronounced compared to that of m-cresol on phenol. This study showed a good potential of the indigenous mixed culture in degrading mixed substrate of phenolics. 相似文献
438.
在线超声对膜-生物反应器活性污泥混合液性质的影响 总被引:1,自引:0,他引:1
采用在线超声控制膜-生物反应器的膜污染,通过测定活性污泥混合液絮体粒径、胞外多聚物含量、上清液有机物浓度、污泥浓度和黏度的变化,探讨了超声波对膜-生物反应器中活性污泥混合液性质的影响.结果表明:在线超声使污泥絮体破碎,其平均粒径与未施加超声波的系统相比降低约20μm左右;污泥胞外聚合物含量降低(28±5)mg·g-1左右,致使混合液上清液TOC增加;但同时超声波的施加可以降低污泥浓度和混合液黏度,使混合液膜过滤性得到改善,有助于膜污染的控制. 相似文献
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