北京不同污染天气PM_(2.5)和PM_(10)染毒对大鼠生理病理参数的影响

为探讨北京不同污染天气大气可吸入颗粒物PM_(10)和细颗粒物PM_(2.5)污染对雄性大鼠血常规、氧化损伤、炎症反应和肺组织的影响,将64只雄性8周龄Wistar大鼠随机分为8组,分别为2个对照组(空白组和生理盐水组)和6个染毒组(清洁、雾霾及沙尘暴3种不同天气的PM_(10)染毒组和PM_(2.5)染毒组),每组8只。用2015年3月—5月在北京南海子麋鹿苑采集的清洁、雾霾和沙尘暴3种不同天气的PM_(10)和PM_(2.5)制备悬液,分别采用气管滴入PM_(10)和PM_(2.5)悬液作为染毒组,空白对照组不做任何处理,生理盐水对照组采用气管滴注生理盐水。急性染毒24 h后处死大鼠。采集血液测定18个血常规指标,分析肺泡灌洗液(BALF)中转化生长因子-β1(TGF-β1)、乳酸脱氢酶(LDH)、总抗氧化能力(T-AOC)、白介素-6(IL-6)及肿瘤坏死因子-α(TNF-α)的含量,并在高倍显微镜下观察肺组织和气管病理形态变化。同时,对PM_(10)和PM_(2.5)中的水溶性离子、有机碳/元素碳、16种多环芳烃和7种重金属等元素进行了测定,并分析了各组分与大鼠生理病理指标的相关性。结果表明:清洁、沙尘暴天气的PM_(10)和雾霾天气的PM_(2.5)急性染毒导致大鼠白细胞系参数即免疫力显著下降。污染天气颗粒物染毒后大鼠BALF氧化炎症因子的改变表明呼吸系统受到感染:沙尘暴和清洁天的PM_(10)染毒均显著提高了TGF-β1,雾霾PM_(10)染毒后IL-6和LDH有一定程度升高。3种天气颗粒物染毒对肺和气管造成的组织病理伤害各有特点,但PM_(2.5)伤害程度普遍大于PM_(10)。染毒颗粒物粒径大小,其化学成分类别、浓度是造成大鼠血常规指标变化、氧化炎症反应和组织学病变的可能原因。     

Propagation characteristics of subaerial landslide-generated impulse waves

Environmental Fluid Mechanics - Subaerial landslide-generated impulse waves were investigated in a rectangular prismatic channel based on the Froude similarity criterion. Landslides were modeled...     

印染废水治理方案分析

某针织印染厂年产3000吨针织高档服装布料,排放的生产废水中含有大量的有机物,COD、BOD5、色度浓度比较高。该厂选择了"厌氧水解酸化+接触氧化法+活性炭吸附"处理工艺。该工艺采用厌氧水解酸化处理工艺进行前期处理,去除大部分有机物,减轻了后续接触氧化处理工艺的压力,同时通过活性碳过滤进行脱色,达到较好的处理效果。运行结果表明,经该工艺处理后,废水中的COD、BOD5、色度等指标均能达标排放,有利于企业的可持续发展。     

城市工业区环境系统中的Cd污染循环及其健康风险——以杭州市半山工业区为例

为揭示重金属元素Cd在城市环境系统多种介质中的迁移途径及其潜在危害性,系统分析了杭州市半山工业区主要环境介质（土壤-尘埃-水-底泥-生物）样品中Cd的指标含量,并用连续提取法分析了土壤、尘埃、底泥中Cd的化学形态特征.结果表明,Cd的迁移途径主要有两种,一是以尘埃为媒介在地表环境中迁移,二是通过水介质进入水体环境（水和...     

火焰原子吸收光谱法测定电镀废水中高浓度的锡

采用盐酸消解样品,用火焰原子吸收光谱法测定电镀废水中高浓度的锡的质量浓度,方法简单可靠。通过实验样品的分析,验证了方法的准确度和精密度。该方法干扰少,数据准确,适合废水分析。     

美国页岩气开采的水环境监管经验研究

页岩气开采所使用的核心技术——水力压裂技术不仅消耗大量水资源,而且向地下注入裂解液可能污染地下水。为应对页岩气开发所带来的环境问题,美国已开展并积累了相对丰富的环境监管经验和技术。文章就美国页岩气开采场地的水环境监管体系、法规、制度及技术等进行探讨和研究,并提出我国在页岩气大规模开采初期的水环境监管思路及技术方向。     

Will polycentric cities cause more CO2 emissions? A case study of 232 Chinese cities

From 2000 to 2010 China experienced rapid economic development and urbanization. Many cities in economically developed areas have developed from a single-center status to polycentricity. In this study, we used exploratory spatial data analysis (ESDA) to identify the population centers, which identified 232 cities in China as having urban centers. COMP was used to represent urban agglomeration, and POLYD (representing how far is the city's sub-centers to the main center), POLYC (representing the number of a city's centers), and POLYP (representing the population distributed between the main center and the sub-centers) were used to indicate urban polycentricity. Night light data were used to determine the CO₂ emissions from various cities in China. A mixed model was used to study the impact of urban aggregation and polycentric data on the CO₂ emission efficiency in 2000 and 2010. The study found that cities with higher compactness were distributed in coastal areas, and the cities with higher multicentricity were distributed in the Yangtze River Delta and Shandong Province. The more compact the city was, the less conducive it was to improving CO₂ emission efficiency. Polycentric development of the city was conducive to improving the CO₂ emission efficiency, but the number of urban centers had no significant relationship with the CO₂ emission efficiency. Our research showed that the compactness and multicentricity of the city had an impact on the CO₂ emission efficiency and provided some planning suggestions for the low carbon development of the city.     

煤炭生物脱硫正交实验研究

通过对取自城门山,杨桃坞,德兴和云南的嗜酸氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)的生理活性的研究比较,选取了氧化活性较好的德兴菌种做正交试验.应用正交试验的方法研究了浸出时间,煤浆质量分数,pH值和接种量这4个因素的组合作用对煤炭生物脱硫效果的影响.对试验结果进行极差分析和方差分析,结果表明各因素对脱硫效果的影响有很大差异.在所研究因素的水平范围内,浸出时间对煤脱硫效率的影响最为显著,影响率达到74.21%;pH值对煤脱硫效率的影响也很显著,影响率为16.80%;接种量对煤脱硫效率的影响较为显著的,其影响率仅为5.27%;煤浆质量分数对脱硫效率的影响率最低,仅为1.78%.通过对正交试验的实验结果的直接观察,极差分析和方差分析,获得了三个可能的最优方案.其中通过实验结果直接观察得到的最优方案的脱硫率可达63.80%.     

Rhizosphere effect of different aquatic plants on phosphorus depletion

A series of pot experiments with Alternanthera philoxeroides, Typha latifolia, Sagittaria sagittifolia and Phragmites communis were conducted to assess the phosphorus depletion effect in the rhizosphere. The ratio of root to shoot, root morphology, phosphorus uptake efficiency and phosphorus utilization efficiency were analyzed. An obvious variation in phosphorus concentrations between the rhizosphere soil and non-rhizosphere soil was observed. The water-soluble P contents in the rhizosphere soil of A. philoxeroides, T. latifolia, S. sagittifolia and P. communis were reduced by 81%, 42%, 18% and 16%, respectively, compared with that in the non-rhizosphere soil. A. philoxeroides had the highest phosphorus uptake efficiency (1.32 mg/m), while T. latifolia achieved the effective phosphorus depletion by the strong rooting system and the high phosphorus uptake efficiency (0.52 mg/m). T. latifolia not only used phosphorus to produce biomass economically, but also adjusted carbon allocation to the roots to explore the soil for more available phosphorus. A. philoxeroides and T. latifolia were more effective in depleting phosphorus in the rhizosphere than S. sagittifolia and P. communis.