碳酸盐岩自转向酸酸液流动模拟实验研究与评价

在自转向酸酸化机理研究的基础上,对实验所用酸液体系从增黏性能、破胶性能和转向性能等方面进行了评价。实验发现,残酸在80℃时黏度可达到1 128.2 mPa·s,具有良好的封堵增黏性能;5%的乙二醇可使残酸黏度降至2 mPa·s,破胶效果好。通过岩心流动实验分别对常规酸和自转向酸在地层中的反应流动进行模拟,绘制了水驱-酸化-水驱全压降曲线。单岩心流动实验表明,自转向酸对于较高渗透率岩心的处理效果优于常规酸液,而对于较低渗岩心改造效果不明显。双岩心流动实验发现,对于不同渗透率差异倍数的两块岩心,自转向酸对于其中的低渗岩心改造效果要好于常规酸,然而随着渗透率极差进一步增大,自转向酸增黏改造效果变差。     

模拟酸雨对土壤酸化和盐基迁移的影响

研究了中国南方主要酸性土壤类型在模拟酸雨影响下土壤酸化和其缓冲性能及盐基的迁移特征,结果表明,酸雨淋洗引起土壤pH降低,盐基离子淋失,随着酸雨溶液pH的降低,土壤酸化趋势加剧,盐基淋失量增加,红壤对酸雨的缓冲性能好于砖红壤,淋出液中K^ ,Na^ ,Ca^2 ,Mg^2 含量加上淋洗后土壤交换性K^ ,Na^ ,Ca^2 ,Mg^2_含量大于原土壤中交换性K^ ,Na^ ,Ca^2 ,Mg^2 总量,说明在酸雨淋洗下,土壤中某些矿物发生风化溶解,释放盐基进入土壤。     

Impact of acidification on phytoplankton and zooplankton communities

Summary Literature concerning the impacts of acidification on the phytoplankton and zooplankton composition has been reviewed. Available data on the species richness and composition of phytoplankton, attached algae and zooplankton of acidifying systems have been summarized. The effects of water acidification on the primary productivity and biomass of zooplankton have been discussed.     

酸化预处理紫茎泽兰厌氧消化能源转化效率和原料利用率对比分析

以脱毒预处理的紫茎泽兰为原料,在室温条件下通过酸化预处理进行厌氧发酵,对发酵体系的能源转化效率和原料利用率进行对比分析.结果表明：酸化预处理发酵的TS产气率和VS产气率分别为199L·kg-1和240L·kg-1,分别是未经酸化预处理发酵的1.72倍和1.73倍;酸化预处理和未经酸化预处理的COD降解率分别为61.50%和44.07%;此外,酸化预处理原料的纤维素、半纤维素、木质素的利用率分别为21.28%、18.18%、13.28%,分别是未经酸化预处理的1.61倍、2.00倍和3.16倍.酸化预处理发酵的原料能源转化效率达到42.13%,分别是未经酸化预处理发酵的和文献值的1.78倍和1.95倍.     

废弃烟叶厌氧消化的实验探究

为获得废弃烟叶的厌氧消化规律,实验采用全混合批量发酵模式,在30℃、料液浓度为4.70%及初始pH为7.0的条件下,对废弃烟叶进行了厌氧消化的探索性研究。结果表明,废弃烟叶的厌氧发酵历时20d,总产气量为2345mL,产气主要集中在前8d,达1700mL,但均不能点燃;第9～20d所产的气体能点燃,但仅有645mL.从实验结果得知,废弃烟叶对厌氧微生物有抑制作用,不能单独用来启动沼气发酵。     

碳酸盐岩缝洞型储层酸化的数值模拟研究

酸化是碳酸盐岩储层地质改造的主要施工工艺,厘清碳酸盐岩储层酸化机理对于提升酸化整体效果具有重要意义。限于缝洞在储层中的准确刻画,目前的研究集中于碳酸盐岩无缝洞型储层的酸化研究。为此,基于数值模拟手段,建立缝洞刻画算法,采用双尺度连续模型,研究了不同注入速度、酸浓度及表面化学反应速率等因素对酸化过程中蚓孔形成及发育的影响机理。发现：缝洞型油藏的酸蚀蚓孔过程受缝和洞共同影响,采用普通油藏进行酸化数值模拟的研究会高估缝洞型油藏酸化行为中的溶蚀量及溶蚀贯通储层的时间。随着酸浓度的增大,碳酸盐岩溶蚀量由5.7%增大为7%;注入速度的增大将影响碳酸盐岩酸蚀形态,且酸化影响范围和次生蚓孔发育数量均不断增多;酸的表面化学反应速率不是影响碳酸盐岩酸化行为的主要原因。     

Vegetation structure and primary production in acidified lakes in southwestern Sweden

Summary Research during the last two decades has clearly pointed out that dramatic ecosystem changes have occured in lakes due to deposition of acid substances and decreased pH. Today a large number of lakes and running waters in Scandinavia are suffering biological damage with disappearing fish populations, overgrowth of the bottom by mosses and filamentous algae, reduced invertebrate fauna, increased transparency etc.—Of all documented biological changes the effect on macrophyte succession, in particular that ofSphagnum, is the most striking effect. Along with the growth of filamentous algae, these changes have brought about major shifts in the composition of the primary producers. The biomass in one lake was estimated to be 6.5 t (dry wt) corresponding to about 24 g m^–2, the relevant proportions being 52% forSphagnum, 34% forLobelia and 15% forIsoetes. Percentage production in the whole lake is 54% forSphagnum, 29% forLobelia and 17% forIsoetes, which gives an estimated production of 2.9 t yr^–1 or 9 g m^–2 yr^–1.Sphagnum is a recent flora element and its occurrence is related to the acidification of the lakes. The investigations also show that the growth ofLobelia is reduced in acid lakes compared to other oligotrophic lakes due to shading by the benthic mat of filamentous algae, detritus andSphagnum debris.—One can conclude that there are several quantitative and qualitative changes in the macrophyte community which are related to acidification. One can also conclude that liming of lakes cause elimination ofSphagnum and some increase in the production ofIsoetids.     

pH对油酸水解废水酸化发酵过程的影响

pH对油酸水解废水酸化发酵影响的研究表明,pH不仅对酸化速率有很大影响,而且也会影响酸化产物的构成;不同pH值下酸化的主要产物是乙酸,但酸化的最佳pH值为6.5,此pH条件下VFA的产量最高可达12.53 g/L;在pH>7时,明显有丙酸生成。     

金家油田疏松砂岩油藏酸化机理室内研究

金家油田砂岩储层泥质含量高,存在常规酸化易出砂,导致酸化效果不佳的问题。本文在储层伤害特征研究的基础上,利用溶蚀实验优选出适合金家油田疏松砂岩油藏的酸液类型,同时通过岩心流动实验及环境扫描电镜、残酸离子浓度评价技术对其酸化机理进行了讨论,结果表明该酸化液配方对于疏松砂岩油藏酸化效果好,可有效防止粘土微粒运移,减少储层二次伤害。     

The effects of acid deposition on benthic animals in lakes and streams

Cellular and Molecular Life Sciences -