絮体性质对纳滤膜污染的影响

混凝过程产生的絮体会对后续膜过滤性能产生一定的影响。实验中利用激光粒度仪研究2种混凝剂(AlCl3和PAC)在不同投加量下的絮体性质,混凝出水(不经过沉淀)直接进入纳滤膜(NF270)装置进行过滤实验。研究表明,投加量低(<0.20 mmol/L)的情况下,混凝出水反而使纳滤通量衰减发生恶化,随着投加量的增加,纳滤膜通量衰减得到有效的减缓。直接过滤腐殖酸(HA)的膜通量衰减(J/J0)为0.65,投加量为0.50 mmol/L时,AlCl3和PAC 2种混凝剂产生的通量衰减(J/J0)分别为0.78和0.75。滤饼层阻力受到絮体尺寸的影响较大,絮体尺寸越大,形成的滤饼层透水性更好。通过污染模型分析,混凝出水的纳滤膜污染机理主要是滤饼层阻力。     

Degradation of diuron in aqueous solution by ozonation

Degradation of diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] in aqueous solution and the proposed degradation mechanism of diuron by ozonation were investigated. The factors that affect the degradation efficiency of diuron were examined. The generated inorganic ions and organic acids during the ozonation process were detected. Total organic carbon removal rate and the amount of the released Cl(-) increased with increasing ozonation time, but only 80.0% of the maximum theoretical concentration of Cl(-) at total mineralization was detected when initial diuron concentration was 13.8 mg L(-1). For N species, the final concentrations of NO3(-) and NH4+ after 60 min of reaction time were 0.28 and 0.19 mg L(-1), respectively. The generated acetic acid, formic acid and oxalic acid were detected during the reaction process. The main degradation pathway of diuron by ozonation involved a series of dechlorination-hydroxylation, dealkylation and oxidative opening of the aromatic ring processes, leading to small organic species and inorganic species. The degradation efficiency of diuron increased with decreasing initial diuron concentration. Higher pH value, more ozone dosage, additive Na2CO3, additive NaHCO3 and additive H2O2 were all advantageous to improve the degradation efficiency of diuron.     

井下无线技术在煤矿安全生产中的应用分析

飞速发展的无线通信系统在今天已经应用于各行各业。特别对于矿业而言,数字信号取代模拟信号使无线通信在煤矿应用成为现实。无线通信应用于井下生产,不但提高了井下工人的安全系数,还大大地提高了生产效率。     

粘土矿胶粒及其含富里酸悬浊体系的电动特性

本文主要研究了氯化铝和聚合氯化铝凝聚二氧化硅、高岭土和蒙脱土胶粒,以及它们分别与含富里酸悬浊体系的电动特性及其影响因素。     

Historical distribution of lynx (<Emphasis Type="Italic">Lynx lynx</Emphasis>) in Northeast China on the basis of historical records

Long-term dynamics of population decline can improve the conservation perspectives and strategies for endanger species. In China, new gazetteers having systematic compilation and wide geographical coverage can be considered as an important complementary for reconstruction historical distribution. For historical and cultural reasons, an endangered species–lynx (Lynx lynx) was recorded regularly in new gazetteers. Therefore, the aim of this paper was to evaluate the population distribution in Northeast China from the 1950s to 2014. The data show that Felis lynx was widely distributed in Northeast China in the 1950s, but the number of the occurrence records have been significantly reduced by 85.6% in the last 60 years. This research also enlightens us that the new gazetteers can contribute to data shortage and it would be helpful to conservation biology.     

铝的水解聚合形态分析方法研究

本文主要探讨了铝的水解聚合形态的两种测定方法，即Ａ１－Ｆｅｒｒｏｎ逐时络合比色法和＾２７Ａ１ ＮＭＲ核磁共振法。扼要地说明了Ａ１－Ｆｅｒｒｏｎ逐时络合比色法中不同比色－缓冲的配制及其测定结果，以及＾２７Ａ１ ＮＭＲ法中大、小管测量方法及其测定结果。最后对这两种铝的水解聚合形态分析方法的相关性作了对比。     

聚合氯化铝与传统混凝剂的凝聚—絮凝行为差异

本文综合阐述无机高分子絮凝剂与传统混凝剂在化学特征和凝聚－絮凝行为机理上的差异。ＰＡＣ的主要成分聚十三铝在预制条件下能大量生成。它们对水解反应有一定的稳定性，直接吸附有颗粒物表面，发挥强烈的电中和及粘结架桥作用，其流动电流，ζ电位，絮凝指数及凝聚－絮凝区域图等，均与传统混凝剂有很大不同，其计算模式应根据表面络合及表面沉淀原理建立。     

环境质量与经济增长的库兹尼茨关系探讨

对环境质量与经济增长的库兹尼茨关系进行了分析，提出了环境质量三种可能的发展轨迹，并探讨了在这三种可能发的发展轨迹中，经济增长对环境质量发展的影响，提出了中国现阶在保证环境质量达一害标准的前提下，实现经济可持 展的政策建议。     

Evaluation of Al30 polynuclear species in polyaluminum solutions as coagulant for water treatment

Polyaluminum coagulant with a content of 76.8% of Al30 (PACAl30) was prepared. Its coagulation behaviors were compared with high Al13 content polyaluminum coagulant (PACAl13) and AlCl3. The species stability was studied using Al-Ferron method and 27Al NMR. The coagulation performances were investigated by studying the rate of flocs development, the turbidity removal efficiency and charge neutralization capacity under fixed pH conditions and uncontrolled pH conditions. The effect of pH on coagulation was also studied. The results show that PACAl30 are stable for using as coagulant. PACAl30 causes less pH depression than PACAl13. The charge neutralization capacity of PACAl30 is slightly lower than that of PACAl13 at pH6.8 and higher at pH 6.5. PACAl30 achieves the most effective turbidity removal in these three coagulants. And it acts effectively within a much broader dosage range and a wider pH range when compared with PACAl13. PACAl30 achieves the highest turbidity removal due to its strong flocs formation capacity. The results verify that Al30 is another highly active coagulation/flocculation species for turbidity removal.     

采用双氰胺甲醛缩聚物混凝去除水中酸性红B染料的研究

以双氰胺和甲醛为原料制备了聚合双氰胺甲醛,并对其进行红外光谱表征.采用聚合双氰胺甲醛与硫代硫酸钠共同作用对酸性红B染料溶液进行混凝脱色实验.对比了单独使用聚合双氰胺甲醛,以及聚合双氰胺甲醛与硫代硫酸钠共同作用的脱色效果.探讨了硫代硫酸钠和聚合双氰胺甲醛的用量以及pH值对脱色率的影响.结果表明,投加硫代硫酸钠可以明显地提高聚合双氰胺甲醛的脱色率,增大絮凝范围,使絮凝剂对pH值的变化有很强的适应性,pH值为7～12的范围内,脱色率均能维持在96%以上.此外,还对混凝脱色的机理进行了研究.