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。     

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。     

深床过滤机理及其在水处理中的应用研究与进展

深床过滤既有过滤功能,又具生物处理作用,具有良好的应用前景;本文阐述了深床过滤的最新研究动向,深床过滤过程的数学模型的构建方法,国内外利用深床过滤技术处理微污染水源水、城市生活污水及污水深度处理的实验研究状况。     

pH调节-Fenton试剂氧化法预处理间甲酚生产氧化废水

采用pH调节结合Fenton试剂氧化的方法对间甲酚生产氧化废水进行预处理,探讨了pH调节条件及Fenton试剂氧化条件对废水处理效果的影响。结果表明,在室温下将废水pH调节至4．0时,由于其中的部分有机污染物析出,COD可以从78000mg／L下降至61000mg／L,COD去除率达20％以上;接着在H2O2质量浓度与COD的比值为0．18、Fe^2＋与H2O2质量浓度的比值为0．267、反应时间为20min的条件下对废水进行Fenton试剂氧化处理,COD可以进一步下降至26000mg／L,COD去除率接近70％。     

Wind-induced noise alters signaler and receiver behavior in vibrational communication

Noise that masks communication signals can affect the evolution of signal form and decisions about when and where to communicate. For the many invertebrates that communicate using plant-borne vibrations, wind is considered to be the major source of environmental noise. However, the influence of wind-induced vibrations on signaling behavior has not been experimentally tested. We tested the hypothesis that wind-induced noise influences signaling behavior in a plant-feeding insect (the treehopper, Enchenopa binotata ‘Ptelea’) in which mating is preceded by a vibrational duet between females and mate-searching males. We first characterized the diel signaling patterns of males in the field to identify the wind conditions under which signaling typically takes place. We then experimentally tested two predictions of the hypothesis: (1) that males use gap detection to initiate signaling during relatively wind-free periods; and (2) that females respond less to signals given in the presence of wind-induced vibrations. Both predictions were met, indicating that wind-induced noise is an important influence on the behavior of insects that use plant-borne vibrations.     

Removal of Methylene Blue from Water by Peach Gum Based Composite Aerogels

Journal of Polymers and the Environment - In this study, novel composite aerogels of peach gum/activated carbon (PGAC) and peach gum/graphene oxide (PGGO) were synthesized by freeze-drying method...     

A modified cyanobacteria prediction model based on cellular automata model using N and P concentration reverse data: a case study in Taihu Lake

The problem of algal bloom caused by eutrophication has attracted global attention. Many scholars have studied the problem associated with algae bloom, but few have carried out dynamic monitoring, instead focusing on the formation mechanism of cyanobacteria. For our study of the Taihu Lake in China, we used Moderate-Resolution Imaging Spectroradiometer (MODIS) and Landsat remote sensing image data from 2017 to establish a prediction model. First, we used MODIS data to retrieve the concentration of N, P, and chlorophyll a in water. Then, we applied the analytic hierarchy process (AHP) model to the inversion results to construct the diffusion potential index. Finally, we used C# to compile the cellular automata (CA) model. We found that the distribution of cyanobacteria predicted by our method was consistent with the algal bloom situation of Taihu Lake in 2017. The results showed that the method effectively predicts the dynamic transfer of cyanobacteria from outbreak to diffusion in a short period of time, which can help decision-makers monitor lake health.

     

防污漆中活性物质海洋环境风险评估关键技术探讨

防污漆中的活性物质对海洋生态环境和人类健康造成的潜在风险受到日益广泛的关注,一些发达国家已建立了针对活性物质海洋环境风险评估的技术体系,但我国相关研究目前尚属空白。综述了防污漆活性物质海洋环境风险评估的研究背景、相关法规、技术标准和发展现状,针对环境风险评估的2个重要组成部分(危害性评估和暴露评估)中的关键技术进行了探讨。在危害性评估中,重点分析和比较了受试生物物种的选择原则、生态毒理数据的要求以及预测无效应浓度的推导方法和应用范围;在暴露评估中,系统阐述了活性物质在水环境中释放速率的计算及修正方法、环境浓度的预测模型、现有的暴露场景及其局限性等。本文以期为我国开展防污漆活性物质海洋环境风险评估提供研究基础和科学依据,并提出了今后的研究重点和方向。     

Montmorillonite-Cu(II)/Fe(III) oxides magnetic material as adsorbent for removal of humic acid and its thermal regeneration

In this work, the adsorption features of montmorillonite and the magnetic properties of Cu(II)/Fe(III) oxides were combined in a material to produce magnetic adsorbent, which can be separated from the medium by a simple magnetic process after adsorption. The magnetic material is effective for the removal of humic acid. At pH 6.1, 96% removal was observed from 4.4 mg l(-1) humic acid solution containing 0.02 M NaCl. The adsorption is pH and ionic strength dependent. Adsorption is favored at lower pH values and dissolved NaCl can enhance the adsorption. The adsorption mechanism of humic acid to the magnetic material was suggested to be the ligand exchange reaction between carboxylic groups of humic acid molecules and the magnetic material surface. The magnetic material can be thermally regenerated. The temperature and time required to achieve good regeneration efficiency were determined to be 300 degrees C and 3 h, respectively. The regenerated adsorbent is still magnetic and approximately has as high specific saturation magnetization and good adsorption capacities as the as-prepared adsorbent.     

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.