Effective sorption of perfluorooctane sulfonate (PFOS) on hexadecyltrimethylammonium bromide immobilized mesoporous SiO2 hollow sphere

The hexadecyltrimethylammonium bromide (HDTMAB) immobilized hollow mesoporous silica spheres were prepared for the efficient removal of perfluorooctane sulfonate (PFOS) from aqueous solution. Besides the traditional sorption behavior including sorption kinetics as well as effect of solution pH and temperature, the effect of increasing volume which simulated the natural river where the rate of solute and solvent was relatively constant and solution volume was always changing was investigated. The result indicated that the residual PFOS concentrations in aqueous phase decreased with increasing solution pH and ionic strength, whereas they increased with increasing temperature. The HDTMAB immobilized material still maintained high efficiency after increasing volume, that is, the removal kept more than 99% after the treatment when the initial PFOS concentration was 1 mg L^?1. The uptake behavior and morphology of spheres which was characterized by transmission electron microscopy (TEM) revealed that the additional HDTMAB and mesoporous shell were responsible for the enhanced sorption of PFOS. It was concluded that electrostatic interaction and Ca-bridge role played an important role in the sorption of PFOS on the mesoporous SiO₂ hollow spheres, whereas, hydrophobic interaction contributed to the nice sorption performance of PFOS on the HDTMAB immobilized sorbent.     

高碱度水库水混凝过程中残留铝控制

针对高碱度水库水源的某水厂残留铝超标问题,选取碱化度(B)与Alb含量不同的3种铝盐絮凝剂,研究不同投量与pH值下混凝效果与残留铝浓度水平。结果表明,碱化度和Alb含量显著影响混凝效果。DOC和浊度的去除率随着3种絮凝剂AlCl3(B=0)、PACl-1(B=1.2)、PACl-2(B=2.2)投量增大而升高。3种絮凝剂投量在1.5～2.0 mg/L(以铝计)范围内,总铝和溶解铝含量最低。对于该水厂自制的絮凝剂PACl-2,可通过降低絮凝剂碱化度,或将水的pH值降低至7～7.5之间,以此可以提高PACl-2混凝效果,而且可以降低出厂水残留铝浓度。考虑工程应用可行性,可优先考虑调整絮凝剂生产工艺。     

不同粒径泥沙理化特性对磷吸附过程的影响

以北京大兴南海子湖表层沉积物为研究对象,测试分析了0.147～0.246 mm(细砂)、0.074～0.147 mm(极细砂)、0.0385～0.0740 mm(粉粒)和<0.0385 mm(粉粒粘粒混合物)4种粒径泥沙对磷的吸附行为,并采用相关分析及逐步回归分析探讨不同粒径沉积物中有机质(OM)、Fe、Al、Ca、Mn和TP含量对磷吸附过程的影响。结果表明,二级动力学方程和Langmuir模型能较好地描述南海子不同粒径泥沙的吸附动力学及等温吸附过程(R2>0.90)。粒径对单位质量泥沙吸附磷量具有明显影响,粉粒粘粒混合物>粉粒>细砂>极细砂。总体上,泥沙有机质(OM)、TP、Fe、Al、Ca和Mn含量随粒径的减小而增大,且粘粒对其影响较大。不同粒径泥沙(OM)、Fe、Al、Ca和Mn含量之间存在极显著正相关关系(P<0.01),且均对单位质量泥沙最大吸附量(Xm)和饱和吸附量(Cse)具有正效应,其中Al含量对该参数的影响更为显著。这说明泥沙对磷的吸附行为可能受到粒径和化学成分的共同影响。     

一种新型活性半焦吸附剂的制备及其表面特征分析

对一种原料半焦进行粉碎、筛分,取其中10～20目的颗粒;用去离子水冲洗后高温下烘干至恒重;依次进行HNO3活化、KOH活化和加压水热化学活化,制备出活性半焦吸附剂。经实验证明,该活性半焦吸附剂对甲苯的吸附等温线符合Langmuir模型,其甲苯吸附容量可达207 mg/g,穿透时间由80 min延长至235 min。该活性半焦吸附剂的比表面积为555.56 m2/g,碘值为811.38 mg/g,表面酸碱总量为0.8649 mmol/g,并通过SEM扫描进行了表面微观形态分析。数据表明,经改性后制备出的新型活性半焦对甲苯的去除率明显增加,其表面物化性质也有明显改变,是一种优良的有机废气吸附剂。     

无机陶瓷膜处理油田采出水

针对陶瓷膜在油田采出水处理过程中操作参数的选择及污染机理进行了研究。通过现场实验,分析了不同的操作参数对膜通量的影响,陶瓷膜对含油量及悬浮物的去除效果,膜阻力组成及膜污染清洗方法。实验结果表明,在确定出水水质达到低渗透油田注水水质A1级标准条件下,陶瓷膜过滤最佳操作条件为:跨膜压差0.16 MPa、温度50℃、膜面流速5.0 m/s。同时发现,NaOH和HNO3联合清洗有助于恢复膜通量。     

氧化物催化剂对非热等离子体催化降解甲苯的影响

考察了在干燥气氛下不同氧化物催化剂对非热等离子体催化降解甲苯的影响。从甲苯降解率、碳平衡、CO2选择性和O3去除4个方面,对比了氧化物催化剂的介电性能、表面供氧能力和比表面积与多孔结构对反应产生影响的强弱。结果表明,催化剂的介电性能有利于甲苯降解率、碳平衡和O3产量的提高,但对CO2选择性和O3去除的影响极小;一定能量密度下,催化剂比表面积与多孔结构对CO2选择性和O3去除所产生的影响要强于介电性能;催化剂表面供氧能力可明显促进反应的进行,其对反应所产生的影响要强于比表面积与多孔结构。     

气相色谱法测定气田产出水中的甲醇含量

文章建立了使用气相色谱仪分析气田产出水中甲醇含量的方法。通过实验在设定不同分流比的情况下,能有效监测出气田产出水中不同浓度的甲醇含量,此方法灵敏度高,最低检出限为0.02%,测定气田产出水中甲醇加标回收率达到93%～94%。     

创意产业集聚区外部交往空间规划探索——“心理-行为-空间”互动视角下的实证研究

创意产业集聚区在促进创意产业发展、优化城市空间结构等方面具有重要意义,而以满足创意阶层特征和需求的创意产业集聚区内部公共空间规划的研究相对较少。从创意阶层交往的“心理-行为-空间”这一互动视角出发,选取南京具有代表性的“创意东8区”为研究对象,通过调查问卷、深入访谈和实地观察对创意阶层的“交往心理-交往行为-交往空间”进行了研究。在此基础上,从人口交往空间、中心交往空间、节点交往空间、道路交往空间等方面提出符合创意阶层心理和行为特征,并能促进交往产生的外部交往空间规划设计建议。     

树脂固定床吸附含酚废水预测模型研究

针对应用于实际工业化的树脂固定床吸附研究较少,而与之相关的固定床吸附穿透曲线可以用来确定固定床吸附操作参数,为固定床的设计和实际操作提供指导。通过对恒定波振荡理论和吸附等温方程的联合,来预测固定床吸附穿透曲线;并研究了不同操作条件对大孔弱碱树脂吸附对硝基酚穿透曲线预测模型的影响。以期望为树脂固定床的设计和实际工业应用产生指导意义。     

Historical change of mercury pollution in remote Yongle archipelago, South China Sea

We collected three ornithogenic coral sand sedimentary profiles from Jinyin Island, Jinqing Island and Guangjin Island of Yongle archipelago, South China Sea and reconstructed the deposition flux of anthropogenic Hg over the past 700 years in the study area. On the whole, the anthropogenic Hg flux is relatively low; it remained at a low level before the Industrial Revolution with a small peak at about 1450-1550 AD, which may record the enhanced metallurgy activity in Ming Dynasty of China. During the 20th century, the deposition flux of anthropogenic Hg increased rapidly, but two troughs occurred during the periods around 1940s and 1970s, corresponding to the economic depression caused by World War II, Civil War in China (1945-1949), and the Culture Revolution (1966-1976) in China. Since the 1970s the deposition flux of anthropogenic Hg has been persistently increasing, apparently the result of fast economic development in East and Southeast Asia countries around South China Sea.