Bioaccumulation of heavy metals by Phragmites australis cultivated in synthesized substrates

Accumulation of heavy metals from various oxides with adsorbed cadmium by wetland plant Phragmites australis was studied to evaluate the fate of heavy metals in the sediment of constructed wetlands. Hoagland solution was used as nutrition supply, and single metal oxide with adsorbed cadmium was applied as contaminant to study the accumulation characteristics of cadmium and the substrate metals by P. australis. After 45-d treatment, the bioaccumulation degree in root followed the order: Al(OH)₃ > Al₂O₃ > Fe₃O₄ > MnO₂ > FeOOH. Heavy metals absorbed by P. australis were largely immobilized by the roots with little translocation to aboveground parts.     

Synthesis, characterization, and adsorption performance of Pb（Ⅱ）-imprinted polymer in nano-TiO2 matrix

Surface ion-imprinted in combination with sol-gel process was applied to synthesis a new Pb(II)-imprinted polymer for selective separation and enrichment of trace Pb(II) from aqueous solution. The prepared material was characterized by using the infrared spectra, X-ray di ractometer, and scanning electron microscopy. The batch experiments were conducted to study the optimal adsorption condition of adsorption trace Pb(II) from aqueous solutions on Pb(II)-imprinted polymer. The equilibrium was achieved in approximately 4.0 h, and the experimental kinetic data were fitted the pseudo second-order model better. The maximum adsorption capacity was 22.7 mg/g, and the Langmuir equation fitted the adsorption isotherm data. The results of selectivity experiment showed that selectively adsorbed rate of Pb(II) on Pb(II)-imprinted polymer was higher than all other studied ions. Desorption conditions of the adsorbed Pb(II) from the Pb(II)-imprinted polymer were also studied in batch experiments. The prepared Pb(II)-imprinted polymer was shown to be promising for the separation and enrichment of trace Pb(II) from water samples. The adsorption and desorption mechanisms were proposed.     

稻壳沸石的合成及其对磷酸盐的吸附/脱附动力学

以稻壳为原料采用煅烧-水热合成法制备了合成沸石,运用XRD和SEM表征了合成沸石的特性,通过静态实验,研究了合成沸石对磷酸盐的吸附和脱附机理。结果表明:12 h后产物发现了Na P沸石的特征峰和亚晶结构,延长水热合成晶化的时间有利于沸石晶核的形成。沸石对磷酸盐的吸附机理符合伪二级模型,实测值与伪二级吸附动力学模型的拟合值相差在1.1%以内。颗粒内扩散速率是由膜扩散和内扩散共同控制,颗粒内扩散速率常数kp随初始浓度的增加而减小。升温有利于磷酸盐的脱附,MNa OH/P>8.0时(MNa OH/P为Na OH物质的量与吸附的磷酸盐物质的量之比),磷酸盐的脱附率可达82.9%。伪二级脱附动力学模型的拟合结果优于伪一级,拟合值与实测值相差在1.7%以内。     

日将二氧化碳转变为可用资源

二氧化碳是一种温室气体,许多人对它的印象很负面。日本研究人员日前开发出一种新技术,使二氧化碳能转变为用于合成塑料和药物的碳资源,从而变“害”为宝。相关论文已经刊登在新一期《美国化学学会会刊》上。二氧化碳的化学性质非常稳定,不容易与其他物质发生反应,因此在工业领域仅用于生产尿素和聚碳酸酯等。     

内蒙镶黄旗人群胃癌环境病因的研究──关于人体内合成亚硝胺的评估

测定了内蒙古自治区锡盟镶黄旗１５个不同地点水样中的ＮＯ＾－２含量。实验结果显示,１５个地点水样中ＮＯ＾－２的含量相差很大,大致分为Ａ、Ｂ、Ｃ３组,其平均值分别为０．１８６、０．６４０、３．８５０μｇ／ｍｌ。     

交联壳聚糖的合成及其吸附处理废水的研究进展

简要评述了交联壳聚糖的合成方法及化学改性方法 ,并从吸附剂的角度综述了交联壳聚糖在废水处理方面的应用     

二甲基二烯丙基氯化铵的合成

为制备聚二甲基二烯丙基氯化铵絮凝剂,采用二步法制备了二甲基二烯丙基氯化铵单体,即在强碱性条件下由烯丙基氯和二甲胺反应先生成二收藏 －烯丙基叔胺,将该叔胺分离出来并再次加入烯丙基氯同会２丙介质中结晶析出委胺晶体。     

尾气中二甲基乙酰胺溶剂的回收

介绍发子薄膜,涂料生产过程中尾气中二甲基乙酰胺溶剂回收处理技术。     

Preparation and catalytic properties of ZrO2-Al2O3 composite oxide supported nickel catalysts for methane reforming with carbon dioxide

ZrO2-Al2O3 composite oxides and supported Ni catalysts were prepared, and characterized by N2 adsorption/desorption, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. The catalytic performance and carbon deposition was also investigated. This mesoporous composite oxide is shown to be a promising catalyst support. An increase in the catalytic activity and stability of methane and carbon dioxide reforming reaction was resulted from the zirconia addition, especially at 5wt% ZrO2 content. The Ni catalyst supported ZrO2-Al2O3 has a strong resistance to sintering and the carbon deposition in a relatively long-term reaction.     

环保型缓蚀剂在油气管道腐蚀防护中的应用

为了延缓油气集输管道的腐蚀速率,延长管道的使用寿命,实验室以丙烯酸(AA)、顺丁烯二酸酐(MA)以及丙烯酸乙酯(EA)为原料,制备了一种环保型缓蚀剂HBY-2,优化了合成工艺条件,并评价了其防腐蚀效果。实验结果表明：在单体的质量分数为20%,单体配比为AA∶MA∶EA=1.2∶1.2∶1.0,引发剂加量为0.5%,反应温度为80℃,反应时间为5 h的合成条件下,制备的环保型缓蚀剂HBY-2的缓蚀效果最好。当HBY-2的加量为0.3%,腐蚀时间为30天时,缓蚀率仍可以达到97.5%,长效腐蚀防护效果较好。在相同的实验条件下,环保型缓蚀剂HBY-2的缓蚀效果明显优于钨酸钠、钼酸钠、硫脲和咪唑啉。现场应用结果表明,油井集输管道中添加缓蚀剂HBY-2后,挂片的腐蚀速率均明显降低。研究结果认为,制备的环保型缓蚀剂HBY-2能够满足油气集输管道的腐蚀防护需求,降低管道的腐蚀速率,延长其使用寿命。