【摘 要】
：
A novel porous nanocomposite, cross-linked chitosan and polyethylene glycol (PEG) bead-supported MnFe2O4 nanoparticles (CPM), was developed as an efficient adsorbent to remove metalloid (As(Ⅲ)) and heavy metals (Cd(Ⅱ), Cu(Ⅱ), and Pb(Ⅱ)). The characteristi
【机 构】
：
National Engineering Research Center for Environment-friendly Metallurgy in Producing Premium Non-fe
论文部分内容阅读
A novel porous nanocomposite, cross-linked chitosan and polyethylene glycol (PEG) bead-supported MnFe2O4 nanoparticles (CPM), was developed as an efficient adsorbent to remove metalloid (As(Ⅲ)) and heavy metals (Cd(Ⅱ), Cu(Ⅱ), and Pb(Ⅱ)). The characteristics of CPM showed a porous structure, well dispersed MnFe2O4, and several of hydroxyl and amino groups (AOH, ANH2). Batch experiments demon-strated that the best adsorption property of As(Ⅲ), Cd(Ⅱ), Cu(Ⅱ), and Pb(Ⅱ) was achieved within 8 h with maximum adsorption capacities of 9.90, 9.73, 43.94, and 11.98 mg/g, respectively. Competitive and syn-ergistic effects (particularly precipitation) were included in the co-adsorption mechanism of As(Ⅲ) and heavy metals. Thereinto, As(Ⅲ) was partly oxidized by MnFe2O4 to As(Ⅴ), and both were coordinated on MnFe2O4 nanoparticles. Pb(Ⅱ) could also bind to MnFe2O4 by ion exchange and electrostatic attraction. Furthermore, Cd(Ⅱ) and Cu(Ⅱ) tended to be coordinated on chitosan. Therefore, CPM can serve as a reme-diation material for water and soil co-contaminated with As(Ⅲ) and heavy metals.
其他文献
半导体可调谐激光器由于其小尺寸、长寿命以及较高的光电转换效率等优点,在光通信、传感探测等领域有着广泛应用。其中,V型腔可调谐激光器具有高边模抑制比、宽调谐范围等优点,同时凭借其特有的选模结构-半波耦合器,避免了多次外延或光栅刻蚀,器件制作简单。基于Ga As/Al Ga As材料体系的可调谐激光器在激光雷达、血液检测等领域扮演着重要的角色,而这些领域始终对可调谐激光器有着高性能、低成本、易于集成的
光波导相控阵是一种新型的激光扫描技术,因其准确度高、稳定性好、抗干扰能力强等特征,广泛应用于无人驾驶,激光雷达等领域。近年来,随着硅基光子技术的不断发展,硅基光波导相控阵已成为研究当中的热点。但由于目前工艺制备的限制,导致了光束中栅瓣的产生,造成了对远场目标识别的干扰。因此,对于光束优化方法的研究具有十分重要的意义。本文主要研究内容如下:首先,以相控阵基本原理为依据,研究了硅基光波导相控阵扫描原理
To achieve the utilization of the abandoned ultrafine ilmenite (-20 μm) produced in the titanium mag-netite processing plant in Panzhihua, the superconducting high-gradient magnetic separation (SMS) tech-nology was proposed in this study. After optimizing
A method based on multiple images captured under different light sources at different incident angles was developed to recognize the coal density range in this study. The innovation is that two new images were constructed based on images captured under fo
Traditional vibrating screen usually adopts the linear centralized excitation mode, which causes the dif-ficulty in particles loosening and low screening efficiency. The variable elliptical vibrating screen (VEVS) trajectory is regulated to adapt the mate
Physical upgrading of graphite is typically achieved with many stages of grinding and flotation to produce a concentrate with approximately 95％carbon grade. An innovative grinding and column flotation process has been developed for efficient graphite upgr
The surface species transformation of oxidized carrollite processing with NaHS and KBX was investigated. Flotation and contact angle tests indicate that the combination of NaHS and KBX takes a better flotation performance than adding NaHS or KBX alone. Th
In this investigation, a chelating agent of amino trimethylene phosphonic acid (ATMP) was introduced to eliminate the adverse effect of seawater in molybdenite flotation. Microflotation results presented that high flotation recovery of molybdenite was ach
基于目前中厚板钛合金激光-电弧复合焊接的研究相对匮乏以及钛合金焊接表面氧化、气孔等问题,本文进行了8mm厚TC4钛合金激光-电弧复合焊接试验,探究合适的工艺确保焊接过程稳定以及焊缝成形优良,结合焊接稳定性、气孔的特征观察以及气孔的变化规律分析了气孔形成机理。建立熔滴受力模型与等离子体-电弧耦合模型,分析了等离子体、电弧二者的相互影响以及熔滴过渡的必要条件。结果表明,光致等离子体中的电子能够吸引以及
As an alternative reductant for fossil fuel in the future, straw-type biomass contributes to emission reduc-tion and green utilization in the suspension roasting process. In this study, the influences of the roasting time, roasting temperature and dose of