共查询到20条相似文献,搜索用时 93 毫秒
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《纤维素科学与技术》2015,(3):61-68
生物质及其衍生物种类丰富,性质多样,在生物质材料的开发中显示出众多的应用特性和功能特性。生物质原料表面粗糙,本身具有一定的与金属离子结合的能力,通过适当的改性使其可以在广泛的p H范围内对金属进行吸附沉淀处理,实现对金属离子的回收再利用。本文综述了现有生物质基金属离子吸附材料的原料、方法及吸附效果,同时讨论了现有生物质基金属离子吸附材料存在的问题及应用开发前景与方向。 相似文献
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综述了生物质热解制备生物炭过程中前驱体的选择、原料粒径、热解方式、热解温度、升温速率、停留时间和热解压力等工艺参数对其物化性能的影响,通过采用各种改性方法来改变生物炭的表面结构、官能团及元素种类数量和形态结构来提高其结构的稳定性、吸附的高效性以及可重复利用性,以期用生物炭来解决废水环境中各类污染物的污染问题。分析了生物炭在制备过程中仍然存在的问题和不足,目前作为吸附材料在应对污水处理、土壤修复和气体净化等方向的吸附性能需要改进和提高,也对未来的制备过程的优化、改性方法的合理选取、使用过程中各种因素的交互影响、成本估算以及可循环利用等研究方向提供科学依据和理论基础。 相似文献
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生物质焦是生物质热化学转化过程中的副产品,是一种潜在的物理吸附剂,能够用作水处理吸附多种污染物。通过不同的改性方式,能够改变生物质焦的物理结构和化学特性,从而改变其对污染物的吸附脱除能力。本文在详细分析液相溶液吸附影响因素的基础上,总结了针对不同种类污染物,提升其吸附容量的有效生物质焦改性方法,包含热处理、添加试剂扩孔、超声波处理以及化学修饰和生物辅助等手段,并认为除孔隙特性外,生物质焦表面含氧官能团的化学特性同样对吸附起重要作用,如酸处理可增加焦表面酸性含氧官能团,并因阳离子交换作用而利于吸附金属离子;碱处理的焦表面因离域π电子密度提高,色散力增强,从而有利于吸附脱除酚酞、染料等有机污染物;而负载原子和化合物的焦能同时提升其对有机和金属污染物的脱除能力。此外,发现微生物作用下的生物吸附有助于脱除难降解的苯酚。该文为提升生物质焦吸附容量的改性方法选择提供了有效思路。 相似文献
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S. Swapna Priya 《Chemical Engineering Communications》2017,204(8):821-839
Over the past few decades, the usage of antibiotics is growing on a rapid phase. The continuous use in the treatment against several bacterial infections paves a way to increased resistant strains. Environmental pollution created by antibiotics is considered as a serious problem though no toxic reports were known until now. The pharmaceutical compounds present in the environment are known as “Emerging Pollutants.” Among antibiotics, tetracycline (TET) class of drugs were known to exist for several years. Within 3–4 years of the discovery of the first class of TET, the resistant strains were also identified. TET usage is not only limited for human therapy but also greatly used in veterinary and agricultural purposes. These compounds have been detected in the environment, especially in aquatic farms, groundwater, surface water, etc., thus, it becomes vital to take some measures in removing these compounds from the ecosystem to some extent. Many degradation methodologies and mechanisms were applied to remove TET but were highly limited to synthetic effluents. Adsorption is a common practice at the industrial level, especially in effluent treatment processes. In this study, removal of TET through adsorption using various adsorbents was reviewed extensively. 相似文献
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Distribution equilibria were investigated for the adsorption of metal ions and acids on Sumichelate MC-10 resin, a polyethylene polyamine type of novel chelating resin. The total exchange capacities for HCl and HNO3 were evaluated as 5.6 and 6.3 mol/kg dry resin, respectively. Adsorption of various divalent transition metals and precious metals was investigated from HCl on the chloride form of the resin. The adsorption of transition metals took place in the sequence Cd>Zn>Cu>Co>Mn. The adsorption of Pt(IV) was only slightly selective over Pd(II); however, the latter was selectively eluted with high concentrations of HCl. Adsorption of Ag(I), Zn(II) and Cu(II) was investigated from 1 mol/dm3 NH4NO3 on the free base form of the resin. It took place in the sequence Cu>Ag>Zn. The mechanism of the adsorption of metal ions mentioned above was qualitatively discussed. 相似文献
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Generally speaking, anionic metal concentrations in wastewater from industries and mineral processing plants are well above the allowed limits for effluent set by the Ministry of Environment of Japan. Nowadays, the removal of anionic ions has been considered difficult and development of new process is desperately needed. In this paper, we report the development of three hydroxide-type adsorbents, illustrating their adsorption efficiency in removing As, Se, Mo and Sb ions from aqueous solutions. The main finding of this work was that the adsorption behavior was influenced very much by both the pH and the adsorbent concentration. Nevertheless, the newly developed hydroxide-type adsorbents were very effective in reducing the concentration of those anionic ions. 相似文献
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以生物吸附剂花生壳和甘蔗渣作为吸附剂,讨论了原料粒径大小、吸附时间、温度、初始溶液p H值、加入量、振荡速率对吸附效率的影响。结果表明最佳吸附条件为:甘蔗渣吸附剂过80目筛,投加量为0. 8 g,吸附溶液初始p H为2. 0,35℃时以200 rpm的速率振荡300 min,对实验室废水中Cr(Ⅵ)的吸附率可达95. 10%;花生壳吸附剂过120目筛,投加量1. 0 g,35℃时以150 rpm的速率振荡180 min,对实验室废水中Cr(Ⅵ)的吸附去除率达到97. 52%。 相似文献