新型功能化改性生物质吸附剂的制备及其对重金属铜的吸附性能研究

为有效解决自然水体中重金属污染的问题,以来源广泛、成本低廉、可再生的废弃生物质材料(花生壳、玉米芯、白果壳、树皮等)为基体,通过表面预处理、高温炭化以及后功能化改性(包括硫酸、硝酸、柠檬酸、高锰酸钾活化)等工艺制备了一系列高效多孔生物吸附剂材料。结果表明,经过高锰酸钾氧化改性的生物吸附剂(花生壳、玉米芯、白果壳、树皮)对重金属铜的吸附率最高,分别达到79.4%、65.3%、83.9%、71.8%,与原始生物材料吸附效果相比,吸附容量显著提高了66.2%、53.7%、70.7%、53.1%。同时,优化了高锰酸钾改性吸附剂对铜的吸附条件(时间、温度、pH)。经过结构特性表征分析,改性后的吸附剂相较于改性之前生物材料比表面积更大、孔隙结构更多,较大幅度提升了对于重金属离子的吸附能力。该研究所开发的高效生物质吸附剂为环境中重金属离子的消除以及资源化利用提供了一种廉价高效的新方法、新思路,同时也提供了一种绿色高效处理农林业废弃物的途径。

Study on the preparation and adsorption properties of new functional modified biosorption for heavy metal copper

In order to solve the problem of serious heavy metal pollution in natural water around the world，the design and synthesis of high-performance adsorbent materials has become the important task for ecological environmental protection in the future． Herein，we report a novel strategy for fabricating a series of high-efficiency biomass adsorbents． Inspired by the abundant， inexpensive and renewable characters offered by nature，four kinds of waste biomass materials of peanut shell，corncob，gingko shell and bark were used as raw materials，and then prepared by surface pretreatment，high temperature carbonization and postmodification ( sulfuric acid modified nitric acid modified citric acid modified potassium permanganate activation) ． Results show that the adsorption rate of Cu modified by potassium permanganate oxidation for sample peanut shell，corncob，gingko shell and bark was the highest，reaching 79. 4%，65. 3%，83. 9% and 71. 8%，respectively． Compared with the original biomass，the adsorption rate of Cu was increased by 66. 2%，53. 7%，70. 7% and 53. 1%． Meanwhile，the effect of adsorption time，the influences of temperature and pH on the adsorption efficiency of potassium permanganate modified adsorbents were also investigated． By characterization，it was found that the original smooth and dense biomass material became a porous structure after chemical modification，which greatly increased the specific surface area and porosity of biomass，and thus significantly improved the adsorption capacity of Cu． The efficient biomass adsorbent developed by this study provides a cheap and efficient strategy for eliminating heavy metal ion pollution and recycling in the environment，and which also provides a green and efficient route to deal with agricultural waste．