纳米SiO_2/氨基淀粉黏合剂秸秆炭的结构及除磷特性  

Structure of straw biochar/amino resin doping nano SiO_2 and its phosphorus removal characteristic

作　　者：孙恩惠[1] 钱玉婷[1] 靳红梅[1] 黄慧[2] 武国峰[1] 常志州[1] 黄红英[1] 

机构地区：[1]江苏省农业科学院循环农业研究中心,南京210014 [2]江西省林业科学院,南昌330013

出　　处：《农业工程学报》2017年第8期211-218,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学青年面上基金项目(21577052);江苏省农科院青年人才自由探索(ZX(15)4006)资助项目;江苏省农科院院基金项目(6111630)

摘　　要：将秸秆粉用氨基淀粉黏合剂均相包覆,并掺杂纳米二氧化硅(nano SiO_2),采用原位发泡、炭化处理技术制备成纳米SiO_2/氨基淀粉黏合剂秸秆炭(掺杂纳米SiO_2秸秆多孔颗粒炭,nano SiO_2/AR-biochar)。通过透射电镜(transmission electron microscope,TEM)、热稳定性(thermogravimetry,TG)、扫描电镜-能谱扫描(scanning electron microscope-energy dispersive spectrometer,SEM-EDS)、比表面积与孔分析(Brunauer,Emmett and Teller,BET)、氮气吸附和压缩测试等技术手段对nano SiO_2/AR-biochar的孔结构特征、比表面积、微观形貌及压应力进行系统表征,并研究了nano SiO_2/AR-biochar对磷酸根吸附过程等温线及动力学模型。结果表明,掺杂nano SiO_2/AR-biochar孔结构分布匀称、比表面积大幅改善;TEM和SEM发现,掺杂nano SiO_2秸秆多孔颗粒炭材料的表面可形成类似海绵絮状结构,为炭材料提供较高的吸附位点;掺杂nano SiO_2可显著提高炭材料的机械压缩性能,当掺杂量为秸秆粉质量的6%时,压缩强度由3.89 MPa增加到7.96 MPa,增幅达104.6%。由于纳米SiO_2的掺杂,nano SiO_2/AR-biochar具有了更强除磷效果,且吸附过程符合准二级动力学模型,在短时间内(5 min)其吸附率可高达18.42 mg/g,体现了该掺杂纳米二氧化硅秸秆多孔颗粒炭具有良好的除磷特性。Phosphorus is one of the key nutrients that cause eutrophication of water bodies, and excessive phosphorus in water will cause water ecosystem structure and function change, deterioration of water quality and landscape, and biodiversity decrease. Therefore, preventive measure of phosphorus pollution in the aquatic environment and processing must be paid more attention. The processing methods of phosphorous water include biological phosphorus removal technology, chemical precipitation, adsorption, and so on. Adsorption technology is efficient and cheap, and has a good removal effect, which has come into notice of researchers. So far, some studies have been conducted on preparation of straw biochar for removal of phosphate radical from aqueous solutions. In this study, a porous nano biochar composite （nanoSiO2/AR-biochar） was prepared by nanoSiO2 doping, which was homogeneously cladded using amino starch resin, and kneading molding, then foaming coking technology were adopted in situ preparation as well as the carbonizing treatment. Transmission electron microscope （TEM）, thermogravimetry, scanning electron microscope （SEM）, specific surface area analysis, nitrogen adsorption-desorption isothermal and compression were used to characterize the pore structure, thermal stability, microstructure and compression performance of nanoSiO2/AR-biochar. Phosphate adsorption process of nanoSiO2/AR-biochar was studied by means of isothermal and adsorption kinetics. Results showed that the specific surface area, total pore volume, and micropore volume of nanoSiO2/1AR-biochars increased monotonously. The nanoSiO2/AR-biochars prepared at 550℃ possessed the maximum single point adsorption total pore volume （0.177 5 cm^3/g）, and the pore diameter of the ultramicropores was mainly in the range from 1 to 50 nm. The t-plot micropore area, and Brunauer-Emmet-Teller surface area of this kind of nanoSiO2/AR-biochar were 302.86 and 352.70 m^2/g, respectively, when the doping amount of nanoSiO2 was 6% of straw powder quali

关 键 词：材料 磷 黏合剂 秸秆炭 表面性质 多孔性 

分 类 号：TB34[一般工业技术—材料科学与工程]