【作者】 杨继亮；

【导师】 周建斌；

【作者基本信息】 南京林业大学 ， 林产化学加工工程， 2013， 博士

【摘要】 为了解卷烟滤嘴用活性炭的应用现状，论文选取国内外8种市售卷烟滤嘴中的活性炭作为吸附剂，对各活性炭进行粒度分析、孔隙分析和红外光谱分析表征，并以氨、乙醛、丁醛、苯、异戊二烯、丙酮、一氧化碳和一氧化氮作为吸附质进行吸附实验，评价其吸附性能，为卷烟滤嘴用活性炭的选择提供一定的理论基础。结果表明：活性炭作为烟滤嘴添加剂目前无统一、具体的标准指标，各品牌市售卷烟中活性炭的添加量、添加方式以及活性炭的粒度、比表面积、孔隙结构都有所不同。由各卷烟滤嘴用活性炭的FTIR谱图以及粒度分布可以推断，各品牌卷烟滤嘴中添加的活性炭多为物理法制备的果壳活性炭，如ZY、SH、SH-2、D、K、M和P；PQR中酸性官能团较多，有可能预先经过改性处理。研究表明二元复合滤嘴中的活性炭（D、K、M和P）由于表面附着大量的三醋酸甘油脂，堵塞部分微孔及中、大孔孔隙并形成空间位阻，增加吸附质分子的传质阻力，导致其吸附性能明显低于三元复合滤嘴中的活性炭（SH）。适当增加活性炭的中、大孔和活性炭表面的C=O结构有利于提高活性炭对大部分吸附质的捕集。论文以杏壳为原料，采用H₃PO₄和H₃PO₄复合KH₂PO₄为活化剂制备出不同孔隙和表面含氧官能团的活性炭，采用N₂吸附-脱附、碘吸附值测定、亚甲基蓝吸附值测定、元素分析和Boehm滴定法对其进行孔隙结构、比表面积和含氧官能团含量分析，并以此作为卷烟滤嘴添加剂，采用DZJ单通道吸烟机对卷烟主流烟气中的重金属元素Hg和Pb进行吸附实验。首次研究得出活性炭吸附重金属元素Hg的最可几孔径为0.852-1.096nm之间，而活性炭吸附重金属元素Pb的最可几孔在1.245-1.534nm之间。活性炭的孔隙分布比比表面积更加重要，比表面积与重金属元素Hg和Pb的吸附并无明显相关性。活性炭表面的酸性含氧官能团在吸附过程中发挥着重要的作用，羧基官能团含量与卷烟烟气中重金属元素Hg和Pb的残留含量呈反比例关系。在活性炭吸附处理卷烟烟气中的重金属元素Hg和Pb过程中，Hg和Pb存在竞争吸附现象。通过浸渍法制备了四种改性杏壳活性炭（氨水改性活性炭、硫改性活性炭、碘改性活性炭和铁盐改性活性炭），采用N₂吸附-脱附、元素分析、傅立叶变换红外（FTIR）、热重分析（TG）、X-射线衍射（XRD）和X-射线能谱分析等方法对改性活性炭进行表征，首次针对降低卷烟烟气中重金属元素Hg和Pb的危害进行相关吸附剂改性及其吸附性能研究，结果表明：改性后，氨水改性活性炭和硫改性活性炭其孔隙结构有不同程度的发展，而碘改性活性炭和铁盐改性活性炭孔隙和比表面积都发生了不同程度的减小。FTIR分析表明，氨水改性活性炭表面引进胺基；活性炭、KI和H₂SO₄之间发生了化学反应，活性炭表面负载了I₂和磺酸基两种活性位。TG结果表明硫改性活性炭、经KI改性的活性炭稳定性降低；经KI和H₂SO₄改性后的活性炭热稳定性显著降低。各改性活性炭在200℃下均较稳定，为其作为卷烟滤嘴用活性炭提供了前提条件。XRD结果表明铁盐改性活性炭表面负载的为α-Fe₂O₃。以上述四种改性活性炭作为吸附剂，采用DZJ单通道吸烟机对卷烟主流烟气中的重金属元素Hg和Pb进行吸附实验，并对安全性作出评价。结果表明：未改性活性炭对主流烟气中的Hg和Pb的吸附能力较弱，主要为物理吸附。活性炭经氨水改性之后，N含量增加使活性炭表面产生新的吸附位，使活性炭的吸附效率显著增加，经N-15吸附后的Hg和Pb含量较对照样分别降低了64.00%和80.00%。硫改性活性炭表现出明显的化学吸附作用，活性炭表面的S与Hg、Pb反应生成HgS、PbS沉积于活性炭孔隙中。S-11吸附能力最强，主流烟气中Hg和Pb含量分别较对照样降低了84.00%和80.00%。在相同制备条件下，适量的添加浓H₂SO₄溶液可以使KI转化为I₂负载在活性炭表面，极大的提高改性活性炭对主流烟气中Hg和Pb的吸附能力。经I-3和I-4吸附后的主流烟气中均未检测出Hg含量。活性炭表面的Fe₂O₃对Hg表现出强烈的亲和力，优先吸附主流烟气中的Hg，表现出强烈的化学吸附作用，Pb的吸附受到Hg的竞争吸附以及活性炭微孔孔隙含量的影响。经F-8吸附后的Hg含量较对照样降低了90.67%，而Pb含量仅降低了70.12%。各种改性活性炭均在一定程度上降低了卷烟主流烟气中TPM含量。由于活性炭改性过程中引入了S、I和Fe元素，为了防止在卷烟抽吸过程中主流烟气带出含S、I和Fe元素颗粒的发生，避免对人体健康造成二次危害，采用能谱分析对吸附前后的剑桥滤片进行元素扫描，结果表明吸附后的剑桥滤片中未发现S、Na₂S、KI、I₂和Fe₂O₃颗粒，保证了改性活性炭作为卷烟滤嘴用添加剂的安全性。以杏壳活性炭为原料，通过水蒸气物理活化法、氯化锌化学活化法对原料进行二次活化，采用硫酸氢钠对原料进行改性处理，并将其应用于烟草加工废水中尼古丁的去除。结果表明：AC-N与AC-H对水溶液中尼古丁静态吸附平衡实验数据可用Freundlich吸附等温线方程进行较好的描述。适当的提高反应温度有利于化学吸附的进行。静态实验结果表明，AC-H在45℃、尼古丁初始浓度为750mg/L条件下的饱和吸附量最大，达355.68mg/g。活性炭对水溶液中尼古丁的饱和吸附量随活性炭表面的酚羟基含量的增加而增加，随羧基含量的增加而减小。更多还原

【Abstract】 In order to understand the application status of activated carbon in cigarette filters,8brands of cigarettes purchased from convenience stores were used to separate activatedcarbons from cigarette filters, and then employed as adsorbent materials for adsorption ofammonia, acetaldehyde, butyraldehyde, benzene, isoprene, acetone, carbon monoxide and nitricoxide. Their adsorption capacities were evaluated to understand the application status ofactivated carbon in cigarettes, and provide theoretical basis for selection of activated carbon.The activated carbons were characterized by particle size analysis, pore structure analysis, andFourier transform infrared spectroscopy （FTIR）. The results indicate no unified standardindicator for activated carbons used in cigarette filters, because the addition amounts, addingmodes, particle sizes, surface areas and pore structures of activated carbons were differentamong the8brands. The FTIR and particle size analysis indicated that the activated carbonsused for cigarettes were most physical ones, such as ZY, SH, SH-2, D, K, M and P; PQRcontained the most acidic oxygen groups, probably because it had been modified by chemicals.The adding mode of activated carbon affected its adsorption properties seriously. Comparedwith the ternary complex cigarette filter （SH）, the adsorption capacities of activated carbonsused in the binary composite cigarette filters （D, K, M and P） were poorer, probably because ofnumerous glyceryl triacetate on the surface of activated carbon used in the binary compositecigarette filters, which could block pore structures and form steric hindrance, and increase themass transfer resistance of the adsorbate molecules. Appropriately increasing the contents ofmespores, macropores and C=O structures in activated carbons were favorable for improvingthe ability to capture most adsorbates. All the activated carbons could not absorb CO.Activated carbons were prepared from almond shells by chemical activation with H₃PO₄orH₃PO₄-KH₂PO₄composite. The samples were characterized by N₂adsorption-desorption,iodine adsorption number determination, methylene blue adsorption number determination,elemental analysis and Boehm titration, and their textures and surface chemistry were studied.Then they were used as adsorbents in the cigarette filters and experiments were carried out toabsorb the heavy metals of Hg and Pb in cigarette main stream by DZJ single-channel smokingmachine. The results are first to show that: The pore size within0.852-1.096nm is conducive toHg adsorption, and the pore size within1.245-1.534nm is conducive to Pb adsorption. The poresize distributions are more important than the surface areas of activated carbons, as there is noobvious relationship between the surface areas and Hg/Pb adsorption amount. The surfaceacidic oxygen groups play an important role in the adsorption; improving the carboxyl groupcontents is favorable for adsorption of Hg and Pb, and Hg was competing with Pb for the sameactive sites during the adsorption. Four modified activated carbons （modified by ammonia, sulfur, iodine, or iron salt） wereprepared by impregnation, and almond shell-based activated carbon was used as raw materials.The modified activated carbons were characterized by N₂adsorption-desorption, elementalanalysis, FTIR, thermogravimetric analysis （TG）, X-ray diffraction （XRD） and X-rayenergy-dispersive spectrum （EDS）. It was the first time to reduce the harms of Hg and Pb incigarette stream smoke by adsorbents related with their modified methods and adsorptionproperties. The results show that: After the modification, the pore structure contents in bothammonia-modified and sulfur-modified activated carbons were improved to different degrees,while the pore contents and surface areas in both iodine-modified and iron salt-modifiedactivated carbons decreased to varying degrees. FTIR analysis showed that amino group wasintroduced onto the surface of ammonia-modified activated carbon; chemical reactions occurredamong activated carbon, KI and H₂SO₄, which led to the generation of two types of active sites（iodine and sulfuric acid group） on the surface of activated carbon. The TGA results indicatedthat the stabilities of sulfur-modified, KI/H₂SO₄composite modified and KI-modified activatedcarbons decreased, especially for KI/H₂SO₄composite-modified activated carbon; eachmodified activated carbon was stable below200℃, and it provided the preconditions formodified activated carbons to be used in cigarette filters. The XRD results show that the surfaceof iron salt-modified activated carbons was loaded with α-Fe₂O₃.The above four modified activated carbons were explored as adsorbents in cigarette filters,and experiments were carried out to absorb the Hg and Pb in cigarette main stream by DZJsingle-channel smoking machine, and their securities were evaluated. The results show that:The adsorption of Hg and Pb by non-modified activated carbon was weak and was mainlyphysical adsorption. Modification by ammonia could improve the N content in modifiedactivated carbons and lead to the generation of a new active site, so the adsorption efficiency ofammonia-modified activated carbons developed significantly. Compared with the blank sample,the contents of Hg and Pb in the cigarette stream smoke after adsorption by N-15decreased64.00%and80.00%, respectively. The adsorption on sulfur-modified activated carbons wasobviously chemical adsorption; the S on the surface of sulfur-modified activated carbons couldreact with Hg and Pb to produce HgS and PbS, which were deposited in the pores of theactivated carbons. S-11had the strongest adsorption capacity. Compared with the blank sample,the contents of Hg and Pb in the cigarette stream smoke after adsorption decreased84.00%and80.00%, respectively. A proper addition of H₂SO₄could transform KI to I₂and load on thesurface of activated carbon under the same preparation conditions, which greatly improved Hgand Pb adsorption capacities of modified activated carbons. There was no Hg in the cigarettestream smoke after adsorption by I-3and I-4. α-Fe₂O₃on the surface of modified activatedcarbons exhibited a strong affinity to Hg; the iron salt-modified activated carbons preferred toabsorb Hg and it was chemical adsorption. Pb adsorption by iron salt-modified activatedcarbons was influenced by the competitive adsorption of Hg and the content of micropores.Compared with the blank sample, Hg content and Pb content in the cigarette stream smoke afteradsorption by F-8decreased90.67%and70.12%respectively. Each modified activated carbon could reduce the TPM content in cigarette main stream to varying degrees. Because S, I and Featoms were introduced into activated carbons during modification, in order to prevent theparticles containing S, I and Fe from exiting through with cigarette stream smoke duringpumping, and to avoid secondary harm to health, the Cambrige filter films which adsorbedbefore and after were analyzed by EDS. The results showed no S, Na₂S, KI, I₂or Fe₂O₃particles on the Cambrige filter films after adsorption experiments, which ensured the safety ofmodified activated carbons to be used in cigarette filters.Finally, almond-shell-based activated carbon was reactivated or modified with steam, zincchloride and sodium bisulfate separately. Then the reactivated/modified activated carbons wereapplied for nicotine adsorption in the tobacco processing wastewater. The results show that:The nicotine adsorption experimental equilibrium data of reactivated/modified activatedcarbons could be described by Langmuir and Freundlich isotherm equations. Appropriatelyincreasing the reaction temperature could promote chemical adsorption. The static experimentaldata show that the saturated adsorption amount was best at45°C and nicotine initialconcentration was750mg/L by AC-H, which was355.68mg/g. The nicotine adsorptionamounts increased with the increasing phenolic hydroxyl content in activated carbons, butdecreased with the increasing carboxyl content.更多还原