【作者】 洪树楠；

【导师】 刘明华；

【作者基本信息】 福州大学 ， 环境工程， 2005， 硕士

【摘要】 以制浆黑液的碱木素为原料,采用反相悬浮法,制备出球形木质素珠体。然后对木质素珠体进行接枝改性,制备出球形木质素吸附剂,并进行球形木质素吸附剂的应用研究,综合研究其对金属离子的吸附性能。首先采用正交实验和单因素实验优选了球形木质素制备的条件,并表征了所制备的木质素珠体的物理化学性能。结果表明最佳制备条件为:分散相变压器油和氯苯的混合比为1:1.5,油水相比为3:1;分散剂十二烷基苯磺酸钠和明胶的加量分别为1.2%和0.6%;搅拌速度为250 r?min-1;环氧氯丙烷加量为8%;采用两步升温,所制备出的球形木质素珠体得率达85.77%。而且木质素珠体具有很好的亲水性和耐酸、碱能力。然后又用正交实验和单因素实验确定了木质素珠体接枝反应的优化条件:引发剂浓度为40 mmol?L-1,丙烯酸浓度为1.25 mol?L-1,反应温度为40℃,反应时间为2 h。所制备的木质素吸附剂接枝率为30.41%,并具有较强的抗氧化能力、抗生物降解能力、热稳定性及抗酸碱降解能力。从静态法和动态法方面综合研究了木质素吸附剂的吸附性能,包括静态等温吸附的各种因素对吸附效果的影响,吸附热力学和吸附动力学研究。结果表明木质素吸附剂对Cu2+,Ni2+、Zn2+、Pb2+、Cd2+具有很好的吸附效果,对上述金属离子的静态吸附量分别达到30.24 mg?g-1、27.15 mg?g-1、32.14 mg?g-1、75.75 mg?g-1和45.39 mg?g-1,而且吸附质溶液浓度越高、pH值越高、吸附时间越长,吸附效果就越好。吸附剂的静态等温吸附符合Langmuir和Freundlich吸附等温式,而且对金属离子的吸附以化学吸附为主。吸附过程由表面扩散和颗粒内扩散联合控制,以颗粒内扩散为主。由于所制备的球形木质素吸附剂具有原料易得,吸附性能好,再生重复使用效果好得优点,有利于制浆黒液的资源化利用,并实现变“废”为“宝”,因此具有广阔得前景。更多还原

【Abstract】 The black liquor from the pulping process was adopted to prepare the spherical lignin beads, denoted as SLB, by the reversed-phase suspension technique. Then the spherical lignin adsorbent (denoted as SLA) was prepared by the graft copolymerization. And, the adsorption performances of the adsorbent were comprehensively studied by using the metal ions as adsorbates.SLB was prepared by the orthogonal and signal-factor experiments to optimize the preparation conditions. And, the ideal spherical lignin beads with the 85.77% of the yield could be obtained under the such conditions as 1:1.5 of volume ratio of the transformer oil with chlorobenzene, 3:1 of the volume ratio of the oil and water, 1.2% of the neopelex dosage and 0.6% of the gelatin dosage as well as 8% of the epichlorohydrin dosage at the agitation speed of 250 r?min-1at 60℃ for 1 h and subsequently at 90℃ for anther 1 h. The physicochemical characteristics of SLB indicated that SLB showed good hydrophilicity, high acid and alkaline endurance.The SLA was prepared by grafting the acrylic acid onto the back-bone of SLB initiated with the Fenton agent. The optimum preparation conditions were also obtained by the orthogonal and signal-factor experiments. The optimum preparation conditions of the SLA included 40 mmol?L-1 of the initiator concentration, 1.25 mol?L-1 of the monomer concentration of acrylic acid, 40℃ of the reaction temperature and 2 h of the reaction time. The grafting percentage of SLA prepared under the above conditions could reach 30.41%. And, the SLA showed high thermal endurance, high oxidation endurance and bio-degradation endurance as well as the acid and alkaline endurance.The adsorption properties of the SLA were comprehensively studied in two ways of static adsorption and mobile adsorption. And, the effect factors were also <WP=4>optimized. Moreover, the adsorption mechanisms, i.e., the adsorption thermodynamics and kinetics were explored. The adsorption of such metal ions as Cu2+,Ni2+、Zn2+、Pb2+、Cd2+ on the SLA has found to be concentration、pH and tenperature dependent. The SLA showed excellent adsorption capacities for the above metal ions. The adsorption capacities could reach 30.24 mg?g-1, 27.15 mg?g-1, 32.14 mg?g-1, 75.75 mg?g-1 and 45.39 mg?g-1 respectively. The static adsorption processes followed the Langmuir and Freundlich adsorption isotherm equations. It could be concluded from the adsorption thermodynamics and kinetics that the chemical adsorption was predominant in the adsorption process of metal ions on the SLA. The adsorption rate was controlled by two diffusion models of surface diffusion process and intraparticle diffusion process, but the intraparticle diffusion process played a more significant role during the adsorption process. And, the SLA had such advantages as easy regeneration, high recovery and reusability etc.Consequently, SLA will have a prospective application in the adsorpetion and purification field owing to its excellent adsorption properties and its renewable and abundant raw materials.更多还原