【作者】 李艳；

【导师】 龙柱；

【作者基本信息】 江南大学 ， 制浆造纸工程， 2010， 硕士

【摘要】 水是人类生存最基本的需求,然而随着工业的迅猛发展,水体污染问题日益突出,同时,人们物质生活水平的不断提高对水质也提出了更高的要求。就目前的水体污染特点看,水体中可溶性有机物质及非生物降解化合物等逐年增多,但目前常规水处理手段对这一类污染物的去除效果并不显著,同时现行的许多水处理试剂还可能产生对环境有害的二次污染物质,这无疑对环境保护以及可持续发展等带来不利影响。因此寻求兼有高效、环保、经济且无二次污染的水处理技术是当前水处理领域的研究热点和前沿课题。本文用共沉淀法制备Fe₃O₄磁性纳米粒子,并对其用油酸进行表面改性;同时制备羧甲基壳聚糖,继而采用反相悬浮法制备羧甲基壳聚糖磁性微粒。考察了交联剂的种类和羧甲基壳聚糖/改性Fe₃O₄的质量比等条件对制备微粒的影响。应用透射电子显微镜（TEM）、原子力显微镜（AFM）、红外谱图（IR）、纳米粒度及Zeta电位分析仪（DLS）、热重分析仪（TGA）及震荡样品磁强计（VSM）等对磁性微粒的形态与特性进行了表征。研究结果表明,在适宜的交联剂,交联剂用量,羧甲基壳聚糖/改性Fe₃O₄的质量比等条件下,可以制得大小为5²0nm的球形颗粒、磁性很强且热稳定性良好的壳聚糖磁性微粒。将改性壳聚糖磁性微粒作为絮凝剂,探讨了该絮凝剂对制浆造纸废水的絮凝作用,着重考察了改性壳聚糖磁性微粒的投入量、体系pH值、搅拌速度、搅拌时间、沉降时间对制浆造纸废水中CODcr去除率的影响。结果表明改性壳聚糖磁性微粒对COD含量高的制浆造纸废水的COD去除率可达56.52%,对COD含量较低的制浆造纸废水的COD去除率可达29.56%,说明改性壳聚糖磁性微粒对CODcr高的制浆造纸废水处理效果比较明显,如果利用改性壳聚糖磁性微粒作为最初的絮凝剂可以大大的降低CODcr值,达到相同去除效果时,可减少不必要的制浆造纸废水后续处理工段,从而降低成本,节省能源消耗,因此改性壳聚糖磁性微粒作为絮凝剂对制浆造纸废水的处理切实可行。同时进一步考察了对COD含量较高的制浆造纸废水的悬浮物SS和色度去除效果的影响,结果表明对SS的去除率达到了52.14%,并且色度最低可达到80倍左右,刚好达到制浆企业的废水排污标准。更多还原

【Abstract】 Water is the basic need to the human existence, however, with the drastic development of industry the problem of water pollution becomes more and more serious. Meanwhile, the continual improvement of the people’s material living standard has caused great demand to the quality of water. As for the features of the current pollution of water, the dissolved organic matter and the non-biodegradation compound,etc have increased gradually year by year. But the effect of the present technical means on reducing water turbidity is not remarkable, and many current reagents used as water treatment may produce the second pollutant which is damaging to the environment.There is no doubt that it will have a harmful influence over the protection of environment and the continuing development. Therefore, nowdays seeking for the efficient, environmental and economic technology of water treatment without the second pollution should be the hot sopt and the foremost issue in the current research on the water treatment.The Fe₃O₄ nano-particles were prepared by co-precipitation method and modified by oleic acid;Then carboxymethyl chitosan magnetic microscopic particles were prepared by inverse suspension method with carboxymethyl chitosan prepared in Lab.. The results demonstrated that crosslinker type , the mass of crosslinker and the mass ratio of carboxymethyl chitosan and modified Fe₃O₄ ,et al. were the most effective parameters for the preparation of the microspheres. The IR and VSM verified that the carboxymethyl chitosan magnetic microscopic particles were successfully synthesized.The AFM, TEM and DLS indicated that the diameter of the microscopic particles were 5²0 nm .The TGA show that carboxymethyl chitosan magnetic microscopic particles have good thermal stability.And based on modified chitosan magnetic microscopic particles as a flocculant, the flocculability experiment on papermaking wastewater was carried out . Relations of flocculability with the dosage of flocculant, pH, agitation speed, agitation time and settling time were discussed. For the high COD value of the pulp and paper wastewater , the removing efficiency for CODcr is 56.52% under the best conditions. For the low COD value of the pulp and paper wastewater, the removing efficiency for CODcr is 29.56% under the best conditions. The removing efficiency for CODcr of the high value of the pulp and paper wastewater is better than the removing efficiency for CODcr of the low of the pulp and paper wastewater by the modified chitosan magnetic microscopic particle handling.It indicated that modified chitosan magnetic microscopic particle as a flocculant has more obvious effect for the high CODcr value of the pulp and paper wastewater.To the same removal effect, the flocculant can greatly reduce the CODcr value if modified chitosan magnetic microscopic particle was the initial flocculant. That may reduce unnecessary pulp and paper wastewater treatment steps, and then reducing costs and saving energy consumption.So it is a good method for treatment of pulp and paper wastewater by modified chitosan magnetic microscopic particles. At the same time, for the high CODcr value of the pulp and paper wastewater ,the the removing efficiency for SS is 52.14% under the best conditions; the chroma value was below 80 times under the best conditions, just meet the wastewater discharge standards of Pulp Enterprise.更多还原