自支撑地质聚合物无机膜的制备及其在废水处理中的应用

发布时间：2018-02-08 19:50

本文关键词： 自支撑地质聚合物膜分离重金属废水高浊度废水　出处：《广西大学》2015年硕士论文　论文类型：学位论文

【摘要】：地质聚合物((Geopolymer)是一种采用天然矿物(高岭土)或固体废弃物(粉煤灰、矿渣等)及人工合成硅铝化合物为原料,在碱激发条件下经缩聚反应聚合成由[SiO4]和[A1O4]组成的一类三维网络凝胶材料。地质聚合物具有早强、耐酸碱腐蚀、耐高温品质佳、凝结时间可控等优良工作性能,独特的三维网络结构对有毒、有害重金属离子的固定能力极强、溶出率低,对重金属废水和生活污水具有显著的分离效果。本课题组制备的自支撑偏高岭土基地质聚合物无机膜较传统商业膜而言具有显著的经济优势,成本低廉、原料广泛、制备工艺简单、几乎无“三废”问题。本论文详细考察了影响偏高岭土基自支撑地质聚合物无机膜微观形貌、孔径和比表面积的主要因素,借助X射线衍射(XRD)、扫描电镜(SEM)、TG-DSC、BET、抗压强度和水通量等测试手段研究自支撑地质聚合物无机膜的结构和力学性能,最终确定自支撑地质聚合物无机膜适用于污水中重金属离子和颗粒物分离的最佳工艺参数,并通过模拟重金属废水和生活废水研究自支撑地质聚合物无机膜的分离能力。(1)根据制备自支撑偏高岭土基地质聚合物无机膜的原料组成及配比,研究了养护温度、n(H2O)/n(Na2O)对自支撑地质聚合物无机膜微观孔结构及力学性能的影响。确定用于膜法水处理的自支撑地质聚合物无机膜最佳制备工艺参数为：水玻璃模数n(SiO2)/n(Na2O)=1.3,n(Na2O)/n(Al2O3)=0.8,n(SiO2)/n(Al2O3)=2.96,n(H2O)/n(Na2O)=19,养护温度60℃,养护时间24 h。由此得到的自支撑地质聚合物无机膜各性能参数为：水通量99.04 kg·m-2·h-1,抗压强度18.67MPa,比表面积37.87 m2.g-1,吸附量35.52 cm3·g-1平均孔径276.11 nm,平均孔隙率62.64%。(2) 自支撑偏高岭土基地质聚合物无机膜处理重金属废水的研究结果表明：自支撑地质聚合物无机膜中过量的碱度对酸性溶液有较强的缓冲能力,无机膜在溶液pH≥4的工作条件下适宜对重金属离子进行吸附、截留,且去除率随溶液pH升高而增大,自支撑地质聚合物无机膜对浓度低于500mg·L-1, pH=5的Ni2+去除率高达90.82%。增大无机膜厚度,降低吸附温度和溶液浓度均有利于Ni2+去除率的提高。在二元和三元体系中,Pb2+和Cu2+均强烈抑制自支撑地质聚合物无机膜对Ni2+的吸附,竞争吸附能力大小顺序为Pb2+Cu2+Ni2+。本文研究了自支撑地质聚合物无机膜对重金属废水的吸附、净化作用机理,即中和微沉淀、絮凝截留作用,离子交换作用和多孔结构物理吸附作用。(3) 自支撑偏高岭土基地质聚合物无机膜处理高浊度废水的研究结果表明：以浊度、SS、粪大肠菌群作为水质评价指标时,其各项去除率均达93%以上,高浊度污水经过滤后浊度可降低至0.19 NTU；然而在对氨氮、CODcr、BODs三项水质指标进行对比时发现其去除率均低于70%,自支撑地质聚合物无机膜水通量衰减约为初始水通量的22%。结果说明自支撑偏高岭土基地质聚合物无机膜对细菌、悬浮颗粒物及大分子有机物等具有较强的分离能力,而对亲水性有机物和亚硝酸盐、硫化物、亚铁盐等无机小分子还原性物质分离效果欠佳,在后期的工作中需辅助性引入传统生物-化学法以提高出水水质。
[Abstract]:Geopolymer ((Geopolymer) is a kind of natural mineral (kaolin) or solid waste (fly ash, slag) and synthetic silicon aluminum compounds as raw materials in alkali activated condition by polycondensation polymerization into a three-dimensional network of gel materials composed of [SiO4] and [A1O4]. Geological polymer has the early strength, acid resistance alkali corrosion, high temperature resistance and good quality, excellent performance of controllable setting time, three-dimensional network structure unique to the toxic and harmful heavy metal ions fixing ability is extremely strong, the dissolution rate is low, has a significant effect on the separation of heavy metal wastewater and sewage. The preparation of self-supporting metakaolin basedgeopolymer compared with the traditional commercial membrane inorganic membrane has significant economic advantages, low cost, wide raw materials, simple preparation process, almost no "three wastes". This paper investigates the influence of metakaolin based self The micro morphology of supporting geological polymer inorganic membrane, pore size and specific surface area of the main factors, by means of X ray diffraction (XRD), scanning electron microscopy (SEM), TG-DSC, BET, means the compressive strength and water flux test study on structure and mechanical self supporting geological polymer inorganic membrane can ultimately determine the self supporting inorganic geopolymer film for optimum parameters in wastewater separation of heavy metal ions and particles, and through the simulation of heavy metal wastewater and domestic wastewater of self supporting geological polymer inorganic membrane separation ability. (1) according to the preparation of self-supporting metakaolin basedgeopolymer inorganic membrane material composition and ratio, curing temperature of n (H2O /n) (Na2O) influence on the micro self supporting geological polymer inorganic membrane pore structure and mechanical properties. For membrane water treatment self supporting geological polymer inorganic membrane preparation process parameters for the best: Modulus of water glass n (SiO2) /n (Na2O) =1.3, n (Na2O) /n (Al2O3) =0.8, n (SiO2) /n (Al2O3) =2.96, n (H2O) /n (Na2O) =19, the curing temperature of 60 DEG C, since the performance parameters of supporting geo polymer inorganic membrane for the maintenance of 24 h. time: the water flux of 99.04 kg - m-2 - H-1, 18.67MPa compressive strength, specific surface area of 37.87 m2.g-1, 35.52 cm3 / g-1 adsorption average pore diameter is 276.11 nm, the average porosity of 62.64%. (2) shows that the self support of metakaolin basedgeopolymer inorganic membrane for treatment of heavy metal wastewater results from excessive alkalinity support geological polymer inorganic membrane in the strong buffer capacity to acid solution, inorganic membrane in solution pH is more than 4 working conditions suitable for heavy metal ion adsorption, retention, and removal rate of pH increased with solution, self support geological polymer inorganic membrane concentration lower than the 500mg of L-1 pH=5, the Ni2+ removal rate of up to 90.82%. Increase of inorganic membrane thickness, reduce the adsorption temperature and solution concentration are favorable to the removal rate of Ni2+ increased. In two yuan and three yuan in the system, Pb2+ and Cu2+ were strongly inhibited the self supporting geological polymer inorganic membrane for Ni2+ adsorption, competitive adsorption ability of the order of Pb2+Cu2+Ni2+. this paper studied self supporting geological polymer inorganic membrane for heavy metal water adsorption, purification mechanism, namely micro neutralization precipitation, flocculation interception, ion exchange and physical adsorption. The porous structure (3) shows that the self support metakaolin basedgeopolymer inorganic membrane treatment of high turbidity wastewater results: turbidity, SS, fecal coliform bacteria as the water quality evaluation index, the the removal rate is above 93%, high turbidity sewage after filtration turbidity can be reduced to 0.19 NTU; however, in the CODcr, ammonia nitrogen, three water quality indexes of BODs were compared when the removal rate of Are less than 70%, since the support of geological polymer inorganic membrane flux attenuation is about the initial water flux of 22%. showed that the bacteria from the support of metakaolin basedgeopolymer inorganic membrane, suspended particles and organic molecules with strong ability of separation, and the hydrophilic organic matter and nitrite, sulfide, ferrous salt and other inorganic small molecule substance reducing separation effect is poor, in the latter part of the work required to introduce traditional bio chemical method to improve water quality.

【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ051.893;X703

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