【作者】 袁峥；

【导师】 姜应和； Grant Douglas；

【作者基本信息】 武汉理工大学 ， 市政工程， 2010， 博士

【摘要】 对工业、农业和城市废水中有机物、营养物质、重金属离子和酸性的有效去除是水处理的关键,大量廉价的选矿和冶炼废渣提供了更加经济的水处理材料,本研究选取钢铁选矿和冶炼废渣(磁铁矿选铁尾矿渣、含钛高炉渣、普通高炉渣、钢渣)、钛选矿废渣(磁铁矿选钛尾矿渣)和铝冶炼废渣(赤泥)作为研究对象,论证将其应用于环境治理尤其是水污染治理的可行性。首先对钢铁、钛、铝矿冶废渣进行物理、化学和矿物学特征分析,它们主要由Al、Fe、Mn氧化物矿物和Ca、Mg矿物组成。这些矿物由于具有特殊的表面吸附效应、沉淀效应、氧化还原效应、离子交换效应、孔道效应、结构效应、结晶效应等,对水中有机物、营养物质、重金属离子有很好的截留和去除能力,对酸有很好的中和能力。最主要的污染物去除机理源于表面吸附效应、沉淀效应、氧化还原效应和离子交换效应。一系列的圆柱试验用来检验钢铁、钛、铝矿冶废渣和填充物质石英砂对水中溶解性有机碳(DOC)、磷酸盐(PO4-P)、氨氮(NH3-N)、硝酸盐/亚硝酸盐氮(NOX-N)、溶解性有机氮(DON)和总氮(TN)的去除能力。结果表明,试验所用的钢渣和磁铁矿选铁尾矿渣对水中有机物和营养物质有良好的去除效果,对磷的去除效果尤佳。其它矿冶废渣对水中含磷营养物也有良好的去除效果,对有机物和含氮营养物有一定的去除效果。一系列的圆柱试验用来检验钢铁、钛、铝矿冶废渣和填充物质石英砂对水中重金属离子Cd2+、Co2+、Cu2+、Mn2+、Ni2+、Zn2+的截留能力以及对水中酸的中和能力。结果表明,各种矿冶废渣对水中重金属离子有很好的截留能力,对酸也有很好的中和能力。钢渣、赤泥和含钛高炉渣对水中重金属离子的截留能力最好。普通高炉渣、钢渣和磁铁矿选铁尾矿渣对水中酸的中和能力最好。使用PHREEQC地球化学模拟计算软件对圆柱中水和矿物之间的相互作用过程进行地球化学模拟分析,评估试验圆柱出水中的含Al、Fe、Mn、Ca、Mg矿物饱和指数(SI)的变化情况,这些矿物会强烈影响试验圆柱或以后在可渗透反应墙等应用中其它大多数主要和痕迹元素的形态分布。PHREEQC软件的模拟结果不但反映了矿冶废渣圆柱体系在去除水中污染物过程中矿物的溶解和沉淀情况,为了解以后在实际应用中体系内地球化学变化的情况提供依据,而且得到了污染物去除过程中可能影响各矿冶废渣去除能力的矿物成分。研究结果表明,钢铁、钛、铝矿冶废渣中Al、Fe、Mn氧化物矿物和Ca、Mg矿物含量对其污染物去除能力有很大的影响,Al、Fe、Mn氧化物矿物和Ca、Mg矿物含量都很高的钢渣对水中污染物的综合去除能力最好。钢铁、钛、铝矿冶废渣在水污染治理方面有很好应用前景,它们可作为具有过滤作用的垫层、湿地的基材以及可渗透反应墙的填充介质等,应用于：(1)治理地表水、地下水、城市和农业废水中的有机物和营养物污染；(2)防止垃圾场和排污渠污染物的扩散与蔓延；(3)处理重金属离子含量高的工业和矿山酸性废水。更多还原

【Abstract】 Effective removal of organic pollutants, nutrients and metals and neutralisation of acidity in industrial, agricultural and domestic wastewater is pivotal to water re-use. Utilisation of abundant, low-cost mining and metallurgical waste residue materials potentially offers a cost-effective wastewater treatment option. Steel and iron-, titanium-, and aluminium-based mining and metallurgical waste residues were selected for this research, including:magnetite ore processing residue (MPR); Ti-containing blast furnace slag (TiBFS); blast furnace slag (BFS); steel slag (SS); magnetite-containing TiO2 processing residue (TiPR) and red sand (RS).The physical, chemical, and mineralogical characteristics of these mining and metallurgical waste residues were characterised. Physico-chemical characterization of these mineral-based waste residues showed that the materials were largely dominated by Fe, Al, Mn-oxides/(oxy)hydroxides and calcium-and/or magnesium-based minerals. The identified mineral phases indicated that the selected waste residues may have capacity for attenuation of contaminants in wastewater via adsorption, precipitation, redox reactions, ion-exchange, physical sequestration, structural incorporation, crystal formation or other mechanisms. Adsorption, precipitation, redox reactions, and ion-exchange processes are likely the most important attenuation mechanisms.A series of column sorption experiments were conducted to examine the removal of dissolved organic carbon (DOC), soluble reactive phosphorus (phosphate, PO4-P), ammonia (NH3-N), nitrate/nitrite (NOx-N), dissolved organic nitrogen (DON) and total nitrogen (TN) from surface water using the selected steel and iron-, titanium-and aluminium-based mining and metallurgical waste residues. Bassendean Sand, comprised of>98% SiO2, was selected for use as a reference material and comprised the nominally unreactive solid phase in all experimental columns. These column experiments demonstrated that steel slag and magnetite ore processing residue exhibited good attenuation of DOC and nutrients, especially phosphorus. Other selected mining and metallurgical waste residues exhibited good attenuation of phosphorus and some attenuation of DOC and nitrogen.A second series of column sorption experiments were conducted to examine the attenuation of Cd2+, Co2+, Cu2+, Mn2+, Ni2+ and Zn2+ and the neutralisation of acidity in synthetic acid drainage water using the selected steel and iron-, titanium-and aluminium-based mining and metallurgical waste residues. Bassendean Sand was again selected for use as a reference material and comprised the nominally unreactive solid phase in all expeirmental columns. These column experiments demonstrated that the selected mineral-based mining and metallurgical waste residues have substantial capacity for attenuation of metals and acid neutralisation. The steel slag, red mud, and Ti-containing blast furnace slag exhibited the best attenuation of metals. The blast furnace slag, steel slag and magnetite ore processing residue exhibited the best acid neutralisation.Geochemical modelling was undertaken to estimate the saturation index (SI) of a suite of mineral phases, in particular, relevant Al, Fe, Mn, Ca, and Mg minerals. Minerals comprised of these elements were modelled as it is likely that they will strongly influence the speciation of the majority of other major and trace elements in the column experiments or in a permeable reactive barrier application. Geochemical modelling using PHREEQC yielded information about the dissolution of mineral-based waste residues and the precipitation or in situ formation of secondary minerals in experimental columns during pollutant removal. This information provided a basis for understanding geochemical changes in the practical application. The potential dominating minerals influencing the pollutant removing are also derived in every selected mining and metallurgical waste residues column.This research demonstrated that the of Fe, Al, and Mn oxide/(oxy)hydroxide and calcium and magnesium content strongly influenced pollutant removal ability of steel and iron-, titanium-, and aluminium-based mining and metallurgical waste residues. The steel slag, which had high contents of both Fe, Al, and Mn oxide/(oxy) hydroxide and calcium-and magnesium-based minerals, exhibited the best pollutant removal ability. Steel and iron-, titanium-and aluminium-based mining and metallurgical waste residues exhibited potential for application in the treatment of wastewater. The mineral-based by-products examined in this study may be effective for the attenuation of nutrients and DOC in surface water, ground water, or other urban and agricultural water sources; the prevention of pollutant diffusion from dumps and sewers; or treatment of acidic, metal-rich industrial or mining wastewater. The use of mining and metallurgical waste residues in environmental remediation is largely influenced by the design of treatment structures. Mineral-based waste residues such as those examined in this report may be particularly useful as treatment media in constructed wetlands, drain liners, permeable reactive barriers or similar applications.更多还原