聚丙烯酰胺(PAM)作为一种高效絮凝剂被广泛应用于水处理过程，残留PAM解聚生成的丙烯酰胺单体(AM)已被列为Ⅱ A类致癌物，对其处理迫在眉睫。选用浮选尾煤(TC)为原料，通过碱激发制备出改性尾煤基体，采用水热法将纳米TiO₂负载到改性尾煤基体，制备了尾煤基纳米TiO₂复合材料(TiO₂/TC)和Pb掺杂尾煤基纳米TiO₂复合材料(Pb-TiO₂/TC)。以PAM为目标污染物分析了TC、改性尾煤基体、TiO₂/TC和Pb-TiO₂/TC的光催化降解性能，通过XRD、SEM、UV-vis和BET对样品进行表征，结合高效液相色谱−质谱联用技术对降解产物的分析与研究，探究了PAM的降解机理。研究结果表明：TC呈不规则状态，表面较为粗糙；TiO₂/TC的表面疏松，孔隙结构明显，细管状TiO₂均匀包覆在改性尾煤基体表面；Pb-TiO₂/TC的结构更加蓬松，改性尾煤基体负载着更多的细管状TiO₂。TiO₂/TC的禁带宽度为3.16 eV，Pb²⁺掺杂使Pb-TiO₂/TC的禁带宽度减小到3.08 eV。TiO₂的比表面积为286.66 m²/g，TiO₂/TC和Pb-TiO₂/TC的比表面积分别为360.33 m²/g和358.54 m²/g，较高的比表面积为反应提供更多活性位点，产生的吸附−催化协同效应显著提升光催化效率。TC和改性尾煤基体对PAM的降解效率分别为3.39%和4.68%，TiO₂负载后的TiO₂/TC和Pb-TiO₂/TC对聚丙烯酰胺的降解率提升至38.92%和63.87%，经过5次循环使用后TiO₂/TC和Pb-TiO₂/TC的光催化性能基本保持不变。PAM的降解过程中大分子PAM断链变成小分子量PAM分子，进一步氧化分解为NO₃⁻、丙烯酸、乙酰胺和乙酸等。

As an efficient flocculant, polyacrylamide (PAM) is widely used in water treatment process. The acrylamide monomer (AM) produced by depolymerization of residual PAM has been listed as a class IIA carcinogen, and its treatment is imminent. Flotation tailing (TC) was used as raw material to prepare a modified tailing matrix by alkali excitation. Nano-TiO₂ was loaded onto the modified tailing matrix by hydrothermal method to prepare tailing-based nano-TiO₂ composite (TiO₂/TC) and Pb-doped tailing-based nano-TiO₂ composite (Pb-TiO₂/TC). The photocatalytic degradation properties of TC, modified coal matrix, TiO₂/TC and Pb-TiO₂/TC were analyzed with PAM as the target pollutant. The samples were characterized by XRD, SEM, UV-vis and BET, and the degradation products were analyzed and studied by high performance liquid chromatography-mass spectrometry. The degradation mechanism of PAM was explored. The results show that TC is irregular and the surface is rough; the surface of TiO₂/TC is loose, the pore structure is obvious, and the fine tubular TiO₂ is uniformly coated on the surface of modified tailings. The structure of Pb-TiO₂/TC is more fluffy, and the modified coal matrix is loaded with more tubular TiO₂. The band gap of TiO₂/TC was 3.16 eV, and Pb²⁺ doping reduced the band gap of Pb-TiO₂/TC to 3.08 eV. The specific surface area of TiO₂ is 286.66 m²/g, the specific surface area of TiO₂/TC and Pb-TiO₂/TC are 360.33 m²/g and 358.54 m²/g. The higher specific surface area provides more active sites for the reaction, and the adsorption-catalytic synergistic effect significantly improves the photocatalytic efficiency. The degradation rates of PAM by TC and modified tailing matrix were 3.39% and 4.68%. The degradation rates of polyacrylamide by TiO₂/TC and Pb-TiO₂/TC loaded with TiO₂ increased to 38.92% and 63.87%. After five cycles, the photocatalytic properties of TiO₂/TC and Pb-TiO₂/TC remained basically unchanged. In the degradation process of PAM, the macromolecular PAM breaks into small molecular weight PAM molecules, and further decomposes into NO₃⁻, acrylic acid, acetamide and acetic acid.