锰氧化物强化过滤处理低浓度含铊工业废水机制及氧化调控

Thallium pollution caused by industrial wastewater discharge is a major problem in the prevention and control of heavy metal pollution in China. To control thallium contamination, it is critical to removal low concentration of thallium from industrial wastewater effectively. Aim at the efficient removal of low concentration of thallium from industrial wastewater, started from the deposition and thallium adsorption ability of manganese oxides, the thallium removal in manganese oxides enhanced filtration using enhanced filtration was studied. By investigating the interactions between manganese oxides and filter material surface as well as interaction between manganese oxide, complex organic matter and thallium, the mechanism of short-term thallium removal could be clear. Then, the long-term removal of thallium by enhanced filtration is studied. Employing microelectrode technology and characterization, the mechanism of long-term strengthening the morphological changes of manganese and strontium in filtration sediments, the transition of interactions, and the mechanism of long-term thallium removal stably is explored. Finally, critical water chemistry of thallium, i.e., the oxidation and catalytic oxidation of Tl(I) by water treatment oxidants, were investigated, and then applied to control the removal of thallium from wastewater by manganese oxide enhanced filtration. The results obtained in this project will deepen the understanding of both short-term and long-term thallium removal from wastewater and the oxidation control strategy for manganese oxide enhanced filtration. Moreover, the data could provide technical support for reducing the cost of thallium containing wastewater treatment, and provide a theoretical basis for the development of effective and low-cost technologies.

工业废水排放造成的铊污染是我国重金属污染防治的一大难题，而工业废水中低浓度铊的高效去除技术是控制铊污染的关键环节。本研究以低浓度含铊工业废水的高效去除为目标，以锰氧化物的沉积、吸附特性为切入点，针对强化过滤快速除铊过程，重点开展锰氧化物在滤料表面的界面作用和锰氧化物、络合性有机物、铊之间相互作用的研究，从微观角度探明快速去除低浓度铊的短期作用机理。继而，研究强化过滤对低浓度铊的长期去除规律，利用微电极技术和表征手段，深入探索强化过滤沉积层中锰、铊的形态转变、相互作用关系变迁及稳定除铊的长效机制。最后，研究Tl(I)在水处理氧化剂中的氧化、催化氧化等重要水处理化学特性及机理，并将其应用于调控锰氧化物强化过滤稳定去除低浓度铊。研究结果将深化对废水中低浓度铊在锰氧化物强化过滤中的快速、长效去除及氧化调控规律和机理的认识，为降低含铊废水处理成本提供技术支撑，也为开发其他高效低成本处理技术提供理论基础。

为开发低浓度含铊废水高效深度处理技术，本项目构建了基于锰氧化物强化过滤去除水中微量铊以及氧化调控技术体系。其中系统性研究了锰氧化物界面环境行为，重点探讨了锰氧化物对铊（I）的吸附氧化特性并建立了相应的吸附模型和表征体系，从微观角度明晰了锰氧化物除铊机理以及技术可行性；利用非平衡对流扩散模型成功拟合并建立铊（I）在滤料介质中的迁移模型并着重考察了关键影响因素，厘清了铊（I）在过滤过程中迁移转化规律；通过将锰氧化物负载至石英砂表面成功实现了水中铊（I）高效过滤截留，在pH 8.0条件下得到757.35 mg/g的截留容量，成功验证了锰氧化物强化过滤除铊可行性；进一步探究了锰氧化物强化过滤中长期运行时的去除表现和活性锰氧化物膜的生成机制，考察了关键工艺参数和水质对工艺效能和稳定性的影响规律，优化了工艺运行条件；系统性考察锰氧化物强化过滤系统活性再生能力以及并阐明了其再生机理，地发现了引入KMnO4+Mn2+体系在滤床表面原位生成活性锰氧化物使滤柱快速恢复以深度除铊的能力；研究了铊与典型氧化剂的氧化、催化氧化特性及机理以及氧化动力学模型，并在次基础上系统探讨了卤素离子对氧化调控过程的影响，明确了铊在常见的氧化水处理中的氧化动力学规律和机理。研究成果揭示了铊与锰氧化物、多孔介质、水处理氧化剂之间的相互作用以及完善了铊的环境行为规律理论基础，并验证了锰氧化物强化过滤快速、长效去除含铊废水效果以及氧化调控方法的技术可行性，为技术的优化和推广应用提供了理论和技术支撑。