混凝型胶质气泡的形成及其对发酵废水中致色有机物的去除机理研究

Organic colorants in fermented wastewaters are difficult to be removed by biological treatment due to their complex composition, anti-oxidant and anti-microbial. Thus, decolorization has become a worldwide research-focus in the treatment of fermented wastewaters. As one of the most widely used decolorization techniques, the coagulation-flotation process is still facing problems of excess chemical dose, great sludge generation and low treating efficiency, significantly limiting its color removal effect. Considering this context, this project will firstly explore characteristics of organic colorants in certain fermented wastewaters via the analysis and identification of their composition, and accordingly, proper coagulants can be decided. Subsequently, coagulants will be loaded on the surface of colloidal gas aphrons (CGAs) which are featured by the high stability and rigid structure, and the coagulative CGAs are expected to form. The novel aphrons will be pumped into the flotation tank as soon as being prepared so as to remove colored organic matters. In this continuous technique, dosing coagulant into influent is unnecessary, and less chemical dosage may be needed and the chemical residue in effluent will be decreased. The flotation performance may no longer be limited by the critical micelle concentration of surfactant. In this project, through the analysis and characterization of organic colorants, novel bubbles, floats and effluent, the interfacial interaction of gas-solid-liquid can be clarified; flotation mechanisms of coagulative CGAs will be figured out, providing both of the theoretical and technical support for the decolorization of fermented wastewater by novel flotation process.

发酵液中的致色有机物因其结构复杂、抗氧化性强而难以被传统的生化方法去除，发酵废水的有效脱色已成为当前国内外的研究热点。混凝-气浮是最为常用的深度脱色方法，但耗药量高、污泥产量大、处理效率低等问题严重影响着其脱色效果。本课题通过对废水致色组分的解析与识别，揭示特定发酵废水中致色有机物特性；据此选用适宜的混凝剂，负载于具有多层表面活性剂分子层的刚性胶质气泡的表面，形成“混凝型胶质气泡”；气泡在改进的气泡发生器中一经生成立即泵入气浮池，分离去除致色有机物。该连续工艺无需向原水投药，能解决一般的泡沫气浮中表面活性剂用量大、出水引入二次污染的问题，且过程不受表面活性剂的临界胶束浓度制约。本研究将致色有机物解析、混凝型胶质气泡性质、气浮出水和浮渣特性三者综合分析，理解气浮过程中气-固-液三相的界面过程，探索气浮特性和特定发酵废水中的脱色机制机理，为新型气浮工艺的发酵废水脱色研究提供实验和理论支持。