处理煤制气废水产生的污泥毒性削减及生态资源化利用新方法与机理研究

It is an urgent issue for the final disposal of excess activated sludge treating coal gasification wastewater due to its’ significant organic toxicity caused by the uncompleted biodegradation of original refractory organics (such as high strengthen phenols and heterocyclic compounds) or their stress impaction to sludge. The organic toxicity of this kind excess sludge would not only restrict its’ ecological resource utilization, but also cause secondary pollution to the disposal environment. With regard to this issue above, a new method for excess sludge toxicity removal and resource utilization for soil amendment is put forward. The algae will be taken as the main body for sludge toxicity removal. The physiological properties along the whole life of algae and the constituents and toxicity of sludge extract will be investigated. In addition, the transformation mechanism from organic toxic substances in sludge into high value ecological fertilizer products (such as polysaccharides, proteins, humic acids, etc.) will be explored. Firstly, the algae are cultured with sludge extract, according to the capability of usage of nitrogen and phosphorus and the removal of toxic substances in sludge extract by algae, the optimal kind of algal will be selected for toxicity removal mechanism investigation. Then, sludge will be pretreated via anaerobic hydrolysis to get the hydrolysis supernatant for culturing the optimal algal from above study. The syntaxial system will be built by algal and bacteria in hydrolysis supernatant, and the mechanism of coordinative removal of organic toxicity by algal and bateria will be studied. At last, the interrelationship between algae growth and sludge toxicity removal are used for development of correlation model. Through the process of this research, not only can the toxicity of biological sludge for coal gasification wastewater treatment be reduced, but also the organic matter with high-value fertilizer effect can be produced, and the ecological utilization of excess biological sludge can be realized. It has important theory and application value.

利用活性污泥法处理煤制气废水时，由于剩余污泥的有机毒性显著，限制了其生态资源化利用。本文研究了一种可同时实现剩余污泥毒性削除和污泥资源化利用的新方法。首先研究了利用微藻将污泥破碎的提取液中有机毒性削减并转化为生态肥效类高价值产物的影响因素、工艺条件，并对微藻进行筛选；然后通过运用毒性、肥效物质鉴定等方法，从微藻生理特性及提取液理化特性等方面，剖析微藻将提取液的有机毒性物质转变为生态肥效类产物的过程机理；再以污泥厌氧水解液培养优选藻，建立水解液中菌群和微藻的共生体系，通过菌群鉴定及菌、藻功能酶活性测定等方法，深入探究藻-菌协同对污泥水解液有机毒性削除机理；最后通过对照得出最优的污泥预处理方法及有机毒性削除模式，探索藻生长与污泥脱毒的相关关系模型。通过本项目研究，不仅可实现处理煤制气废水的生物污泥毒性削减，还可产生高价值的肥效有机质，实现剩余污泥的生态资源化利用，具有重要的理论与应用价值。

本研究以经苯二酚驯化的活性污泥为对象，考察污泥毒性变化规律及利用苯二酚污泥提取液培养三种土壤藻（小球藻、绿球藻和斜生栅藻）在毒性削除及有机质重分配方面的机制。研究中分别考察了不同的污泥破碎方式、不同的污泥提取液稀释比例、不同的污泥水解液稀释比例及不同的外源CO2浓度对藻类生理性能的贡献及差异；通过分析优势降解菌群的构成、藻类的酶活性与污泥有机毒性的关系并从宏观和微观的角度，剖析和揭示了污泥毒性的去除机制，并通过宏观参数控制实现微藻更好的生物处理活性。取得主要进展如下：.a. 成功培养并构建有效降解二羟基苯异构体污染物的活性污泥系统。该系统中三种不同苯二酚对污泥毒性贡献的大小顺序依次为邻苯二酚﹥对苯二酚﹥间苯二酚，毒性抑制率先升高后降低，最大值分别为78.5%、63.9%和46.7%。.b. 揭示了污泥提取液不同稀释比例对微藻生物处理性能的影响规律。在20%-80%稀释范围内可有效促进微藻生物质的积累和提取液毒性的去除。当稀释比例为80%时，微藻生物量可达0.720±0.038 g/L，并能吸收67.2%的TOC降低53.3%的毒性。.c. 探究了污泥水解液不同稀释比例对微藻生物处理性能的影响规律及藻菌协同脱毒机制。在20%-100%稀释范围内，水解液毒性抑制率从83.67%下降至38.6%。毒性环境胁迫下，甲基杆菌属均为最高优势菌群，通过分泌二级产物增强抗逆性，物种丰度分别为 23.4%、28%、19.8%、16.5%。.d. 揭示了外加碳源强化微藻对污泥提取液毒性削除及固碳能力和肥效的研究机制。在30%CO2浓度下，微藻可去除70.44%的有机质，89.88%的N和92.04%的P，且固碳速率可达190.07±10.32 mg/L/d。生菜在施用50%的藻液后，鲜重达3.60±0.22 g/株。.e. 阐明了污泥毒性下微藻的代谢特征和蛋白调控机制。蛋白组学分析表明，微藻主要通过调节光合固碳、碳代谢、光合作用、糖酵解/糖异生和次生代谢产物的合成响应毒性环境，实现对污泥毒性的应激调节。