典型抗生素菌丝体发酵残渣（药渣）的亚临界水热反应特性基础研究

Antibiotic mycelial fermentation residues (ARs), existing as biomass supra-colloids, are not only environmental pollutants but also biological resources. However, techniques for the treatment and utilization of ARs are limited, due to the fact that ARs have high water content and poor mechanical dewatering ability. In this study, the hydrothermal reaction characteristics of typical ARs in sub-critical water will be carefully investigated on the basis of the properties of ARs components. (1) To obtain the release and interaction mechanism of heavy metal (Ca/Zn/Al) releasing from ARs, the effects of hydrothermal reaction conditions and ARs-based P element and organic components on the removal efficiency of heavy metal will be studied. The changes for the valence, fraction distribution and crystal composition of residual heavy metal in ARs-derived hydrochar will be simultaneously explored. (2) To build the balance of C and N element, the effects of hydrothermal reaction conditions and ARs-based organic and metal components on the distribution of liquefaction products (such as amino acid, organic acids, sugar and N-containing compounds) will also be studied. Accordingly, both the hydrothermal reaction mechanism of the ARs-based organic components and catalytic effects of released heavy metal will be determined. (3) The effects of hydrothermal reaction conditions on the changes of products, toxicity and pathway for the transformation of antibiotics under sub-critical water will be studied. The reduction and oxidation mechanism of nano-Fe and H2O2 catalyst for the hydrothermal transformation of antibiotics will be analyzed. Simultaneously, the effects of ARs-based components on the degradation of antibiotics will also be explored. (4) The hydrothermal reaction conditions for the harmless treatment of typical ARs will be established in our study. This study is of great scientific significance to extend the technological development for the resource utilization and pollution control of ARs.

以生物超胶体形式存在的抗生素菌丝体发酵残渣（药渣）既是环境污染物又是生物资源，因高含水量且难机械脱除而限制其利用与处置技术发展。本申请依据药渣组分的特点，研究典型药渣的亚临界水热反应特性。分析亚临界水热条件、药渣携带磷元素和有机组分对药渣金属（Ca/Zn/Al）释放效率与药渣水热炭的金属价态、形态与晶相变化的影响，阐明药渣携带金属的释放规律与交互作用机制；分析亚临界水热条件、药渣携带有机组分和金属对药渣水热产物特性（氨基酸、有机酸、糖和含氮化合物等）的影响，构建C、N元素平衡，阐明药渣有机组分的水热反应机理与金属的催化机制；分析亚临界水热条件对抗生素水热转化的产物、毒性与降解路径的影响，揭示纳米铁协同H2O2对抗生素转化的还原与氧化机制，并阐述药渣携带组分对抗生素降解的影响机制；确立典型抗生素药渣无害化处置的亚临界水热反应条件。项目对拓展药渣的资源化利用与污染控制技术具有重要科学意义。

抗生素药渣是一种新定义的危险废物，含有高浓度的抗生素；但同时又含有丰富的生物质资源，含有高浓度氮/磷和Ca/Mg元素。项目研究发现，抗生素分子在低温水热反应（< 200 oC）中能有效降解，但是矿化效果不好（< 12.0%），并且高温水热反应诱导了抗生素降解产物的聚合，后续研究应该关注抗生素水热转化产物的毒性转化。在亚临界水热反应体系中，溶解态金属Ca和Mg元素的存在，诱导了氮和磷元素的不同路径；高温水热反应促使药渣中有机物质分解，有机磷矿化为无机磷，无机磷与溶解态Ca/Mg元素结合，可将磷元素固定在固相水热炭中；而高温水热反应促使药渣中有机氮矿化为无机氮，表现为溶液中高浓度的NH4+-N和固相水热炭的脱氮行为，高温水热反应促使吡啶和吡咯氮向杂环氮素的缩合转化反应。项目进一步利用药渣及其水热炭的富含磷素和碳酸盐的生物质资源属性，定向调控生物炭改性反应，提高有效无机磷素含量并抑制有效碳酸盐分解，利用表面沉淀反应，提高药渣生物炭对金属Pb（> 400 mg/g）的吸附固定能力。本项目研究成果为危险抗生素药渣的无害化处置与资源化技术提供了大量强有力的支撑。