催化铁与生物耦合工艺条件下表面附着层特征分析

Characteristics of adhesive layer on the surface of catalyzed iron coupled with biotreatment processess

催化铁与生物耦合在污水处理中有独特技术优势,处理过程中催化铁表面易形成附着层,对界面反应影响较大.使用扫描电镜、X射线能谱、X射线粉末衍射及红外光谱等表征手段对催化铁表面附着物的微观形态、元素组成、物质构成等理化性质进行了表征.不同工艺条件下,铁、碳、氧均为催化铁表面附着层的主要元素,纯曝气氧化条件下附着层相对疏松,主要为羟基氧化铁等铁氧化物;耦合生物除磷工艺条件下主要为非晶态物,较密实且易附着微生物;耦合生物脱氮工艺条件下附着物微观结构呈颗粒或絮状,含有复杂铁矿物.对比发现:微生物的参与促进附着层的非晶化,增强催化铁表面结合有机物的能力;曝气可加速铁表面更新,厌氧条件利于微生物附着.

The catalyzed iron coupled with biotreatment process is a unique and effective technology for wastewater treatment. During operation period, adhesive layer was easily formed on the surface of catalyzed iron to affect the interface reaction significantly. Scanning electron microscopy, energy dispersive spectrometer, X-ray fluorescence spectroscopy and infrared spectra were used to characterize and analyze the physical and chemical properties of adhesive layer, such as morphologies, microstructure, elements and speciation. Fe, C and 0 were major elements of the adhesive layer in varied coupling processes. Under aerobic conditions of pure catalyzed iron process, the unconsolidated adhesive layer identified was mainly hydroxyl iron oxides. In the coupled process for phosphorus removal, the compact adhesive layer was amorphous iron corrosion products and easy to adhere organisms. In coupled process for denitrification, the adhesive layer was granular and flocculent, identified for complex iron minerals. The participation of microorganisms promoted the non-crystallization of adhesive layer and enhanced the ability of catalytic iron on organics adsorption. Aeration accelerated the oxidation of iron and the surface renewal rate. Anaerobic condition was favorable to microorganism adhesion.