厌氧颗粒污泥人工床层快速培养与吸附动力学分析

Rapid Cultivation of Anaerobic Granular Sludge within Artificial Sludge Bed and Analysis of Adsorption Kinetics

摘要:

为加快颗粒污泥的形成速率，解决颗粒污泥培养时间长、污泥活性差的问题，通过向厌氧池中加入人工污泥床层快速培养厌氧颗粒污泥，实现厌氧颗粒污泥培养的可控性。采用电子扫描电镜对培养好的厌氧颗粒污泥微观形态进行观察，通过电子显微镜观察颗粒污泥形态变化，确定颗粒污泥分形维数。以颗粒污泥的数量分布、平均粒径、含水率为表征参数，建立厌氧颗粒污泥的吸附动力学模型。结果表明，厌氧颗粒污泥附着在人工污泥床层上，由于人工污泥床层均匀分布使得形成粒径为4~5mm的厌氧颗粒污泥质量占总污泥质量的80%，分形维数在2.68~2.83之间，颗粒轮廓清晰，颗粒污泥在水力负荷达到5kg/(L·d)时，人工污泥床层上形成的颗粒污泥质量浓度仍保持在5.84kg/m3，颗粒污泥耐冲击能力强；针对吸附在人工污泥床层上的厌氧颗粒污泥建立吸附动力学模型，发现反应池中污泥的内循环可以促进厌氧颗粒污泥的形成，当厌氧反应池任意断面颗粒污泥向上和向下的污泥浓度之比为0.8~0.9时，形成的厌氧颗粒污泥吸附性能最强。

Abstract:

The installation of artificial sludge blanket layer to the anaerobic ponds has accelerated the sludge formation rates, shortened the cultivation time and improved the sludge activity. It also enhances the operability of the formation process of the anaerobic granular sludge.The impacts on the formation of anaerobic granular sludge from the artificial sludge bed and the mechanisms of granular sludge adsorption were investigated. Scanning electron microscope (SEM) was used to measure the shapes of the anaerobic granular sludge and furthermore determine their fractal dimension. A granular sludge adsorption model was developed based on the distribution patterns, average particle sizes and water contents of the granular sludge. Results show that when attached to the artificial sludge blanket layer, the anaerobic granular sludge was evenly distributed across the layer, with particle sizes between 4mm and 5mm, and made up to 80% of the total sludge in the system. Under the SEM, their shapes were clearly observed and their fractal dimensions were between 2.68 and 2.83. Results also show strong stability of granular sludge on the artificial sludge layer. When the hydraulic loading rate reached 5kg/(L·d), they still maintained an average concentration of 5.84kg/m3. Results from the granular sludge adsorption model indicated that the internal circulation of the sludge inside the reaction pond can stimulate the formation of the anaerobic granular sludge. Peak adsorption capacity of the anaerobic granular sludge was achieved when the concentration ratio of upflow/downflow sludge fell between 0.8 and 0.9. This study will provide a reference to the formation of anaerobic granular sludge for the industrial treatment of wastewater with high organic concentrations.