堆存污泥深度脱水及其干化泥饼焚烧特性研究

堆存污泥的深度脱水及后续处置一直是制约污泥填埋场发展的难题.焚烧是实现填埋场堆存污泥最大量减容的有效途径，而高效的深度脱水过程却是污泥焚烧处置的必要前提.以抽滤曲线、毛细吸水时间（CST）和泥饼含水率为评价指标探究了聚合氯化铝（PAC）-生石灰-秸秆粉末组合调理剂对堆存污泥深度脱水的效果，并分析了各因素的影响强弱关系和经济成本；此外，通过热重试验建立TG-DTG曲线，分析脱水后干化泥饼的焚烧特性.结果表明:聚合氯化铝（PAC）-生石灰-秸秆粉末组合调理剂中各成分对城市堆存污泥CST削减的影响大小表现为PAC>生石灰>秸秆粉末，PAC和生石灰主要通过吸附架桥或压缩双电子层作用促进结合水向自由水的转变，而秸秆对压滤过程中构建骨架结构起到重要作用；当PAC、生石灰和秸秆粉末添加量（干基比）分别为35%、20%、29%时，堆存污泥的泥饼含水率和CST均达到最优，分别为56.3%和47.9 s，且组合配方经济成本优势显著；脱水干化后的泥饼点燃温度相较原状污泥有所提高，秸秆粉末的添加保障了泥饼在焚烧过程中的可持续性燃烧，泥饼燃烧过程中最大燃烧失重速率（T_m）达到3.828%/min.研究显示，PAC-生石灰-秸秆粉末组合调理剂通过改变堆存污泥的化学性能和压滤性能增强了污泥深度脱水的效果，同时改善了干化泥饼的燃烧行为，对堆存污泥的减量化及焚烧处置具有重要意义. 

Deep Dewatering of Stocked Sludge and Incineration Characteristics of Dehydrated Sludge Cake

The deep dewatering and subsequent disposal of stocked sludge are the problems that restrict the development of landfills. Incineration is the most effective way to reduce the volume of sludge in landfill, and efficient deep dewatering is a necessary prerequisite for sludge incineration. Suction filtration curve, capillary water absorption time (CST) and moisture content of sludge cake were used as evaluation indexes to explore the effect of polyaluminum chloride (PAC)-quicklime-straw powder on deep dehydration of stockpile sludge, and to analyze the influence of various factors and the economic cost. In addition, the incineration characteristics of dehydrated sludge cake were analyzed by TG-DTG curve through thermogravimetry experiment. The results showed that the effect of various components in the combined conditioner on CST reduction of stocked sludge was PAC > quicklime > straw powder. PAC and quicklime promoted the transition from bound water to free water mainly by adsorption bridging or compressing the thickness of the electric double layer, while straw powder played an important role in the construction of skeleton structure during the process of pressure filtration. When the dosage of PAC, lime and straw powder (dry basis ratio) was 35%, 20% and 29%, respectively, the moisture content of sludge cake and CST were optimal, 56.3% and 47.9 s, respectively, and the economic cost advantage of the combined conditioner was significant. Compared with the original sludge, the ignition temperature of dehydrated sludge cake was higher. The addition of straw ensured the sustainable combustion of sludge in the combustion process. The maximum combustion loss rate (T_m) of dehydrated sludge cake reached 3.828%/min. The results showed that PAC-quicklime-straw could enhance the effect of deep dewatering by changing the chemical properties and pressure filtration properties of stocked sludge, and improve the combustion behavior of the dehydrated sludge cake, which was of great significance to the reduction and incineration of the stocked sludge.