低温热水解对剩余污泥DOM的溶出特征分析

为了研究剩余污泥在低温热处理条件下的理化性质及溶出特征，采用批次试验探究了热处理温度对剩余污泥溶解性有机物（SCOD）、溶解性碳水化合物（SC）、溶解性蛋白质（SP）的溶出变化情况，分析了溶解性有机物质（DOM）荧光组分的平行因子分析模型特征.研究发现，随着热处理温度的升高，SCOD在80℃的破解度增幅最高，在90℃溶出量最大；SC在70℃时溶出率增幅最高，在90℃质量浓度最高；SP在60℃质量浓度最大；挥发性脂肪酸（VFAs）在60℃达到最大含量；液相色谱-有机碳测定仪（LC-OCD）分析表明，溶解性有机碳在90℃分子质量浓度最大，但生物聚合类物质的比例在80℃最高；三维荧光平行因子分析（PARAFAC）显示，剩余污泥热处理后的DOM均包含类蛋白质C1（282，324nm）、代谢类蛋白质C2（310，364nm）、可见腐殖酸C3（278/338/358nm，424nm）、土壤富里酸C4（270/318/354nm，476/524nm），对于热水解法预处理污泥，类蛋白质在80℃下具有最大荧光强度，代谢类蛋白质在60℃下具有最大荧光强度.在60min条件下，污泥中有机物溶出的最佳温度是80℃.

Low temperature thermal hydrolysis on DOM dissolution characteristics of excess sludge analysis

Batch experiments were conducted to investigate the dissolution of excess sludge organic matter (SCOD) to understand the physical and chemical properties and dissolution characteristics of excess sludge under low temperature heat treatment. The dissolution rate of soluble carbohydrate (SC), soluble protein(SP) and the fluorescence properties of the dissolved organic matter (DOM) were also investigated. With the increase of heat treatment temperature, the cracking degree of SCOD achieved its highest level at 80℃, while the dissolution rate reached its peak value at 90℃ and the SC was the highest at 70℃. Along with the treatment the mass concentration maximized at 90℃, that of the SP was on its top at 60℃, while the content of VFAs was the largest at 60℃. The results of the liquid chromatography with online organic carbon (LC-OCD) analysis demonstrated that the biopolymer fraction got its highest proportion in DOM at 80℃. The results of fluorescence analysis showed that the DOM contained C1organics (Ex/Em, 282/324nm), metabolic proteins C2(310/364nm), visible humic acids C3(278,338,358/424nm), and soil fumarates C4 (270,318,354/476,524nm) after heat treatment of excess sludge. For the sludge handled by hot water decomposition pretreatment, its protein-like organics presented maximum fluorescence intensity at 80℃ while corresponding metabolic protein has its maximum fluorescence intensity at 60℃. According to the above results, the optimzed operational condition for the dissolution of organic matter from sludge could be set as treatment duration of 60minutes under 80℃.