城市污水厂污泥碱性热水解的分离特性

SEPARATION CHARACTERISTICS IN ALKALINE THERMAL HYDROLYSIS OF SLUDGE FROM MUNICIPAL WASTEWATER TREATMENT PLANT

为考察碱性热水解技术分离城市污水厂污泥中有机物和无机物的特性,设计单因素试验研究了Na OH投加量、反应温度和反应时间对分离效果的影响。结果发现:随着Na OH投加量升高,无机物先增多后减少,有机物变化趋势反之;反应温度升高,无机物变化不一致,有机物含量减少;反应时间延长,无机物增多,有机物减少。试验得出:最佳反应条件为Na OH投加量10%、反应温度150℃、反应时间2 h。在此条件下,固相中无机物和有机物含量分别为76.6%和23.4%,液相中COD、NH3-N、TN和TP分别为139 733,446,3 326,238 mg/L。由电子扫描显微镜(scanning electron microscope,SEM)表征结果可知,反应后细胞结构破碎,有机物和无机物均被释放减少;由X射线荧光光谱(X-ray fluorescence,XRF)可知,反应后金属元素含量增加;而GC-MS分析结果表明,水解后有机化合物的种类、含量均有减少。

To study the separation characteristics of organics and inorganics in the sludge of municipal wastewater treatment plant by alkaline thermal hydrolysis technology,the effect of Na OH dosage,reaction temperature and reaction time on separation efficiency was studied by single factor experiment. Experimental results showed that with Na OH dosage increasing,the inorganic concentration increased at first and then decreased,while the organic concentration decreased rapidly in the beginning and increased slowly afterwards. When the reaction temperature increased,the change of inorganic concentration differed while the organic concentration decreased gradually. When the reaction time was extended,the inorganic concentration increased slowly,while the organic concentration decreased slowly. According to the experiment results,the optimum reaction conditions were obtained as follows： Na OH dosage of 10%,reaction temperature of 150 ℃ and reaction time of 2 h. Then the concentration of inorganics and organics in the solid phase changed into 76. 6% and 23. 4%,respectively,and COD,NH3-N,TN and TP was 139 733,446,3 326,238 mg/L,respectively. It was found by scanning electron microscope（SEM） that cell structure of sludge was broken after reaction and organics and inorganics were released. X-ray fluorescence spectroscopy（XRF） suggested that the concentration of metal elements increased after the reaction. The GC/MS revealed that the kinds and concentration of organic compounds decreased after the reaction.