污水污泥动态间壁热干燥特性及工艺-污泥处理.PDF

58 9 Vol1 58 No1 9 2007 9 Journal of Chemical Industry and Engineering ( China) eptember 2007 王兴润, 金宜英, 杜 欣, 聂永丰 ( , 100084) : , ( V ) ( T OC) ; : 160e , , ; 180 e , , , , T OC , : ; ; : X 705 : A : 0438- 1157 (2007) 09- 2211- 05 Process and mechanism of indirect thermal drying of sewage sludge WA NG Xingrun, JIN Yiying, DU Xin, NIE Yongfeng (Department of Environmental Science and Engineering , Tsinghua University , Beij ing 100084, China) Abstract: U sing an improved rotary indirect agitated drying laboratory rig operating w ith recirculation gas in a closed system, this study investigated the influence of drying temperature on drying efficiency, calorific heating value and volatile solid content ( V ) of the dry solid and total organic carbon ( TOC) content of the condensate1 In the meantime, the relationship betw een w ater evaporation rate and w ater content w as also investigated1 Experimental results indicated that w hen the drying temperature w as under 160 e , water evaporation rate w as very low and about tw o hours w ere needed for w ater content decreasing from 80% to 60% 1 How ever, the w ater evaporation rate increased significantly w hen the temperature reached 180 e because hydrolysis and cytolysis of microorganism cells in sew age sludge occurred and the form of w ater existence w as changed1T he calorific heating value of dried solid decreased and the TOC of the condensate increased as a result1T he condensate belonged to highly concentrated organic w astew ater and must be treated before discharging to meet the effluent COD standard. Key w ords: indirect th