%0 Journal Article
%T Effect of Acidification on the Dewaterability of Sewage Sludge in Bioleaching<br>生物沥浸的酸化效应对城市污泥脱水性能的影响
%A ZHU Hai-feng
%A ZHOU Li-xiang
%A WANG Dian-zhan
%A <br>朱海凤
%A 周立祥
%A 王电站
%J 环境科学
%D 2012
%I 
%X Batch experiments were performed to exploit the effect and the mechanism of bioleaching on sludge dewaterability by the inoculation of Acidithiobacillus ferrooxidans LX5 in this study. Besides, chemical leaching experiments using sulphuric acid were also performed as control to study the effect of acidification on sludge dewaterability. During the processes of both biological and chemical leaching, Zeta potential, cell lyses, morphology and structure of sludge flocs were monitored. Results showed that along with the acid production and hence the decrease of pH during bioleaching, the specific resistance of bioleached sludge decreased systematically from 1.81×1012 m·kg-1 to 0.59×1012 m·kg-1, whilst Zeta potential increased from -25.2 mV to 9.6 mV, and the natural sedimentation rate increased to as high as 48% at pH 2.90.In chemical leaching, the specific resistance decreased continuously to a minimum value of 2.6×1012m·kg-1 at pH 3.35 and then started to increase. Zeta potential increased with the decrease of pH, and reached zero at pH 2.90.At strong acid condition, sludge cells could be decomposed, resulting in the increase of total dissolved phosphorus in centrifugal liquor of chemical leached sludge. However, this phenomenon was not observed in bioleaching process because that the phosphorus was utilized by the abundant microorganism in system. Observation by SEM showed that there was no obvious change in the flocs structure of both sludge at pH 3.35 except for that some secondary minerals appeared only in bioleached sludge. These results revealed that decrease of absolute value of Zeta potential and formation of secondary minerals caused by bioleaching were responsible for the improvement of sludge dewaterability.
%K bioleaching
%K chemical acidification
%K sewage sludge
%K dewaterability
%K secondary minerals<br>生物沥浸
%K 化学酸化
%K 城市污泥
%K 脱水性能
%K 次生矿物
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=3FF3ABA7486768130C3FF830376F43B398E0C97F0FF2DD53&cid=A7CA601309F5FED03C078BCE383971DC&jid=64CD0AA99DD39F69401C615B85F123EF&aid=B42EDD6608FE925A448B9C7EE770EB0D&yid=99E9153A83D4CB11&vid=27746BCEEE58E9DC&iid=38B194292C032A66&sid=DE4E739E935BD9A7&eid=9BA5B7BDD4CE0596&journal_id=0250-3301&journal_name=环境科学&referenced_num=0&reference_num=25