曝气及搅拌强化超声预处理污泥试验研究  

Experimental study for enhancing the ultrasonic disintegration of sewage sludge through aeration and agitation

作　　者：张小玲[1] 赵艳红[1] 李正群[1] 张帆[1] ZHANG Xiao-ling;ZHAO Yan-hong;LI Zheng-qun;ZHANG Fan(Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang＇ an University, Xi＇ an 710064, China)

机构地区：[1]长安大学旱区地下水与生态效应教育部重点实验室

出　　处：《安全与环境学报》2018年第2期755-760,共6页Journal of Safety and Environment

基　　金：国家自然科学基金项目(51408041)

摘　　要：超声是一种具有很大研究价值的污泥预处理技术,但超声波能耗较大,限制了其大规模应用。曝气和搅拌作为辅助技术可以使超声技术在较低的能耗下达到较高的破解效率。以污泥破解后上清液中SCOD增加值为主要评价指标,探究在曝气及搅拌辅助下超声预处理污泥的最佳条件,进一步考察在最佳条件下曝气及搅拌对超声破解污泥效率的提高和能耗的降低作用。结果表明,曝气最有效的超声声能密度为0.9 W/mL,最佳曝气量为20 mL/min,最有效的曝气时间为10 min,在超声10 min的后5 min曝气、前5 min不曝气比在整个超声过程中曝气破解溶出的SCOD更高。在最有效的条件下对污泥进行超声加曝气处理后的SCOD为388.45 mg/L,而相同条件下仅超声溶出的SCOD为196.5 mg/L,溶出的SCOD增加了97.7%,污泥经超声加曝气处理后SCOD溶出率为3.85%,比达到近似SCOD的仅超声处理方式的能量消耗降低了25%。搅拌作为另一个辅助技术,转速为600 r/min时对提高超声破解污泥的SCOD最有效,超声加搅拌比相同条件下仅超声破解污泥溶出的SCOD增加了83.8%,超声加搅拌破解污泥的SCOD溶出率为1.98%。在超声加曝气和搅拌的条件下,污泥SCOD溶出率为4.38%,污泥破解产生的SCOD比相同条件下仅超声破解的污泥SCOD增加了120.8%,比达到近似SCOD的仅超声处理方式的能量消耗降低了12.5%。This paper is aimed at introducing an experimental study for enhancing the ultrasonic disintegration of the sewage sludge through aeration and agitation in hoping to promote the ultrasonic sludge disintegration efficiency and reduce energy consumption.As is known,ultrasonic disintegration of sewage sludge has already been proven to be an effective and environment-pollution preventive approach,which is promising for its great research value for sludge disintegration.Nevertheless,its application remains limited due to its high energy consumption.To overcome the difficulty,we have done an experiment with a FS-600 N ultrasonic processor,an ACO-9601 adjustable air pump and a 85-2 A magnetic stirrer for the sludge disintegration.Furthermore,in order to realize the optimal working conditions,we have made an analysis of the parameters involved in the technology of the ultrasonication combined with aeration and agitation to heighten the efficiency,such as the ultrasonic intensity,the treating time,the aeration flow rate,the stage of aeration in the process and the stirring rate of the agitator adopted.The results of our experiment show that the optimal ultrasonic irradiation density turns out to be 0.9 W/mL,whilst the optimal aeration flowing rate tends to be 20 mL/min,with the optimal aeration time length being 10 min.More exactly speaking,the 5 min of aeration during the later stage proves more effective than the aeration for the entire 10 min process.Under the same ultrasonic condition without aeration,the SCOD can be made high up to 388.45 mg/L under the optimal condition of aeration with the ultrasound,whereas,in comparison with the similar conditions with no condition of aeration with the ultrasound,the SCOD used to be merely 196.5 mg/L means a SCOD increase of 97.7%.At the same time,the SCOD dissolution rate tends to reach 3.85% due to the ultrasound treatment,which implies a 25% decrease of energy consumption under the ultrasonic condition with aeration than with no aeration.Thus,the experiments we have done indic

关 键 词：环境工程学 剩余污泥 预处理 超声破解 曝气 搅拌 

分 类 号：X703.1[环境科学与工程—环境工程]