摘要
为研究超声波促进污泥缺氧/好氧消化的机制,采用均匀试验得到的最佳超声波参数与缺氧/好氧消化衔接进行间歇试验,通过生物化学分析法研究了消化过程污泥EPS指标(多糖、蛋白质、DNA和总量)和相应溶出物的变化趋势,同时以未经超声处理的消化过程作对照.均匀试验结果表明,在超声波声能密度0.1 W/mL,超声处理时间15 min以及超声处理间隔时间12 h的条件下,缺氧/好氧污泥消化效果最好,污泥VSS去除率经10 d消化后达到42.45%.超声波-缺氧/好氧消化试验中,污泥的EPS指标在10 d的消化过程中呈现先增加后减少的变化趋势,其中蛋白质、DNA以及总量的峰值均出现在第2 d,而多糖的峰值出现在第4 d.消化0～6 d,超声污泥的EPS含量大于对照,到了消化6～10 d,由于前期释放了大量EPS和胞内聚合物,超声污泥的EPS含量少于对照.上清液溶出物的变化趋势与污泥相似,污泥经超声破解后,溶出物浓度大幅度增加.超声污泥的总溶出物最大值比初始值高出34.61 mg.L-1,约为对照最大值所增加浓度的3.5倍,表明超声波使EPS和胞内有机物大量释放到上清液中;可溶性物质的增加使污泥有机物降解比例提高,因此超声污泥的VSS去除率大于对照.污泥EPS官能团结构的红外光谱分析表明,蛋白质、多糖以及DNA是消化污泥EPS的主要成分,超声波不会改变EPS中多糖、蛋白质等有机物的结构.
In order to investigate the mechanisms of ultrasonic promotion for sludge anaerobic/aerobic digestibility,the index of EPS（polysaccharide,protein,DNA and total content）and dissolved substances were measured by using biochemistrical methods.The optimal conditions of ultrasonic treatment were decided from the uniform design.The uniform design results showed that at the optimal ultrasonic conditions of 15 min ultrasonic time,0.1 W/mL density and 12 h ultrasonic interval time,the performances of anaerobic/aerobic digestion were greatly improved,the removal rate of VSS reached 42.45% after 10d digestion.The results of sludge anaerobic/aerobic digestion promoted by ultrasonic treatment showed that the variational trend of EPS index in sludge increased firstly and then fell off during 10 d digestion,the maximum of protein,DNA and total content were appeared in the 2 d,while the maximum of polysaccharides was came out in the 4 d.The total content of EPS in ultrasonic sludge was more than the control sludge during 0-6 d digestion,and then less than control in 6-10 d because of a large amount of EPS and cellular substances had been released out.The variational trend of dissolved substances in the supernatant was similar with that in sludge,the dissolved substances concentrations were highly increased after ultrasonic treatment.The maximum of total concentrations in ultrasonic sludge was 34.61 mg·L-1 higher than the beginning,it was about 3.5 multiple of the increased concentrations of control＇s maximum,indicated that ultrasonic treatment could release EPS and cellular substances into the supernatant.The greatly release of soluble organics enhanced the consumed proportion of organics,resulted in the removal rate of VSS in ultrasonic sludge was markedly improved.The infrared spectrum analysis of EPS showed that polysaccharide,protein and DNA were the major components of EPS in anaerobic/aerobic sludge,ultrasonic treatment wouldn＇t change the organic structure of them.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2011年第6期1665-1672,共8页
Environmental Science
基金
广东省教育部产学研合作专项(2008B0905200253)
关键词
剩余污泥
超声波处理
缺氧/好氧消化
胞外聚合物
溶出物
分子结构
sewage sludge
ultrasonic treatment
anaerobic/aerobic digestion
extracellular polymeric substances
dissolved substances
molecular structure
