阴离子型PAM在水厂污泥脱水中的应用

以污泥比阻、离心液体积和离心液浊度作为污泥脱水性能的比较依据,研究了阴离子型PAM AN934PWG对污泥脱水性能的影响.结果表明:阴离子型PAM能有效改善污泥的脱水性能,且投加量较阳离子型PAM低,可作为污泥脱水首选药剂;阴离子型PAM存在一个最佳投加量范围,超过最佳值时,污泥脱水性能反而下降;在测量污泥比阻和离心液体积时得到的PAM最佳投量范围比较一致,可用离心液体积来快速确定PAM最佳投加量.     

粉煤灰调理自来水厂排泥水污泥的比阻

自来水厂污泥直排水体会使水环境恶化,为此开展了掺调理剂改善其脱水性能的试验研究。结果表明,自来水厂污泥不宜采用混凝处理,而利用电厂粉煤灰作调理剂,可使污泥比阻大幅度下降,改善了脱水性能;细粉煤灰的最佳投量是20g/100mL,粗粉煤灰的最佳投量是30g/100mL;粉煤灰与污泥混合形成的滤饼掺入一定比例的煤炭后可做成燃料,实现了自来水厂污泥的焚烧处置。     

溶菌酶预处理对剩余污泥脱水性能的影响

将溶菌酶应用于剩余污泥的预处理,考察了不同酶投加量对污泥脱水性能的影响,通过测定滤饼含水率、污泥比阻、污泥毛细吸水时间（CST）、Zeta电位及污泥上清液中的蛋白质和多糖含量,并采用显微镜和扫描电镜观测污泥絮体和颗粒结构的变化,同时结合三维荧光光谱分析,研究原污泥和酶处理后污泥的脱水性能差异。结果表明,适宜的溶菌酶投加量可显著改善剩余污泥的脱水性能,与原污泥相比,当酶投加量为15%时,真空抽滤后的含水率由91.4%降到63.6%,比阻降低了82%,CST降低了65%,Zeta电位从-14.8 mV上升到2.7 mV。溶菌酶对污泥结构的破坏是其改善污泥脱水性能的重要原因。     

腐殖土改善活性污泥沉降与脱水性能的研究

考察了腐殖土对活性污泥沉降和脱水性能的改善效果.结果表明,投加腐殖土可显著改善污泥的沉降和脱水性能,随着腐殖土投量的增加,活性污泥的初沉速度、压缩比、泥饼含固率均明显提高,污泥容积指数(SVI)、污泥比阻(SRF)及毛细吸水时间(CST)均明显降低;当活性污泥浓度为2 300 mg/L、腐殖土的投加量为5.0 g/L时,污泥的初沉速度由原来的1.72 m/h增至3.01m/h,压缩比由原来的2.86增至7.14,SVI由原来的152 mL/g降至61 mL/g;当污泥浓度为7 300mg/L、腐殖土的投加量为5.0 g/L时,污泥比阻由原来的1.33×1012m/kg降至5.7×1011m/kg,CST由原来的20.3 s降至15.7 s,泥饼含固率由原来的13.4%增至33.0%.     

改性粉煤灰用于污泥脱水的试验研究

利用聚丙烯酰胺(PAM)作为絮凝剂、经氢氧化钠改性的粉煤灰(MCFA)作为助凝剂,分别进行单独投加PAM和联合投加PAM、MCFA的污泥脱水试验。结果显示,加入30g/L的MCFA作为助凝剂后,能进一步减小污泥比阻和泥饼含水率,同时改性粉煤灰的使用使PAM的投加量从30mg/L降低为10mg/L,相当于降低经济投入,因此这种污泥调理方法具有可行性。     

高分子混凝剂对污泥脱水性能的影响

城市污水处理厂每天产生大量的污泥，为了减少最终处置的污泥体积，污泥脱水是重要的处理环节。通过对不同性质的污泥进行性质分析，并选用几种高分子混凝剂对污泥进行调理试验，通过比较试验测得的污泥比阻抗值和观察试验中的矾花生成现象，以及对比滤液中的TP、COD浓度变化，确定最佳混凝剂及其投量，从而达到改善污泥脱水性能的目的。     

污泥浓缩深脱一体机在供水污泥脱水中的应用

针对不同泥质的供水污泥,开发了污泥浓缩脱水一体化工艺及其成套中试设备(浓缩深脱一体机),并优化了设计和运行参数。对于脱水性较好的供水污泥,仅需投加聚丙烯酰胺(PAM),该设备在进泥量较小的条件下即可使出泥含水率低于70%;对于脱水性较差的污泥,分别考察了联合投加PAM和污泥改性剂,以及联合投加PAM和石灰乳两种调理方案对污泥脱水效能的影响,并对不同调理方案进行了技术和经济指标分析。结果表明,在达到目标含水率前提下,当单独投加PAM、联合投加PAM和改性剂、联合投加PAM和石灰乳调理污泥时,设备处理量分别为130、200和330 kgDS/h,处理成本分别为171.24、262.44和150.60元/tDS。因此,联合投加PAM和石灰乳进行供水污泥调理可提高产能、降低处理成本,推荐在实际生产中使用。     

厌氧消化污泥脱水性能变化的试验与分析

研究了剩余污泥在中温厌氧消化条件下脱水性能的变化及其作用机制。剩余污泥厌氧消化过程中,消化污泥的比阻(SRF)相比于剩余污泥有一定的减小,消化污泥的过滤速度有一定的改善,但改善不明显。聚丙烯酰胺(PAM)、FeCl3和聚合氯化铝(PAC)3种絮凝剂调理试验显示,消化污泥的最佳投药量相对于剩余污泥均有所增加,说明消化污泥脱水性能变差。分析了2种污泥中胞外聚合物(EPS)含量及污泥颗粒特性的变化,表明消化过程导致EPS的降解并向液体中释放。随着EPS含量的减少,由EPS架桥形成的较大絮体解体成为较小的污泥颗粒,污泥中小颗粒的比例增加,污泥的脱水性能变差。     

碱改性煤渣预调理强化污泥脱水性能的中试研究

提出了一种高效廉价的污泥脱水性能提高方法,即采用碱改性煤渣预调理污泥,并通过中试考察了调理后污泥在叠螺式脱水机与新型板框式压滤机组合脱水工艺中的脱水性能。结果表明,与原煤渣相比,碱改性后的煤渣比表面积增加,吸附活性增强,经其调理后污泥的脱水效果明显增强。在24 g/L的碱改性煤渣投量下,污泥比阻由7.9×10~(12)m/kg降到3.72×10~(12)m/kg,泥饼含水率由98.5%降到63.2%,并且采用多次等量投加的方式能够更好地降低污泥比阻,提高脱水效果。在脱水过程中,碱改性煤渣不仅能够作为吸附调理剂,也能起到增强骨架结构的作用,使得新形成的污泥絮体强度增加,在脱水挤压下不会由于剪切力而破碎,从而强化污泥脱水效果,同时煤渣这种固体废弃物也得到了资源化利用。     

高效微生物絮凝剂用于污泥脱水及其动力学研究

从活性污泥中筛选出一株高效微生物絮凝剂产生菌TJ-1,经16S rDNA相似性分析鉴定为奇异变形杆菌（Proteus mirabilis）。将TJ-1在优化培养条件下所产絮凝剂（MBF）用于污泥脱水,并与PAM、PAC进行了脱水效果对比。正交试验结果表明,该微生物絮凝剂用于污泥脱水的最佳条件是：pH=6.5,1%的CaCl2投加量为4%（体积分数）,MBF的投加量为6%（体积分数）;在此条件下污泥脱水率可达82%,比单独投加PAC和PAM的脱水效果好。同时,还研究了该微生物絮凝剂在最佳条件下的污泥脱水动力学,并得到了脱水动力学经验方程。     

超声预处理对污泥絮凝脱水性能的影响

为确定超声预处理对污泥脱水性能的影响,在固定频率为25 kHz、不同声强及作用时间下,考察和比较了超声预处理前后污泥结合水及过滤比阻的变化,并就超声预处理污泥的絮凝脱水性能进行了相关测试.结果表明,低声强（0.1～0.15 W/mL）、短时间（2～3 min）的超声预处理可有效降低污泥的结合水量及过滤比阻;当药剂投量相同时,经超声预处理的污泥絮凝脱水性能明显优于未预处理的污泥,即采用超声预处理改善污泥脱水性能是可行的.     

武汉某湖泊底泥的机械脱水性能研究

通过测定污泥比阻值来评价污泥的脱水性能,探讨采用机械脱水的方法处理武汉某湖泊疏浚底泥的可行性和经济性。结果表明,底泥脱水性能良好,可以采用机械脱水的处理方法。CaO、PAC、FeCl3和PAM都可以进一步改善污泥的脱水性能,而CaO和PAC的处理效果更好,且PAC的成本更低。较佳的控制条件：温度为16～18℃,过滤压强为0．015MPa左右,PAC投加量为0．09％左右。采用机械脱水方式处理底泥,操作压强低、药剂投加量少、脱水效果好、经济可行。     

Co-conditioning and dewatering of chemical sludge and waste activated sludge

The conditioning and dewatering behaviors of chemical and waste activated sludges from a tannery were studied. Capillary suction time (CST), specific resistance to filtration (SRF), and bound water content were used to evaluate the sludge dewatering behaviors. Zeta potentials were also measured. Experiments were conducted on each sludge conditioned and dewatered separately, and on the sludge mixed at various ratios. Results indicate that the chemical sludge was relatively difficult to be dewatered, even in the presence of polyelectrolyte. When the waste activated sludge was mixed with the chemical sludge at ratios of 1:1 and 2:1, respectively, the dewaterability of chemical sludge improved remarkably while the relatively better dewaterability of the waste activated sludge deteriorated only to a limited extent. As the mixing ratios became 4:1 and 8:1, the dewaterability of the mixed sludge was equal to that of the waste activated sludge. The optimal polyelectrolyte dosage for the mixed sludge was equal to or less than that of the waste activated sludge. It is proposed that the chemical sludges act as skeleton builders that reduce the compressibility of the mixed sludge whose dewaterability is enhanced. Bound water contents of sludge decreased at low polyelectrolyte dosage and were not significantly affected as polyelectrolyte dosage increased. Advantages and disadvantages of co-conditioning and dewatering chemical sludge and waste activated sludge were discussed.     

斜管沉淀池处理净水厂排泥水工艺优化研究

以净水厂排泥水为研究对象,考察了斜管沉淀池对排泥水的处理效果。结果表明,随着进泥负荷的不断增大,斜管沉淀池出水的上清液浊度和CODMn含量都逐渐升高,阴离子聚丙烯酰胺或聚合氯化铝与聚丙烯酰胺的联合投加都可以改善排泥水的沉降性能,且只要聚丙烯酰胺的投加量大于2 mg/L,就可以形成较大且密实的矾花;投加聚丙烯酰胺药剂后,可应对由于净水工艺进行沉淀池冲洗后排泥水性质的恶化,改善排泥水的沉降性能,降低出水浊度,提高出泥浓度。     

电石渣浆脱水性能的研究

电石渣的脱水问题是利用电石渣作原料生产水泥首先要解决的问题.以聚丙烯酰胺(PAM)为絮凝剂处理电石渣浆,通过正交试验研究电石渣浆的脱水效果.结果表明,对于所研究的电石渣浆,PAM絮凝剂使用最佳浓度为0.08%,最佳投加量90 mg/L;快速搅拌200 r/min,搅拌时间30 s,慢速搅拌20 r/min,搅拌时间3min,得到电石渣浆脱水效果最好.     

利用硅藻土与PAM进行污泥絮凝沉淀的实验研究

为了选择高效絮凝剂,提高污泥的脱水效率,采用正交实验和单因素实验,对武汉某污水处理厂剩余污泥进行絮凝沉降实验,进一步验证了硅藻土和PAM两种絮凝剂的投加量有一个最佳值,大于或小于这个值都会降低絮凝效果;PAM与硅藻土均以湿法投加效果为好,且PAM最好熟化2h,硅藻土浸泡1h;通过PAM与硅藻土的配伍使用实验,最后找到硅藻土占干污泥的0.83%和PAM占干污泥的0.17%的量配合使用时,污泥沉降效果大大强于单独使用一种絮凝剂,而且费用经济。     

Enhanced sludge dewatering by dual polyelectrolytes conditioning

Sludge dewatering by dual polyelectrolytes conditioning was investigated in this study. Single polyelectrolyte is utilized in sludge conditioning conventionally, in which charge neutralization and bridging are involved in the reactions. In the current study, both cationic and non-ionic polyelectrolytes were utilized simultaneously in the conditioning. Waste activated sludge was sampled from a synthetic fiber plant, and used in the experiment. Capillary suction time (CST), specific resistance to filtration (SRF), and settling rate were used to evaluate the sludge dewatering behaviors. Zeta potentials were also measured. Sludge dewatering behaviors resulting from single and dual polyelectrolytes conditioning were compared. It was found that sludge conditioned with dual polyelectrolytes performed better in fine particle capture and in the formation of larger flocs that resulted in a better dewaterability and less chance of overdosing. The dosing sequence in dual polyelectrolytes also affected the sludge dewaterability. Reaction mechanisms in dual polyelectrolyte conditioning were proposed based on enhanced flocculation of sludge particles.     

A novel bioflocculant produced by Klebsiella sp. and its application to sludge dewatering

A bioflocculant‐producing bacterium, named N‐10, was isolated from activated sludge and was identified as Klebsiella sp. The bioflocculant (named MBF10) produced by Klebsiella sp. had a good flocculating capability and could achieve a flocculating rate of 86.5% to kaolin suspension at the dosage of 0.034 g/L. Compared with chemical flocculants, such as Al₂(SO₄)₃, polyaluminum chloride (PAC) and cationic polyacrylamide (PAM) at their optimal dosages, MBF10 showed a similar performance for sludge dewatering. After preconditioning, dry solids (DS) and specific resistance to filtration (SRF) of the sludge were 17.5% and 3.36 × 10¹² m/kg, respectively. The combined use of MBF10 and Al₂(SO₄)₃ resulted in optimum sludge dewatering properties, SRF reduced from 10.87 × 10¹² m/kg to 1.72 × 10¹² m/kg, and DS increased from 13.1% to 21.3%. Charge neutralisation and interparticle bridging were proposed as the reasons for the enhanced performance based upon the experimental observations.