腐殖活性污泥工艺在日本和韩国的应用

腐殖活性污泥工艺是在传统活性污泥工艺的基础上增加了填充腐殖土填料的生物培养装置，用于改善活性污泥特性，提高处理效果的新型污水处理方法。自20世纪80年代起，日本已成功地将该工艺应用于岛内住宅小区污水净化站、山之内水质净化中心、乌栖市饭田地区和永吉地区农田排水处理站等多个污水处理厂，在韩国也已有200多个污水处理厂应用了该技术。运行结果表明，该工艺具有脱氮除磷效果好、污泥产量低、污泥脱水性好和污泥不产生臭气等显著优点。     

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%.     

低温下腐殖SBR对活性污泥沉降、脱水性能的影响

为考察10℃左右低温环境下腐殖土填料对活性污泥胞外聚合物(EPS)以及沉降、脱水性能的影响,采用SBR工艺处理模拟废水,将内置和外置腐殖土填料的SBR工艺(HS-SBR)与传统SBR工艺(cSBR)进行对比研究。结果表明:添加腐殖土可显著提高活性污泥的初沉速度,外置HS-SBR反应器初沉速度比cSBR提高了9.559 mm/min,改善率达192%;内置HS-SBR反应器初沉速度比cSBR提高了10.599 mm/min,改善率高达213%。外置、内置HS-SBR的污泥沉降性能明显比cSBR的好,SVI值明显较小。HS-SBR的CST值均较cSBR的CST值小,特别是内置HSSBR反应器的CST值最小,比cSBR反应器的CST值小0.68 s·L/gSS,更有利于污泥脱水。     

三沟式氧化沟的活性污泥特性

三沟式氧化沟作为活性污泥法的一种新工艺,活性污泥的状况直接影响到该工艺的运行效果。结果邯郸市东污水处理厂的运行实践,做了大量的测试工作,总结出三沟式氧化沟活性污泥的特性对工艺系统及污泥脱水性能的影响等。     

阳离子表面活性剂改善污泥脱水性能的机理研究

研究了两种含有不同长度疏水链的阳离子表面活性剂CSG—1和CSG-2对活性污泥脱水性能的影响，探讨了两种活性剂在活性污泥体系中的作用机理。结果表明，投加约为干污泥质量10％的CSG-1可使滤饼的含水率降至78％左右，此时污泥的沉降效果较好，污泥毛细吸水时间（CST）也较短（约为62s）；与CSG-1相比，CSG-2虽可使滤饼含水率降至约74％，但其对污泥过滤性能和沉降效果的改善均较差。对CSG—1和CSG-2改善污泥脱水性能的机理研究表明，阳离子表面活性剂通过静电引力和范德华力而被吸附于污泥表面，改变了活性污泥絮体的特性，并引起胞外聚合物（EPS）的分布发生变化，从而改善了污泥的脱水性能，同时也导致了絮体颗粒粒径发生了显著变化。     

污泥热水解技术的发展及应用

总结了热水解技术在污泥处理中的工业应用和研究现状。热水解技术在20世纪30年代开始用于改善污泥脱水性能，70年代末开始用来提高污泥厌氧消化性能，90年代起用于获取反硝化碳源和活性污泥工艺中的污泥减量研究。通过分析热水解发展历程，指出在发展污泥末端治理技术的同时应注重污泥的首端减量控制技术。     

沸石强化A/O工艺的污泥特性研究

沸石强化A/O工艺具有脱氮除磷功能。投加适量沸石能改善活性污泥的沉降性能,并降低了污泥的比阻。但当沸石投量过大时会增加污泥的粘滞性,使得污泥脱水时的压缩性能降低,并增加了二沉池的固体通量,给二沉池的运行和污泥的管道输送带来了不利影响。     

对污泥机械脱水滤液的有效利用

对污水处理厂污泥机械脱水滤液进行了循环利用试验，结果表明，滤液能够改善污泥的浓缩脱水性能、提高污泥的固体负荷率、增大浓缩污泥的浓度，这为污泥处理系统的工艺优化开辟了新途径，既可降低污泥的处理成本，亦可减少污泥处理系统的基建投资。     

污泥龄与沉降性能的相关性分析

前言 近年来,国外对活性污泥处理工艺中泥龄控制技术的研究日趋活跃,并将其应用于工艺设计及运行管理中。污泥龄θ_x对活性污泥的沉降性能有很大的影响;泥龄直接反映了处理过程有机负荷的变化及整个处理系统的基本工况。良好的污泥沉降性能是活性污泥工艺正常运行的先决条件之一。影响污泥沉降性能的因素颇多,其中极为重要且在工艺运行控制中极为方便的是污泥龄。     

改性硅藻土絮凝剂的制备及对污泥的脱水效能

以硅藻土为主要原料、聚合氯化铝为添加剂制备得到一种改性硅藻土污泥脱水絮凝剂,研究了该絮凝剂的制备工艺条件及其对城市污泥的脱水性能.结果表明,制备改性硅藻土絮凝剂的最佳工艺条件如下:硅藻土与聚合氯化铝的质量比为30:1、热处理温度为350℃、焙烧时间为3 h.投加上述条件下制备的改性硅藻土后,污泥的沉降比和脱水性能得到显著提高,SV<,30>从88%降为45%、污泥比阻从11.4×10<'12>m/kg减小至1.23×10<'12>m/kg、泥饼含水率从96.8%降至79.6%.可见,经该絮凝剂处理后,污泥的脱水性能得到较好改善.     

腐殖土强化活性污泥工艺的除污效果研究

分别采用腐殖土强化活性污泥系统与普通活性污泥系统处理生活污水,考察了对COD、NH3-N、TN、TP的去除效果.结果表明,腐殖土强化活性污泥系统与普通活性污泥系统对有机物的去除效果差别不大,平均去除率都在86%左右;腐殖土可以强化普通活性污泥系统对营养盐的去除,特别是明显提高了TP的去除效果,腐殖土强化活性污泥系统对NH3-N、TN和TP的平均去除率分别为71.50%、54,83%和62.67%,比普通活性污泥系统分别高出8.67%、8.16%和33.84%.可见,增加腐殖土反应器是改善普通活性污泥系统脱氮除磷效果的有效方法.     

腐殖土活性污泥中重金属的浸出行为研究

在不同pH值和腐殖土投加量条件下,对活性污泥中Zn、Ni、Cu和Pb四种重金属的浸出行为进行了研究。结果表明,污泥中Zn和Ni的浸出率随pH值的降低而呈明显升高的趋势,Cu和Pb的浸出率也随pH值的降低而升高,但变化幅度相对较小。在酸性条件下,随着腐殖土投量的增加,活性污泥中Zn、Ni、Cu和Pb的浸出率明显降低;而在中性偏碱性条件下,这种变化趋势不明显。投加腐殖土能明显改变活性污泥中重金属的形态分布,促进重金属的稳定化,进而显著改善重金属的浸出行为。     

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.     

Effect of acid and surfactant treatment on activated sludge dewatering and settling.

The effect of pretreating activated sludge with sulfuric acid and surfactant on its exocellular polymer(ECP), dewaterability and settleability was investigated. It was observed that the centrifugal dewatering efficiency was increased with the decrease of sludge pH value, and which was further improved if the surfactant was simultaneously applied. However, to the filtration dewatering, the water content reached the minimum in the case of pH 2.5, and the additional use of surfactant was also favorable. The water content of sludge dewatered with filtration reached 73.99% when a pH 2.5 and a 0.1 g surfactant were employed, which was reduced by around 2% as compared with surfactant unused. Experimental results indicated that the sludge sedimentation rate was significantly accelerated under pH 2.5 condition, and which was increased once more by the utilization of surfactant. Further studies revealed that treating activated sludge with sulfuric acid at pH 2.5 or combined with surfactant was an effective method to remove the polymers from sludge surface and induced the decrease of ECP, which resulted in the improvement of dewaterability and settleability. This study suggested the potentiality of improving activated sludge mechanical dewaterability by the use of sulfuric acid to control its pH at 2.5 or together with a surfactant.     

Sludge dewatering in a conventional plant with phosphorus removal-I: Analysis of additional costs

The aim of this research is to assess the differences in quantity and quality of sludges produced in a conventional activated sludge plant, modified for phosphorus chemical removal. Tests were carried out at the Cesenatico sewage treatment plant, where in summer phosphorus is removed simultaneously to the biological process with the aid of aluminium or ferrous sulphate. Characteristics of the sludge produced with or without phosphorus removal were compared. The sludge was then dewatered by a centrifuge and a filter-press on pilot scale and many tests were carried out under different operating conditions.In this part, the plant's most important performances are discussed with regard to phosphorus removal efficiency, sludge production, characteristics and dewaterability. The experiments showed that phosphorus could be removed up to residual concentration of 1.6 mg 1^?1 without detrimental effects on the biological process, with an increase of sludge production of 21 and 36% using aluminium or ferrous sulphate respectively. On the basis of experimental results a costs analysis was carried out to assess the costs for phosphorus removal, including the additional ones for sludge conditioning, dewatering and cake transport to landfill. It results that additional costs vary from 3290 to 6380 Lit per capita per year (29–54%). The higher costs refer to smaller plants (50,000 inhabitants), in which aluminium sulphate is used and sludge dewatered by centrifuge. The use of ferrous rather than aluminium sulphate allows savings of 1300–1600 Lit per capita per year.     

Conditioning of wastewater sludge using freezing and thawing: role of curing

Freeze/thaw (F/T) treatment is an efficient pre-treatment process for biological sludges. When bulk sludge was frozen, tiny unfrozen regimes in the ice matrix were continuously dehydrated by surrounding ice fronts, termed as the “curing stage”. This work demonstrated that the F/T treatment could not only enhance sludge dewaterability, but also solubilize organic matters from sludge matrix. Most enhancement of sludge dewaterability was achieved during bulk freezing stage, with the waste activated sludge more readily dewatered than the mixed sludges after treatment. Conversely, the freezing stage released only limited quantities of organic matters to liquid. Conversely, the curing contributed mostly on chemical oxygen demand (COD) solubilization and NH₃-N release. The crystallization of intra-aggregate moisture was claimed to damage cell membranes so to release intracellular substances to surroundings. The F/T treatment with sufficient curing is advised to effectively condition biological sludge as the feedstock of the following anaerobic digestion process.     

Filtration properties of activated sludge in municipal MBR wastewater treatment plants are related to microbial community structure

In the conventional activated sludge process, a number of important parameters determining the efficiency of settling and dewatering are often linked to specific groups of bacteria in the sludge – namely floc size, residual turbidity, shear sensitivity and composition of extracellular polymeric substances (EPS). In membrane bioreactors (MBRs) the nature of solids separation at the membrane has much in common with sludge dewaterability but less is known about the effect of specific microbial groups on the sludge characteristics that affect this process.     

腐殖土SBR工艺处理生活污水的试验研究

考察了添加腐殖土的SBR工艺处理生活污水的效果,并与传统SBR反应器进行对比.结果表明,腐殖土SBR工艺对有机物、NH4+-N和TP的去除率分别为85%、83%和72%,与传统SBR工艺相比,提高了对有机物的降解速率,且添加腐殖土有助于SND现象的发生,从而提高了对氮的去除率.腐殖土的添加缩短了SBR系统的有机物氧化和氨氮硝化的时间,对于提高处理效率和降低运行费用具有重要意义.