北京市高碑店污水处理厂污泥膨胀的研究及控制对策

通过分析高碑店污水处理厂发生污泥膨胀前后的运行参数及污泥膨胀可能的原因 ,认为此次污泥膨胀主要由于污泥负荷偏低引起的中度丝状菌膨胀 ,通过调节泥龄、污泥负荷、溶解氧等运行参数成功地控制了污泥膨胀     

绍兴污水处理厂一期工程污泥膨胀控制对策

介绍绍兴污水处理厂一期工程中污泥膨胀的处理对策,对发生污泥膨胀的水质特点、工况条件进行分析,认为污泥膨胀主要是由高浓度冲击负荷造成的。通过对泥龄、回流方式、污泥负荷、溶解氧等运行参数进行调节,使污泥膨胀得到有效控制。     

北京高碑店污水处理厂污泥膨胀的研究及控制对策

通过分析高碑店污水处理厂发生污泥膨胀前后的运行参数及污泥膨胀可能的原因,认为此次污泥膨胀主要由于污泥负荷偏低引起的中度丝状菌膨胀,通过调节泥龄、污泥负荷、溶解氧等运行参数成功地控制了污泥膨胀.     

氧化沟工艺污泥膨胀原因分析与控制

为了有效预防和控制污泥膨胀的发生,针对氧化沟工艺,以昌平污水处理中心2010年9月至2011年4月发生的污泥膨胀为例,对设计工艺和运行数据进行分析,发现进水水质、水温、pH、溶解氧含量、污泥负荷以及营养物质都与污泥膨胀有着密切的联系。针对污泥膨胀的原因及相关的机理,根据实际情况,通过控制进水水质、适当增加溶解氧含量以及加大排泥,污泥膨胀可得到有效控制。     

城市污水处理厂的污泥膨胀研究分析

通过对北京市大型城市污水处理厂优势丝状菌鉴定及温度、生物选择器和溶解氧对污泥膨胀影响的研究分析,发现脱氮除磷工艺普遍会在冬季发生由Microthrix parvicella茵引起的污泥膨胀.研究了温度与SVI的变化规律,分析了出水亚硝酸氮和SVI的相关性,并对生物选择器和不同DO浓度对污泥膨胀的影响进行了分析.     

氧化沟工艺污泥膨胀及出水水质影响因素的研究

针对丝状菌污泥膨胀造成改良式氧化沟工艺处理城市生活污水超标的问题,通过分析进水水质、溶解氧、温度、污泥膨胀指数、出水水质变化的关系,探讨了导致丝状菌膨胀的主要限制因子以及出水水质的变化.研究结果表明,此工艺中进水BOD5、CODcr、TP浓度和pH值变化不是导致污泥膨胀的原因,进水TN和环境温度对污泥膨胀略有影响,DO、NH3-N变化与SVI有较强的相关性,DO和NH3-N越高,SVI越低.     

某化工废水处理厂A/O工艺污泥膨胀原因分析与控制措施

介绍了某化工废水处理厂A/O工艺发生污泥膨胀的成因与措施,主要从引起污泥膨胀的丝状菌与非丝状菌过度繁殖两大诱因排查,通过对系统进水水质、溶解氧以及处理负荷等分析,确定为丝状菌过度繁殖引起的污泥膨胀,并通过采取预曝气、控制溶解氧浓度和水温、调节pH和进水负荷等措施,有效解决了污泥膨胀问题。     

好氧生物选择器工艺中曝气池运行参数的研究

就好氧生物选择器工艺系统中曝气池的停留时间、泥龄等运行参数对COD去除率、污泥沉降性能的影响与常规完全混合法系统作了对比研究。并通过污泥对溶解性有机物的吸附试验和动力学参数的分析对好氧生物选择器的工作原理进行了探讨。在达到同样处理效率的前提下，选择器系统中曝气池所需的停留时间和泥龄小于对比系统。选择器系统在低负荷条件下能有效地控制污泥丝状菌性膨胀。但长泥龄条件下选择器系统有失效的趋势。     

剩余污泥减量化技术研究进展与发展趋势

按照物理、化学、生物及组合工艺的分类对污泥减量技术的研究发展状况进行了分析,并 通过污水处理效果来评价各污泥减量工艺。总结出污泥减量化的两个发展趋势:通过调整反应器和 工艺参数实现在污泥产生过程中减少污泥产量;在污泥回流过程中通过细胞溶解实现在污泥产生后 减少污泥外排量。     

低强度超声波强化膨胀污泥好氧消化

污泥膨胀是城市污水处理厂经常遇到的棘手问题。试验采用低强度超声波对膨胀污泥的好氧消化过程进行强化,选取超声强度、超声时间、超声间隔三个因素设计正交试验。对试验结果的极差分析和方差分析表明,低强度超声波强化膨胀污泥好氧消化的最佳参数为:超声强度0.2W/cm~2、超声时间5min、超声间隔8h。试验中经超声辐照的膨胀污泥,其好氧消化达标最短仅需6.73d,比未加超声的对照试验提前了5.34d。试验还研究了膨胀污泥达标前后溶解性化学需氧量(SCOD)和总化学需氧量(TCOD)的变化情况。结果表明,达标时污泥的SCOD变化不大,而TCOD较对照得到了不同程度的降低,最大达到76.1%,污泥的稳定性得到不同程度的提高。     

Performance of high-rate sludge digesters fed with sonicated sludge.

A major limitation of anaerobic sludge digestion is the long hydraulic retention time (HRT) required for satisfactory stabilization which results in large digester size. This study explored a possibility of operating digesters at shortened HRTs by sonication pretreatment of secondary sludges. Four identical digesters designated D1, D2, D3 and D4 were fed with untreated and sludge sonicated at densities of 0.18 W/ml, 0.33 W/ml and 0.52 W/ml, respectively. All digesters were operated at three HRTs of 8-day, 4-day and 2-day. Comparing with the control digester (D1), total solids removal efficiencies improved by 12-19%, 17-36% and 20-39% in digesters D2, D3 and D4, respectively. The volatile solids removal was also increased by 11-21%, 17-33% and 19-36% in the respective digesters. The improved solids degradation corresponded with increase in biogas production by 1.4-2.5, 1.9-3.0 and 1.6-3.1 times, respectively. Increase in methane composition by 2-17% was also noted in all digesters fed with sonicated sludge. An analysis indicated that sonication pretreatment could enhance degradation of carbon, nitrogen and sulfur substances in the digestion. The study suggested that sonication of sludge is a possible pretreatment to shorten the digester operating HRT with improvement in solids degradation, biogas production and methane content. It can be deduced that to maintain a consistent solids loading at a desire performance, sludge digester with smaller size can be designed.     

Anaerobic thermophilic digestion of sewage sludge with a thickened sludge recycle

The process of anaerobic thermophilic digestion of municipal wastewater sludge with a recycled part of thickened digested sludge, was studied in semi-continuous laboratory digesters. This modified recycling process resulted in increased solids retention time (SRT) with the same hydraulic retention time (HRT) as compared with traditional digestion without recycling. Increased SRT without increasing of HRT resulted in the enhancement of volatile substance reduction by up to 68% in the reactor with the recycling process compared with 34% in a control conventional reactor. Biogas production was intensified from 0.3 L/g of influent volatile solids (VS) in the control reactor up to 0.35 L/g VS. In addition, the recycling process improved the dewatering properties of digested sludge.     

Aerobic granular sludge technology: an alternative to activated sludge?

Laboratory experiments have shown that it is possible to cultivate aerobic granular sludge in sequencing batch reactors. In order to direct future research needs and the critical points for successful implementation at large scale, a full detailed design of a potential application was made. The design was based on the laboratory results, and two variants of a full-scale sewage treatment plant based on Granular sludge Sequencing Batch Reactors (GSBRs) were evaluated. As a reference a conventional treatment plant based on activated sludge technology was designed for the same case. Based on total annual costs both GSBR variants proved to be more attractive than the reference alternative (7-17% lower costs). From a sensitivity analysis it appeared that the GSBR technology was less sensitive to the land price and more sensitive to a rain weather flow (RWF). This means that the GSBR technology becomes more attractive at lower permissible RWF/DWF ratios and higher land prices. The footprint of the GSBR variants was only 25% compared to the reference. However, the GSBR with primary treatment only cannot meet the present effluent standards for municipal wastewater in The Netherlands, mainly because of a too high suspended solids concentration in the effluent. A growing number of sewage treatment plants in the Netherlands are going to be faced with more stringent effluent standards. In general, activated sludge plants will have to be extended with a post treatment step (e.g. sand filtration) or be transformed into Membrane Bioreactors. In this case a GSBR variant with primary treatment as well as post treatment can be an attractive alternative.     

用污泥沉降比指导活性污泥法运行的探讨

总结讨论了污泥沉降比在活性污泥法污水处理过程中与MLSS的关系和对活性污泥法处理效果的影响,分析其与季节变化的关系,指出污泥沉降比在预防污泥膨胀及维持曝气池稳定运行方面的作用,影响污水处理效果因素之间的关系,以及污泥沉降比在实际生产运行管理中的指导作用。     

Co-conditioning and dewatering of alum sludge and waste activated sludge.

Co-conditioning and dewatering behaviors of alum sludge and waste activated sludge were investigated. Two different sludges were mixed at various ratios (2:1; 1:1; 1:2; 1:4) for study. Capillary suction time (CST) and specific resistance to filtration (SRF) were utilized to assess sludge dewaterability. Relatively speaking, waste activated sludge, though of higher solid content, was more difficult to be dewatered than alum sludge. It was found that sludge dewaterability and settlability became better with increasing fraction of alum sludge in the mixed sludge. Dosage required of the cationic polyelectrolyte (KP-201C) for dewatering was reduced as well. It is proposed that alum sludge acts as skeleton builder in the mixed sludge, and renders the mixed sludge more incompressible which is beneficial for sludge dewatering. Implications of the results of the study to the sludge management plan for Taipei City that generates both alum sludge and waste activated sludge at significant amount are also discussed. The current sludge treatment and disposal plan in Metropolitan Taipei could be made more cost-effective.     

臭氧氧化污泥工艺的剩余污泥零排放理论可行性研究

以臭氧氧化污泥工艺为模型,通过把曝气池产生的剩余污泥进行臭氧处理后,变成可生物降解的有机物,然后流回曝气池被微生物重新利用来实现污泥的零排放。从理论上研究了,只需要把H=3/(1+2S_e/S_a)倍的预计剩余污泥进行臭氧氧化处理,即把曝气池实际产生的剩余污泥进行臭氧处理,然后回流到曝气池进行生物降解,就可以实现剩余污泥零排放。臭氧氧化污泥工艺剩余污泥零排放的理论可行性,为剩余污泥零排放工艺的设计和运行提供理论支持。同时分析了许多成功的实例,进一步验证了理论。     

Rapid start-up of a nitrifying reactor using aerobic granular sludge as seed sludge

In this study, the effectiveness of aerobic granular sludge as seed sludge for rapid start-up of nitrifying processes was investigated using a laboratory-scale continuous stirred-tank reactor (CSTR) fed with completely inorganic wastewater which contained a high concentration of ammonia. Even when a large amount of granular biomass was inoculated in the reactor, and the characteristics of influent wastewater were abruptly changed, excess biomass washout was not observed, and biomass concentration was kept high at the start-up period due to high settling ability of the aerobic granular sludge. As a result, an ammonia removal rate immediately increased and reached more than 1.0 kg N/m(3)/d within 20 days and up to 1.8 kg N/m(3)/d on day 39. Subsequently, high rate nitritation was stably attained during 100 days. However, nitrite accumulation had been observed for 140 days before attaining complete nitrification to nitrate. Fluorescence in situ hybridization analysis revealed the increase in amount of ammonia-oxidizing bacteria which existed in the outer edge of the granular sludge during the start-up period. This microbial ecological change would make it possible to attain high rate ammonia removal.     

Impact of sludge retention time on sludge characteristics and microbial community in MBR

In this study, the impact of sludge retention time (SRT) on sludge characteristics and microbial community and the effect on membrane fouling in membrane bioreactor (MBR) was investigated. The results show that MBR with longer SRT has less fouling propensity, in agreement with other studies, despite the fact that the MBR with longer SRT contained higher MLSS and smaller particle size. However, much more soluble microbial products (SMPs) were released in MBR with shorter SRT. More slime on the membrane surface was observed in MBR with shorter SRT while sludge cakes formed on the membrane surface in MBR with longer SRT. The results show that SMP contributes to the severe fouling observed in MBR with shorter SRT, which is in agreement with other studies showing that SMPs were the major foulants in MBR. Under different SRTs of operation, the bacterial community structures of the sludge obtained by use of polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) were almost identical, but those on the membrane surface differed substantially. It suggests that, although SRT has impact on sludge characteristics, it doesn't affect the microbial community in the suspension.     

Analysing sludge balance in activated sludge systems with a novel mass transport model

In activated sludge systems the mechanically treated wastewater is biologically cleaned by biomass (activated sludge). The basic requirement of an efficient biological wastewater treatment is to have as a high biomass concentration in the biological reactor (BR) as possible. The activated sludge balance in activated sludge systems is controlled by the settling, thickening, scraper mechanism in the secondary settling tank (SST) and sludge returning. These processes aim at keeping maximum sludge mass in the BR and minimum sludge mass in the SST even in peak flow events (storm water flow). It can be, however, only reached by a high SST performance. The main physical processes and boundary conditions such as inhomogeneous turbulent flow, geometrical features of the SST, wastewater treatment plant (WWTP) load, return sludge flow, sludge volume index etc. all influence settling thickening and sludge returning. In the paper a novel mass transport model of an activated sludge system is presented which involves a 2-dimensional SST model coupled with a mixed reactor model of the biological reactor. It makes possible to investigate different sludge returning strategies and their influence on the sludge balance of the investigated activated sludge system, furthermore, the processes determining the flow and concentration patterns in the SST. The paper gives an overview on the first promising model results of a prevailing peak flow event investigation at the WWTP of Graz.     

Biological sludge solubilisation for reduction of excess sludge production in wastewater treatment process.

A novel sludge disintegration system (JFE-SD system) was developed for the reduction of excess sludge production in wastewater treatment plants. Chemical and biological treatments were applied to disintegrate excess sludge. At the first step, to enhance biological disintegration, the sludge was pretreated with alkali. At the second step, the sludge was disintegrated by biological treatment. Many kinds of sludge degrading microorganisms integrated the sludge. The efficiency of the new sludge disintegration system was confirmed in a full-scale experiment. The JFE-SD system reduced excess sludge production by approximately 50% during the experimental period. The quality of effluent was kept at quite a good level. Economic analysis revealed that this system could significantly decrease the excess sludge treatment cost.