颤蚓反应器结构和曝气方式对剩余污泥处理的影响

通过181 d的连续运行试验,考察了一种新型颤蚓污泥生物减量反应器处理排放剩余污泥的减量效果,并探讨了两种反应器结构和曝气方式对污泥减量效果的影响.结果表明,两种颤蚓反应器均有明显的污泥减量效果(分别为44%和33%),连续曝气的污泥减量效果(46%)优于间歇曝气的污泥减量效果(31%).经过颤蚓反应器处理后,污泥粒径减小,但污泥沉降性能得到改善.试验过程中出现了营养元素N、P的释放,尤其是P释放明显.     

过滤工艺中颤蚓的迁移分布规律

中试条件下研究了颤蚓在过滤工艺中的迁移分布规律,并考察了滤速和过滤周期对颤蚓迁移分布的影响,以及反冲洗后滤池中颤蚓的分布情况。结果表明:颤蚓在滤池中沿滤床深度方向的迁移与颤蚓体长和滤料粒径有关,颤蚓体长越小、滤料粒径越大,则迁移幅度越大;滤速是颤蚓迁移的主要动力,滤速的提高会引起下层滤床中颤蚓数量的增加,颤蚓泄露风险加大;过滤周期的延长将促进颤蚓的迁移,适当缩短过滤周期有利于水厂颤蚓泄露风险控制;反冲洗可以实现颤蚓从净水工艺中的彻底去除,反冲洗强度越大,颤蚓的去除效果越好。为有效控制颤蚓泄露风险,滤池滤速和过滤周期宜分别控制在9.4 m/h和12 h以下,反冲洗强度则控制在25 L/s.m2左右,此时颤蚓去除率为97.7%。     

接种嗜热菌对剩余污泥的溶解效果研究

研究了在65℃、微曝气条件下接种嗜热菌对剩余污泥溶解和污泥中各种营养成分变化的影响.将嗜热脂肪芽孢杆菌AT07-1的培养液接种到2种不同浓度(TSS分别为14、21g/L)的剩余污泥中,并与不接种的进行对比.结果表明,接种嗜热茵AT07-1能够促进污泥中悬浮固体的溶解,2 d时TSS的溶解率分别为38.58%、31.98%,比不接种的分别提高了14.23%、10.14%,挥发性悬浮固体(VSS)的溶解率分别为53.83%、46.64%,比不接种的分别提高了21.99%、18.64%;微曝气条件下溶解性COD(SCOD)和挥发性脂肪酸(VFA)得到累积,SCOD的最大累积量分别为5 459、7 838 mg/L,VFA的分别为4 285、5 578 mg/L,这有利于厌氧消化产气;污泥溶解产生的蛋白质被蛋白酶快速水解,蛋白质浓度先升高后降低;总糖浓度总体呈现先升高后降低的趋势;pH则是先升高后略微降低.     

污泥接种量对剩余污泥水解酸化的影响研究

研究了厌氧条件下水解酸化污泥接种量及污泥浓度对剩余污泥水解产酸、污泥减量的影响.在各反应瓶污泥浓度不同的情况下接种等体积的水解酸化污泥,当污泥停留时间为7 d时,剩余污泥具有较高的产酸量,超过7 d则反应进入厌氧消化的产甲烷阶段,表明接种污泥在反应的前7 d对剩余污泥产酸具有促进作用;水解酸化污泥接种量最多(35%)时其产酸量最高,7 d后作用逐渐减弱,污泥浓度成为影响产酸的主要因素.剩余污泥的水解过程与产酸过程具有相似的规律,MLVSS浓度随着时间的增加而逐渐下降,7 d后降幅趋缓,经过7 d的反应,污泥接种量最多(35%)的MLVSS浓度较开始时下降了27%,MLSS浓度下降了25.5%.     

剩余污泥的超声处理试验研究

分别考察了超声处理剩余污泥过程中声能密度和作用时间对污泥絮体形状、污泥上清液中溶解性化学需氧量(SCOD)和污泥温度的影响。结果表明，虽然声能密度和作用时间都是重要的影响因素，但超声作用时间的长短更为重要。污泥上清液的SCOD和污泥温度的变化表明，生物细胞分解主要是白超声空化引起的力学效应造成的。     

城市生活污泥生物减水技术研究

利用微生物好氧发酵实现城市污水厂污泥生物减水试验研究表明,翻堆及通风方式等因素影响好氧发酵过程中微生物数量及种群的变化,从而影响含水率的变化,在45℃～50℃中高温阶段,中、高温菌共存,污泥减水速率最大,为污泥生物减水的主要阶段。     

泥龄对剩余污泥产率影响的中试研究

利用处理规模为100 m3/d的多模式A2/O工艺中试装置,研究了泥龄对剩余污泥产率和出水水质的影响。试验结果表明,泥龄越长,剩余污泥产率越低,泥龄为16和38 d时,剩余污泥表观产率(Yobs)分别为0.60和0.35 kgVSS/kgBOD5,短泥龄比长泥龄的剩余污泥产率高了70%以上;合成产率(Y)与泥龄无关,衰减系数(Kd)随泥龄的增加而有所增大,泥龄为16和38 d时,Y分别为0.79和0.77 kgVSS/kgBOD5,Kd分别为0.020和0.032 d-1。两种泥龄下,对NH4+-N、TN、COD的去除效果差别不大,而对TP的去除效果却有明显差异。泥龄越长,对TP的去除效果越差,泥龄为38 d时出水TP浓度比泥龄为16 d时高73.5%。     

污泥浓度与曝气强度对MBR运行的综合影响

高污泥浓度可以在减少剩余污泥产量的同时提高系统的容积负荷，但经济曝气强度随污泥浓度的增加呈指数递增，从而使能耗大大增加。为解决这一矛盾，进行了一体式A／O法膜生物反应器处理城市污水的试验，结果表明：过高或过低的污泥浓度和曝气强度都会影响膜生物反应器对COD、NH3-N、TN等污染物的去除效果，并且会加剧膜污染。膜生物反应器存在临界污泥浓度和经济曝气强度，在试验条件下分别为4．73g／L和451L／（m^2·h）。     

超声处理对系统剩余污泥减量效果的研究

在运行稳定的连续流活性污泥系统中采用超声处理剩余污泥并将其返回系统,考察声能密度、超声作用时间和超声污泥回流比对系统剩余污泥减量效果的影响.结果表明,当超声污泥回流比为1∶24、声能密度为0.4 W/mL、超声时间为5 min时,系统污泥日平均产量为13.6 mg/(L·d),减量效果达到95.81%,此时出水COD为73 mg/L、NH4+-N为7.99 mg/L、TN为18.67mg/L,达到<城镇污水处理厂污染物排放标准>(GB 18918-2002)的二级排放标准.此外,系统中污泥的沉降性能及其有机质含量并没有受到显著影响.     

超声破解污泥技术研究

大量剩余污泥的安全处理问题已经成为污水处理厂可持续发展的瓶颈。以增强污泥隐性生长的污泥原位减量工艺为该问题的解决带来了新的希望,但是如何打开污泥微生物细胞壁的刚性结构是其关键步骤。超声处理污泥是近年来新兴的污泥破解手段,由于污泥成分复杂,污泥破解效果也不甚相同,本文从超声时间、超声频率、超声功率以及超声脉冲比四方面总结了超声对污泥破解的影响,同时还考虑了超声与其他污泥破解手段的联用对污泥破解效果的影响,为超声破解污泥的进一步发展提供参考。     

利用微型动物捕食进行污泥减量的研究进展

介绍了目前用来作为污泥减量的微型动物种类,并阐述了在线减量工艺和离线减量工艺两种生物捕食减量工艺,总结了生物捕食污泥减量技术的污泥减量效果,最后提出了其今后的研究方向。     

Possible cause of excess sludge reduction in an oxic-settling-anaerobic activated sludge process (OSA process)

Modification of a conventional activated sludge process by inserting a sludge holding tank in a sludge return line forms an oxic-settling-anaerobic (OSA) process that may provide a cost-effective way to reduce excess sludge production in activated sludge processes. In this paper we systematically evaluate the following possible scenarios that may explain the reduction of excess sludge in the OSA process: (i). energy uncoupling, (ii). domination of slow growers, (iii). soluble microbial products (SMPs) effect and (iv). sludge decay in the sludge holding tank under a low oxidation-reduction potential (ORP) condition. Results show that only the final scenario may reasonably explain this reduction. It has also been found that the sludge decay process in the sludge holding tank may involve the reduction of the cell mass.     

有机负荷对污泥减量HA-A/A-MCO工艺吸放磷的影响

开发了一种具有同步除磷脱氮和污泥减量功能的HA-A/A-MCO工艺,分析了该工艺的方法及流程,并对其进行了试验研究,通过静态试验发现,当负荷增加至一定程度,有机物不再是磷释放的限制性因子,HA-A/A-MCO系统厌氧释磷的临界有机负荷为0.141 g COD/（g MLSS.d）,单位污泥最大可释放贮磷量为5.7 mg P/g MLSS。     

Bacteria permeabilisation and disruption caused by sludge reduction technologies evaluated by flow cytometry

Technologies proposed in the last decades for the reduction of the sludge production in wastewater treatment plants and based on the mechanism of cell lysis-cryptic growth (physical, mechanical, thermal, chemical, oxidative treatments) have been widely investigated at lab-, pilot- and, in some cases, at full-scale but the effects on cellular lysis have not always been demonstrated in depth. The research presented in this paper aims to investigate how these sludge reduction technologies affect the integrity and permeabilisation of bacterial cells in sludge using flow cytometry (FCM), which permits the rapid and statistically accurate quantification of intact, permeabilised or disrupted bacteria in the sludge using a double fluorescent DNA-staining instead of using conventional methods like plate counts and microscope.Physical/mechanical treatments (ultrasonication and high pressure homogenisation) caused moderate effects on cell integrity and caused significant cell disruption only at high specific energy levels. Conversely, thermal treatment caused significant damage of bacterial membranes even at moderate temperatures (45-55 °C). Ozonation significantly affected cell integrity, even at low ozone dosages, below 10 mgO₃/gTSS, causing an increase of permeabilised and disrupted cells. At higher ozone dosages the compounds solubilised after cell lysis act as scavengers in the competition between soluble compounds and (particulate) bacterial cells. An original aspect of this paper, not yet reported in the literature, is the comparison of the effects of these sludge reduction technologies on bacterial cell integrity and permeabilisation by converting pressure, temperature and ozone dosage to an equivalent value of specific energy. Among these technologies, comparison of the applied specific energy demonstrates that achieving the complete disruption of bacterial cells is not always economically advantageous because excessive energy levels may be required.     

推流廊道式曝气池丝状菌性污泥膨胀分析

介绍了丝状菌性污泥膨胀的诱发机理,对推流廊道式曝气池引起丝状菌污泥膨胀的原因做了深入分析,并介绍了在实际生产中控制污泥膨胀的方法,解决了污水处理工艺中的难题,以供同行参考。     

The contribution of biotic and abiotic processes during azo dye reduction in anaerobic sludge

Azo dye reduction results from a combination of biotic and abiotic processes during the anaerobic treatment of dye containing effluents. Biotic processes are due to enzymatic reactions whereas the chemical reaction is due to sulfide. In this research, the relative impact of the different azo dye reduction mechanisms was determined by investigating the reduction of Acid Orange 7 (AO7) and Reactive Red 2 (RR2) under different conditions. Reduction rates of two azo dyes were compared in batch assays over a range of sulphide concentrations in the presence of living or inactivated anaerobic granular sludge. Biological dye reduction followed zero order kinetics and chemical dye reduction followed second-order rate kinetics as a function of sulfide and dye concentration. Chemical reduction of the dyes was greatly stimulated in the presence of autoclaved sludge: whereas chemical dye reduction was not affected by living or gamma-irradiated-sludge. Presumably redox-mediating enzyme cofactors released by cell lysis contributed to the stimulatory effect. This hypothesis was confirmed in assays evaluating the chemical reduction of AO7 utilizing riboflavin, representative of the heat stable redox-mediating moieties of common occurring flavin enzyme cofactors. Sulfate influenced dye reduction in accordance to biogenic sulfide formation from sulfate reduction. In assays lacking sulfur compounds, dye reduction only readily occurred in the presence of living granular sludge, demonstrating the importance of enzymatic mechanisms. Both chemical and biological mechanisms of dye reduction were greatly stimulated by the addition of the redox-mediating compound, anthraquinone-disulfonate. Based on an analysis of the kinetics and demonstration in lab-scale upward-flow anaerobic sludge bed reactors, the relative importance of chemical dye reduction mechanisms in high rate anaerobic bioreactors was shown to be small due to the high biomass levels in the reactors.     

Promotion and inhibition of oxygen transfer under fine bubble aeration by activated sludge

The promotion and inhibition of inactivated and activated sludge on oxygen mass transfer (OMT) were studied using lab‐scale experiments. The results showed that the α‐values and oxygen transfer efficiency (OTE) decreased with increasing mixed liquor suspended solids (MLSS) concentration (1–10 g/L). Although OMT promotion rate by microbial respiration in activated sludge system increased from 39.8–97.5% for the α‐values and OTE, the two parameters were found to fall sharply when MLSS concentration was over 5 g/L. This indicated that the sludge concentration is a major influence factor on OMT in activated sludge system. Such results provide valuable knowledge for the operating optimization of the aeration system in wastewater treatment process.     

Studies on dissolved oxygen concentration and sludge retention time affecting the full-scale activated sludge process

We have made a series of experiments on dissolved oxygen (DO) concentration and sludge retention time (SRT) to affect the full-scale activated sludge process.

For DO control, a better effluent water quality and a reduced current consumption have been achieved as compared with those in a constant air flow operation. The best control point for the DO control operation is at the outlet side of the aeration tank.

For SRT control, effluent COD seems to fluctuate slightly, and is favorably stable when SRT is between 10 and 20 days. It takes about twice as many days as SRT value set up for the total mass of sludge in the process (M) to be stabilized in case of making set value change as a result of simulation using mathematical models.     

城市污泥对固废陶粒的强度影响研究

以城市污泥、建筑弃土等固废烧制陶粒,利用XRD、MIP孔结构和SEM等测试手段研究城市污泥对陶粒强度影响。结果表明:通过正交试验获得较优的烧结制度,烧制出污泥掺量为20%的轻质高强陶粒;污泥掺量及对应陶粒氧化物含量(SiO₂及Al₂O₃)均影响陶粒强度;陶粒内部结构随着污泥掺量的增加而变得疏松,污泥掺量为20%的陶粒较掺量为5%的陶粒孔隙率大3.9%以上,陶粒孔径也随着污泥掺量的增加而增大,进而影响陶粒强度;对于氧化物,Al₂O₃含量是影响陶粒强度的主要因素,当其含量超过20.5%以后,陶粒主晶相由石英相逐渐转变为蓝晶石,对陶粒强度提升明显。     

Behavior of inorganic elements during sludge ozonation and their effects on sludge solubilization

The behavior of inorganic elements (including phosphorus, nitrogen, and metals) during sludge ozonation was investigated using batch tests and the effects of metals on sludge solubilization were elucidated. A decrease of ∼50% in the ratio of sludge solubilization was found to relate to a high iron content 80-120 mgFe/gSS than that of 4.7-7.4 mgFe/gSS. During sludge ozonation, the pH decreased from 7 to 5, which resulted in the dissolution of chemically precipitated metals and phosphorus. Based on experimental results and thermodynamic calculation, phosphate precipitated by iron and aluminum was more difficult to release while that by calcium released with decrease in pH. The release of barium, manganese, and chrome did not exceed 10% and was much lower than COD solubilization; however, that of nickel, copper, and zinc was similar to COD solubilization. The ratio of nitrogen solubilization was 1.2 times higher than that of COD solubilization (R² = 0.85). Of the total nitrogen solubilized, 80% was organic nitrogen. Because of their high accumulation potential and negative effect on sludge solubilization, high levels of iron and aluminum in both sewage and sludge should be considered carefully for the application of the advanced sewage treatment process with sludge ozonation and phosphorus crystallization.