Microbial activity in a combined UASB-activated sludge reactor system

A combined upflow anaerobic sludge bed-activated sludge (UASB-AS) reactor system with consistently wasting of excess biomass was used to treat suspended-solids pre-settled piggery wastewater (COD=2000 mg l(-1), total Kjeldahl nitrogen TKN=400 mg l(-1), suspended solids=250-400 mg l(-1)). Thus, the activity of nitrogen-related microbial groups in each individual bioreactor was investigated. When the granules retention time (GRT) of 20-50 d in the UASB reactor, the solids retention time (SRT) of 10-25 d in the AS reactor and the recycle-to-influent ratio (Re) of 1 were maintained, the combined system removed 95-97% of chemical oxygen demand (COD), 100% of TKN and 54-55% of total nitrogen (TN). Denitrification and methanogenesis occurred in the UASB reactor so that both biochemical processes contributed to most of the COD removal and, complete nitrification (most of the TKN removal) occurred in the AS reactor. Compact granules with good settling abilities developed in the UASB reactor, and rapid rates of granulation of break-up granules in the UASB reactor were confirmed by experiments. The activity of nitrifiers and denitrifiers (an=0.68-0.87; adn=0.55-0.70) and the calculated specific nitrification and denitrification rates (qn=0.26-0.47 mg NH4+ -N mg VSS(-1)d(-1); qdn=0.046-0.076 mg NOx- -N mg VSS(-1)d(-1)) significantly increased with decreasing SRT and GRT, respectively. Accordingly, the combined UASB-AS reactor system should be regarded a promising alternative for the removal of organic carbon and nitrogen from piggery wastewater.     

抗生素类污染物对活性污泥酶活的影响研究

对6种抗生素(3种四环素类和3种磺胺类)类污染物对活性污泥过氧化氢酶、脲酶、脱氢酶3种酶活的影响进行研究.结果表明,四环素类抗生素对活性污泥酶活的影响大于磺胺类抗生素,且对胞内酶脱氢酶的影响大于对另外2种胞外酶脲酶和过氧化氢酶,而磺胺类抗生素对过氧化氢酶的影响最大.6种抗生素类污染物对活性污泥酶活的2h培养时间的半数有...     

Pyrolysis of oil sludge in a fluidised bed reactor

The oil sludge of tanker cleaning was pyrolysed in fluidised bed reactors. Three experiments were conducted in a laboratory plant and two on a technical plant. Separation of oil from the solids and distribution of the oil products were investigated at temperatures from 460 degrees C to 650 degrees C. Between 70% and 84% of the oil could be separated from the solids. Distribution of the oil products depended on the feed material and the pyrolysis conditions. The higher the temperature the more the oil was cracked into low boiling compounds. Under the conditions of pyrolysis carbon reduced gridiron to iron. Thus some solid fractions were pyrophoric and oxidised with high heat generation. Therefore the solid products have to be turned into inert substances. The fluidised bed pyrolysis is an adequate process to recycle oil sludge with high yields.     

盐度对活性污泥硝化功能的影响

利用批量试验研究了盐度对常规活性污泥(非耐盐污泥)硝化功能的影响;通过逐步提高试验水的NaCl浓度驯化活性污泥,考察了驯化污泥的硝化功能;并进一步研究了适应于某NaCl浓度的耐盐硝化菌在受到盐度冲击时,其硝化功能的变化.结果表明,常规活性污泥中的硝化菌对盐度较敏感,当试验水中的NaCl质量浓度达到10.0 g/L时,污泥比硝化速率降低86%;通过逐步提高试验水的NaCl浓度对活性污泥进行长期驯化,可以驯化出耐盐硝化菌,耐盐污泥的比硝化速率接近于常规活性污泥的比硝化速率;适应于某NaCl浓度的耐盐硝化菌在受到盐度冲击时,NaCl浓度突然增加会对其产生更强的抑制作用.     

污泥干化焚烧联用系统最佳运行工况研究

污泥干化焚烧联用系统将污泥焚烧产生的能量用于污泥干化,可实现污泥处理的节能降耗。对于污泥干化焚烧联用系统的运行,进厂污泥负荷、初始含水率、热值、污泥干化目标含水率是最大的影响因素。为实现污泥干化焚烧联用系统的低能耗和安全稳定运行,结合国内某污泥干化焚烧处理工程,建立了污泥干化焚烧联用系统能量和物料平衡模型,在此基础上研究了变工况条件下污泥干化焚烧联用系统的运行模式,分析了运行负荷、污泥热值、进厂污泥含水率、入炉污泥含水率发生波动时,对污泥干化单元和污泥焚烧单元所产生的影响,并提出了对应的运行策略。     

絮凝剂对高速厌氧反应器污泥颗粒化的强化作用

以考察絮凝剂对厌氧反应器中活性污泥性能的影响为目的,将聚合氯化铝(PAC)、聚丙稀酰胺(PAM)、聚季铵盐3种不同类型絮凝剂以不同投加量添加到反应器中,采用生物化学甲烷势(BMP)和厌氧毒性测定(ATA)分析方法,评价了3种絮凝剂的厌氧生物可降解性以及3种絮凝剂对厌氧污泥产甲烷活性、沉降性能等方面的促进或抑制作用。确定以聚季铵盐作为厌氧污泥颗粒化促进剂,建议采用多次投加方式,反应器中聚季铵盐质量浓度以10-50mg／L为宜。     

一体化生物膜反应器处理生活污水试验研究

根据传统好氧硝化和缺氧反硝化生物脱氮的工艺原理,开发了一体化生物膜反应器,并对其进行了处理生活污水的试验研究。试验结果表明,在有机负荷提高的前提下,通过对进水方式和曝气速率的调节,反应器对COD和TN的去除率达到97％和82％;污泥活性测定表明,硝化反应和反硝化反应分别在反应器的好氧区和缺氧区占优势,但由于生物膜内部微环境的存在,反应器不同区域均有同时硝化和反硝化(SND)现象的发生。     

Simultaneous nitrification and denitrification in an aerobic reactor with granular sludge originating from an upflow anaerobic sludge bed reactor.

Anaerobic granular sludge, obtained from an upflow anaerobic sludge bed reactor at a brewery waste treatment station, was cultured for 3 months under aeration conditions until the diameter of sludge was in the range 1.8 to 2.6 mm. The aerobic granular sludge gathered acquired the ability of catalyzing simultaneous nitrification and denitrification (SND) and was applied in the study of the process of nitrogen removal in a bioreactor. The ratio between chemical oxygen demand (COD) and ammonium-nitrogen (NH4(+)-N) concentration in the influent was found to be an important factor influencing the process of SND. The final percentage removal of NH4(+)-N reached 100% under the optimal condition of 500 mg/L COD and 0.39 NH4(+)-N/COD. Intermediate products, such as nitrite-nitrogen and nitrate-nitrogen, were also analyzed to clarify the SND process with the aerobic granular sludge.     

Influence of reactor configuration on reliability of activated sludge process

The effect of uncertainty in system parameters and the accuracy of the mathematical model used on the design and reliability of the activated sludge process is investigated by Monte Carlo simulations. Simulations indicate that the coefficient of variation for a reactor volume varies from 0.56 for a single mixed tank reactor to 0.44 for a plug flow reactor. The coefficient of variation for effluent for reactors designed on nominal values was found to be 0.56 for a mixed-tank reactor, 1.28 for two reactors in series, 1.56 for three reactors in series and 1.6 for a plug flow reactor. Significant contributing parameters to the reliability of the process are established. Reactor volumes for desired reliability levels are also calculated.     

上流式多级厌氧反应器中厌氧颗粒污泥特性研究

高品质厌氧颗粒污泥是厌氧反应器实现高效、稳定运行的关键和基础.在实现上流式多级厌氧反应器(UMAR)处理木薯变性淀粉废水高效运行的基础上,对厌氧颗粒污泥的浓度分布、粒径分布、沉降速度、产甲垸活性,辅酶F420和生物相等作进一步的研究.根据在实验工艺条件下培养得到的厌氧颗粒污泥的性能,探讨厌氧颗粒污泥的可能形成机制.     

缺氧折流板反应器的流态及污泥颗粒运动分析

采用缺氧折流板反应器(ABR)处理印染废水,当HRT为8 h时,ABR内的下向导流室雷诺数(Re)为1.1,上向漉反应室Re为0.1,均为层流.污泥颗粒经绕流运动分析.下向导流室污泥颗粒受到的绕流阻力和重力均向下,只有浮力向上,由于污泥颗粒密度大于流体的密度,此时重力大于浮力,污泥颗粒不能在下向导流室内稳定停留,即没有污泥层,与观察到的试验现象一致.在上向流反应室的污泥颗粒受到的绕绕阻力向上,重力与绕漉阻力、浮力处于动态平衡时的污泥颗粒的临界粒径(dcr)为85 μm.     

去除污泥中重金属铬的生物淋滤反应器设计与应用

用微生物方法去除污泥中重金属（生物淋滤法）是近年来发展的新技术，探索工程化的条件有重要的应用价值。设计了一套容积为1m^3的生物淋滤反应器，由生物淋滤池、搅拌器、曝气器和空气压缩机等构成。其中，搅拌叶轮由平叶桨和斜叶桨组合而成。利用制革污泥进行了半连续的生物淋滤试验，结果表明，在反应器中污泥与菌体和营养物质能充分混匀，经过2-5d的处理，污泥pH持续下降到2．0以下，污泥中铬的溶出率达90％-99．5％。     

Microbial community dynamics in a chemolithotrophic denitrification reactor inoculated with methanogenic granular sludge

Denitrification is applied in the tertiary treatment of wastewater to reduce nitrogen pollution. Fluorescence in situ hybridization (FISH), catalyzed reporter deposition (CARD)-FISH, cloning, and scanning electron microscopy (SEM) were applied to follow the evolution of the microbial composition and structure of granular sludge in chemolithotrophic denitrifying bioreactors fed with nitrate and thiosulfate. FISH oligonucleotide probes for the chemolitoautotrophic denitrifiers Thiobacillus denitrificans and Thiomicrospira denitrificans were designed and their utility tested. CARD-FISH and cloning data showed that bacterial diversity in the biofilms changed during the reactor operation. Chemoorganotrophic fermentative Gram-positive strains in the phyla, Actinobacteria and Firmicutes, were dominant in the methanogenic inoculum, both in terms of biodiversity and in number. Other significant phyla were Bacteroidetes and Chloroflexi. After 6 months of operation, Proteobacteria became dominant (83% of the clones). The diversity of Gram-positive bacteria was partially maintained although their abundance decreased notably. After 110 d of operation, the abundance of Tb. denitrificans cells increased considerably, from 1% to 35% of total DAPI-stained cells and from no isolated clones to 15% of the total clones. Tm. denitrificans only represented a minor fraction of the microorganisms in the sludge (1-4% of the DAPI-stained cells). These findings confirm that Tb. denitrificans was the dominant chemolitoautotrophic denitrifying microorganism in the bioreactors. The Archaeal diversity remained almost unchanged and it was represented mostly by Methanosaeta soehngenii. SEM results indicated a considerable loss in the integrity of the sludge granules during the operation, with risk of sludge buoyancy.     

污泥减量过程中臭氧氧化对硝化和反硝化影响的试验研究

采用AO工艺,考察了在污泥减量过程中臭氧(O3)氧化对生物系统硝化和反硝化能力的影响.结果表明,在每克SS中O3投量为0.05 g时,氧化后污泥中的CODcr由37.5 mg/L增至700mg/L,TN由4.86 mg/L增至36.6 mg/L,NH4 -N由0.353mg/L增至7.49 mg/L,NO3--N由2.19 mg/L增至5.15 mg/L.虽然氧化系统出水NH4 -N浓度略高于对照系统,但氧化系统NH4 -N的去除率大于98%,硝化能力基本没有受到O3氧化的影响.O3氧化污泥后增加的有机物作为附加的碳源循环至缺氧段,提高了反硝化的效果,当污泥氧化比例分别为10%、20%、30%时,进入缺氧段的CODCr/TN分别平均增至11.21、11.56、11.88,氧化系统的反硝化效果也随之分别提高5%、25%、37%.     

超声处理对活性污泥系统污泥减量效果的研究

在活性污泥系统采用超声波处理剩余污泥以考察污泥减量效果及其对系统处理效果的影响.结果表明：在声能密度0.25～0.50 W/mL范围内,经过1～30 min的超声波处理,系统表观产率显著下降,剩余污泥的产量可以减少20%～50%左右.同时发现,污泥的沉降性能指标SVI有所下降,而污泥的稳定性有所提高,活性污泥系统的出水水质略有不同程度的下降.     

Understanding the granulation process of activated sludge in a biological phosphorus removal sequencing batch reactor

The granulation of activated sludge was investigated using two parallel sequencing batch reactors (SBRs) operated in biological nitrogen and phosphorus removal conditions though the reactor configuration and operating parameters did not favor the granulation. Granules were not observed when the SBR was operated in biological nitrogen removal period for 30 d. However, aerobic granules were formed naturally without the increase of aeration intensity when enhanced biological phosphorus removal (EBPR) was achieved. It can be detected that plenty of positive charged particles were formed with the release of phosphorus during the anaerobic period of EBPR. The size of the particles was about 5-20 μm and their highest positive ζ potential was about 73 mV. These positive charged particles can stimulate the granulation. Based on the experimental results, a hypothesis was proposed to interpret the granulation process of activated sludge in the EBPR process in SBR. Dense and compact subgranules were formed stimulated by the positive charged particles. The subgranules grew gradually by collision, adhesion and attached growth of bacteria. Finally, the extrusion and shear of hydrodynamic shear force would help the maturation of granules. Aerobic granular SBR showed excellent biological phosphorus removal ability. The average phosphorus removal efficiency was over 95% and the phosphorus in the effluent was below 0.50 mg L⁻¹ during the operation.     

热水解超声组合预处理对污泥厌氧消化产气潜力的影响研究

针对城市污泥厌氧消化由于融胞困难所导致的消解速率低、产气量低等问题,采用热水解与超声组合的方法对污泥进行预处理,考察经预处理后污泥融胞效率的变化及对厌氧消化产气潜力的影响.结果显示,热水解与超声波组合工艺对污泥的破胞作用明显,在30 min热水解与0.53 W/mL超声声能密度组合工艺反应60 min条件下,相对于处理前污泥,预处理后污泥溶解性COD(SCOD)溶出率可提高41.6％,蛋白质增加值达282.7 mg/L,污泥厌氧消化的产气潜力显著增加;30 min热水解分别与0.53、0.33 W/mL超声声能密度组合工艺对污泥破胞效率的差异不大;随着超声时间的延长,在组合预处理工艺前20 min内SCOD的溶出速率较慢,20260 min时溶出速率逐渐提高.试验结果可为城市污泥厌氧消化预处理工艺的选择提供一定的理论依据.     

Simultaneous nitrification-denitrification and clarification in a pseudoliquified activated sludge system.

This paper describes results from a pilot study of a novel wastewater treatment technology, which incorporates nutrient removal and solids separation to a single step. The pseudoliquified activated sludge process pilot system was tested on grit removal effluent at flowrates of 29.4 to 54.7 m3/d, three different solid residence times (SRT) (15, 37, and 57 days), and over a temperature range of 12 to 28 degrees C. Despite wide fluctuations in the influent characteristics, the system performed reliably and consistently with respect to organics and total suspended solids (TSS) removals, achieving biochemical oxygen demand (BOD) and TSS reductions of > 96% and approximately 90%, respectively, with BOD5 and TSS concentrations as low as 3 mg/L. Although the system achieved average effluent ammonia concentrations of 2.7 to 3.2 mg/L, nitrification efficiency appeared to be hampered at low temperatures (< 15 degrees C). The system achieved tertiary effluent quality with denitrification efficiencies of 90 and 91% total nitrogen removal efficiency at a total hydraulic retention time of 4.8 hours and an SRT of 12 to 17 days. With ferric chloride addition, effluent phosphorous concentrations of 0.5 to 0.8 mg/L were achieved. Furthermore, because of operation at high biomass concentrations and relatively long biological SRTs, sludge yields were over 50% below typical values for activated sludge plants. The process was modeled using activated sludge model No. 2, as a two-stage system comprised an aerobic activated sludge system followed by an anoxic system. Model predictions for soluble BOD, ammonia, nitrates, and orthophosphates agreed well with experimental data.     

膨胀颗粒污泥床反应器启动过程中颗粒污泥性质变化研究

采用小试规模的膨胀颗粒污泥床(EGSB)反应器,考察其启动规律及运行特点.在60 d内EGSB反应器的COD容积负荷达到12 kg/(m3·d),COD去除率保持在95%以上.试验中对不同水力负荷下污泥床状态进行了分析.结果表明,将水力负荷控制在1.0 m3/(m2·h)以上,可以确保污泥颗粒化的进行及EGSB反应器的稳定,否则易发生沟流、活塞式漂浮等污泥床异常现象.同时,对颗粒污泥性质及微生物相变化进行了跟踪分析.随着运行条件的改变,由上流式厌氧污泥床(UASB)反应器接种的污泥结构、性能和微生物群落都在不断发生变化.最终得到的颗粒污泥结构密实,沉降速率为38.8～64.6 m/h,比产甲烷活性达到314.25 mL/(g·d),内部微生物相丰富,各菌种呈混杂分布.     

外循环厌氧反应器接种好氧污泥的启动研究

内蒙古自治区某啤酒厂的外循环厌氧反应器完成了首次启动后由于操作问题,导致系统运行崩溃.第2次接种后续生物接触氧化池的好氧污泥进行重新启动,经过20 d的驯化,好氧污泥转变为活性较高的厌氧污泥;采用低负荷高去除率的方式运行40 d后,塔内形成了部分颗粒污泥;之后,为了提高颗粒污泥量快速提高进水流量,COD去除率先突然下降然后缓慢升高.当进水流量达到最大时启动结束,此时塔内颗粒污泥量和COD去除率仍在缓慢上升.