低强度曝气技术修复河道黑臭水体的可行性研究

以受污染河道的黑臭水体为研究对象,比较了三种曝气方式(低强度连续曝气、间歇曝气和高强度连续曝气)对水体的修复效果,分析了低强度曝气技术的可行性.结果表明,对于流量较小的缓速滞流河道,长期采用低强度曝气可达到降低污染负荷、消除水体黑臭的效果;以氨氪去除率达98%为控制指标,低强度曝气能耗仅为高强度连续曝气的6.25%和间歇曝气的17.24%,大大降低了曝气经济成本.     

Model-based energy optimisation of a small-scale decentralised membrane bioreactor for urban reuse

The energy consumption of a small-scale membrane bioreactor, treating high strength domestic wastewater for community level wastewater recycling, has been optimised using a dynamic model of the plant. ASM2d was chosen as biological process model to account for the presence of phosphate accumulating organisms. A tracer test was carried out to determine the hydraulic behaviour of the plant. To realistically simulate the aeration demand, a dedicated aeration model was used incorporating the dependency of the oxygen transfer on the mixed liquor concentration and allowing differentiation between coarse and fine bubble aeration, both typically present in MBRs. A steady state and dynamic calibration was performed, and the calibrated model was able to predict effluent nutrient concentrations and MLSS concentrations accurately. A scenario analysis (SCA) was carried out using the calibrated model to simulate the effect of varying SRT, recirculation ratio and DO set point on effluent quality, MLSS concentrations and aeration demand. Linking the model output with empirically derived correlations for energy consumption allowed an accurate prediction of the energy consumption. The SCA results showed that decreasing membrane aeration and SRT were most beneficial towards total energy consumption, while increasing the recirculation flow led to improved TN removal but at the same time also deterioration in TP removal. A validation of the model was performed by effectively applying better operational parameters to the plant. This resulted in a reduction in energy consumption by 23% without compromising effluent quality, as was accurately predicted by the model. This modelling approach thus allows the operating envelope to be reliably identified for meeting criteria based on energy demand and specific water quality determinants.     

Role of hydrodynamic factors in ammonia desorption by diffused aeration

Dimensional analysis and the theory of models were used to derive an equation describing the rate of ammonia removal from water by diffused aeration. The mass transfer process was correlated with hydrodynamic variables reflecting the geometry of the system, the air flow and the liquid properties.A proposed mathematical model describes this relationship in the form of the criterial equation     

曝气吹脱法去除水中三氯乙烷的试验研究

研究了曝气吹脱法对水中1,1,1-三氯乙烷和1,1,2-三氯乙烷的去除效果。结果表明,曝气吹脱法对水中1,1,1-三氯乙烷具有理想的去除效果,但是对1,1,2-三氯乙烷的去除效果很差;当曝气量为0.4～1.0 L/min,气水比为3～5时,能将初始质量浓度为5倍国家标准限值的1,1,1-三氯乙烷降低至《生活饮用水卫生标准》(GB 5749—2006)限值以内;在相同曝气量条件下,气水比越大,对1,1,1-三氯乙烷的去除效果越好。     

河道复氧/生物填料工艺处理受污染河水的中试

设计人工模拟河道,考察了河道复氧/生物填料工艺净化受污染河水的效果.通过筛选生物填料以及改变曝气强度、曝气方式和水体流速,探寻了该组合工艺用于苏州受污染河流治理时适宜的运行方式和工艺参数.结果表明,在进行曝气复氧的同时于河道中设置弹性填料,对COD、NH,-N和TP的去除率分别可达38%、62%和42%,浊度也降至8 NTU左右.这表明,对于流速缓慢的滞流水体,采用河道复氧/生物填料工艺进行净化是可行的.     

Effect of synthetic iron colloids on the microbiological NH(4)(+) removal process during groundwater purification

Subsurface aeration is used to oxidise Fe in situ in groundwater that is used to make drinking water potable. In a groundwater system with pH>7 subsurface aeration results in non-mobile Fe precipitate and mobile Fe colloids. Since originally the goal of subsurface aeration is to remove iron in situ, the formation of non-mobile iron precipitate, which facilitates the metal's removal, is the desired result. In addition to this intended effect, subsurface aeration may also strongly enhance the microbiological removal of ammonium (NH(4)(+)) in the purification station. Mobile iron colloids could be the link between subsurface aeration and the positive effect on the NH(4)(+) removal process. Therefore, the objective of this study was to assess whether synthetic iron colloids could improve the NH(4)(+) removal process. The effect of synthetic iron colloids on the NH(4)(+) removal process was studied using an artificial purification set-up on a laboratory scale. Columns that purified groundwater with or without added synthetic iron colloids were set up in duplicate. The results showed that the NH(4)(+) removal was significantly ( alpha = 0.05 ) increased in columns treated with the synthetic iron colloids. Cumulative after 4 months about 10% more NH(4)(+) was nitrified in the columns that was treated with the groundwater containing synthetic iron colloids. The results support the hypothesis that mobile iron colloids could be the link between subsurface aeration and the positive effect on the NH(4)(+) removal process.     

A simplified kinetic model to simulate soluble organic substances removal in an activated sludge aeration tank

A simple kinetic model for the removal of soluble organic substances, SOS, in the activated sludge aeration tank was proposed. The model consists of the instantaneous biosorption of SOS in the influent wastewater and the consecutive biooxidation of the remaining SOS in contact with the activated sludge under the aerated condition. By using samples taken from a municipal wastewater treatment plant, model parameters such as the amount of instantaneous biosorption and the rate of biooxidation, respectively, of SOS were empirically determined, and given as a function of soluble COD concentration. By combining the obtained kinetic data of SOS removal with the quantitative information of the liquid mixing characteristics in a multi-staged aeration tank, a mathematical model to simulate the distributions of SOS concentration in the aeration tank was presented. The simulation calculation was illustratively carried out and the results were shown in comparison with the experimental data in the same plant.     

铁砷复合污染下铁砷比对除砷效果的影响研究

针对铁砷复合污染型地下水,以原水铁砷比作为控制参数,通过烧杯试验研究了曝气接触氧化除铁工艺的除砷效果。结果表明,当初始砷含量分别为100,200,300和400μg/L时,原水铁砷比分别为35∶1,50∶1,52∶1和55∶1,能达到除铁效果且同时满足出水砷含量小于10μg/L的限值要求;根据氢氧化铁对砷的吸附机理,利用Freundlich吸附等温式建立了铁砷比与残余砷含量的数学模型,试验数据拟合结果与模型相吻合。此外,采用曝气氧化工艺处理铁砷复合污染地下水时,可以通过投加二价铁盐控制原水铁砷比,以实现同时去除铁砷的目的。     

曝气量对SBBR生物除磷的影响研究

为了考察曝气量对序批式生物膜反应器（SBBR）除磷效果的影响,采用厌氧/好氧交替运行的方式,通过控制好氧反应过程中的曝气量,研究了不同曝气量时SBBR的好氧吸磷效果,以及不同曝气量对生物膜脱落量的影响,并推导了生物除磷过程中生物膜内溶解氧的扩散模型。结果表明,曝气量是影响生物除磷效果的一个重要因素,为了满足生物膜内聚磷菌对氧的需求量,加快氧的传递速率,增加活性生物膜的厚度,加快聚磷菌的好氧吸磷速率,必须提高液相主体中溶解氧的含量。选择适宜的曝气量能够促进生物膜的脱落与更新,起到调控污泥龄的作用,从而增强生物除磷的稳定性。     

Influence of mixed liquor recycle ratio and dissolved oxygen on performance of pre-denitrification submerged membrane bioreactors

The conflicting influence of mixed liquor recycle ratio and dissolved oxygen on nitrogen removal and membrane fouling of a pre-denitrification submerged MBR was investigated in this study. It was found that a high aeration rate of 10 L air/min was able to minimize membrane fouling as compared with lower aeration rates of 5 and 2.5L air/min in this study. Faster fouling at lower aeration rate was due to the decrease in cross-flow velocity across the membrane surface. However, high DO concentration (average of 5.1+/-0.5mg O2/L) present in the recycle mixed liquor at an aeration rate of 10 L air/min deteriorated the TN removal efficiency when operating at a recycle ratio of more than 3. A lower aeration rate of 5L air/min, resulting in an average DO concentration of 3.4+/-0.7 mg O2/L in the recycle mixed liquor, led to an improvement in TN removal efficiency: 63%, 80%, 84% and 89% for mixed liquor recycle ratio of 1, 3, 5 and 10, respectively. Further decrease in aeration rate to 2.5L air/min, resulting in an average DO concentration of 1.9+/-0.8 mg O2/L, did not improve the TN removal efficiency. Using a newly developed simplified nitrification-denitrification model, it was calculated that the COD/NO3(-)-N required for denitrification at 10 L air/min aeration rate was higher than those associated with 5 and 2.5L air/min aeration rates. The model also revealed that denitrification at an aeration rate of 10 L air/min was limited by COD concentration present in the wastewater when operating at a mixed liquor recycle ratio of 3 and higher.     

砾间接触氧化/水平潜流人工湿地净化微污染河道水

以微污染河道水为处理对象,研究了砾间接触氧化/水平潜流人工湿地复合工艺对水质的净化效果。经过26 d改变进水配比、曝气方式等的调控运行,成功启动复合工艺模拟装置,砾间接触氧化区(简称砾石区)的COD、NH4⁺-N去除率均稳定在75%左右,TN去除率在45%~60%。为进一步强化净化效果,探讨了砾石区水力停留时间(HRT)和砾石曝气区与非曝气区(O/A)分段进水配比对砾石区及后置潜流人工湿地出水水质的影响。当砾石区HRT为5 h时,砾石区对污染物的去除效果较好,COD、NH4⁺-N、TN平均去除率分别可达72%左右、75.28%、67.79%,人工湿地对三者的去除率分别为31%、43%、28%;当O/A区分段进水配比为1∶1时,对COD、NH4⁺-N的平均去除率较高,分别为77.39%和84.91%,分段进水配比为1∶2时,对TN的去除率最高,达到68.5%,人工湿地对TN的去除率为24.47%。因此,砾石区HRT为5 h为较佳参数,分段进水配比可根据进水污染状况灵活选择,研究结果可为实际工程应用提供理论支撑。     

曝气方式对M—CAST工艺处理生活污水的影响

将CAST和MBR工艺结合而构成M-CAST工艺,考察了在非限量曝气、限量曝气及间歇曝气方式下,该系统对生活污水的处理效果.试验结果表明,曝气方式对COD去除效果的影响较小(对其平均去除率>90%),但对总氮的去除影响较大;当MBR和CAST工艺同时运行且采用间歇曝气时,MBR对总氮的去除效果最好,出水TN平均浓度仅为3.55mg/L,达到了优质杂排水的水质标准.研究还表明,M-CAST工艺可根据污水排放要求实现CAST和MBR工艺的灵活切换,且利用膜组件出水就可满足小水量的回用要求,具有节约工程投资和减小占地面积的优点.     

曝气吹脱法去除水中挥发性有机污染物试验研究

在实验室静态试验条件下,研究了曝气吹脱法对氯乙烯、1,1-二氯乙烯、氯丁二烯等10种挥发性有机物的去除效果.结果表明,在曝气量为0.4～1.4 L/min、气水比不大于25时,能将初始质量浓度为5倍国家标准限值的氯乙烯、1,1-二氯乙烯、氯丁二烯、反式-1,2-二氯乙烯、三氯甲烷、二氯一溴甲烷和二氯甲烷降低至国家标准限...     

新型滤料生物滤池除锰技术在农村饮用水中的应用

根据锰氧化细菌的生物除锰作用,依托于新型滤料生物滤池,提出了简单曝气+一级生物过滤的饮用水生物处理工艺,实现了锰的高效生物去除效果;同时,对新型滤料生物滤池除锰的长期运行效果进行了分析。结果表明,这种饮用水生物除锰工艺是一种经济高效、运行稳定的处理方法,适合应用于受锰污染的农村饮用水水源的处理中。     

高效生物除铁除锰工程菌MSB-4的特性研究

采用贫营养培养基,从运行多年的生物除铁除锰水厂的跌水曝气池壁上筛选获得了生物除铁除锰菌种MSB-4.16S rDNA的测序表明,菌株MSB-4为金黄杆菌属,同源性为99%.MSB-4是具有除铁除锰功能的好氧菌,具有异染颗粒、类脂粒,易形成菌胶团.除锰最适温度为8～12℃,最适pH值为8,少量的Fe2+对Mn2+的去除具有明显的促进作用.在模拟高锰高铁地下水环境(即水温为12℃,pH值为7.5,Mn2+和Fe2+的初始浓度分别为5.6 mg/L和14 mg/L)中,菌株MSB-4于48 h内对Mn2+的去除率达94.44%,对Fe2+的去除率达90%.该工程菌株的获得将为高效生物除锰滤池的构建,及生物除铁除锰水厂的快速启动提供有力的技术支持.     

CAST工艺处理城市污水的强化脱氮研究

介绍了镇江征润州污水处理厂CAST工艺的运行情况，结合该厂实际运行状况开展了强化脱氮效果的生产性试验研究。结果表明，该工艺对COD、SS和TP的去除率均能维持在80％以上，但对氨氮的去除效果较差；在该厂运行模式下，控制进水／曝气前30min的DO〈0．5mg／L、进水／曝气后30min的DO浓度在1．0-3．0mg／L、纯曝气DO浓度在2．0-3．0mg／L，可以实现同步硝化反硝化和硝化／反硝化作用下的共同脱氮，使脱氮效率提高了57％左右；在控制进水／曝气后DO〈0．5mg／L、纯曝气DO浓度在1．0-3．0mg／L的条件下，可以实现同步硝化反硝化作用下的脱氮，但较难实现理想的脱氮效果。     

硫自养波形潜流人工湿地的脱氮机理及工况优化

将硫自养反硝化工艺与潜流人工湿地相结合,考察了其对低碳氮比污水中氮的去除效果。结果表明,增加曝气装置后硫自养波形潜流人工湿地的脱氮效果可以得到保障,在气水比为8∶1、水力负荷为0.8 m³/(m²·d)时,TN去除率为(70±5)%,出水TN浓度低于8 mg/L;NH4+-N去除率在90%以上,出水NH4+-N浓度低于3 mg/L;COD去除率为(50±2)%,出水COD浓度低于40 mg/L;p H值可维持在7~9。同时,石灰石填料具有同步除磷的效果。该工艺具有脱氮效率高、效果好、运行费用低的特点。     

Water surface contacting cover system--the basic study for improving the oxygen transfer coefficient and the BOD removal capacity

In order to construct an environmental aeration basin in a sewage treatment plant, the suggested novel aeration basin was examined for the oxygen transfer coefficient by using tap water on a lab-scale and pilot-scale. We called it water surface contacting cover system (WSCCS) that was installed with a cover plate on the wafer surface and a slant plate in aeration basin, compared to a standard aeration basin (SRAS, spiral roll aeration system). Finally, the novel basin could be compared by adopting the slant and cover plates into the actual sewage treatment plant (W x L x D (m)=5.0 x 2.65 x 4.25, treatment capacity: 600 m3/d). As a result, only by adding a slant plate, the oxygen transfer coefficient (K(L)a) increased approximately by 15% more than that with a SRAS basin. And the slope of slant plate was optimized at 10 degrees . Additionally, in the WSCCS, the increasing efficiency of the oxygen transfer coefficient, affected only by the cover, was proved at about 25% on the lab-scale aeration basin and about 20% on the pilot plant. After all, the increasing effect of the oxygen transfer coefficient on WSCCS that was installed with the water contacting cover and the slant plate on standard aeration basin was proved to be above 35%. The distance between the air diffuser and the slant plate was 20-30 cm in the pilot-scale plant. As an effective factor for increasing the oxygen transfer rate, the width/depth ratio of aeration basin was proved to be 2. Through the short-term results of actual sewage treatment plant, it was known that BOD removal efficiency could be improved by about 3% by adopting tile WSCCS not but SRAS.     

上向流曝气生物滤池去除氨氮效果及影响因素分析

在滤速为0.8 m/h、曝气量为25 L/h的条件下,研究了水温、COD容积负荷、NH4--N容积负荷对上向流曝气生物滤池(UBAF)去除城市污水中NH4--N效果的影响.结果表明,水温是影响UBAF去除NH4--N效果的主要因素,水温较高时UBAF对NH4--N的去除效果较好,但低温时其对NH4--N去除率的影响较大;当COD容积负荷较高时,其对NH4--N的去除有明显的抑制作用,且低温条件下其对NH4--N去除率的影响较高温条件下显著;在NH4--N容积负荷相对较高而水温较低时,NH4--N容积负荷对NH4--N去除率的影响相对较大.     

自生动态膜生物反应器处理城市污水

采用自生动态膜生物反应器（SFDMBR）处理城市污水，结果表明，在整个试验期间反应器对COD的平均去除率为81％，在稳定运行期间，对氨氮的平均去除率为87％，对总磷的平均去除率为70％；两边侧向曝气的效果明显优于单边侧向曝气，它不仅能够加大膜片间的错流流速，而且还能使错向流更加均匀；自生动态膜的形成较恢复快，且恢复速度随运行时间的延长呈递增趋势；出水水头、污泥浓度、膜通量、混合液粘度、膜面错流流速等对膜阻力有影响。