Optimal Aerations in the Inverse Fluidized Bed Biofilm Reactor When Used in Treatment of Industrial Wastewaters of Various Strength

The aim of this work was the determination of the optimal aerations, and more specifically the corresponding optimal air velocities uopt, at which the largest COD removals were achieved in treatment of industrial wastewaters of various strength conducted in the inverse fluidized bed biofilm reactor. The largest COD removals were achieved at the following air velocities uopt and retention times ts, and (Vb/VR) = 0.55: i) for CODo = 72,780 mg/l at uopt = 0.052 m/s and ts = 80 h;ii) for CODo = 62,070 mg/l at uopt = 0.042 m/s and ts = 65 h;iii) for CODo = 49,130 mg/l at uopt = 0.033 m/s and ts= 55 h;iv) for CODo = 41,170 mg/l at uopt = 0.028 m/s and ts = 45 h;v) for CODo = 35,460 mg/l at uopt = 0.025 m/s and ts = 27.5 h;and vi) for CODo = 26,470 mg/l at uopt= 0.014 m/s and ts = 22.5 h. In the treatment operation conducted in a reactor optimally controlled at the above values of uopt, ts and (Vb/VR), the following decreases in COD were obtained: i) from 72,780 to 5410 mg/l;ii) from 62,070 to 3730 mg/l;iii) from 49,130 to 2820 mg/l;iv) from 41,170 to 1820 mg/l;v) from 35,460 to 1600 mg/l;and vi) from 26,470 to 1180 mg/l, that is, approximately a 93%, 94%, 95%, 96%, 95% and 96% COD reduction was attained, respectively.

Oxygen Transfer and Hydrodynamics in a Flexible Fibre Biofilm Reactor for Wastewater Treatment

A flexible fibre biofilm reactor was developed for treatment of organic wastewaters.The hydrodynamic characteristics and mass transfer coefficients of oxygen were studied and compared with those of the conventional activated sludge processes.Tracer experiments were performed to obtain the residence time distributions of the reactors.The results indicated that both reactors could be treated as mixed flow reactors.The effects of flow rates of water and air on the overall mass transfer coefficient of oxygen were investigated,and the correlations between the mass transfer coefficient and the ratio of flow rates were obtained.Compared to the conventional activated sludge reactor,the mass transfer coefficients in the flexible fibre reactor were similar to but slightly lower,and less sensitive to the variation in the ratio of flow rates.It indicated that the fibre packing in the reactor hindered the oxygen transfer to some extent.

Treatment of Wastewater with Modified Sequencing Batch Biofilm Reactor Technology

This paper describes the removal of COD and nitrogen from wastewater with modified sequencing batch biofilm reactor. The strategy of simultaneous feeding and draining was explored.The results show that introduction of a new batch of wastewater and withdrawal of the purified water can be conducted simultaneously with the maximum volumetric exchange rate of about 70%.Application of this feeding and draining mode leads to the reduction of the cycle time, the increase of the utilization of the reactor volume and the simplification of the reactor structure. The treatment of a synthetic wastewater containing COD and nitrogen was investigated. The operation mode of F(D) O ( i.e ., simultaneous feeding and draining followed by the aerobic condition) was adopted. It was found that COD was degraded very fast in the initial reaction period of time, then reduced slowly and the ammonia nitrogen and nitrate nitrogen concentrations decreased and increased with time respectively, while the nitrite nitrogen level increased first and then reduced. The relationship between the COD or ammonia nitrogen loading and its removal rate was examined, and the removal of COD, ammonia nitrogen and total nitrogen could exceed 95%, 90% and 80% respectively. The fact that nitrogen could be removed more completely under constant aeration (aerobic condition) of the SBBR operation mode is very interesting and could be explained in several respects.

Evaluation of the Inverse Fluidized Bed Biological Reactor for Treating High-Strength Industrial Wastewaters

The aim of this work was to investigate the aerobic degradation of high-strength industrial (refinery) wastewaters in the inverse fluidized bed biological reactor, in which polypropylene particles of density 910 kg/m3 were fluidized by an upward flow of gas through a bed. Measurements of chemical oxygen demand (COD) versus residence time t were performed for various ratios of settled bed volume to reactor volume (Vb/VR) and air velocities u. The largest COD reduction, namely, from 54,840 to 2,190 mg/l, i.e. a 96% COD decrease, was achieved when the reactor was operated at the ratio (Vb/VR) = 0.55, air velocity u = 0.046 m/s and t = 65 h. Thus, these values of (Vb/VR), u and t can be considered as the optimal operating parameters for a reactor when used in treatment of high-strength refinery wastewaters. In the treatment operation conducted in a reactor optimally controlled at (Vb/VR) = 0.55, u = 0.046 m/s and t = 65 h, the conversions obtained for all phenolic constituents of the wastewater were larger than 95%. The conversions of about 90% were attained for other hydrocarbons.

Start-up and Performance of a Novel Reactor----Jet Biogas Inter-loop Anaerobic Fluidized Bed

A novel anaerobic reactor, jet biogas inter-loop anaerobic fluidized bed （JBILAFB）, was designed and constructed. The start-up and performance of the reactor was investigated in the Process. of .artificial glucose wastewater treatment. With the wastewater recycle ratio of 2.5 ： 1, the recycled wastewater with biogas could mix sludge and wastewater in the JBILAFB reactor completely. The start-up of the JBILAFB reactor could be completed in less than 70 d through maintenance of hydraulic retention time （HR^I＂） and stepwise increase of feed total organic carbon （TOC） concentration. After the start-up, with the volumetric TOC loadings of 14.3 kg·m ^-3·d^-1, the TOC removal ratio, the effluent pH, and the volatile fatty acids （VFA）/alkalinity of the JBILAFB reactor were more than 80%, close to 7.0 and less than 0.4, respectively. Moreover, CH4 was produced at more than 70% of the theoretical value, The reactor exhibited high stability under the condition of high volumetric TOC loading. Sludge granules in the JBILAFB reactor were developed during the start-up and their sizes were enlarged with the stepwise increase of volumetric TOC loadings from 0.8 kg.m^-3.d ^-1 to 14.3 kg.m^-3.d^-1. Granules, an offwhite color and a similar spherical shape, were mainly comprised of global-like bacteria. These had good methanogenic activity and settleability, which were formed probably through adhesion of the bacteria. Some inorganic metal compounds such as Fe, Ca, Mg, Al, etc. were advantageous to the formation of the granules.

Research Development and Application of Nitrogen and Phosphorus Removal in Sequencing Batch Biofilm Reactor

Frequent variations of the wastewater quality and quantity and other uncertain factors are the challenges faced by many wastewater treatment plants during the operation. Sequencing batch biofilm reactor（ SBBR） process provides a new idea for an effective solution to this problem. This paper introduces the basic processes and characteristics of the sequencing batch biofilm reactor（ SBBR） process,and summarizes the research status of this process in wastewater treatment. Factors affecting the nitrogen and phosphorus removal effect of the SBBR process are also analyzed.

五格式净粪池与三格式化粪池处理农村生活污水效果及成本对比

针对三格式化粪池(TcST)出水COD及氮、磷浓度高,直排或溢流造成当地局部水体污染或黑臭的问题,构建了等容积五格式净粪池(FcPTR),并以实际生活污水为处理对象,对比研究2种反应器的运行特性和单位污染物去除成本。结果表明:FcPTR连续运行120 d,出水COD平均值为74 mg/L,TN、NH_(4)^(+)-N、TP平均浓度分别为26、20、1.6 mg/L,在我国进水水质相似的农村地区使用时,可满足11个省(区、市)发布的农村生活污水处理设施水污染排放地方标准二级水质要求。厌氧折流区、好氧区填料与污泥上变形菌门(Proteobacteria)的生长代谢促进了含氮和含磷物质的去除。相比于TcST,FcPTR明显增强了系统对有机物的降解和脱氮除磷效果,提高了系统的抗冲击负荷能力。经成本核算,在设计容积和运行场景相同时运行10年,FcPTR削减1 kg COD、1 kgNH_(4)^(+)-N的成本均比TcST降低19.8%。

IC厌氧反应器处理技术的应用研究及发展

IC厌氧反应器是第三代厌氧反应器,已广泛应用于高浓度有机废水处理。介绍了厌氧生物处理技术的特点及厌氧生物反应器的发展,重点介绍了IC厌氧反应器的构造、反应原理、特点、应用现状及发展趋势等,以期为IC厌氧反应器的应用提供参考。

碱激活PMS氧化法协同SBBR深度处理焦化废水研究

采用碱激活过一硫酸盐(PMS)氧化法协同序批式生物膜反应器(SBBR)工艺深度处理焦化废水,研究当以NaOH作为激活剂时,pH、PMS浓度和温度对碱/PMS体系去除焦化废水生化出水COD和色度的影响,之后考察SBBR工艺处理碱/PMS体系出水的效果。研究结果表明,碱/PMS体系深度处理焦化废水的最佳条件为温度25℃、pH=10、PMS投加浓度7 mmol/L、反应时间4 h,在此条件下色度和COD的去除率分别为96.1%和45.9%。电子顺磁共振实验表明碱/PMS体系存在^(1)O_(2)、O_(2)•-、∙OH和SO_(4)•-等活性氧物种。废水经碱/PMS体系处理后可生化性提高,之后经SBBR工艺进一步处理后出水COD<60 mg/L。总体而言,碱激活PMS氧化法协同SBBR工艺对COD的平均去除率达66.7%。焦化废水生化出水处理前后的三维荧光光谱分析表明,碱/PMS体系协同SBBR工艺能去除焦化废水生化出水中的芳香蛋白类物质和类腐殖酸物质。

MBBR耦合多段AO工艺在大型市政污水处理厂的运行初探和实践成效

新建城市污水处理厂或提标改造老旧污水处理厂普遍存在出水水质差、污染物负荷与占地面积等不可调和的矛盾,基于纵向扩大池容会增加建设成本、高负荷运行具有超标风险,因此,急需一种污泥/容积负荷高、运行稳定、操作简单的污水处理新技术。对此,某大型市政污水处理厂利用移动床生物膜反应器(MBBR)泥膜共混技术提高生化池有效污泥浓度、实现功能微生物的强化和富集,耦合多段AO工艺,经历雨/旱、夏/冬季,已稳定运行227 d,当进水COD_(Cr)、氨氮、TN质量浓度分别为277.97、34.92、45.95 mg/L,对应出水质量浓度分别降低至12.68、0.33、7.55 mg/L,MBBR挂膜前后的氨氮污泥负荷为0.011、0.015 g氨氮/(g MLSS·d)、TN污泥负荷为0.014、0.020 g TN/(g MLSS·d)。系统稳定运行期间,好氧Ⅰ段氨氮硝化速率为7.27 mg/(L·h)、缺氧Ⅰ段NO-3-N还原速率为3.48 mg/(L·h)。结果表明,通过负载微生物和游离污泥的交互作用,寻求复杂微生物群落功能的强化和调控,可以设计出更加合理、高效的污水处理新工艺。

曝气方式对AFBBR处理污水过程中脱氮性能的影响

探索了曝气强度、曝气孔间距和曝气孔径对好氧流化床生物膜反应器(aerobic fluidized bed biofilm reactor,AFBBR)内污水脱氮效率、脱氮速率、微生物群落组成及脱氮功能微生物相对丰度的影响,揭示了不同曝气方式条件下污水脱氮机理。结果表明,在曝气强度5.77 m^(3)/(h·m^(3))、曝气孔间距10 mm和曝气孔径0.27 mm条件下氨氮和总氮的去除率较高,可达到75.0%和70.6%;在曝气强度5.77 m^(3)/(h·m^(3))和曝气孔间距10 mm条件下标准氧传质效率(SOTE)和氧利用率(E)较高,且较小曝气孔径条件下氧气充氧性能较佳;曝气方式影响了同步硝化反硝化速率(SND)、硝化速率(NR)和反硝化速率(DNR),改变了脱氮效率及硝氮和亚硝氮质量浓度;在曝气孔间距10 mm和曝气孔径0.27 mm条件下SND、NR和DNR均达到最高,分别为78.8%、4.9×10^(-4)mg/(h·mg)和4.6×10^(-4)mg/(h·mg),而在曝气强度5.77 m^(3)/(h·m^(3))条件下仅DNR达到最大值;AFBBR系统中共检测出16种脱氮微生物,且反硝化细菌相对丰度显著高于氨氧化细菌和亚硝酸氧化细菌;合适的曝气方式通过形成合适的氧环境条件,提高了Proteobacteria门类中具有脱氮功能的微生物(反硝化细菌)丰度,实现了污水的高效脱氮。合适的曝气强度、曝气孔间距和曝气孔径设计有助于提高AFBBR系统的脱氮性能。

基于生物膜反应器的电厂含氨废水生物处理技术研究

水污染处理是目前我国面临的巨大难题,由于水污染以流域形式存在,因此治理难度较大。生物治理是近些年我国广泛采用的技术,本文主要探讨了基于生物膜反应器的电厂含氨废水生物处理技术,所得结论仅供参考。

污水处理过程中溶解氧浓度对好氧生物膜反应器性能影响的实验研究

本研究旨在探究溶解氧浓度对好氧生物膜反应器性能的影响。通过一系列实验发现,不同溶解氧浓度下反应器的去除效率存在显著差异。结果显示,在一定范围内,较高的溶解氧浓度有助于提升废水处理效率,但过高的溶解氧浓度可能导致反应器性能降低。这些发现为优化好氧生物膜反应器的运行提供了重要参考。

移动床生物膜反应器在污水处理中的应用研究

应用好氧移动床生物膜反应器处理生活污水 ,厌氧复合床生物膜反应器处理高浓度有机废水 ,厌氧 -好氧移动床生物膜工艺处理食品废水的试验均取得良好的效果。试验结果表明 ,该工艺具有处理效率高 ,出水水质稳定 ,耐冲击负荷能力强 ,占地少 ,结构紧凑 ,维护管理简单的特点。

工业废水电化学处理技术的进展及其发展方向

综述了工业废水电化学处理技术的进展和应用。介绍了电化学氧化、电化学还原、电絮凝、电气浮、电渗析等方法。阐述了电化学氧化技术目前没有工业化的主要原因是低的电流效率、高能耗和大的操作费用,如何提高传质特性、电流效率、开发用于废水处理的高效电解槽是亟待解决的问题。特别指出了未来工业废水电化学处理技术的发展方向是生物难降解废水处理用的阳极材料、电化学反应器、电化学组合技术、生物膜电化学反应器工艺。

生物膜反应器中生物膜脱落的机理及数学模型

生物膜法是一种高效的废水处理方法。对生物膜反应器中的生物膜形成、流体力学、传质以及反应动力学特性都做了较深入的研究。目前,在反应机理研究方面,生物膜的脱落是了解最少的,而反应器中生物膜的脱落对生物膜的形态、稳定性以及转化效率都有直接的影响,因此,生物膜脱落的研究具有十分重要的意义。介绍了生物膜反应器中生物膜脱落的过程及其机理,讨论了影响生物膜脱落的种种因素,并对有关研究生物膜脱落的数学模型作了总结和分析,最后提出了今后生物膜脱落研究的重点。

生物膜-电极法在废水处理中的应用

生物膜-电极反应器(BER)是一种非常新颖的废水脱氮技术,同传统的生物反硝化法相比,具有不需要外加碳源或者需要投加少量碳源等优点。作者重点介绍了BER在处理生活污水、含重金属废水和高浓度有毒有机废水中的应用研究状况,并对有待研究的问题进行了探讨,认为该方法在废水处理中极具潜力。

内循环式厌氧反应器启动过程中颗粒污泥的特性

研究了IC反应器的快速启动方法和启动过程中颗粒污泥性质 .结果表明 ,由于反应器成功滞留了大量活性高、沉降性能好的颗粒污泥 ,反应器初次启动可在 2 0d内完成 ,二次启动 1 5d内完成 ,反应器负荷可达 1 2～ 1 5kg·(m3·d) -1,COD去除率 85%以上 ;IC反应器启动结束后 ,其颗粒污泥的性质发生显著变化 ,平均粒径由 0 .88mm增大到 1 .2 5mm ,平均沉降速度由接种污泥的 35 4m·h-1增加到 1 0 5 1 7m·h-1,最大比产甲烷活性 [382 98ml·(g·d) -1]几乎为初期的 4倍 ,产甲烷优势菌由Methanothrix转变为产甲烷球菌和短杆菌 .

厌氧折流板反应器(ABR)的水动力学及污泥特性

ABR作为一种新型的厌氧反应器工艺 ,具有许多优良的性能 ,如良好的水力条件及抗冲击能力、简单的构造、良好的生物种群分布及处理效果等。目前 ,其在不同废水处理中运行效果已得到越来越多的研究和实际应用。

新型填料生物膜法处理城市污水的试验研究

利用新型天然生物质植物中空纤维填料生物膜反应器对城市生活污水处理进行了小试研究。在同等条件下,与传统球形聚乙烯填料生物膜反应器相比,新型填料生物膜反应器挂膜效率提高了78.57%。进入稳定运行期间,新型生物质填料生物膜反应器对COD、NH3-N、TN、TP的平均去除效率分别达到了77.75%、94.78%、71.01%和79.91%,明显高于传统填料生物膜反应器的处理效果。