Simultaneous removal of carbon,nitrogen and phosphorus from wastewater by coupling two-step anaerobic digestion with a sequencing batch reactor

The objective of this study was to develop an integrated process for simultaneous removal of carbon, nitrogen and phosphorus from industrial wastewaters. The process consisted of a-two step anaerobic digestion reactor, for carbon removal, coupled with a sequencing batch reactor (SBR) for nutrient removal. In the proposed process, carbon is eliminated into biogas by anaerobic digestion: acidogenesis and methanogenesis. The volatile fatty acids (VFA) produced during the first step of anaerobic digestion can be used as electron donors for both dephosphatation and denitrification. In the third reactor (SBR) dephosphatation and nitrification are induced through the application of an anaerobic–aerobic cycle. This paper describes the first trials and experiments on the SBR and a period of 210 days during which the SBR was connected to the acidogenic and methanogenic reactors. It was shown that nitrification of ammonia took place in the SBR reactor, during the aerobic phase. Furthermore, denitrification and VFA production were achieved together in the acidogenic reactor, when the efflux of nitrates from the SBR reactor was added to the first reactor influx. The proposed process was fed with a synthetic industrial wastewater, the composition of which was: total organic carbon (TOC)=2200 mg dm⁻³, total Kjeldahl nitrogen (TKN)=86 mg dm⁻³, phosphorus under phosphate form (P-PO₄)=20 mg dm⁻³. In these conditions, removals of carbon, nitrogen and phosphorus were 98%, 78% and 95% respectively. The results show that the combination of the two-step anaerobic digestion reactor and an SBR reactor is effective for simultaneous carbon, nitrogen and phosphorus removal. Reactor arrangements enabled zones of bacterial populations to exist. Complete denitrification occurred in the acidogenic reactor and hence the anaerobic activity was not reduced or inhibited by the presence of nitrate, thus allowing high TOC removal. Stable phosphorus release and phosphorus uptake took place in the SBR after coupling of the three reactors. A fast-settling compact sludge was generated in the SBR with the operational conditions applied, thus giving good separation of supernatant fluid. The benefits from this process are the saving of (i) an external carbon source for denitrification and phosphorus removal, (ii) a reactor for the denitrification step. © 1998 Society of Chemical Industry     

序批式反应器中反硝化除磷脱氮的研究

为了提高污水脱氮除磷的效率,研究采用序批式反应器(SBR工艺)厌氧、好氧和缺氧(AOA)的运行方式富集反硝化聚磷菌(DPB),实现同步脱氮除磷。结果表明:在好氧段投加甲醇作为碳源(25—40 mg/L)可有效抑制好氧吸磷,对硝化反应影响较小,能够在缺氧段实现同时反硝化脱氮除磷。SBR反应器稳定运行10个月,当进水NH4+-N、PO43--P分别为30,15 mg/L时,总氮(TN)和PO43--P的平均去除率分别为82.5%和92.1%。聚磷菌能够利用硝酸盐作为电子受体,DPB占总聚磷菌的比例达到44.8%。与A2O运行方式相比,AOA运行方式更有利于实现DPB的富集。     

污水除磷脱氮与磷回收技术

磷作为一种不可再生资源,在现代工农业生产中起着重要的作用。但污水中大量P元素的排放,对环境造成了一定的影响。采用除磷脱氮工艺处理污水,不但可以有效回收磷,而且可以解决水体富营养化问题。     

序批式移动床生物膜反应器脱氮除磷影响因素及特性

考察了曝气量、进水C/N比（COD/TN）及进水氮、磷浓度对序批式移动床生物膜反应器（SBMBBR）脱氮除磷效果的影响,分析了该复合生物系统的污染物去除特性。实验结果表明,反应器脱氮主要是基于好氧段发生的同时硝化反硝化（SND）作用实现的,而除磷是基于常规生物除磷和反硝化除磷过程而完成;在保持载体良好流化状态的前提下,反应器硝化效果和TP去除受曝气量变化影响不大,反硝化效果随曝气量的减小而改善;采用厌氧/好氧序批式运行方式,能够使进水中的有机物被反硝化聚磷菌优先利用,实现一碳两用,节省了脱氮对外部碳源的需要,在进水C/N为2.8～4.0时能获得良好的硝化、反硝化和TP去除效果;随着进水氮、磷浓度的提高,反应器除磷效果相对稳定,脱氮效果变差,最大氮、磷去除负荷分别达到0.17 kg TN·m^-3·d^-1和0.06 kg TP·m^-3·d^-1。     

Fenton oxidation and sequencing batch reactor (SBR) treatments of high-strength semiconductor wastewater

Treatment of a high-strength semiconductor wastewater was experimentally investigated in this study. The wastewater is characterized by a strong dark color, high chemical oxygen demand (COD) concentration, presence of refractory volatile organic compound and low biodegradability. Treatment of this wastewater by traditional activated sludge method is essentially impossible. In the present work, combined physical, chemical and biological methods were synergistically utilized to tackle the wastewater. The combined treatment consisted of air stripping, modified Fenton oxidation and sequencing batch reactor (SBR) method. Experimental tests were conducted to determine the effectiveness and the optimum operating conditions of the combined method. Test results clearly demonstrated the synergistic advantages of the combined treatments. The treatment train was capable of lowering the wastewater COD concentration from as high as 80,000 mg/l to below 100 mg/l and completely eliminating the wastewater color. The overall water quality of the final effluent exceeded the direct discharge standard and better yet, this effluent can even be considered for reuse.     

提高单级SBR系统总氮去除率方法的探讨

针对单级SBR系统在脱氮过程中的碳源矛盾,从几个方面对如何提高单级SBR系统的总氮去除率进行了探讨,提出了单级SBR系统中混合液内循环比的概念,并在分析TN去除率和内循环比关系的基础上得出了单级SBR反应器TN去除率的计算公式。另外,介绍了一种提高SBR工艺TN去除率的改进运行方式,并对如何将SBR和目前新兴的几种脱氮工艺相结合以提高反应器的TN去除率进行了探讨。     

温度对AOA-SBR工艺同步脱氮除磷的影响

为了提高脱氮除磷的效率,采用序批式生物反应器（SBR）工艺处理模拟生活污水,考察了不同温度下N/P、污泥龄（SRT）对厌氧/好氧/缺氧序批式生物反应器（AOA-SBR）工艺同步脱氮除磷效能的影响。结果表明：当温度为10 ℃、N/P为2～3、SRT为20 d时,NH4+-N、TN和TP去除率分别为78%、69%和56%,污泥产率YS为0.339 kgSS/(kgBOD5),污泥含磷率PC为4.68%。当温度为25 ℃、N/P为3～5、SRT为15 d时,NH4+-N、TN和TP的去除率分别为88%、83%和91%,污泥产率YS为0.253 kgSS/(kgBOD5),污泥含磷率PC为6.35%。当温度为35 ℃、N/P为5～7、SRT为10 d时,NH4+-N、TN和TP去除率分别为80%、66%和73%,污泥产率YS为0.225 kgSS/(kgBOD5),污泥含磷率PC为7.42%。污泥产率YS随着温度和污泥龄的增加而降低,通过调节温度和污泥龄能够实现污泥减量。     

移动床生物膜反应器脱氮除磷技术

本文简要介绍了移动床生物膜反应器的特点,总结了移动床生物膜反应器脱氮和除磷的影响因素,指出序批式的运行方式可以同时达到脱氮和除磷的效果。     

Biological nutrient removal in a sequencing batch reactor using ethanol as carbon source

BACKGROUND: When organic matter is limiting for biological nutrient removal (BNR) from wastewater, external organic carbon can be added to a wastewater treatment plant (WWTP). This increases the overall treatment cost, so the choice of substrate is critical. The effect of using ethanol as the carbon source for BNR is investigated. RESULTS: The results clearly showed that using ethanol as a carbon source is a promising strategy for removing nutrients from wastewater. Effluent concentrations of 3.0 mg total nitrogen (TN) L^?1 (96% N removal efficiency) and 0.05 mg phosphate (P‐PO₄) L^?1 (99.9% P removal efficiency) were obtained. Furthermore, tests performed in order to identify the carbon source used by polyphosphate‐accumulating organisms (PAOs) showed that the phosphorus release/carbon uptake ratio using ethanol (0.41 mmol P mmol^?1 C) was slightly lower than that with acetate (0.50 mmol P mmol^?1 C) but close to that with propionate (0.42 mmol P mmol^?1 C). CONCLUSION: Therefore, taking into account the results presented for ethanol‐acclimatised biomass and the fact that the cost of ethanol is lower than that of acetate or propionate, ethanol can be considered as an alternative carbon source if one is needed in a WWTP. Copyright © 2007 Society of Chemical Industry     

Simultaneous methanol removal and destruction from wastewater in a trickle-bed reactor

The stripping of methanol from wastewater was studied in a trickle-bed reactor packed with a mixture of hydrophobic catalyst and hydrophilic support. The process involves air stripping of methanol followed by a gas phase oxidation of methanol into CO₂ and H₂ O over a platinum catalyst. At temperatures between 25 and 70°C, the overall rate was found to be controlled by the stripping step. Since the oxidation results in a lower concentration of methanol in the gas phase, the increased driving force for interfacial mass transfer leads to higher overall methanol removal efficiency.     

序批式IAL-CHS反应器去除氨氮和总磷的试验研究

为研究序批式IAL-CHS反应器处理去除总磷(TP)和氨氮的特性,用模拟废水进行小试研究。试验结果表明:进水氨氮为12.35～20.22mg/L,出水氨氮为0.79～9.52mg/L,去除率为41.85%～96.09%,平均去除率为76.3%;进水TP为1.89～3.33mg/L,出水TP为1.55～3.12mg/L,去除率为3.05%～24.32%,平均去除率为11.31%;该生物反应器具有良好的耐氨氮冲击负荷能力,而且丝状菌大量繁殖对氨氮和TP去除率的影响不明显。     

生物膜反应器SBBR的动力学研究

采用序批式生物膜反应器(SBBR)处理经Fenton预处理后的偶氮染料活性嫩黄K-6G模拟染料废水。试验结果表明:该反应器的COD去除效果稳定,平均去除率达63%,且具有一定抗冲击负荷能力;好氧段COD降解过程服从扩散控制下的生物膜反应动力学模型:rA=1.69(S-55.2),其中包含扩散作用的膜表面反应速率常数k1A为1.69 m/d,生化反应速率常数k1Vf为47 867～95 733 d-1。     

SBBR工艺的研究现状与发展

叙述了序批式生物膜丁艺（SBBR）的原理与工艺特点,介绍了SBBR技术在国内外污水处理实验室的研究现状,以及有待发展、完善的问题。     

SBR法处理酚氰废水的研究

焦化厂酚氰废水毒性大、有机物含量高,较难处理。引入SBR工艺处理酚氰废水,研究了曝气时间及污泥负荷对污染物去除率的影响。结果表明,通过对普通活性污泥的培养与驯化,利用SBR工艺处理焦化厂酚氰废水是可行的;当污泥质量浓度为4g/L,污泥负荷(CODCr)为0.15kg/(kg·d),曝气时间为4h时,COD、酚、氰的去除率分别可达86.6%、99.7%,95.9%;改变SBR的运行程序,对氨氮也有较好的处理效果。     

复合式MUCT工艺用于城市污水除磷脱氮的研究

采用复合式MUCT工艺在天津某城市污水处理厂进行试验研究,重点考察了该工艺在不同泥龄条件下的脱氮除磷效果。试验结果表明,投加组合填料可以强化系统的硝化性能。在一定范围内,泥龄的降低有利于提高系统除磷效果。当泥龄为8 d时,出水NH3-N、TP的平均质量浓度分别为5.1、0.8 mg/L,TN的质量浓度小于20 mg/L;当泥龄为6 d时,出水NH3-N的平均质量浓度为7.7 mg/L,达到《城镇污水处理厂污染物排放标准》(GB18918-2002)的一级A标准。     

低碳源条件下反硝化同步除磷脱氮的研究

对低碳源条件下反硝化同步除磷脱氮的影响因素进行了研究.结果表明,在低碳源情况下,硝基氮的消耗与磷的吸收呈线性关系,在厌氧段维持合适硝基氮与磷的质量比,可较好地实现同步去除氮磷,而污泥泥龄控制不当则影响反硝化除磷的效果.