微生物浓度对SFBR工艺去除营养物的影响

采用序半连续式反应器(SequentialFed-batchReactor,简称SFBR,下同。)就不同微生物初始浓度对人工配置废水营养物去除效率的影响进行了研究。探讨了微生物初始浓度对COD、氮化合物(NH4-N和NO3-N)除去和微生物生长的影响。结果表明,当微生物初始浓度为140.4g/L时,COD有最高除去率(69.5%)。当微生物初始浓度≥46.8g/L,总氮除去率可达100%。菌体初始浓度对废水中营养物的去除有利。过高浓度的微生物生长,受营养物和供氧的限制。用一组涉及多个微生物反应的动力学模型,分析了微生物初始浓度对同时去除碳、氮化合物效率和微生物生长的影响。     

添加原水改善SBR工艺处理猪场废水厌氧消化液性能

采用序批式反应器(SBR)工艺直接处理猪场废水厌氧消化液,处理系统的效率较低,COD去除率仅有10%左右,NH₄⁺-N去除率70%左右;处理出水水质较差,出水COD高于1 000mg/L,出水NH₄⁺-N在200mg/L左右;处理系统的工作不稳定,效能逐渐恶化.在猪场废水厌氧消化液中添加部分未经厌氧消化的猪场废水(原水),处理系统的处理效率明显提高,COD去除率高于80%,出水COD降到250～350mg/L;NH₄⁺-N去除率高于99%,出水NH₄⁺-N小于10mg/L;处理系统的稳定性也得到增强.添加原水后,猪场废水厌氧消化液的BOD₅/COD比值从0.19上升到0.54,BOD₅/TN比值从0.28上升到2.04,增加了微生物生长和反硝化所需的碳源,强化了反硝化作用,不仅提高了总氮去除效率,而且通过回补碱度,维持了处理系统的pH值稳定.     

猪场废水厌氧氨氧化脱氮的短程硝化反硝化预处理研究

在常温(13～20℃)、不调节pH的条件下,采用短程硝化反硝化预处理低C/N（2左右）猪场废水,考察了反硝化与亚硝化过程,并以经过短程硝化反硝化预处理的猪场废水为进水,分析了厌氧氨氧化的脱氮效果.结果表明,采用短程硝化反硝化预处理低C/N猪场废水,可以达到去除部分COD、部分脱氮、控制出水氨氮和亚硝态氮浓度之比在1∶1左右、pH在7.5～8.0左右的目的,为厌氧氨氧化创造了进水条件,全程COD和总氮平均去除率分别为64.3%和49.1%;经过短程硝化反硝化预处理的猪场废水,其厌氧氨氧化脱氮效果稳定,氨氮、亚硝态氮、总氮的平均去除率分别为91.8%、99.3%、84.1%.     

生物活性碳反应器强化生活污水同步硝化反硝化:C/N影响研究

在生物活性碳(BAC)反应器中探究了C/N对实际生活污水同步硝化反硝化的影响。结果表明C/N对化学需氧量(COD)的去除影响不明显,然而对NH+4-N和总氮(TN)的去除影响较显著。随C/N由3.2升高至7.2,NH+4-N的去除效率由81%升高至91%,TN的去除效率也由35%升高至68%。然而继续升高C/N至9.1,NH+4-N和TN的去除效率却分别下降至87%和51%。生物活性碳反应器处置实际污水的最佳C/N为7.2。较传统SBR活性污泥反应器,BAC反应器能够依赖活性碳实现溶解氧区域化,从而有助于反硝化过程。     

AF反应器对芳香族化合物反硝化降解特性研究

以苯、联苯和萘为模型化合物,研究了厌氧滤池（AF）反应器在反硝化及连续运行条件下对含这几种芳香族化合物模拟废水的处理效果,并以葡萄糖为补充碳源,考察了不同C/N对有机物反硝化降解特性的影响.结果表明,在长期连续流运行及反硝化条件下,AF反应器对废水中几种典型芳香族化合物具有良好地去除效果,当进水COD浓度约为1?000mg/L,苯、联苯和萘总浓度为60mg/L时,出水COD去除率可达到90％,芳香族化合物的去除率可达到84％.苯比萘和联苯更易于反硝化降解.C/N在5～30范围内,苯的降解率均达到90%,C/N对苯的降解没有明显影响;COD、萘和联苯去除率受C/N影响较大,C/N为15时,COD、萘和联苯去除率最大,分别为90%、78%和82%.     

生物膜系统同时硝化和反硝化的实验研究

实验采用人工配水,对生物膜系统中COD和氮的去除进行了研究。实验中pH控制在7.0～7.5左右,温度为20℃～28℃。本实验研究了不同溶解氧、水力停留时间和碳氮比对总氮去除率的影响。实验结果表明,生物膜系统中同时硝化和反硝化具有一定的可行性。在C/N比为8∶1,水力停留时间6h时,溶解氧为0.5～1.0mg/L时,总氮的去除率达53.6%。     

地下渗滤处理村镇生活污水的中试

以红壤土作为填充土壤,在2cm/d的水力负荷下,进行了地下渗滤系统处理村镇生活污水的现场中试.结果表明,地下渗滤系统对COD、氨氮、总磷和总氮有着良好的去除效果,去除率分别达到84.7%、70.0%、98.0%和77.7%,出水COD、氨氮、总磷和总氮的平均浓度分别为11.7mg/L、4.0mg/L、0.04mg/L、4.7mg/L,达到建设部颁发的生活杂用水水质标准对总氮去除机理的分析表明,由硝化/反硝化实现生物脱氮是地下渗滤系统去除总氮的主要途径.在本中试系统中,反硝化效果良好但硝化效果不够理想,改善土壤环境以促进硝化作用是提高总氮去除率的关键.对土壤中氧化还原电位的测定结果表明,土壤内部的还原性质是阻碍硝化反应进行的主要原因.     

MBR-RO组合工艺深度处理高碳高氮废水的研究

采用A/O-MBR/RO工艺深度处理模拟高碳高氮废水,考察了不同进水的COD/N对有机物和氨氮去除效果的影响,并且 深入考察反渗透膜的污染特性结果表明,A/O-MBR能够实现95.6％的有机污染物去除率,反渗透的出水水质指标TOC<0.9mg·^-1、TN<12.65mg·L^-1、总硬度<0.038 mol·L、总碱度<14.6mg·L^-1,达到了城镇污水回用级标准.COD/N对有机物去除率影响不大,但影响总氮的脱除过程当COD/N的平均值为10.2时,总氮的去除主要通过好氧区内同步硝化反硝化过程完成,总氮的平均去除率为89.4％;当COD/N的平均值为7.1、5.6时,总氮的去除主要通过传统的硝化反硝化和同步硝化反硝化共同完成,总氮的平均去除率分别为72％、74％通过扫描电镜观察了反渗透膜污染的状态,利用傅立叶变换红外光谱测定了膜污染物质的红外吸收光谱,指出膜污染的主要污染物是A/O-MBR出水中的溶解性微生物产物     

A/O生物脱氮工艺处理生活污水中试(二)系统性能和SND现象的研究

应用A/O中试装置处理实际生活污水,研究了低DO浓度下系统对有机物、氨氮和总氮的去除效果.研究结果表明,低DO浓度下COD和氨氮的平均去除率分别为85%和92%.由于进水C/N比仅为2.93,总氮平均去除率仅为64%,但提高亚硝酸氮积累率可以提高总氮去除率,当亚硝化率从15%增加到85%,总氮去除率将增加12%.氨氮去除率和硝化速率、总氮去除率具有较好的相关性.维持低DO浓度可以实现亚硝酸型同步硝化反硝化反应,基于氮的物料平衡可知它占系统总氮去除率的5%～12%,增加DO浓度将破坏同步硝化反硝化(SND)现象.     

溶解氧对膜生物反应器处理高氨氮废水的影响

采用膜生物反应器(MBR)处理高氨氮有机废水,探讨了溶解氧(DO)对有机物、氨氮、总氮等去除效果的影响。当进水COD1500mg/L,NH4+-N150mg/L,TP为15mg/L,pH7.5～8.0,MLSS控制在6000～7000mg/L,DO在0.5～4mg/L时对COD的去除效果没有明显影响,都可高达95%;在DO为4.0和2.0mg/L时对NH4+-N的去除率都很高,最高可达99.17%,在DO为0.5mg/L时明显降低,最低降至48.30%。在DO2.0mg/L时,取得了较好的同步硝化反硝化效果,COD、NH4+-N、TN去除率分别高达97%、97%、68%。MBR中硝化反应的比氨氮消耗速率与氨氮浓度成零级反应动力学,比氨氮硝化速率为0.0979/d,比常规处理系统中的污泥硝化活性高。     

改良UCT分段进水工艺处理生活污水性能优化研究

在某大型污水处理厂采用中试规模的改良UCT分段进水脱氮除磷工艺处理低COD/N生活污水,重点研究了流量分配比和原水营养元素比（COD/N、COD/P和TN/P）对工艺脱氮除磷性能的影响,目的是分析探索工艺对有机物和氮磷去除机制和污泥特性.连续运行试验表明,该工艺取得稳定高效的去除性能.在进水COD负荷为0.79～0.9...     

竹丝填充床对高有机负荷及低C/N水质的脱氮特性

利用竹丝填料作为生物载体而组建的接触氧化工艺对高浓度难降解水质和低C/N水质的脱氮特性进行了研究.结果表明,当进水COD为804～5100mg/L,BOD为45.0～1100mg/L,BOD/COD为0.01～0.46的情况下,TN去除率为26.6%～96.95%,出水BOD/COD为0.07～0.75;当COD为98～251mg/L,TN为28.0～105.1mg/L,COD/TN为1.6～4.6时,TN去除率为4.94%～48.8%,说明竹丝填料接触氧化工艺在高浓度难降解水质和低C/N比水质条件下具有很好的脱氮效果,但竹子囊腔内的竹汁会使系统脱氮效果波动;对反应器内的主要菌群的分布特征研究发现,在处理高浓度难降解水质过程中,进、出口处细菌浓度相当;而在处理低C/N水质过程中,细菌、硝化细菌主要分布在反应器的进口处,反硝化细菌沿程均匀分布.     

两段式沸石多级土壤渗滤系统强化脱氮试验

针对两段式沸石多级土壤渗滤系统(MSL)第2段(缺氧段)反硝化不足的问题,采取分段进水的方式,探讨处理生活污水和受污染河流时,MSL系统的强化脱氮效果.结果表明,在分段进水后,MSL系统TN平均去除率提高26%,缺氧段反硝化能力明显提高,但仍存在最终出水NO3--N平均去除率为负值的问题.进一步将进水C/N从0.8增加到2.5后,MSL系统TN去除率从53.7%上升到89.4%,说明适宜的进水C/N是决定MSL系统氮去除能力的因素之一.分段进水对MSL系统有机物和磷的去除效果无明显影响.     

Enhanced biological nutrient removal by the alliance of a heterotrophic nitrifying strain with a nitrogen removing ecosystem

Nitrogen removal from synthetic wastewater was investigated in an airlift bioreactor （ALB）, augmented with a novel heterotrophic nitrifier Pseudonocardia ammonioxydans H9^T under organic carbon to nitrogen ratios （Corg/N） ranging from 0 to 12. Effect of the inoculated strain was also determined on the settling properties and the removal of chemical oxygen demand （COD）. Two laboratory scale reactors were set up to achieve a stable nitrifying state under the same physicochemical conditions of hydraulic retention time （HRT）, temperature, pH and dissolved oxygen （DO）, and operated under the sequencing batch mode. The level of DO was kept at 0.5- 1.5 mg/L by periodic stirring and aeration. Each specific Corg/N ratio was continued for duration of 3 weeks. One of the reactors （BR2） was inoculated with P ammonioxydans H9^T periodically at the start of each Corg/N ratio. Sludge volumetric index （SVI） improved with the increasing Corg/N ratio, but no significant difference was detected between the two reactors. BR2 showed higher levels of nitrogen removal with the increasing heterotrophic conditions, and the ammonia removal reached to the level of 82%-88%, up to10% higher than that in the control reactor （BR1） at Corg/N ratios higher than 6; however, the ammonia removal level in experimental reactor was up to 8% lower than that in control reactor at Corg/N ratios lower than 2. The COD removal efficiency progressively increased with the increasing Corg/N ratios in both of the reactors. The COD removal percentage up to peak values of 88%-94% in BR2, up to 11% higher than that in BR1 at Corg/N ratio higher than 4. The peak values of ammonia and COD removal almost coincided with the highest number （18%-27% to total bacterial number） of the exogenous bacterium in the BR2, detected as colony forming units （CFU）. Furthermore, the removal of ammonia and COD in BR2 was closely related to the number of the inoculated strain with a coefficient index （R2） up to 0.82 and 0.85 for ammonia and     

智能化控制SBBR处理不同C/N城市污水脱氮除磷性能研究

采用自主研发的智能化控制系统,以智能化控制的运行方式使序批式生物膜反应器(SBBR)形成交替运行的好氧-缺氧环境,对不同C/N人工模拟城市污水进行了脱氮磷实验研究.该实验中控制反应器内水温为25℃±1℃,曝气量为150 L/h,进水COD浓度为300 mg/L、TP浓度为5 mg/L,以TN浓度为30、60、90 mg...     

碳氮比及HRT_S对交替缺氧/好氧CAST去除营养物的影响

以实际生活污水为处理对象,分别研究了碳氮比(COD/TN)为2.6、3.5及4.4时,HRTS(选择器水力停留时间)对交替缺氧/好氧(A/O)CAST工艺去除营养物性能的影响.结果表明,采用交替A/O运行方式,进水COD/TN比及HRTS的变化对COD去除性能影响不明显;而对脱氮性能影响较大.当进水COD/TN比分别为2.6和3.5时,系统氨氮去除率均维持在98%以上,TN去除率则随HRTS的增大而升高;HRTS由1.8h增至5h时,2种碳氮比下的TN去除率分别由62.9%、72.1%升至76.2%、84.6%.当进水COD/TN比为4.4时,HRTS由1.8h增至5h导致系统硝化不完全,TN去除率由86.3%降至58.2%.研究还发现,提高COD/TN比和增大HRTS均能改善系统的除磷性能.本研究中交替A/O运行方式下,进水COD/TN比为4.4(远低于一般城市生活污水的8～10),HRTS为1.8h时,CAST工艺获得较好的脱氮除磷效果,TN及磷的去除率分别为86.3%和93.8%,出水达到我国城镇污水处理厂污染物排放标准(GB18918-2002)一级A要求.     

曝气生物滤池处理性能影响因素实验研究

采用上向流曝气生物滤池处理生活污水,考察了气水比、水力负荷、有机负荷、滤料层高度等因素对曝气生物滤池处理性能的影响。结果表明,气水比为5：1时,COD和NH3-N的去除率分别为87．6％和60．1％;水力负荷在0．21—0．86m^3／（m^2·h）的条件下,COD的去除率随水力负荷的增加降幅较小,NH3-N的去除率下降明显;有机负荷在1．15～2．96kg／（m^3·d）的条件下,BAF表现出很好的抗有机负荷冲击能力。BAF对有机物的去除主要发生在滤料层0～70cm段,对NH3-N的硝化主要发生在滤料层40—100cm段。     

Nitrogen removal from wastewater and bacterial diversity in activated sludge at different COD/N ratios and dissolved oxygen concentrations

The impact of the organic carbon to nitrogen ratio (chemical oxygen demand (COD)/N) in wastewater and dissolved oxygen (DO) concentration on carbon and nitrogen removal efficiency, and total bacteria and ammonia-oxidizing bacteria (AOB) communities in activated sludge in constantly aerated sequencing batch reactors (SBRs) was determined. At DO of 0.5 and 1.5 mg O₂/L during the aeration phase, the efficiency of ammonia oxidation exceeded 90%, with nitrates as the main product. Nitrification and denitrification achieved under the same operating conditions suggested the simultaneous course of these processes. The most effective nitrogen elimination (above 50%) was obtained at the COD/N ratio of 6.8 and DO of 0.5 mg O₂/L. Total bacterial diversity was similar in all experimental series, however, for both COD/N ratios of 6.8 and 0.7, higher values were observed at DO of 0.5 mg O₂/L. The diversity and abundance of AOB were higher in the reactors with the COD/N ratio of 0.7 in comparison with the reactors with the COD/N of 6.8. For both COD/N ratios applied, the AOB population was not affected by oxygen concentration. Amplicons with sequences indicating membership of the genus Nitrosospira were the determinants of variable technological conditions.     

Enhancing nitrogen removal from low carbon to nitrogen ratio wastewater by using a novel sequencing batch biofilm reactor

Removing nitrogen from wastewater with low chemical oxygen demand/total nitrogen (COD/TN) ratio is a difficult task due to the insufficient carbon source available for denitrification. Therefore, in the present work, a novel sequencing batch biofilm reactor (NSBBR) was developed to enhance the nitrogen removal from wastewater with low COD/TN ratio. The NSBBR was divided into two units separated by a vertical clapboard. Alternate feeding and aeration was performed in the two units, which created an anoxic unit with rich substrate content and an aeration unit deficient in substrate simultaneously. Therefore, the utilization of the influent carbon source for denitrification was increased, leading to higher TN removal compared to conventional SBBR (CSBBR) operation. The results show that the CSBBR removed up to 76.8%, 44.5% and 10.4% of TN, respectively, at three tested COD/TN ratios (9.0, 4.8 and 2.5). In contrast, the TN removal of the NSBBR could reach 81.9%, 60.5% and 26.6%, respectively, at the corresponding COD/TN ratios. Therefore, better TN removal performance could be achieved in the NSBBR, especially at low COD/TN ratios (4.8 and 2.5). Furthermore, it is easy to upgrade a CSBBR into an NSBBR in practice.