短程硝化-强化生物除磷序批式反应器处理畜禽养殖废水

畜禽养殖废水有机物水质水量变化大,有机物、氨氮与磷的浓度较高,直接排放会严重危害环境。通过构建厌氧-好氧序批式反应器（SBR）处理预酸化畜禽养殖废水,分析了不同进水负荷条件下反应器对污染物的去除性能和微生物群落结构的变化规律。结果表明：SBR反应器对高负荷进水中TN、PO^3-₄—P和COD的平均去除率可分别达到64.5%、97.5%和94.5%。反应器出现NH⁺₄—N和NO₂—N亚硝酸同时积累的短程硝化现象,这可能与高进水负荷对氨氧化菌和亚硝酸盐氧化菌的活性和种群的影响有关。与乙酸盐相比,以丙酸盐作碳源时污泥的强化生物除磷活性更高。随着进水负荷的增大,聚糖菌（GAOs）的相对丰度明显升高。四联球状菌（Tetrasphaera）为反应器中始终占优势的聚磷菌（PAOs）,对反应器除磷性能有重要贡献。在高有机负荷条件下,SBR内PAOs与GAOs之间不存在明显的底物竞争关系,系统脱氮除磷性能未受影响。     

CIBR 脱氮试验研究

试验研究了CIBR在曝气3 h、搅拌2 h、静沉1 h的周期循环条件下的脱氮效果,考察了氮的时间形态转化和空间浓度分布,以及整个周期内DO和pH的变化规律.试验结果显示,反应器的CODCr、NH3-N及TN出水平均浓度分别为23.64 mg/L、4.21 mg/L和12.73 mg/L,稳定地达到了<城镇污水处理厂污染物排放标准(GB 18918-2002)的一级A标准.D0与pH的变化规律一致,均可以在一定程度上指示微生物适应阶段、COD降解阶段和硝化反应阶段,而区别仅在于pH比DO稍稍滞后.     

新疆和田地区地下水“三氮”污染特征及健康风险评价

为探明新疆和田地区地下水“三氮”污染的现状及其对当地居民健康的影响,对采集的76组地下水水样中的NH₄⁺—N、NO₂^-—N和NO₃^-—N的浓度进行检测,通过统计分析地下水“三氮”的污染特征,采用健康风险评价模型在饮水暴露途径下,进行地下水“三氮”对不同人群的非致癌风险评估。研究结果表明：和田地区地下水中NO₃^-—N的污染程度最大,超标率为2.63%,对不同人群人体产生的非致癌风险指数范围为0~8.438×10^-1（成人）和0~2.360（儿童）;其次为NH₄⁺—N,超标率为1.32%,对人体产生的非致癌风险指数范围为0~3.689×10^-2（成人）和0~1.032×10^-1（儿童）;NO₂^-—N无超标点,非致癌风险指数范围为0~8.573×10^-3（成人）和0~2.398×10^-2（儿童）。研究区地下水中NH₄⁺—N和NO₂^-—N对人体产生的非致癌风险均在可接受范围内,NO₃^-—N对人体产生的非致癌风险应引起重视,且对儿童的影响大于成人。本次研究可为当地地下水污染风险防控提供理论依据。     

高氨氮废水低溶解氧条件下亚硝化试验研究

在进水氨氮浓度为 85 6mg/L ,低溶解氧浓度下迅速启动并运行了亚硝化反应器 ,考察了反应器中氨氮的氧化和亚硝酸氮的积累情况。试验结果表明 :在其他工况不变的条件下长期运行 ,DO浓度对氨的氧化和亚硝酸积累具有显著影响。当DO在 0 2mg/L以上时 ,亚硝酸氮能够在反应器中完全稳定地积累 ;当DO小于 0 2mg/L时 ,氨氮的氧化作用显著下降 ;当DO增加到 1 5mg/L以上时 ,氨氮的氧化作用明显改善 ,反应器具有很好的抗DO变化的能力。反应器在高氨氮浓度和低DO条件下长期运行 ,可以完全抑制亚硝酸氧化菌 ,反应器中已经培养出较纯的氨氧化细菌     

溶解氧对同步硝化反硝化脱氮影响研究

以实际生活污水为处理对象,利用生物膜内所具有的A/O环境,针对DO浓度对生物膜法同步脱氮效果影响进行试验研究.研究结果表明,在DO为2.5 mg/L时SND脱氮效果达最佳,TN去除率近70%;DO浓度过高或过低都不利于生物膜内部DO浓度梯度的形成,合理控制DO浓度,对生物膜法同步脱氮尤为重要.     

复合型CAST工艺处理低碳源污水的影响因素研究

研发了一种新型复合式CAST系统,可用于低碳源市政污水的脱氮除磷。分别考察了运行周期、污泥回流比和DO浓度对该系统处理有机物、氮、磷效能的影响。中试结果表明,提高污泥回流比能够有效提高该工艺的脱氮除磷能力,而曝气时间过长将会提高系统出水悬浮物浓度,当该系统中DO浓度低于2mg/L时会降低有机物去除、生物硝化和生物除磷的效率,而系统中DO浓度高于3mg/L会抑制生物反硝化过程。复合型CAST系统处理低碳源市政污水的最佳运行工况为:进水1h、曝气1.5h、沉淀1h、滗水0.5h,污泥回流比20%,DO浓度为2~3mg/L。     

碎麦秸垫膜覆盖对民勤绿洲食葵产量及土壤酶活性的影响

为解决民勤绿洲灌区水资源短缺、土壤耕层状况恶化、食葵产量不佳等问题,在民勤灌区设置无覆盖（CK）、秸秆覆盖（S）（秸秆量为4 500 kg/hm²）、地膜覆盖（F）、碎麦秸垫膜覆盖（SF₁）（秸秆量为4 000 kg/hm²）、碎麦秸垫膜覆盖（SF₂）（秸秆量为4 500 kg/hm²）5个处理,采用当地农户普遍的灌溉水平（750 m³/hm²）,研究了食葵生长状况及土壤酶活性的变化。结果表明：碎麦秸垫膜覆盖（SF₁）处理下土壤温度显著高于其他处理,并且有着更高的保水效果,保证了食葵的正常生长发育;碎麦秸垫膜覆盖（SF₁）条件下平均出苗率较CK处理提高了12.1%（P<0.05）,较S处理的出苗率提高了9.7%（P<0.05）;碎麦秸垫膜覆盖（SF₁）条件下食葵产量达到4 780.95 kg/hm²,较SF₂、F、S、CK处理分别提高了2.8%（P>0.05）、7.3%（P>0.05）、34.1%（P<0.05）、44.7%（P<0.05）,且在碎麦秸垫膜覆盖（SF₁）处理下食葵的株高、茎粗、叶面积均为最优,与CK、S、F处理均呈显著性差异(P<0.05）,该覆盖方式更有利于食葵干物质的积累;碎麦秸垫膜覆盖（SF₁）条件下的土壤蔗糖酶和脲酶活性显著高于CK、S、F、SF₂处理,且全生育期表现基本一致。可见,碎麦秸垫膜覆盖可解决民勤绿洲秸秆覆盖引起的土壤温度低、保水率差、出苗率低和产量低等问题,也可改善长期单一地膜覆盖而引起的地力下降的情况。     

溶解氧对A~2/O工艺脱氮除磷效果的影响及解决方法

溶解氧对微生物生长的影响很大,通过溶解氧对硝化、反硝化、除磷的影响试验,详细论述了溶解氧对A2/O工艺脱氮除磷的效果影响.试验结果表明,在保证足够好氧泥龄的前提下,提高曝气池的溶解氧,可以改善硝化效果.在好氧段末端设置20～30 min的非曝气区,可以使内回流中的DO降低2～3 mg/L,当内回流比为400%时可节约碳源28～41 mg/L.曝气段中过度曝气会造成生物除磷能力下降.因此,必须通过自动控制维持好氧段的溶解氧在合理水平,并通过设立非曝气区和预缺氧区,消除内外回流中溶解氧过高造成的缺氧区和厌氧区氧化还原电位的提高,从而保证进水中碳源有效用于脱氮除磷.     

灌溉方式及施肥量对食用玫瑰生长、生理和产量的影响

为探究食用玫瑰（Rosa rugosa Thunb.）生长、生理和产量对灌溉方式与施肥量的响应特征,以两年生“墨红”食用玫瑰作为试验材料,设灌溉方式（微喷灌W;滴灌D）和施肥量（F0、F1、F2、F3分别为0、60、135、225 kg/hm²）2因素完全组合试验方案进行研究。结果表明：灌溉方式与施肥量对“墨红”食用玫瑰株高、茎粗有显著影响（P<0.05）,WF3处理有利于“墨红”食用玫瑰株高的增长,DF3处理有利于其茎粗的生长。各生育期,灌溉方式与施肥量均对食用玫瑰净光合速率有显著影响（P<0.05）,其中食用玫瑰净光合速率和蒸腾速率在现蕾期达到峰值,DF2处理的净光合速率最高（17.93 μmol/(m²·s)),DF3处理的蒸腾速率最高（6.10 mmol/(m²·s)）。灌溉方式与施肥量的交互效应对“墨红”食用玫瑰叶片类胡萝卜素含量和叶绿素含量影响显著（P＜0.05）,DF2处理下叶绿素和DF1处理下类胡萝卜素含量水平较高,分别为1.83和0.30 mg/g。滴灌方式下食用玫瑰总产量高于微喷灌方式,且随施肥量的增加总产量呈现先增后减的趋势,DF2处理的总产量最高（11 036 kg/hm²）。综合比较表明,DF2为避雨设施大棚条件下“墨红”食用玫瑰适宜的灌溉方式和施肥量组合。     

垃圾渗滤液曝气生物处理中好氧氧反硝化现象探讨

通过试验,对垃圾渗滤液间歇曝气(曝气时D0为5.5～7 mg/L;停止时DO为1.1～5.5 mg/L),在仅有有机碳、无机氮的条件下进行好氧反硝化脱氮研究.试验结果表明:间歇曝气条件下,渗滤液中存在的好氧反硝化土著微生物茵落会成为优势菌种,在溶解氧充足的条件下,能够发生好氧反硝化反应,使得硝化和反硝化可以真正同步进行;外加碳源不仅是厌氧反硝化所必须的,同样也是好氧反硝化的必要条件;好氧反硝化的最佳曝气方式为间歇曝气.     

Achieving and maintaining of short-cut nitrification in a cyclic activated sludge system

A lab-scale Cyclic Activated Sludge Technology (CAST) system was operated more than 5 months to evaluate the effects of the operation mode on nitrogen removal performance and investigate a feasible method for achieving short-cut nitrification in the system. Results showed that nitrogen was removed by conventional biological nitrification and denitrification in traditional operation mode (fill/aeration 2 h, settle 1 h, decant 1 h), whereas short-cut nitrification and denitrification was the main nitrogen removal pathway in modified operation mode and the nitrogen removal performance was enhanced. Short-cut nitrification was successfully achieved in CAST system at 17 ± 1 °C by adjusting operation conditions and the average total nitrogen removal efficiency increased by 11.4% compared to traditional mode. It was assumed that low dissolved oxygen (<1.0 mg/L) limitation combined with free ammonia (0.28-0.34 mg/L) inhibition on nitrite-oxidizing bacteria caused nitrite accumulation in modified mode. During maintaining period of short-cut nitrification, preset aeration time enhanced ammonium-oxidizing bacteria dominance. It was also found that low DO could result in overgrowth of filamentous microorganisms and poor sludge settleability. The pH variation could provide effective information for controlling aeration duration in modified mode. However, no evident breakpoint appeared on pH and DO profiles in traditional mode.     

Influence of extracellular polymeric substances on nitrogen removal in an intermittently-aerated membrane bioreactor.

Influence of EPS on fouling of intermittent aeration MBR reactor (denitrification MBR) was investigated changing intermittent aeration cycle (10 minute-cycle and 120 minute-cycle) in laboratory-scale reactors using synthetic wastewater. EPS were extracted from bacterial cells using cation resin method and molecular weight fractioning of EPS was conducted using gel chromatography. In both of the reactors, nitrogen removal rate was almost 100% after 50th day although DO concentration was not very high during the aerated phase because of accumulation of nitrifying bacteria in the reactors. In the 120 minutes-cycle reactor, trans-membrane pressure increased more rapidly than in the 10 minutes-cycle reactor. The reason might be that EPS of more than 1000 kDa, which are the main fouling substances, are produced more rapidly in the 120 minute-cycle condition. It was also found that three peaks at around 100 kDa, 500 kDa and 2000 kDa are prominent in EPS in intermittent-aeration MBR irrespective of cycle and higher molecular weight EPS are decomposed to smaller molecular weight EPS on membrane surface.     

Granulation of Anammox microorganisms in up-flow reactors.

Experimental studies were performed to evaluate the feasibility of granulation of Anammox microorganisms for biomass retention in up-flow reactors. Two experimental studies, one using a 6.4-L lab-scale reactor with synthetic medium and the other using a 200-L pilot-scale reactor with half-nitrified reject water from a sludge digester were conducted. To enhance the granulation process, seed granules from a UASB reactor were added to both experimental reactors. Granulation of Anammox microorganisms was observed using both the synthetic medium and the reject water. The core of a large proportion of Anammox granules retained part of the original seed biomass. The Anammox granules had a slightly lower density than the seed granules from the UASB process, but the size and other physical properties were comparable. The successful granulation of the Anammox microorganisms led to a stable nitrogen removal performance. The maximum nitrogen removal rate of the lab-scale reactor was observed to be 2.9 kg/(m3 x d) after 173 days of operation and that of the pilot-scale reactor was 6.4 kg/(m3 x d) after 12 months of operation.     

污染河道水质强化脱氮生化工艺研究

应用生化工艺对河道污染水体进行修复是目前最经济的一条途径,但其面临的一个突出问题是在生物脱氮过程中可利用碳源不足,从而影响其处理效果。本研究采用分段进水生物接触氧化工艺来强化受污染水脱氮性能,与传统单点进水方式相比,两段进水对有机物和总氮去除率有显著提升,CODMn平均去除率从50.6%提升到66.3%;总氮平均去除率从31.4%提升到60.9%。沿程统计硝化细菌和反硝化细菌数量,硝化细菌主要集中在曝气区,数量为5.58×106,反硝化细菌主要集中在非曝气区的中后段,数量为6.49×105。同时检测沿程溶解氧和各氮素浓度,溶解氧浓度沿程降低,最后出水仅为0.2 mg/L;氨氮在曝气区转化为硝态氮,在非曝气区硝态氮还原成氮气,其结果进一步证实了硝化细菌和反硝化细菌的分布特征。     

Dissolved oxygen as a factor influencing nitrogen removal rates in a one-stage system with partial nitritation and Anammox process

A biofilm system with Kaldnes biofilm carrier was used in these studies to cultivate bacteria responsible for both partial nitritation and Anammox processes. Due to co-existence of oxygen and oxygen-free zones within the biofilm depth, both processes can occur in a single reactor. Oxygen that inhibits the Anammox process is consumed in the outer layer of the biofilm and in this way Anammox bacteria are protected from oxygen. The impact of oxygen concentration on nitrogen removal rates was investigated in the pilot plant (2.1 m3), supplied with reject water from the Himmerfj?rden Waste Water Treatment Plant. The results of batch tests showed that the highest nitrogen removal rates were obtained for a dissolved oxygen (DO) concentration around 3 g O2 m(-3) At a DO concentration of 4 g O2 m(-3), an increase of nitrite and nitrate nitrogen concentrations in the batch reactor were observed. The average nitrogen removal rate in the pilot plant during a whole operating period oscillated around 1.3 g N m(-2)d(-1) (0.3 +/- 0.1 kg N m(-3)d(-1)) at the average dissolved oxygen concentration of 2.3 g O2 m(-3). The maximum value of a nitrogen removal rate amounted to 1.9 g N m(-2)d(-1) (0.47 kg N m(-3)d(-1)) and was observed for a DO concentration equal to 2.5 g O2 m(-3). It was observed that increase of biofilm thickness during the operational period, had no influence on nitrogen removal rates in the pilot plant.     

Feasibility of controlling nitrification in predenitrification plants using DO, pH and ORP sensors.

Experimental studies were carried out on a bench-scale nitrogen removal system with a predenitrification configuration to gain insights into the spatial and temporal variations of DO, pH and ORP in such systems. It is demonstrated that these signals correlate strongly with the operational states of the system, and could therefore be used as system performance indicators. The DO concentration in the first aerobic zone, when receiving constant aeration, and the net pH change between the last and first aerobic zones display strong correlations with the influent ammonia concentration for the domestic wastewater used in this study. The pH profile along the aerobic zones gives good indication on the extent of nitrification. The experimental results also showed a good correlation between ORP values in the last aerobic zone and effluent ammonia and nitrate concentrations, provided that DO in this zone is controlled at a constant level. These results suggest that the DO, pH and ORP sensors could potentially be used as alternatives to the on-line nutrient sensors for the control of continuous systems. An idea of using a fuzzy inference system to make an integrated use of these signals for on-line aeration control is presented and demonstrated on the bench-scale system with promising results. The use of these sensors has to date only been demonstrated in intermittent systems, such as sequencing batch reactor systems.     

多种修复技术对城市内河水质及微生物群落的影响

采集城市内河水样,分别采用曝气增氧、碳源添加、生物投菌和综合修复等技术,在实验室进行水质修复模拟实验,并以水质参数、微生物多样性及丰度为鉴定指标,分析不同修复技术对城市河流水质的修复效果及其对河流微生物群落结构的影响。结果表明,曝气、生物投菌和综合修复技术可以提高河流微生物群落结构多样性,水体微生物群落以变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria)和疣微菌门(Verrucomicrobia)为主;而使用碳源添加技术的水样,河流微生物的多样性下降明显,变形菌门(Proteobacteria)的相对丰度达到了93%;水质修复方面,曝气增氧技术和生物投菌技术都仅能降低水体COD质量浓度,无法降低水体TN及NH+4-N质量浓度;碳源添加和综合修复技术,对水体TN和NH+4-N的去除效果明显,但投加碳源的河流水体中的COD质量浓度显著上升;相关性分析结果表明,影响水体微生物群落结构的主要环境因子为COD和DO。     

Nitrogen removal and sludge reduction in a symbiotic activated sludge system between anaerobic archaea and bacteria.

The possible symbiosis between bacteria and anaerobic archaea was investigated in intermittent aeration (I/A) systems. Archaea solution added to I/A reactor might play an important role in biological activities as well as in improvement of mineralization of organic matter. I/A reactor with archaea solution (I/A-arch) could increase both nitrification and denitrification rate and also reduce the sludge yield remarkably. These results indicate the possibility of the symbiotic activated sludge system with anaerobic archaea by controlling the DO level in the aeration tank. In this study, DO was controlled by intermittent aeration schemes and a successful symbiotic activated sludge system was achieved to reach the following conclusions. 1) SOUR of I/A-arch system was 2.9 mg-O2/g-VSS x min. SOUR and nitrification rate of the sludge from I/A-arch was higher than those from the I/A and A/S reactors. 2) Removal efficiencies of organic matter (TCOD(Cr)) in I/A-arch, I/A and conventional activated sludge (A/S) reactors were 93, 90 and 87%, respectively. 3) Nitrification occurred successfully in each reactor, while denitrification rate was much higher in the I/A-arch reactor. Efficiencies of TN removal in A/I-arch, I/A and A/S reactors were 75, 63 and 33%, respectively. 4) Observed yield coefficients of I/A-arch, I/A and A/S reactors were 0.28, 0.41 and 0.37 g-VSS/g-COD.     

Conditions and technologies of biological wastewater treatment in Hungary

A survey has been carried out involving 55 Hungarian wastewater treatment plants in order to evaluate the wastewater quality, the applied technologies and the resultant problems. Characteristically the treatment temperature is very wide-ranging from less than 10 °C to higher than 26 °C. Influent quality proved to be very variable regarding both the organic matter (typical COD concentration range 600-1,200 mg l(-1)) and the nitrogen content (typical NH(4)-N concentration range 40-80 mg l(-1)). As a consequence, significant differences have been found in the carbon availability for denitrification from site to site. Forty two percent of the influents proved to lack an appropriate carbon source. As a consequence of carbon deficiency as well as technologies designed and/or operated with non-efficient denitrification, rising sludge in the secondary clarifiers typically occurs especially in summer. In case studies, application of intermittent aeration, low DO reactors, biofilters and anammox processes have been evaluated, as different biological nitrogen removal technologies. With low carbon source availability, favoring denitrification over enhanced biological phosphorus removal has led to an improved nitrogen removal.     

Evaluation of a hybrid vertical membrane bioreactor (HVMBR) for wastewater treatment

A new hybrid membrane bioreactor (HMBR) has been developed to obtain a compact module, with a small footprint and low requirement for aeration. The aim of this research was to assess its performance. The system consists of a single vertical reactor with a filtration membrane unit and, above this, a sponge fixed bed as support medium. The aeration system is located under the membrane unit, allowing for membrane cleaning, oxygenation, biofilm thickness control and bulk liquid mixing. Operated under continuous aeration, a bench-scale reactor (70 L) was fed with pre-treated, raw (unsettled) municipal wastewater. BOD(5) and suspended solids removal efficiencies (96 and 99% respectively) were comparable to those obtained with other membrane bioreactors (MBRs). Total nitrogen removal efficiencies of 80% were achieved, which is better than those obtained in other HMBRs and similar to the values reached using more complex MBRs with extra anoxic tanks, intermittent aeration or internal deflectors.