不同污泥源条件下ANAMMOX启动及其与反硝化协同脱氮对比

采用城市生活污水配水同时启动两组ASBR,R1接种好氧硝化污泥,R2按2∶1混合接种短程硝化和厌氧氨氧化污泥,研究2个ANAMMOX反应器启动的可行性及其差异。实验结果表明,R1和R2均可成功启动ANAMMOX,R1需130 d,R2仅需73 d;稳定期R1和R2反应器NH4+-N、NO2--N和TN去除率分别达95.30%、91.30%、76.28%和96.2%、98.3%、90.1%,且周期内NH4+-N、NO2--N和NO3--N降解规律相似;R1和R2反应器发生的主要反应为厌氧氨氧化,但同时存在反硝化作用;2组反应器稳定运行后污泥颜色、形态及微生物组成相似,经SEM观察多为球状菌。     

两级ANAMMOX串联快速启动后置反应器的性能及机理

外源添加酰基高丝氨酸内酯类信号分子(AHLs)可以提高厌氧氨氧化菌(AAOB)的活性,有助于厌氧氨氧化(ANAMMOX)的快速启动,然而,AHLs的获取会增加操作成本。基于此,本研究构建了两级ANAMMOX串联反应器,以充分利用一级反应器(R1)出水有效成分实现后置反应器(R2)的快速启动。以R1的出水为进水,并逐渐过渡到以R1出水上清液和合成废水为进水的策略运行R2;通过脱氮性能、污泥特性和微生物群落变化来验证该策略的可行性,并进行了相关的机理分析。结果表明,R2在第56天实现了快速启动,运行90 d后,在总氮容积负荷为0.6～0.7 kg·(m³·d)^-1时,总氮去除率达到93%以上,显著高于直接以合成污水启动的对照组(R3,61%)。这可归因于R1流失污泥为R2提供了稳定的生物量补充,并且其上清液包含的群体感应信号分子促进了R2中AAOB的活性提高。高通量测序结果表明,R1出水引入的有机物导致R2群落多样性升高,反硝化菌等异养菌相对丰度增加,ANAMMOX功能菌Candidatus Brocadia占比下降,然而,与R1相比,R2物质运输和代谢相关功能基因表达水平上调。以上结果说明,通过两级ANAMMOX串联实现后置反应器的快速启动是可行的。     

MnO_2对海底沉积物ANAMMOX菌的富集培养影响

采用上流式固定床反应器,在常温下连续运行,考察MnO2对海洋性ANAMMOX菌富集培养的影响,其中接种的海洋海底沉积物采自大连市附近海域。结果表明,在反应器运行近150 d中,加入MnO2的R1反应器的最大总氮去除速率为137.82 g N/(m3·d),比没有加入MnO2的R2反应器高出近20 g N/(m3·d)。在低温环境(10~15℃)运行时,R1反应器的氨氮和亚硝氮去除率比R2反应器均高出10%,且R1反应器对温度变化的适应性和运行稳定性都好于R2反应器。这表明MnO2的加入确实在一定程度上促进了海洋性ANAMMOX细菌的富集,并增强了ANAMMOX反应器对温度变化的适应性,使其能够在较宽的温度范围下运行。     

MnO2对海底沉积物ANAMMOX菌的富集培养影响

采用上流式固定床反应器,在常温下连续运行,考察MnO2对海洋性ANAMMOX菌富集培养的影响,其中接种的海洋海底沉积物采自大连市附近海域。结果表明,在反应器运行近150d中,加入MnO2的R1反应器的最大总氮去除速率为137．82gN／（m3·d）,比没有加人MnO2的R2反应器高出近20gN／（m3·d）。在低温环境（10～15℃）运行时,R1反应器的氨氮和亚硝氮去除率比R2反应器均高出10％,且Rl反应器对温度变化的适应性和运行稳定性都好于R2反应器。这表明MnO2的加入确实在一定程度上促进了海洋性ANAMMOX细菌的富集,并增强了ANAMMOX反应器对温度变化的适应性,使其能够在较宽的温度范围下运行。     

升流式生物膜反应器中CANON工艺处理中低浓度氨氮废水的快速启动

为了实现中低浓度氨氮废水情况下CANON工艺的快速启动和稳定运行,在升流式生物膜反应器中,通过调控水力停留时间、溶解氧和回流比,研究进水氨氮浓度为200 mg·L⁻¹时CANON工艺的快速启动过程。结果表明：1~17 d,污泥处于驯化阶段,HRT为12 h,DO控制在0.1~0.2 mg·L⁻¹,50%的回流比满足污泥上升流态;18~60 d,HRT逐步缩短至8 h,DO控制在0.3~0.5 mg·L⁻¹,回流比增大至150%,AOB和 ANAMMOX在该阶段成功富集,填料上初步形成生物膜;61 d时,HRT缩短至6 h,加大回流比至200%,溶解氧控制在0.3~1.0 mg·L⁻¹,系统启动加速,此时,进水氨氮负荷增加至0.795 kg·(m³·d)⁻¹;运行至第93天,氨氮和总氮平均去除率分别达到95%和82%,ANAMMOX完成挂膜,CANON工艺成功启动。高通量测序结果显示,在整个启动过程中,优势菌群AOB和ANAMMOX的丰度呈增长趋势,启动完成时,生物膜中AOB占比19.46%,ANAMMOX占比22.49%,分别属于Brocadiaceae和Nitrosmonadaceae。CANON系统集成絮体、颗粒和填料挂膜3种污泥形态为一体,实现了在中低浓度氨氮废水中的高效稳定运行。     

浅谈ANAMMOX反应的启动研究

厌氧氨氧化（ANAMMOX）是一种新型的生物脱氮技术,在废水处理方面具有良好的应用前景。但由于厌氧氨氧化细菌生长缓慢,倍增时间长达11d,因此,厌氧氨氧化反应器的启动成为众多学者的研究对象。文中概述了近年来的学者们在研究厌氧氨氧化启动时,以选择不同反应器、接种不同污泥和采用不同方法,富集培养的过程及经验。同时通过分析启动过程中各种氮的变化情况,来进一步理解启动过程。     

局部包埋ANAMMOX活性填料启动生物滤池

以厌氧氨氧化细菌(AAOB)混培物、聚乙烯醇(PVA)、碳酸钙和粒径2~4 mm的颗粒活性炭作为主要包埋材料,制备出局部包埋ANAMMOX活性填料。研究了该填料在生物滤池启动过程中的运行效果。实验结果表明,局部包埋固定化技术可使生物滤池在较高的水力负荷和高反冲洗强度条件下仍保持稳定的AAOB生物量,滤池中AAOB的比生长速率为0.0027 h-1,经过包埋固定后AAOB的增殖过程不会受到不利的影响且活性恢复较快。滤池内存在反硝化与ANAMMOX耦合的现象。通过监测进出水的pH值变化可快速判断ANAMMOX工艺脱氮负荷的变化情况。用Logistic模型模拟局部包埋ANAMMOX生物滤池细菌增殖规律相关性极强,相关系数R值达0.983。局部包埋固定化技术可以有效地固定AAOB,有助于解决AAOB在大规模工程应用中发生的细菌流失等问题,具有一定的应用前景。     

IC反应器厌氧氨氧化启动与运行特性研究

采用一套有效容积为20 L的IC反应器,接种啤酒废水厌氧处理池污泥,保持反应器进水NH+4-N浓度为120 mg/L,NO-2-N浓度为150 mg/L,在温度为30±1 ℃的条件下,对ANAMMOX反应过程的启动和运行特性进行了研究.结果表明反应器的启动经历了污泥低负荷驯化期、负荷提高期和高负荷运行期3个阶段;在反应器运行到第130 d,反应器启动成功;NH+4-N和NO-2-N的去除率分别约82.1%和94.5%;去除的NH+4-N和NO-2-N及生成的NO-3-N三者之间的比值为11.160.3;在反应器中形成了粒径为1～2 mm的颗粒污泥.     

水力停留时间对反应沉淀一体化反应器中半亚硝化反应的影响

由于反应沉淀一体化反应器的HRT与SRT不同,因此HRT是否会影响反应器中氮的存在状态,亚硝态氮积累是否能实现尚无明确结论。针对以上问题,研究不同水力停留时间对反应沉淀一体化反应器中半亚硝化反应的影响,研究结果表明：反应器运行虽然运行过程中无污泥流失,但仍可实现亚硝酸盐的积累,出水亚硝态氮和氨氮的浓度比例受水力停留时间的影响。HRT为24h时,亚硝酸盐积累率可达到70％,但出水氨氮接近于0,很难满足ANAMMOX的进水要求;HRT为16h和12h时,亚硝酸盐积累率均可超过80％,出水氨氮和亚硝态氮的比例分别达到1．39：1和1．46：1,可为后续ANAMMOX反应提供良好进水条件。水力停留时间对污泥亚硝化潜力的影响为12h〉16h〉24h,对硝化潜力的影响为24h〉16h〉12h。不同水力停留时间下氨氧化速率和亚硝酸盐氧化速率均为24h〉16h〉12h。     

水力停留时间对反应沉淀一体化反应器中半亚硝化反应的影响

由于反应沉淀一体化反应器的HRT与SRT不同,因此HRT是否会影响反应器中氮的存在状态,亚硝态氮积累是否能实现尚无明确结论。针对以上问题,研究不同水力停留时间对反应沉淀一体化反应器中半亚硝化反应的影响,研究结果表明：反应器运行虽然运行过程中无污泥流失,但仍可实现亚硝酸盐的积累,出水亚硝态氮和氨氮的浓度比例受水力停留时间的影响。HRT为24 h时,亚硝酸盐积累率可达到70%,但出水氨氮接近于0,很难满足ANAMMOX 的进水要求;HRT为16 h和12 h时,亚硝酸盐积累率均可超过80%,出水氨氮和亚硝态氮的比例分别达到1.39：1和1.46：1,可为后续ANAMMOX反应提供良好进水条件。水力停留时间对污泥亚硝化潜力的影响为12 h>16 h>24 h,对硝化潜力的影响为24 h>16 h>12 h。不同水力停留时间下氨氧化速率和亚硝酸盐氧化速率均为24 h>16 h>12 h。     

Optimization of Height of Release of Air Pollutants

A number of key projects in the Environmental Protection Agency (EPA) particulate R&;D program having applicability to industry are presented. For electrostatic precipitators (ESP) there is presented the result of work on large diameter discharge electrodes which provide a decrease in penetration of up to a factor of 4 when compared to conventional small diameter electrodes. Also discussed is the multistage ESP which provides a collection efficiency that would require a collecting plate area 4 or 5 times larger with conventional ESP technology. The E-SOX technology makes use of the multistage concept to free up space in the ESP for SO₂ removals of up to 90%. Electrostatically augmented fabric filtration provides a reduction in pressure drop of about 5 0% as compared to conventional fabric filtration. Wind tunnel modeling of windbreaks for material storage piles indicates a potential for providing engineering design data that would allow significant emission reduction caused by wind erosion     

Investigation of the characteristics of the reflectivity of clouds

This paper investigates some of the reflectivity characteristics that clouds (when modelled as solid bodies) must exhibit to be compatible with observations that the reflecting surface of a cloud (i) appears almost equally bright across its face, (ii) is brightest when the cloud is opposite to the Sun but decreases in brightness as the cloud moves to other positions and (iii) increases in brightness with increasing optical thickness of the cloud in the observer's line of sight. These observations, respectively, are shown to imply that the peak value of the bidirectional total reflectivity from a cloud surface (i) increases in inverse proportion to the cosine of the angle between the Sun and the normal to the cloud surface, as the incident angle increases, (ii) appears to be directed back in the direction of the incident radiation, and (iii) increases as optical thickness of the cloud in the observer's line of sight increases. The results could have application in many fields (e.g. modelling diffuse radiance distributions for cloudy skies).     

实验室质量管理体系内部审核的实施

在实施ISO／IEC17025：1999标准《检测和校准实验室能力的通用要求》过程中，通过实验室质量管理体系内部审核的实践与系统分析，识别出内部审核实施阶段的关键环节，提出召开首次会议、收集审核证据、确定审核发现和召开末次会议的技术方法，对提高内部审核的质量和有效性、获得可靠的审核结论具有重要意义。     

Estimation of uncertainty of sampling for analysis of pesticide residues

Abstract

A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits.     

扬中生态环境建设的思考与实践

结合扬中生态环境的基本情况和存在的不足，进行了具体分析，对扬中未来生态建设的发展方向提出了建议及实施措施。     

An application of the theory of kinematics of mixing to the study of tropospheric dispersion

The most common technique used for numerical simulations of tracer mixing is that of the numerical solution of the advection–diffusion equation with the unresolved fluxes parameterized using the similarity theory. Despite correct predictions of the overall directions of transport, models based on a numerical solution of the advection–diffusion equation lack sufficient accuracy to correctly reproduce the coupling of mixing with small scale processes which are sensitive to the microstructure of the tracer distribution. The objective of this paper is to revisit the basic formalism employed in numerical models used to investigate atmospheric tracers. The main mathematical method proposed here is the theory of kinematics of mixing which could be applied effectively for simulations of atmospheric transport processes. At the beginning of the paper, we introduce simple mathematical transformations in order to demonstrate how complex topological structures are created by mixing processes. These idealistic flow systems are essential to explain transport properties of much more complex three-dimensional geophysical flows. An example of the application of the kinematics of mixing to the analysis of tracer transport on a planetary scale is presented in the following sections. The complex filamentary structures simulated in the numerical experiment are evaluated using some commonly applied statistical measures in order to compare the results with the data published in the literature. The results of the experiment are also analysed with the help of simple conceptual models of fluid filaments. The microstructure of the tracer distribution introduced in the paper is essential to increase our understanding of atmospheric transport and to develop more realistic parameterizations of small-scale mixing. The presented results could also be used to improve calculations of the coupling between microphysical processes and tracer mixing.     

次氯酸钠发生器的研制

介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠     

Comparison of methods for evaluation of activity of photocatalytic films

Objective

This work aims to investigate the correlation between the photocatalytic activity determined by methylene blue bleaching (DIN 52980), stearic acid degradation, and degradation of acetone in gas phase.

Method

The photocatalytic TiO₂ coatings included in this investigation ranged from thin commercially available coatings (Activ^TM and BioClean^TM) and ready to use suspensions (Nano-X PK1245) to lab-produced PVD and sol?Cgel coatings. XRD analysis of the photocatalytic coatings showed that all the coatings consisted of nanocrystalline anatase, although the thickness and porosity varied considerably.

Results

The study showed that the reproducibility of the activity measurements was good. However, more importantly, the investigation showed that there is a good correlation between the activities determined by the different methods even though the characteristics of the photocatalytic coatings and the organic probe molecules varied considerably.

Conclusion

The overall findings of this work suggest that there is a good correlation between the investigated methods. These results are promising for the future work concerning standardization of methods for determination of the activity of photocatalytic films.     

Impact of overexploitation of shellfish: northeastern coast of India

India has a very extensive coastline of about 7515 km, rich in diverse living resources. These resources continue to deteriorate with rampant harvesting or are altered for other uses such as aquaculture and fisheries. The present paper deals with degrading coastal habitats in northeastern India, and projects the intensity of the stress arising from the collection of tiger prawn seeds (Penaeus monodon) for aquacultural farms and molluskan shells for poultry feed and edible lime. Indiscriminate exploitation of these resources leads to a heavy reduction of the species concerned and other associated marine communities. The magnitude of such destruction has been quantified. The impacts of biodiversity loss and their after-effects on the ecobalance of this coastal system have become a matter of great concern to ecologists to maintain security and sustainability. The authors propose a public awareness program on themes relating to the importance of biodiversity for human livelihoods.