膨胀颗粒污泥床厌氧反应器原废水循环启动的实验研究

在室温条件下,以水葫芦汁液为废水来源,对自行设计的膨胀颗粒污泥床(EGSB)厌氧反应器进行原废水循环启动实验。结果表明:在启动运行65d后,进水有机负荷可以达到7kg/(m~3·d)左右,COD去除率达到90%以上,容积产气率达到1.35m~3/(m~3·d),甲烷体积分数达到61%,颗粒污泥粒径达到2~4mm。因此,EGSB厌氧反应器的原废水循环启动方式是可行的,对水葫芦汁液的降解是高效的,为EGSB厌氧反应器的工程应用提供一种新的启动方式,也为水葫芦汁液的能源化利用提供了一套高效、节能的厌氧发酵装置。     

低COD浓度废水启动EGSB反应器

以厌氧活性污泥和好氧活性污泥接种于2个膨胀颗粒污泥床(EGSB)反应器中,进水流量为10 mL/min,回流量为180 mL/min,进水COD浓度在180 mg/L左右,有机负荷率(OLR)为1.728 kg COD/m3·d左右,污泥负荷率(SLR)为0.19 kg COD/kg MLSS·d左右,出水COD浓度维持在40mg/L左右,COD去除率达80%以上.控制温度在32～35 ℃,pH在6.8～7.2,反应器内氧化还原电位在-340 mV以下,水力停留时间(HRT)4.2 h,上升流速4.86 m/h以及加入80 mg/L絮凝剂(硫酸铝钾),缩短了启动时间,促进了颗粒污泥的形成.分别经过60 d和120 d运行,反应器启动成功.结果表明,上升流速、絮凝剂和污泥类型对颗粒污泥的形成有影响;接种好氧活性污泥在低浓度COD下,合理控制负荷速率能成功启动EGSB反应器.     

有机负荷及水力条件对EGSB运行效果影响的研究

在以葡萄糖为基质长期运行的EGSB反应器中 ,研究了以循环为特征EGSB基质降解特性。结果表明 ,在厌氧膨胀颗粒污泥床反应器 (EGSB)启动初期 ,由上流式厌氧污泥床反应器 (UASB)接种的颗粒污泥存在一个转型过渡期 ,此时污泥对基质代谢有较大的恢复潜力。有机负荷为 4～ 2 9kgCOD /m3 ·d时 ,处理效果较为稳定 ,2 9～ 4 0kgCOD /m3 ·d时 ,处理效率有所下降。当负荷 >4 0kgCOD /m3 ·d后 ,反应器处理效果急剧下降。上升流速和回流比对EGSB反应器运行效果影响较大 ,高上升流速和回流比运行条件下有利于发挥反应器的运行潜能     

厌氧折流板反应器处理低浓度废水的运行特性研究

接种厌氧絮状污泥,采用厌氧折流板反应器在中温下进行了处理低浓度废水的试验研究.结果表明,厌氧折流板反应器有效去除了废水中的有机物,平均去除率稳定在80%以上;启动迅速,在35 d内完成,启动性能较EGSB优;水力负荷起着重要的作用;在提高负荷阶段的初期,反应器COD去除率有较大波动,随着负荷的加大,这一现象逐渐消失;在容积负荷小于2.15 kg COD/m3·d时,进水容积负荷与基质去除负荷率之间具有明显的线性正比关系;反应器的前面隔室对有机物的去除起到主要作用;在长期运行的处理低浓度废水的ABR反应器中存在产酸相和产甲烷相的自然分离现象.     

EGSB反应器处理米酒废水的启动方法研究

米酒厂废水由洗米、制曲用大豆蒸煮和酒蒸馏 3道工序中所排出的废水组成 ,是一种典型的高浓度有机废水。在采用EGSB反应器对其进行处理时 ,以处理啤酒废水的 UASB反应器中的颗粒污泥作为接种污泥可以实现快速启动。启动过程中 ,容积负荷的提高幅度以每次 2～ 3 kg COD/( m3· d)为宜 ,同时要保持出水的 p H维持在 8以上 ;为了防止酸化 ,应当适当地在进水中投加碱剂。采用 EGSB反应器在中温条件下处理该废水时 ,容积负荷可以达到 2 0 kg COD/( m3· d) ,COD去除率在 70 %以上。     

EGSB反应器的启动运行

系统考察接种市政消化污泥EGSB反应器的初次启动和二次启动运行情况,以确定在EGSB反应器内接种市政消化污泥时快速形成高活性、稳定颗粒污泥的可行性和EGSB反应器所形成的颗粒污泥长期放置后能重新用于其他EGSB反应器作种泥并快速启动的可行性.接种市政消化污泥EGSB反应器在中温(35℃左右)条件下能够在46 d内快速启动,所形成的颗粒污泥沉淀性良好,产甲烷活性高,菌群丰富.接种市政消化污泥EGSB反应器初次启动宜采用低进水浓度、高有机负荷的方式.在7～15 ℃的低温下放置一段时间的EGSB反应器的快速二次启动是可行的.仅仅经历了7 d,有机负荷率高达24.84 kg COD/m3·d、COD去除率为94.6%.EGSB反应器二次启动宜采用高启动负荷,快速提高负荷的方式.     

EGSB反应器处理产氢发酵液

以厌氧颗粒污泥为接种污泥，对厌氧颗粒污泥膨胀床（EGSB）反应器处理产氢发酵液的启动性能进行了研究。结果表明，在温度为（35±1）℃，水力停留时间（HRT）为6h的条件下，逐渐提高进水COD，经过40d连续运行，EGSB反应器启动成功。容积负荷达到14kgCOD／（m3·d）时，COD去除率约为80％，产气量为26．84L／d，甲烷含量为57．9％。     

强化循环厌氧反应器处理印染废水的中试启动研究

应用自主研制的强化循环厌氧反应器(SCAR)中试规模处理实际印染废水,研究反应器的启动特性。反应器接种厌氧颗粒污泥后启动运行83 d,形成连续内循环并实现了对印染废水处理的高效稳定运行。在进水COD浓度1 000~3 650 mg/L、系统容积负荷0.7~6.4 kg/(m3·d)条件下,废水COD和色度平均去除率分别达到55%和73%。反应器内较高浓度的NH+4-N保证了系统pH的稳定性,350~600 mg/L的NH+4-N浓度没有对强化循环厌氧反应器产生抑制作用,系统内也没有出现VFA(以乙酸计)积累。启动过程中,厌氧颗粒污泥的粒径增大、沉降性能变好。启动实验完成时,反应器内微生物的脱氢酶活性(以TF计)和辅酶F420浓度分别为3.4973 mg/(g·h)和0.1872μmol/g。     

低温厌氧处理低浓度废水研究进展

对低温下厌氧处理低浓度废水的最新进展进行了较全面综述。高效厌氧反应器为这一发展提供了可能。首选反应器是膨胀颗粒污泥床 (EGSB)反应器。若废水中颗粒有机物含量较高 ,采用两级系统 (两个EGSB ,水解上流式污泥床(HUSB)反应器 +EGSB ,上流式厌氧污泥床 (UASB)反应器 +EGSB等 )处理效果较好。新兴的厌氧膜生物反应器也是该领域的一个发展方向。低温 ( 3— 12℃ )、低浓度 (COD <10 0 0mg L)废水中培养的嗜温种泥保持令人满意的产甲烷活性。其最佳代谢温度仍在中温范围 ( 30— 40℃ ) ,表明主要菌群仍是嗜温菌。     

膨胀颗粒污泥床反应器启动过程中颗粒污泥性质变化研究

采用小试规模的膨胀颗粒污泥床(EGSB)反应器,考察其启动规律及运行特点.在60 d内EGSB反应器的COD容积负荷达到12 kg/(m3·d),COD去除率保持在95%以上.试验中对不同水力负荷下污泥床状态进行了分析.结果表明,将水力负荷控制在1.0 m3/(m2·h)以上,可以确保污泥颗粒化的进行及EGSB反应器的稳定,否则易发生沟流、活塞式漂浮等污泥床异常现象.同时,对颗粒污泥性质及微生物相变化进行了跟踪分析.随着运行条件的改变,由上流式厌氧污泥床(UASB)反应器接种的污泥结构、性能和微生物群落都在不断发生变化.最终得到的颗粒污泥结构密实,沉降速率为38.8～64.6 m/h,比产甲烷活性达到314.25 mL/(g·d),内部微生物相丰富,各菌种呈混杂分布.     

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).     

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。     

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。     

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     

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.     

Spectrophotometric Determination of Atmospheric Acidity by means of the Displacement of the Equilibrium of Acid-Base Indicators

A method is described for determining acidity by means of the spectrophotometric determination of the displacement of the equilibrium of açid-base indicators. The method is simple, sensitive and free of known interferences. There is no dependence on costly or sophisticated equipment and the results obtained are reliable and reproducible.     

实验室质量管理体系内部审核的策划

在实施ISO／IEC 17025：1999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，识别出内部审核策划阶段的关键环节，提出审核范围确定、审核计划和抽样方案制订的质量控制要求，为有序高效地实施内部审核提供了技术方法。