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1.
构建生态塘/生态沟渠耦合系统的中试工程并在低温条件下连续运行,考察耦合系统对微污染水体的净化效果。结果表明,生态塘/生态沟渠耦合系统在低温运行阶段对COD、TN、氨氮及TP的平均去除率分别为54.50%、37.43%、53.00%、44.20%。pH对COD和TP的去除率影响不明显,与氨氮呈正相关关系,线性相关系数R2=0.705 92;耦合系统中DO供给充足,因此DO对COD、TN、TP去除率的影响并不明显,DO仅与氨氮去除率呈显著正相关,线性相关系数R2=0.771 64。  相似文献   

2.
针对黑水污染物浓度高、悬浮成分多、碳氮磷比例失调等问题,小试条件下探索了采用倒置AAO-MBR工艺处理黑水的技术可行性,开展了水温、水力停留时间、外加碳源和溶解氧对主要污染物去除的影响。结果表明:冬季低温、HRT为42 h与夏秋季HRT为31 h的除污效果相近,出水的COD、氨氮、TN分别为110、26.7和104.5 mg·L~(-1);碱度是影响氨氮去除效率的最主要因素;HRT为31 h条件下,未加外碳源(C/N为3.14)时,COD、氨氮、TN平均去除率分别为83.8%、88.2%和52.9%,磷酸盐没有去除效果;外加碳源至C/N为4.63,COD、氨氮、TN和磷酸盐的平均去除率分别提高到93.4%、98.1%、91.3%和20.7%;随着运行时间的延长,MBR出水COD呈下降趋势,平均达到56 mg·L~(-1),达到一级B排放标准;好氧区的DO控制0.2~0.4 mg·L~(-1)时生物脱氮效率较佳。  相似文献   

3.
将加压溶气气浮技术与加压曝气生物氧化技术相结合,开发了加压溶气生化气浮(PA-DAF)法,用于处理生活污水。结果表明,DO和C/N对反应器的脱氮效果有显著影响。DO质量浓度提高到3.5mg/L后,氨氮去除率提高到将近99%。当DO质量浓度为2.5mg/L时,TN去除率达到最大值77.50%。高C/N条件下系统会抑制硝化能力。该反应器能很好地创造缺氧微环境,出现了同步硝化反硝化现象,并对其形成机制进行了分析。  相似文献   

4.
将生物阴极型微生物燃料电池(BCMFC)阳极室的出水引进阴极,同时阴极采用间歇曝气的方式运行,以人工模拟的氨氮有机废水作为处理对象,探究外接电阻、DO、水力停留时间(HRT)以及碳氮质量比(C/N)对BCMFC的氨氮和有机物(以COD表征)去除效果以及产电性能的影响。结果表明:(1)开路以及50、100、500、1 000Ω条件下,最后出水中氨氮去除率分别为95.33%、86.12%、67.68%、100.00%、99.39%。外接电阻变化对COD的降解无太大的影响。500Ω条件下产电性能最佳。(2)DO为0.2、2.0、3.0、4.0、5.0、7.0mg/L条件下,最后出水中氨氮去除率分别为48.55%、56.56%、84.40%、93.25%、95.76%、97.01%,COD去除率分别为68%、96%、99%、99%、99%、99%。DO会影响整个电池的产电功率。DO设为4.0~5.0 mg/L较合适。(3)C/N为8.3∶1.0、12.5∶1.0、25.0∶1.0、50.0∶1.0条件下,最后出水中氨氮去除率分别为74.68%、73.86%、94.07%、100.00%。C/N对COD的去除没有太大的影响。C/N为25.0∶1.0条件下最大产电功率密度最大。(4)HRT为8、10、13、20、24h条件下,最后出水的氨氮去除率分别为67.67%、79.01%、86.70%、92.72%、96.80%,COD去除率分别为96%、98%、98%、100%、100%。随着HRT的缩短,最大产电功率密度先增大后减小。HRT为20h时BCMFC性能较好。  相似文献   

5.
为解决分散式小型屠宰厂在生产过程中产生的高浓度有机废水处理的问题,开展了物化单元(混凝沉淀)、生化单元(上流式厌氧污泥床反应器(UASB)工艺和膜生物反应器(MBR)工艺)对屠宰废水处理效果及影响因素的研究。结果表明:在混凝沉淀实验中,聚合氯化铝(PAC)最佳投加量为60mg/L、最佳pH范围为6.5~8.5;UASB工艺中,最佳进水上升流速为0.12m/h;MBR工艺中,最佳C/N(质量比)为5∶1~7∶1,DO在0.92~1.24mg/L时,对TN有较好处理效果,DO在1.24~1.68mg/L时,对COD及氨氮有较好处理效果。混凝沉淀—UASB—MBR耦合工艺连续运行的28d中,生化单元COD、TN和TP平均去除率分别为95.78%、89.17%、92.46%,出水水质良好。  相似文献   

6.
人工湿地因其低能耗、易管理的优点被广泛应用于水处理和生态修复,尤其在发展中国家有其适用性。为探讨COD/N对潜流人工湿地脱氮效能及氧化亚氮(N2O)的排放影响,分别构建5组微型人工湿地CW1~CK,进水化学需氧量/总氮(COD/N)分别为20∶1、10∶1、7∶1、4∶1和0∶1。结果表明,湿地出水DO浓度均低于0.5 mg·L~(-1),不同的COD/N下无显著差异,但pH表现为随COD/N的升高而降低。进水COD/N为10、7和4的湿地中COD去除率在80%以上,而进水COD/N=20的湿地中COD去除率不足70%。5组COD/N湿地中氨氮(NH+4-N)的平均去除率依次为(61±16.6)%、(23±14.1)%、(30±12.5)%、(28±14.5)%和(74±7.0)%,在碳源充足或无碳源的条件下有利于NH+4-N的去除。除COD/N=0外,其余湿地中出水未检测到硝态氮(NO_3~--N)。湿地中总氮(TN)的去除变化与NH+4-N相似。5组湿地系统中,N2O的平均释放通量和累积排放量,分别在0.83~11.84 mg·(m2·h)~(-1)和30.65~490.80 mg·m~(-2)之间。COD/N=4的人工湿地系统中,N2O的平均释放通量和累计排放量显著高于其他处理(p0.05),且在其中以N2O形态去除的氮占系统去除TN的百分比为4.87%。COD/N对潜流人工湿地的脱氮和N2O减量具有调控作用。  相似文献   

7.
A/O膜生物反应器处理高浓度氨氮废水试验研究   总被引:4,自引:0,他引:4  
对A/O膜生物反应器处理高浓度氨氮废水进行了研究,着重考察硝化液回流比和C/N对系统脱氮效能的影响.研究表明,当硝化液回流比为2、C/N为6时.系统对COD、氨氮、TN的平均去除率分别达96.17%、97.76%、76.29%;A/O膜生物反应器稳定运行期间,氨氮容积负荷去除量与进水氨氮容积负荷呈现良好的线性关系;当A/O膜生物反应器内MLSS稳定在9~13 g/L时,上清液COD较低,膜压差增长缓慢.  相似文献   

8.
以普通竹炭为原料,采用氢氧化钾活化法改性制备低湿密度竹炭,扫描电镜(SEM)、比表面积和孔径分析(BET-BJH)和傅立叶变换红外光谱(FT-IR)等表征结果表明改性后的竹炭总孔容增多,湿密度降低。将低湿密度竹炭作为悬浮生物载体应用到移动床生物膜反应器(MBBR)中,用以处理模拟生活污水,研究不同影响因素下,对COD、氨氮、TN和TP的去除效果,探索最佳运行工艺。结果表明,低湿密度竹炭悬浮生物载体流化状态好,去除效果较好。对于进水COD质量浓度为200mg/L的模拟生活污水,适宜的MBBR工艺条件为气水比100∶1(体积比)、竹炭填充率15%、水力停留时间4h,处理后出水COD、氨氮、TN和TP去除率分别为83%、77%、48%、57%。  相似文献   

9.
污染物负荷对曝气生物滤池处理效果的影响研究   总被引:1,自引:0,他引:1  
考察了进水有机负荷和氨氮负荷对曝气生物滤池出水水质的影响.结果表明,系统COD、氨氮和TN的去除率随进水有机负荷的增加而下降,在氨氮为28.3~33.6 mg/L、TN为39.0~45.8 mg/L条件下,有机负荷小于3.53 kg/(ms3·d)时,出水COD、氨氮和TN分别小于50、5、15 mg/L,去除率分别在85%、85%和65%以上;氨氮和TN的去除率随氨氮负荷的增加而下降,在COD为287.6~313.4 mg/L、氨氮负荷小于0.56 kg/(m3·d)时,出水氨氮小于8 mg/L,去除率在85%以上,出水TN小于15mg/L,去除率在65%以上.  相似文献   

10.
针对垃圾填埋场渗滤液生物脱氮高耗能的问题,通过对A/O/N工艺处理垃圾渗滤液进行短程硝化反硝化调试,对溶解氧(DO)、污泥浓度(MLSS)、污泥龄(SRT)、混合液回流比、pH、碱度进行定性定量分析,研究了不同条件下垃圾渗滤液生物处理阶段COD、氨氮及总氮去除效果,探讨了影响亚硝酸盐氮积累的因素。结果表明,好氧池低溶解氧能成功启动短程硝化,垃圾渗滤液稳定实现短程硝化反硝化脱氮。运行条件为:O反应器DO浓度0.5~0.8 mg·L~(-1),N反应器DO浓度1.5~2.2 mg·L~(-1),MLSS 3 500~4 500 mg·L~(-1),污泥龄9~13 d,混合液回流比1 100%,N反应器pH 7.6~8.2,N反应器碱度1.1 g·L~(-1)。短程硝化调试后,硝化阶段亚硝化率稳定在85%以上,COD、氨氮及总氮去除率分别达95%、98.6%、94.2%以上,节省30%碳源量和20%曝气量。  相似文献   

11.
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  相似文献   

12.
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).  相似文献   

13.
14.
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  相似文献   

15.
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。  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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。  相似文献   

19.
张仁泉 《污染防治技术》2005,18(2):15-17,34
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。  相似文献   

20.

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 (ActivTM and BioCleanTM) 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.  相似文献   

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