还原焙烧-酸浸回收电镀污泥中的铜

采用还原焙烧—酸浸工艺处理电镀污泥,可以实现对铜的选择性回收.研究了不同焙烧条件下,电镀污泥的失重率和金属含量,并探索了焙烧温度、焙烧时间、煤粉用量、CaCO3投加量对金属浸出率的影响.结果表明,还原焙烧有利于污泥减量和金属富集;并且经还原焙烧污泥中金属的浸出效果明显优于直接焙烧;在电镀污泥中添加10％(质量分数)的煤...     

废旧线路板次氯酸盐法浸金的实验研究

研究了酸性条件NaClO-HCl和碱性条件NaClO-NaOH下浸出废旧线路板中的金.通过正交设计优化实验比较发现,NaClO-NaOH碱性体系浸金较有优势,其最佳的浸金条件为NaClO浓度6 mol/L,NaOH浓度8 mol/L,固液比l∶6,反应时间40 min,金的浸出率可达到94.5%.次氯酸盐浸金具有浸金效...     

生物沥浸含锰烟粉尘中的锰及其浸出机理研究

含锰烟粉尘是钢铁行业产生的一类含有锰、锌、铅和硅等元素的工业固废，既存在一定的环境风险，又具有潜在的资源回收价值。对含锰烟粉尘分别用生物酸和无机酸进行沥浸，分析锰的浸出机理，进一步通过响应面法确定生物酸沥浸锰的最佳工艺条件。结果表明，锰的浸出机理为酸溶和生物酸还原的复合机理，生物酸中的还原性物质和沥浸过程中产生的Fe²⁺能够将高价锰还原为Mn²⁺,使生物酸体系锰的浸出率比无机酸体系高。生物酸浸出锰的最佳工艺条件：固液比为1.22 g∶100 mL,初始pH为0.81,温度为29.14℃,转速为152.29 r/min,此条件下实际锰浸出率为76.51%。     

Pb/Zn冶炼废渣中重金属的生物浸出-盐浸处理

利用中温嗜热菌对某铅锌冶炼废渣进行生物浸出盐浸处理研究,并根据国家固体废物浸出毒性方法(HJ/T299-2007)对盐浸后余渣进行毒性分析。研究结果表明,在pH 1.5、温度65℃、矿浆浓度5%的优化条件下生物浸出3 d后,废渣中Cu、In、Ga和Zn的浸出率分别达到了91.5%、91.8%、84.9%和93.4%;盐浸生物浸出渣,其浸出液中Ag、Pb浓度分别为7.6和247.5 mg/L,可从废渣中有效回收Cu、In、Ga、Zn、Ag和Pb。生物浸出盐浸处理后余渣约为原渣量的70%;毒性分析浸出液中重金属元素Ag、As、Cd、Cu、Pb和Zn浓度分别为2～3.5、2～3、0.3～0.5、30～50、2～4、20～60 mg/L,低于国家危险废物鉴别标准(GB5085.3-2007)。根据试验结果,提出了针对冶炼废渣资源化、减量化、无害化的生物浸出盐浸联用工艺。     

自养-异养分步生物沥浸铅锌冶炼废渣中的有价/有毒金属

针对铅锌冶炼废渣组分复杂、含有多种金属类型、难以用单一沥浸体系溶释所有目标金属的特点,提出自养-异养分步生物沥浸的处理思想.结果表明:自养生物沥浸对锌、镉、铟、砷、铅的最高沥浸效率分别为90％、86％、71％、25％、12％,对银的沥浸效率为0;异养生物沥浸对于自养生物沥浸残渣可获得最高37％ 的银沥浸效率,而铅锌冶炼...     

微生物营养剂浓度对生物沥浸法处理猪场沼液的影响

猪场沼液是规模化猪场沼气工程排出的具有高悬浮固体(SS)和高污染负荷的一类高浓度有机废水。采用生物沥浸法调理实现其深度固液分离,对该废水生化处理达标排放意义重大。通过摇瓶实验,研究了猪场沼液在不同浓度营养剂下的生物沥浸处理,并将获得的沥浸泥作为接种物回流,回流比为1∶1,共连续处理6批,测定pH、过滤比阻(SRF)、泥饼重金属含量及滤水水质等指标。结果表明:当营养剂浓度≥15 g·L~(-1),其处理效果较好且稳定;pH降至3.5以下,SRF降至5.0×10~(11) m·kg~(-1)左右,脱水速率提高86.1%,泥饼重金属的浸出率高,其中Cu≥49.5%、 Zn≥72.7%。沼液经生物沥浸处理后体积减少40%～50%,抽滤水的化学需氧量(COD)、氨氮(NH_3)含量、总磷(TP)含量和SS分别从原稀释沼液的27 669.8、1 014.8、582.1和27 857.1 mg·L~(-1)降至423.8～499.3、671.4～704.0、0.7～1.1和0 mg·L~(-1),去除率最高可达98.5%、33.8%、99.9%和100%,大大降低了后续生化处理的难度。采用生物沥浸法处理猪场沼液具有良好的应用前景。     

生物沥浸法去除猪粪中重金属的研究

探讨以猪粪为培养介质,驯化和加富培养获得硫细菌混合菌液,并研究其对猪粪中重金属的生物沥浸效果。结果表明：猪粪可以在18 d内完成驯化,经3轮富集培养的猪粪粪液可作为硫细菌接种菌液。采用此菌液对猪粪粪液接种并投加硫粉,经过9 d的生物沥浸,Cu、Zn和Cd的沥出率分别达到93.0%、90.1%和67.8%。     

微生物沥浸法去除底泥中的重金属

以硫酸亚铁盐为底物,培养以氧化亚铁硫杆菌为主要菌种的土著沥滤微生物,采用批式方法对湘江长沙段底泥进行微生物沥浸实验。实验结果表明,底物投加量与底泥固体浓度比(Sd/Sc)为1.5时已能满足底泥的微生物沥浸要求,进一步研究发现底泥固体浓度为13%、底物投加量为19.5 g/L、沥浸时间为6 d时,底泥中超标重金属Cd、Zn和Cu的去除率可分别达到83.1%、75.3%和61.2%;沥浸后底泥中大部分重金属以残渣态存在,且含量低于农用污泥中污染物控制标准,其中硫化物有机结合态Cu浸出较Zn、Cd需更低的pH,且Cu以间接机理浸出为主;以Fe2+为底物的沥浸体系中,黄铁矾的重吸附或共沉淀是沥浸实验后期重金属浸出率下降的原因之一。     

预酸化下营养剂添加量对生物沥浸处理洗毛废水的影响

洗毛废水是洗毛生产工艺排出的兼具高COD、高悬浮固体浓度、高色度、难固液分离等典型特征,且对环境存在潜在污染的一类工业废水。通过摇瓶实验,研究了预酸化条件下,生物沥浸技术对洗毛废水的处理效果。结果表明,当洗毛废水经预酸化至p H 5.5、营养剂浓度≥4 g/L、回流比例为1∶1的情况下,3个批次实验内复合菌群生物沥浸过程稳定,洗毛废水能够很好地完成生物沥浸过程。反应结束后体系p H稳定在3.0左右,COD去除率高达90%以上,色度由原来的1 875倍降到20倍,沉淀中油脂去除率高于65%,且比阻降低至原来的0.2%~0.3%。而在对照处理中,体系p H值稳定在8.0左右,COD去除率小于10%,油脂去除率不足10%,洗毛废水比阻仅降低20%。因此,采用预酸化及生物沥浸作用有利于洗毛废水酸化处理的连续运行并具有良好的应用前景。     

循环流化床灰制备聚合氯化铝铁絮凝剂

以煤矸石电厂循环流化床灰(CFB灰)为原料,采用酸浸、水解、聚合和熟化等工艺过程,制备聚合氯化铝铁(PAFC)絮凝剂产品。重点对制备PAFC絮凝剂的酸浸工艺参数进行研究,其最佳工艺条件为:盐酸浓度为20.2%、酸浸温度为110℃、酸浸时间为2 h、液固比为4∶1;Fe2O3浸出率为90.6%,Al2O3的浸出率为48.5%。同时采用实验得出的最优工艺参数进行了产品制备,并对产品进行了絮凝性能实验。结果表明,在相同条件下PAFC的絮凝效果明显好于聚合氯化铝(PAC),用CFB灰制备PAFC絮凝剂产品是可行的。     

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.