乙酰丙酮光度法测定甲醛方法的改进

用乙酰丙酮溶液将CODcr反应管制成标准反应管,CODcr消解器加热回流30min,DR／2010分光光度计比色测定甲醛含量。方法精密度、准确度满足甲醛测定的分析要求。     

血粉对废水中镉离子的高效去除效应

以屠宰场废弃动物血液为原料,经高温干燥、粉碎为血粉,以此血粉为吸附剂,研究血粉添加量、溶液初始浓度、吸附温度、溶液pH、吸附时间对废水中Cd2+吸附量与去除率的影响。结果表明,在25℃、pH=5时,4 g血粉对初始浓度为20mg·L~(-1)的镉离子溶液(100 m L)振荡吸附2 h后,溶液中剩余镉离子浓度为0.1 mg·L~(-1),Cd2+的去除率为99.38%,达到污水综合排放标准(GB 8978-1996)中镉排放限值0.1 mg·L~(-1);血粉对镉离子的吸附反应符合Langmuir等温吸附方程,可决系数为0.999 7,Cd2+的理论饱和吸附量为10.24 mg·g-1。为了使剩余Cd2+浓度达到更低(电镀废水排放标准),在吸附工艺上设计出2步吸附法,即第1次吸附后的混合液进行过滤,再将滤液加1 g血粉进行第2次吸附。结果表明,2步吸附法大大降低了溶液中剩余Cd2+离子浓度,即经过第1步、第2步吸附后,溶液中剩余Cd2+离子浓度降至0.006 mg·L~(-1),达到或低于电镀污染物排放标准(GB 21900-2008)对Cd2+的排放限值(0.05 mg·L~(-1))。这是常规吸附剂活性炭、石英砂、高岭土等所不能达到的技术指标,为废水去除Cd2+提供了一种可能的新技术。     

泡沫镍负载改性TiO_2降解甲醛

为了消除甲醛气体对人类的危害,对甲醛气体的光催化降解行为进行了研究。采用沉淀-胶溶法制得了具可见光活性的纳米TiO2溶胶,然后将其负载于经过预处理的泡沫镍板上,置于自置的光催化反应器中,考察了在可见光照射下对密闭空间里面一定浓度的甲醛气体的降解情况。采用乙酰丙酮分光光度法,在最佳的检测条件下检测气相中甲醛气体经不同光照时间后的浓度。研究发现,负载了氮掺杂改性的TiO2的泡沫镍板在可见光照射下能够有效降解气相中的甲醛,反应240 min后对甲醛气体的降解率为93%;而同样条件下反应器中只有处理过的泡沫镍板时,甲醛气体浓度基本保持不变。     

酸碱改性活性炭吸附微污染水源水中的Ni~(2+)

通过HNO_3-KOH对活性炭进行改性,采用扫面电镜(SEM)、比表面积分析(BET)、红外光谱分析(FT-IR)和Boehm滴定法对改性前后的活性炭进行表征,研究了改性前后的活性炭在不同条件下对微污染水源水中Ni~(2+)的吸附能力和动力学。结果表明:改性活性炭表面含氧酸性官能团数量增加,比表面积和总孔容均略有降低,孔径变化不明显。在Ni~(2+)浓度为0.4 mg·L~(-1),改性活性炭投加量5.0 g·L~(-1),温度30℃时,反应1 h去除率可达95.55%,剩余Ni~(2+)浓度为0.017 8 mg·L~(-1),达到《生活饮用水卫生标准》(GB5749-2006)中的要求。相同条件下,改性前活性炭对Ni~(2+)的去除率仅为74.45%,剩余Ni~(2+)浓度达不到标准要求。活性炭对Ni~(2+)的等温吸附更符合Langmuir方程,吸附动力学数据符合准二级动力学方程。     

剩余污泥在微氧条件下利用VFAs合成PHAs的工况优化

针对2种脱氮除磷工艺的剩余污泥,在微氧条件下,以花生渣厌氧发酵产生的VFAs为碳源,控制反应时间为5 h,DO≤0.2 mg·L~(-1),COD为650～750 mg.L~(-1),对比2种不同工艺的剩余污泥合成聚羟基脂肪酸酯(PHAs)的量,并探究了增设前置曝气对微氧条件下剩余污泥合成PHAs的影响。结果表明,在微氧条件下,连续流中同步亚硝化反硝化脱氮除磷系统二沉池的剩余污泥(R1)和采用A~2O工艺的实际水厂的剩余污泥(R2)合成PHAs最高量分别为108.6 mg·g~(-1)和58.58 mg·g~(-1),R1比R2更具有合成PHAs的能力;在增设前置曝气实验中,曝气时间的延长和曝气量的增大均可促进PHAs的合成;当曝气气量为50 L·h~(-1)时,曝气20 min后,R1合成的PHAs最高为172.5 mg·g~(-1)。氧化还原电位(Eh)是微氧条件下PHAs合成过程中的重要指示参数,当Eh值为最低时,PHAs合成量最多。以上结果可为脱氮除磷工艺剩余污泥利用廉价碳源合成PHAs提供参考。     

三峡库区垃圾渗滤液-城镇污水合并处理时的重金属含量研究

应用微波消解-电感耦合等离子体发射光谱法（ICP-OES）测定三峡库区垃圾渗滤液、渗滤液城镇污水合并处理厂进、出水以及剩余污泥中重金属元素的浓度。结果表明,合并处理后,除5个污水厂出水Ni超标（浓度为59.79～104.30 μg/L）外,其余重金属元素均低于GB 18918-2002污水排放标准;剩余污泥中的总重金属含量在15.31～27.73 g/kg之间,各元素含量均远低于污泥农用标准。因此,在目前各合并处理厂的运行条件下,控制渗滤液与城镇污水比例在1∶2 700～1∶50（V/V）范围内,渗滤液汇入生活污水进行合并处理是解决渗滤液重金属污染的有效方式。     

秸秆成型燃料锅炉污染物排放规律试验研究

根据锅炉烟尘测试方法(GB 5468-91)及锅炉大气污染物排放标准(GB 13271-2001),在不同风门的工况下,分别对设计的双层炉排秸秆成型燃料锅炉污染物排放规律进行试验.试验表明,在较好工况下,双层炉排锅炉排烟中CO等中间产物及烟尘含量低于单层炉排锅炉,其排烟中CO、NOx、SO2和烟尘浓度等指标远远低于燃煤锅炉,符合国家关于工业锅炉大气污染物排放标准要求,有较好环保效益.     

负载铂的酸活化高岭土室温甲醛氧化性能

通过盐酸活化高岭土,再利用浸泡-还原法在其表面负载金属Pt颗粒,制备出甲醛氧化催化剂。通过X射线衍射(XRD)、场发射扫面电镜(FE-SEM)、透射显微镜(TEM)、氮气吸附-脱附等温线和傅里叶红外光谱(FTIR)等对催化剂进行表征测试。结果表明:酸化处理后的高岭土的比表面积增大近1倍,负载金属Pt颗粒后作为催化剂,室温氧化甲醛具有较高的催化氧化性能,甲醛初始浓度为200 mg·m~(-3)左右,催化氧化1 h后,甲醛剩余浓度仅为50 mg·m~(-3)。连续循环5次,催化氧化性能变化不明显,具有稳定的催化氧化活性。     

水体中常见无机阴离子对TiO2薄膜光催化降解甲醛的影响

选择了5种水体中常见的阴离子（Cl^-,SO4^2-,HPO4^2-/HPO4^2-,HCO3^-/CO3^2-和NO3^-）,分别考查了其对TiO2薄膜光催化降解模拟甲醛废水的反应速率的影响;从上述离子的光吸收,对.OH的捕获及其生成的相应的无机自由基的氧化作用以及与甲醛的竞争吸附3个方面讨论了上述离子影响TiO2薄膜光催化降解模拟甲醛废水的反应速率的原因。结果表明,HCO3^-/CO3^2-对TiO2薄膜光催化降解甲醛具有抑制作用,Cl^-和SO4^2-的影响不大,H2PO4^-/HPO4^2-和NO3-具有促进作用。造成上述结果的主要原因是HCO3^-/CO2^3-具有很强的.OH捕获作用;Cl^-,SO4^2-对.OH捕获作用以及竞争吸附都较弱;H2PO4^-/HPO4^2-在TiO2表面具有较强的吸附能力,释放出的H＋起到了酸催化剂的作用;NO3^-在紫外光的照射下可以产生.OH,此外NO3^-作为电子受体而降低了TiO2表面光生电子和空穴的复合几率。     

臭氧光催化降解水中甲醛的研究

研究比较了3种光化学方法对水中低浓度甲醛的降解效果,考察了初始pH值、甲醛浓度和臭氧投加速率等因素对臭氧光催化(TiO_2/UV/O_3)降解甲醛的影响。结果表明,紫外臭氧(UV/O_3)、光催化(TiO_2/UV)和TiO_2/UV/O_3对甲醛的降解均符合表观一级反应动力学,TiO_2/UV/O_3降解甲醛的一级表观速率常数大于TiO_2/UV与UV/O_3之和,说明臭氧、光催化有明显的协同作用。pH值对臭氧光催化降解甲醛的速率几乎没有影响;甲醛初始浓度增加,表观反应速率常数下降,但甲醛的绝对去除量仍随初始浓度的增加而显著增加;臭氧投加速率增加,降解速率增加。甲醛降解的主要中间产物为甲酸,但甲酸在臭氧光催化反应过程中也快速降解而被矿化,说明臭氧光催化是一种能安全有效去除甲醛的方法。     

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.