城市典型屋面径流的排污特征

对城市中典型的2种材料(油毡和水泥)屋面降雨径流中颗粒物(SS)、氮(N)和磷(P)污染物排放特征进行了研究。结果表明,屋面径流中颗粒物主要是以10~100μm粒径范围的颗粒物为主(约占75%),氮主要是以溶解态形式排放(80%~95%),且主要形式是以硝态氮和氨态氮为主,水泥屋面增加了径流中硝态氮的比例,而沥青屋面增加了氨态氮和溶解态有机氮的比例。而磷主要是以颗粒物形态排放(约占40%~70%,平均57.5%),且主要结合10~50μm粒径范围的颗粒物。去除10~50μm粒径颗粒物可以降低屋面径流中50%颗粒物和47.9%磷的排放,而氮却需采用不同处理方法。同时,EC和TSS与TN和TP相关关系表明,EC和TSS可分别作为屋面降雨径流溶解态氮和颗粒态磷污染程度检测和评价指示指标。研究结果为有效地去除降雨径流中污染物、降低城市面源污染对水环境的影响,提供了一定的科学依据。     

粗媒体颗粒流化床半干法烟气脱硫

开发了粗媒体颗粒流化床半干法烟气脱硫技术.在流化床内加入惰性粗媒体颗粒,改善脱硫剂与烟气的接触,延长脱硫剂在床内的停留时间,促进脱硫反应进行,提高脱硫效率和脱硫剂利用率.以工业用石灰石为脱硫剂,实验研究了粗媒体颗粒的加入量及其他操作条件对此过程脱硫效率的影响.结果表明:随着粗媒体颗粒粒径减小及床内加入量增加,烟气脱硫效率提高;随着Ca/S增大、饱和接近度降低、空速及脱硫剂颗粒粒径减小,脱硫效率提高.当粗媒体颗粒的静止床高为122 mm,饱和接近度为15～18℃、空速为2850 h-1、钙硫比为1.0～1.1、脱硫剂粒径为64μm时,脱硫效率可达90%以上.     

物理分离技术在微量金属形态研究中的应用

本文论述了粒径分级技术在天然水中痕量金属形态研究中的应用.在痕量金属污染、吸附效应和粒径的选择性研究中。都已在考虑采用离心、过滤、超滤(UF)、渗析和凝胶过滤色谱(GFC)等方法.妨碍粒径离心分级是由于密度对颗粒沉降速度的影响.过滤法是区分痕量金属形态最普遍应用的方法,,但它往往只能鉴别“溶解态”和“颗粒态”的级份.用稀硝酸可以清除滤器的污染,并且用硝酸钙稀溶液可使吸附效应减至最小。用过滤法进行粒径选择分级的一些研究指出,目前只有Nu-clepore聚碳酸脂滤膜适合于粒径分级的研究。采用UF法也碰到上述的这些困难,而且一般也没有得到很好的解决,尤其是吸附作用.超滤时的吸附作用将造成对金属络合物分子量的过高估计.为了离析真溶液中的痕量金属形态,渗析技术已获得了一定的成绩,但已证实它只限于在总形态分析程序图中的应用。GFC在物理化学形态研究中具有相当的潜力.其主要的优点是它能给出连续的粒径范围,而不是间歇的粒径范围.与其它方法相反:GFC的吸附作用将会造成对有机金属络合物分子量的过低估计.本文考查了每种技术在环境中应用的一些例子,并列举了天然水中金属形态的粒径分布的研究结果.     

铁促电解去除高浊度老龄垃圾渗滤液COD的机理

铁促电解是去除水中有机污染物的新型方法,采用箱式电化学反应器研究了该法去除填埋场高浊度老龄垃圾渗滤液COD的机理.实验结果表明：用浊度衡量老龄垃圾渗滤液非溶解态有机物的含量是合理的;垃圾渗滤液中非溶解态有机物对铁促电解去除COD的效率有显著影响.铁促电解对高浊度垃圾渗滤液COD的去除存在三种机理,即电化学氧化、电解气浮和絮凝沉淀.随着水质与实验参数的变化,三种机理对COD总去除率的贡献亦发生变化;对比了Fe^2＋与Fe^3＋促进COD去除的效果,提出了一种铁离子循环电解处理老龄垃圾渗滤液的新工艺.     

改性γ-聚谷氨酸络合重金属离子性能

研究了不同控制条件(温度、Pb2+浓度、pH)对交联改性γ-聚合谷氨酸(γ-PGA)吸附重金属离子所形成的絮凝颗粒性质的影响,对于治理水中重金属污染的相关研究有一定参考价值。实验表明,C-L-γ-PGA絮凝吸附Pb2+的最佳温度段在30℃附近。随着交联度的增加,不同的Pb2+浓度影响絮凝颗粒的大小,当处于较低浓度时,静电引力成为影响絮凝颗粒粒径最主要的因素,当Pb2+浓度增加到一定程度时,重金属的吸附量成为絮凝颗粒的粒径的决定因素。溶液pH达到7附近时,能够形成粒径最大的絮凝颗粒,并出现了最大的Pb2+去除率。C-L-γ-PGA对其他重金属离子也有类似的吸附絮凝作用,且絮凝吸附强弱顺序为Cu2+>Cr3+>Pb2+>Hg2+。吸附絮凝颗粒的粒径反映了重金属被吸附之后分离的难易程度,因此研究不同条件对絮凝颗粒粒径的影响对重金属离子的吸附和去除有重要意义。     

城市生物质废物厌氧消化前后粒径分布特征解析

在稳定运行的城市生物质废物厌氧消化中试研究结果基础上,对基质及消化液的有机物粒径分布特征进行解析。在反应器有机负荷为2.4、6.0和8.0 kg VS/(m3·d),停留时间为50、20和15 d 3个状态下,反应器对城市生物质废物有良好的去除效果,VS去除率均在60%以上。其中粒径96μm的大颗粒有机物去除率均在80%以上,负荷及停留时间对大颗粒有机物的去除效果没有表现出明显影响;随着负荷的增加及停留时间的缩短,消化液中粒径范围0.45~74μm的有机物及溶解性有机物的含量增加,去除率降低;研究结果表明,在传统的厌氧消化条件下,对于本研究中的城市生物质废物而言有机物的酶解过程是主要限速步骤。     

道路径流SS和COD污染特征及出流规律

选择芜湖市火车站点进行长期监测,采集降雨7次;同时选择5个不同功能区,采集典型降雨1次。探讨了道路径流中总固体悬浮物(SS)和化学需氧量(COD)的污染特征、影响因素及出流规律,结果表明,7次降雨事件SS和COD平均值范围分别为198～1 529 mg/L和66～367 mg/L。SS和COD污染较为严重。SS在不同功能区中大小顺序为:工业区>居民区>商业区>交通区>文教区,总COD大小顺序为:工业区>交通区>居民区>商业区>文教区,溶解态COD大小顺序为:工业区>交通区>商业区>文教区>居民区,颗粒态COD大小顺序为:工业区>居民区>交通区>文教区>商业区。工业活动对地表径流SS和COD含量影响最大。SS受降雨历时影响较大,溶解态COD受平均雨强影响较大,颗粒态COD受最大雨强影响较大。不同降雨强度下,SS、溶解态COD及颗粒态COD的出流规律不同,降雨强度对径流初期效应的影响显著。     

浓缩脱水污泥水混凝预处理效果及混凝剂的选择

以白龙港污水处理厂浓缩脱水污泥水为处理对象,考察了聚合氯化铝(PAC)对污泥水颗粒物沉降特性和污染物去除效果的影响,比较了PAC、聚合氯化铁(PFC)、阳离子型聚丙烯酰胺(cPAM)和阴离子型聚丙烯酰胺(aPAM)对浓缩脱水污泥水的预处理效果。实验结果表明,PAC的投加可以去除颗粒态污染物和溶解态的磷,但其形成絮体粒径随PAC投加量增大而减小,导致污泥沉降性能恶化。因此,PAC不适合浓缩脱水污泥水的混凝预处理。与PAC相比,投加PFC、cPAM和aPAM均能有效去除颗粒态污染物,并改善污泥水沉降性能,其中cPAM的预处理效果最佳。     

金矿污染河流的水体和沉积物中重金属分布特征及生态风险评价

金矿开采导致严重的水体和沉积物重金属污染。采用电感耦合等离子体质谱仪(ICP/MS)分析了金矿开采区河道32个采样点的水体和表层沉积物样品,研究了水样的溶解态及颗粒态重金属(As、Pb、Cd、Cr、Cu、Zn)组成;通过分步化学提取法研究了各重金属在沉积物中的地球化学形态组成,利用地累积指数法和潜在生态风险指数法评价了河流沉积物中重金属污染状况。结果表明:水体中Cu、Zn、As主要以溶解态存在,Pb、Cr、Cd以颗粒态为主。水体中重金属元素形态分布主要受点源污染排放影响。沉积物中,Cd浓度较低;As、Zn主要以氧化物结合态、有机物结合态和残渣态存在;Pb、Cr、Cu以有机物结合态和残渣态为主。结合地累积指数和潜在生态风险指数分析表明,Cd和Cu为主要的风险元素。     

生物吸附-多级A/O-活性焦组合工艺对污水中氮磷及有机污染物的去除

利用生物吸附(biological absorption,AB)-多级缺氧/好氧(anaerobic/oxic,A/O)-活性焦滤池组合工艺对城市污水进行处理研究。结果表明:该组合工艺出水COD、TN、TP平均浓度为20、8.5、0.25 mg·L~(-1),对COD、TN、TP平均去除率为95%、76.5%、80%,3个工艺段对有机污染物的平均去除率分别为55%、26%、14%。其中生物吸附段主要去除粒径较大的颗粒态有机物,多级A/O段可以去除进水中53%左右溶解性有机物;活性焦滤池利用活性焦丰富的中孔结构有效吸附多级A/O出水中难生物降解的芳香类及环烷类有机物。该组合工艺能实现高标准出水、高效脱氮除磷、能源节约、资源回收,是具有良好应用前景的污水处理工艺。     

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).     

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     

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。     

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.     

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。