转轮式洗轮机对车轮带泥的冲洗效果简

施工车辆车轮带泥是我国道路扬尘污染控制面临的共性和突出问题。为在国内推广使用洗轮机提供技术依据，通过检测工地出口外道路积尘负荷来估算转轮式洗轮机对车轮带泥的冲洗效率，并以该洗轮机作为车轮带泥检测设备，检测和统计北京市车轮带泥量。结果表明，（1）转轮式洗轮机可以将工地出口外100 m道路积尘负荷增量由64.4 g/m²降至5.9 g/m²，转轮式洗轮机对车轮带泥的冲洗效率大于90%；（2）渣土车和混凝土车车轮带泥量的平均值分别为5.1和2.2 kg/车；（3）北京市未来车轮带泥量将超过8.8万t/a，施工车辆全部经过转轮式洗轮机冲洗后，车轮带泥量可削减7.9万t/a。建议在相关法律法规中以强制性条款落实施工车辆车轮带泥机械化冲洗要求。     

北京市城市道路尘土残存量和湿式积尘量特征

道路扬尘是大气细颗粒物的来源之一,道路清扫保洁可以降低道路积尘量和道路扬尘排放。收集北京市2015年道路尘土残存量(d≤2 mm)数据,采用道路积尘湿式采样器采集秋季道路积尘量(d≤180μm),分析道路积尘的空间和道路类型分布特征,道路积尘中有机物和无机物含量等,并与瑞典斯德哥尔摩城市道路积尘特征进行比较。结果表明:春、夏、秋、冬和年均值道路尘土残存量分别为26.1、15.7、14.9、15.0和17.9 g·m~(-2),4类城市功能区的道路尘土残存量分别为13.8、15.0、24.8和20.6 g·m~(-2);秋季首都功能核心区和城市功能拓展区道路积尘量分别是道路尘土残存量的3.2和2.5倍,是斯德哥尔摩市道路积尘量的5.3和3.9倍;道路积尘量主要来自车辆遗撒、车轮带泥、非铺装路肩风蚀水蚀和大气降尘等无机物,无机物约占道路积尘量的(86.8±5.1)%,最高可达95.8%。建议严格控制渣土车遗撒和车轮带泥等污染源,并加强道路清扫保洁。     

道路积尘湿式采样器研发与测试评价

道路扬尘是大气细颗粒物的来源之一,道路清扫保洁可以降低道路积尘负荷和道路扬尘排放。干式吸尘方法在检测潮湿路面和未来更加清洁道路的积尘负荷时有局限性,研发了一款基于高压水冲洗回收的道路积尘湿式采样器,并对采样器的供水量稳定性、冲洗水回收率、道路积尘收集率和道路积尘粒径分布重现性等指标进行评价,结果表明:当水桶(20 L)水位为50%和100%时,采样器供水量分别为(604±3)m L和(606±2)m L,稳定且无差异;在3种粗糙度(大理石、水泥混凝土、沥青混凝土)道路的冲洗水回收率都≥95%;道路积尘收集率随尘土残存量增加而增加,收集率为88%~95%;采样器收集到道路积尘(≤180μm)的粒径分布与原始样品具有很好的重现性;湿式和干式吸尘积尘量的线性关系式为y=2.97x+29.58,R~2=0.63。建议采用道路积尘湿式采样器评价城市道路清扫保洁质量。     

Fenton氧化深度处理高浓度造纸废水的中试实验

采用Fenton氧化开展了对高浓度造纸废水深度处理的中试实验，对Fenton氧化的COD的去除效果，各药剂加药量及成本，排泥量和装置运行的稳定性等进行探讨和分析，结果表明，一级Fenton氧化的COD去除率可达到90％以上，出水COD在100mg／L左右，总加药成本在6元左右，排泥量约为1～1．2kg／t废水；二级Fenton氧化的COD去除率在96％左右，出水COD小于60mg／L，总加药成本在8元左右，排泥量约为1．15～1．4kg／t废水，验证了Fenton氧化用于高浓度造纸废水深度处理达到新的排放标准的可行性。     

固定床连续流反应器厌氧生物处理电厂锅炉柠檬酸洗废液的研究

报道了用固定床连续流反应器厌氧处理电厂锅炉柠檬酸洗废液的试验结果。试验表明，该法可有效降解柠檬酸，当温度36℃～38℃时，CODcr去除率平均为81．2％，进料CODcr体积负荷为3kg／m2·d，进料速度0．6mL／min，平均停留时间为1．234d／L     

巢湖蓝藻的机械清除工艺以及藻水分离实验研究

对巢湖蓝藻进行机械清除以及藻水分离实验研究，实验采用的浮式围栏引导一机械清除．投加剥离液辅助机械清除工艺处理量大，除藻效率高，筛网过滤-浓缩-卧螺离心机脱水成藻泥的藻水分离工艺较为理想，藻泥含水率仅为89％。2011年5-10月在巢湖运用上述方法清除湖面水华蓝藻，共处理富藻水1．6万m3，得到藻泥970t，累计清除蓝藻106．7t（干重）。按照所清除蓝藻的总氮、总磷的平均含量计算，相当于从湖中移除了氮6．25t，磷2．1t。表明在富营养湖泊中水华蓝藻大量暴发时，采用上述方法除藻，对控制蓝藻水华污染，有效降低内源氮、磷等污染物负荷具有十分重要的作用。     

耐酸厌氧消化污泥处理餐厨垃圾

采用耐酸驯化的厌氧消化污泥处理餐厨垃圾，在酸性条件下（pH=4．5），对实验装置容积负荷从1．0kgVS／（m3·d）分9次逐级增加到5．0kgVS／（m3·d）的过程进行了跟踪监测，并较深入地研究了驯化污泥代谢活性和处理效果。实验结果表明，pH4．5的耐酸厌氧消化污泥，最佳投加负荷约为4．5kgVS／（m3·d），此负荷下容积产气率，CH4含量平均值均达最大，分别为1．68m3／（m3·d），75．0％。耐酸厌氧消化装置持续增料运行46d，产甲烷菌仍能保持较高的活性，其COD去除率范围为40．4％-75．0％，仍能保持pH7．2时处理效果的65．0％-91．8％，表明在低pH、低碱度下实现稳定的产甲烷过程是可行的。     

市政污泥与生活垃圾混烧技术验证

对市政污泥与生活垃圾混烧进行了验证研究。结果表明，与生活垃圾单独焚烧相比，污泥与生活垃圾混烧后烟气中NOx、CO和HCl的浓度没有出现明显变化，而SO2浓度出现了下降（从82～93mg／m3下降至41～70mg／m3）；Hg、Pb、Sn、Cr和Zn的浓度均表现为不同程度的上升，但仍然符合GB[g485；二恶英从0．0087μgTEQ／m3降至O．0047μgTEQ／m3。掺烧半干污泥比例为10％、12％和15％时，吨物质的发电量分别为311．8kWh／t、306．7kWh／t和296．1kwh／t。混烧污泥在一定程度上降低了系统的发电量，因此建议混烧污泥的比例不应大于15％。测算的污泥混烧成本约209元／t（80％含水率）。     

微米级负载型TiO2催化剂在光催化-膜分离反应器中的应用

基于光催化．膜分离三相流化床反应器的结构特点及膜分离特性，以微米级MCM-41分子筛为载体，采用原位生成法制备微米级负载型TiO2催化剂。针对微米级负载型TiO2催化剂在光催化一膜分离反应器中的分布特性、悬浮特性、分离特性及膜污染特性进行研究。结果表明，曝气量一定的情况下，微米级负载型TiO2催化剂在光催化一膜分离反应器中具有良好的悬浮特性，且优于纳米TiO2。随着催化剂投加量的增加，悬浮浓度也随之增加。光催化反应器底部曝气0．3m。／h、催化剂投加量为1g／L时为宜。膜分离器中催化剂悬浮浓度明显低于光催化反应器；该微米级催化剂与纳米TiO2相比具有不粘附、不堵塞膜孔等优良特性，能够有效降低膜污染，延长分离膜使用寿命。膜底曝气为0．1m3／h时，反应器连续运行5h（未加反冲洗）后，微米级负载型TiO2催化剂和纳米TiO2对膜组件的污染程度分别为膜通量衰减率4．3％和37．4％。反应器连续运行72h，膜组件依然具有很好的分离特性。     

水力负荷和回流比对前置反硝化BAF系统处理玉米青贮液的影响

采用前置反硝化BAF系统处理玉米青贮液，在前期实验的基础上重点考察了水力负荷和回流比对COD、NH3-N、TN的去除效果。结果表明，前置反硝化BAF系统处理玉米青贮渗出液有着良好的除碳脱氮效果；在气水比为2：1、水力负荷2．60m3／（m2·h）、回流比为300％的条件下COD、NH3-N、TN的去除率分别达到89．6％、84．5％和81．3％；出水浓度分别为22．36、16．28和22．81mg／L；水力负荷影响着系统内生物膜的更新速度、生物膜的厚度以及水的剪切力大小；回流比对该系统脱氮性能有着重要影响，当回流比从50％提高到300％时TN去除率显著提高，从42．3％增加到81．3％，增加了39．0％。     

Particulate Emissions from Construction Activities

Abstract

Although it has long been recognized that road and building construction activity constitutes an important source of particulate matter (PM) emissions throughout the United States, until recently only limited research has been directed to its characterization. This paper presents the results of PM₁₀ and PM_2.5 (particles ≤10 μm and ≤2.5 μm in aerodynamic diameter, respectively) emission factor development from the onsite testing of component operations at actual construction sites during the period 1998 –2001. Much of the testing effort was directed at earthmoving operations with scrapers, because earthmoving is the most important contributor of PM emissions across the construction industry. Other sources tested were truck loading and dumping of crushed rock and mud and dirt carryout from construction site access points onto adjacent public paved roads. Also tested were the effects of watering for control of scraper travel routes and the use of paved and graveled aprons at construction site access points for reducing mud and dirt carryout. The PM₁₀ emissions from earthmoving were found to be up to an order of magnitude greater than predicted by AP-42 emission factors drawn from other industries. As expected, the observed PM_2.5:PM₁₀ emission factor ratios reflected the relative importance of the vehicle exhaust and the resuspended dust components of each type of construction activity. An unexpected finding was that PM_2.5 emissions from mud and dirt carryout were much less than anticipated. Finally, the control efficiency of watering of scraper travel routes was found to closely follow a bilinear moisture model.     

Particulate emissions from construction activities

Although it has long been recognized that road and building construction activity constitutes an important source of particulate matter (PM) emissions throughout the United States, until recently only limited research has been directed to its characterization. This paper presents the results of PM10 and PM2.5 (particles < or = 10 microm and < or = 2.5 microm in aerodynamic diameter, respectively) emission factor development from the onsite testing of component operations at actual construction sites during the period 1998-2001. Much of the testing effort was directed at earthmoving operations with scrapers, because earthmoving is the most important contributor of PM emissions across the construction industry. Other sources tested were truck loading and dumping of crushed rock and mud and dirt carryout from construction site access points onto adjacent public paved roads. Also tested were the effects of watering for control of scraper travel routes and the use of paved and graveled aprons at construction site access points for reducing mud and dirt carryout. The PM10 emissions from earthmoving were found to be up to an order of magnitude greater than predicted by AP-42 emission factors drawn from other industries. As expected, the observed PM2.5:PM10 emission factor ratios reflected the relative importance of the vehicle exhaust and the resuspended dust components of each type of construction activity. An unexpected finding was that PM2.5 emissions from mud and dirt carryout were much less than anticipated. Finally, the control efficiency of watering of scraper travel routes was found to closely follow a bilinear moisture model.     

Characterization of the fugitive particulate emissions from construction mud/dirt carryout

Although the fugitive dust associated with construction mud/dirt carryout can represent a substantial portion of the particulate matter (PM) emissions inventory in nonattainment areas, it has not been well characterized by direct sampling methods. In this paper, a research program is described that directly determined both PM10 and PM2.5 (particles < or =10 and 2.5 microm in classical aerodynamic diameter, respectively) emission factors for mud/dirt carryout from a major construction project located in metropolitan Kansas City, MO. The program also assessed the contribution of automotive emissions to the total PM2.5 burden and determined the baseline emissions from the test road. As part of the study, both time-integrated and continuous exposure-profiling methods were used to assess the PM emissions, including particle size and elemental composition. This research resulted in overall PM10 and PM2.5 emission factors of 6 and 0.2 g/vehicle, respectively. Although PM10 is within the range of prior U.S. Environmental Protection Agency (EPA) guidance, the PM2.5 emission factor is far lower than previous estimates published by EPA. In addition, based on both the particle size and chemical data obtained in the study, a major portion of the PM2.5 emissions appears to be attributable to automotive exhaust from light-duty, gasoline-powered vehicles and not to the fugitive dust associated with reentrained mud/dirt carryout.     

Characterization of the Fugitive Particulate Emissions from Construction Mud/Dirt Carryout

Abstract

Although the fugitive dust associated with construction mud/dirt carryout can represent a substantial portion of the particulate matter (PM) emissions inventory in non-attainment areas, it has not been well characterized by direct sampling methods. In this paper, a research program is described that directly determined both PM₁₀ and PM_2.5 (particles ≤10 and 2.5 μm in classical aerodynamic diameter, respectively) emission factors for mud/dirt carryout from a major construction project located in metropolitan Kansas City, MO. The program also assessed the contribution of automotive emissions to the total PM_2.5 burden and determined the baseline emissions from the test road. As part of the study, both time-integrated and continuous exposure-profiling methods were used to assess the PM emissions, including particle size and elemental composition. This research resulted in overall PM₁₀ and PM_2.5 emission factors of 6 and 0.2 g/vehicle, respectively. Although PM₁₀ is within the range of prior U.S. Environmental Protection Agency (EPA) guidance, the PM_2.5 emission factor is far lower than previous estimates published by EPA. In addition, based on both the particle size and chemical data obtained in the study, a major portion of the PM_2.5 emissions appears to be attributable to automotive exhaust from light-duty, gasoline-powered vehicles and not to the fugitive dust associated with re-entrained mud/dirt carryout.     

微米Cu／Fe对污染土壤洗脱液中有机氯农药的降解

以表面活性剂TritonX-100（TX-100）为洗脱剂，某有机氯农药（organochlorinepesticides，OCPs）污染场地土壤为对象，七氯、氯丹和灭蚁灵为目标污染物，研究微米Cu／Fe双金属对污染土壤洗脱液中OCPs的降解效果。考察了洗脱液中OCPs初始浓度、洗脱液pH值、微米零价铁加入量和cu负载量对Cu／Fe去除OCPs效果的影响。结果表明，微米Cu／Fe可以有效的去除土壤洗脱液中目标污染物。当微米零价铁加入量为1．0g（25g／L），cu负载量为1．0％，洗脱液pH值为6．89时，Cu／Fe对2号土壤洗脱液中七氯、γ-氯丹、α-氯丹和灭蚁灵的去除效果最好，去除率分别为100．0％、99．3％、80．8％和71．1％。洗脱液中OCPs初始浓度越低，微米零价铁加入量越大，Cu／Fe对OCPs去除率越高；偏酸性条件有利于Cu／Fe对γ-氯丹和灭蚁灵的去除，而α-氯丹在中性条件下去除效果最好；1号土壤和2号土壤洗脱液的最佳铜负载量分别为2．O％和1．0％。     

Evaluating Speed Differences between Passenger Vehicles and Heavy Trucks for Transportation-Related Emissions Modeling

Abstract

Heavy-duty trucks make up only 3% of the on-road vehicle fleet, yet they account for >7% of vehicle miles traveled in the United States. They also contribute a significant proportion of regulated ambient emissions. Heavy vehicles emit emissions at different rates than passenger vehicles. They may also behave differently on‐road, yet may be treated similarly to passenger vehicles in emissions modeling. Input variables to the MOBILE software, such as average vehicle speed, are typically specified the same for heavy trucks as for passenger vehicles. Although not frequently considered in modeling emissions, speed differences between passenger vehicles and heavy trucks may influence emissions, because emission rates are correlated to average speed. Differences were evaluated by collecting average and spot speeds for heavy trucks and passenger vehicles on arterials and spot speeds on freeways in Des Moines, IA, and Minneapolis/St. Paul, MN. Speeds were compared by study site. Space mean speeds for heavy trucks were lower than passenger vehicle speeds for all of the arterials with differences ranging from 0.8 to 19 mph. Spot speeds for heavy trucks were also lower at all of the arterial and freeway locations with differences ranging from 0.8 to 6.1 mph. The impact that differences in on‐road speeds had on emissions was also evaluated using MOBILE version 6.2. Misspecification of average truck speed is the most significant at lower and higher speed ranges.     

Testing Re-entrained Aerosol Kinetic Emissions from Roads : a new approach to infer silt loading on roadways

PM₁₀ and PM_2.5 emissions from roadways are currently estimated using the silt loading on the road surface as a surrogate for the emissions potential of road dust. While the United States Environmental Protection Agency prescribes this method in AP-42, there is considerable cost associated with silt loading measurements; it is feasible to sample only a small portion of a roadway network. A new approach for measuring the concentration of suspendable PM₁₀ above road surfaces has been developed to obtain a more spatially representative estimate of a road's potential to emit dust. The Testing Re-entrained Aerosols Kinetic Emissions from Roads (TRAKER) system uses real-time aerosol sensors mounted on a vehicle to measure the concentration of dust suspended from the road while the vehicle is in motion. When coupled with a Global Positioning System (GPS) instrument, TRAKER can be used to efficiently survey the changes in suspendable particles due to varying road conditions over a large spatial domain.In a recent study on paved roads in Las Vegas, the TRAKER system was compared with collocated silt loading measurements. The TRAKER system was also used to survey the relative amounts of suspendable road dust on approximately 300 miles of paved roads. The system provides a unique perspective on road dust sources and their spatial distribution.Results of this study indicated that the difference of the PM₁₀ concentrations measured behind the tire and on the hood is exponentially related to vehicle speed. This was an interesting finding because current AP-42 road dust emissions estimation methods do not include vehicle speed as a factor in the emissions calculations. The experiment also demonstrated that the distribution of suspendable material on roadways is highly variable and that a large number of samples are needed to represent road dust emissions potential on an urban scale for a variety of road and activity conditions.     

烟气脱硫新型催化剂水洗再生工艺研究

对脱硫失活后的新型催化剂进行水洗再生研究，着重探讨了再生时间、洗涤水温度和喷淋密度对脱硫后的新型催化剂活性恢复能力的影响，并对3种影响因素进行了正交实验研究。结果表明，洗涤水温度、再生时间和喷淋密度是影响催化剂活性恢复的主要因素；在洗涤水温度为60℃、再生时间为30min、喷淋密度为47．9m^3／（m·h）时，催化剂活性恢复的最好；催化剂经过水洗再生后，其比表面积比未再生时的有所增加，说明在脱硫过程中堵塞催化剂活性位的硫酸物种被洗出，催化剂活性位得到了部分恢复。     

Near-road air pollution impacts of goods movement in communities adjacent to the Ports of Los Angeles and Long Beach

A mobile platform was outfitted with real-time instruments to spatially characterize pollution concentrations in communities adjacent to the Ports of Los Angeles and Long Beach, communities heavily impacted by emissions related to dieselized goods movement, with the highest localized air pollution impacts due to heavy-duty diesel trucks (HDDT). Measurements were conducted in the winter and summer of 2007 on fixed routes driven both morning and afternoon. Diesel-related pollutant concentrations such as black carbon, nitric oxide, ultrafine particles, and particle-bound polycyclic aromatic hydrocarbons were frequently elevated two to five times within 150 m downwind of freeways (compared to more than 150 m) and up to two times within 150 m downwind of arterial roads with significant amounts of diesel traffic. While wind direction was the dominant factor associated with downwind impacts, steady and consistent wind direction was not required to produce; high impacts were observed when a given area was downwind of a major roadway for any significant fraction of time. This suggests elevated pollution impacts downwind of freeways and of busy arterials are continuously occurring on one side of the road or the other, depending on wind direction. The diesel truck traffic in the area studied was high, with more than 2000 trucks per peak hour on the freeway and two- to six-hundred trucks per hour on the arterial roads studied. These results suggest that similarly-frequent impacts occur throughout urban areas in rough proportion to diesel truck traffic fractions. Thus, persons living or working near and downwind of busy roadways can have several-fold higher exposures to diesel vehicle-related pollution than would be predicted by ambient measurements in non-impacted locations.