CHARACTERIZATION OF INORGANIC PARTICLES IN SELECTED RESERVOIRS AND TRIBUTARIES OF THE NEW YORK CITY WATER SUPPLY1

ABSTRACT: Individual particle analysis (IPA) by scanning electron microscopy interfaced with automated image and X‐ray analyses was used to characterize inorganic particles in five reservoirs and four tributaries located within the Catskill and Delaware systems of the New York City water supply. Individual particle analysis provides combined elemental and morphologic characterizations. Results are presented in terms of particle projected area per unit volume (PAV), consistent with optical impacts, and partitioned into seven generic particle types according to composition. Minerals of terrigenous origins, particularly clay minerals, dominated the inorganic particle populations of all the study systems except one downstream reservoir. Higher PAV levels were observed in the Catskill system. Particle dynamics represented by PAV were driven primarily by runoff, while the reservoirs were also greatly influenced by the timing of sediment resuspension promoted by drawdown of the surface and fall mixing. The benefit of the serial configuration of the reservoirs in decreasing inorganic particles with progression downstream towards the city is demonstrated. The patterns in PAV levels among the study systems generally tracked those of more common metrics of impacts of suspensoids, including mass concentrations of suspended solids, turbidity, and Secchi disc transparency.     

极性基湿润剂与矿岩类粉尘颗粒的作用机理

根据矿岩类粉尘微颗粒的表面性质和极性基湿润剂的特性，应用分子热力学和表面物理化学理论探讨了湿润型抑尘剂与矿岩类粉尘之间的相互作用机理。矿岩类粉尘吸附水的本质是由于它们之间的相互吸引作用，是分子之间的短程相互作用力和长程作用力共同作用的结果。当矿岩类粉尘与水相碰撞时，只有当吸引力大于排斥力时，水分子才能牯附于矿岩类粉尘，表面张力和体系自由能足够小时，水才能湿润矿岩类粉尘。分析了湿润剂对水和矿岩类粉尘的表面改性的原理，它增加水和矿岩类粉尘之间的相互作用力，减小了界面表面张力和体系自由能，使矿岩粉尘被水湿润能自由地进行。     

聚合硅酸硫酸铝铁的制备与应用

在n(Fe A1)／n(Si)为0．5～1．0、n(Al)／n(Fe)为2．5～3．0、SiO2质量分数为2．3％、硅酸钠溶液的活化pH为5．5、硅酸钠溶液的活化时间为12min或SiO2的质量分数为2．0％、硅酸钠溶液的活化pH为6．0、硅酸钠溶液的活化时间为3min的条件下，制备出的聚合硅酸硫酸铝铁对废水的除浊效果最佳，除浊率大于98％。     

Proposing of new building scheme and composite towards global warming mitigation for Malaysia

The building sector has been regarded as a potential sector where there is large capacity to reduce the climate change effect. This study has proposed solutions to mitigate environmental impacts and achieve low CO₂ emission from residential sector. Therefore, full life cycle assessment (LCA) has been run to assess the CO₂ emission and its effect on the atmosphere and climate change. Based on the result, timber scheme is the best choice due to releasing less CO₂ emissions to the atmosphere. However, house builders in Malaysia have almost completely neglected timber as a building material, with timber use as building components reduced to 5%. In this study, LCA Software was used to assess CO₂ emissions from different wall construction. The alternative building scheme has been made by reinforce steel stud, wooden beam and timber wall (S8) to improve the scheme deficiency while releasing less CO₂ emissions compared to other schemes. Therefore, S8 has a decreased CO₂ effect by 85% less than precast concrete frame and 90% less than brick over their lifetime. (S8) increased the load bearing compared to conventional timber beam. Thus, new scheme S8 could be replaced by current scheme and promote more adjustable scheme for Malaysian housing.     

An analysis of end-of-life terminology in the carbon fiber reinforced plastic industry

While many studies and reviews into the practices conducted by industry and academia to recycle and remanufacture carbon fibre-reinforced plastic (CFRP) exist, to date no investigation exists which regards the correctness of the use of the terms recycling and remanufacturing. As such, this paper seeks to analyse the CFRP reuse industry’s attempt to recycle and remanufacture manufacturing waste CFRP and end-of-life (EOL) CFRP with an emphasis on the terminology used to describe these practices. Firstly, this paper presents a justification of the importance of using EOL terminology correctly; outlining the benefits and problems associated with using the correct and incorrect terminology. This paper finds that in the case of CFRP remanufacturing, terminology is being applied incorrectly and in the case of CFRP recycling, particular care should be taken when applying the term recycled to CFRP or stating that CFRP has been recycled. Further, this paper proposes new terminology (in keeping with EU directives) which could be adopted by industry and academia working in this area. This paper also finds that in the case of remanufacture, CFRP is incapable of being remanufactured.     

广州夏季办公室内细颗粒中多环芳烃污染特征研究

大部分的都市办公人群每天在办公室至少度过8 h。而室外环境的渗透、办公室内吸烟、办公设备使用和中央通风系统均可能导致细颗粒物及多环芳烃(PAHs)在室内积聚而造成微环境污染。2015年5—6月,在广州市3种不同功能区(商住区、高新产业区、工业区)共选取了14间不同类型的办公室,对其室内外PM_(2.5)和多环芳烃进行同步监测。结果表明,(1)14间中有12间办公室内的PM_(2.5)浓度水平高于世界卫生组织(WHO)的推荐值25μg·m-3;(2)与国内外类似研究相比,办公室内外∑16PAHs及Ba P-eq的监测浓度水平均较低,并呈现一致规律:文印>室外>吸烟>多人>单人>无窗(无人),其中Ba P-eq低于欧盟规定的安全限值1 ng·m-3;(3)文印工作和吸烟行为与室内PM_(2.5)和PAHs浓度升高有密切关系,分别对5环和4环PAHs贡献明显;(4)其他无明显内源的办公室的细颗粒中PAHs污染在监测期间主要来源于室外贡献。     

Robustness testing of a free-fall triboelectric separation process for plastic waste recovery

Among the separation techniques used in industries, the triboelectric separation of insulating particles using a rotary tube is an effective way employed in the waste recovery of plastic and mineral products. This process, also called free-fall triboelectric separation, is widely used for the sorting of granular mixtures resulting from industrial plastic wastes. Given that the robustness of such a separation process is an important issue, a standard procedure is used for determining the set point and for minimising the process sensitivity of sorting mixed particles of different polymers to changes in the values of some critical factors. The aim of this paper was to analyse the efficiency of the triboelectric separation process of polymers with respect to any slight variation in the values of the most significant factors. Experiments with a sample of high-density polyethylene and polyvinyl chloride plastic granules were carried out on a laboratory experimental bench. Several one-factor-at-a-time experiments, followed by two factorial designs (one composite and the other fractional), were performed based on the following experimental procedure: (1) determination of the variation limits of the input variables; (2) identification of the set point and (3) robustness testing of the process, i.e. testing whether the performance of the system remains high even when the factors vary slightly around the set point.     

西南山地区域森林火险综合预报模型研究——以重庆市为例

森林火灾严重破坏森林生态系统的结构和功能,针对其风险预报开展研究具有重要的理论意义和应用价值。通过融合气象、地表覆盖和人类活动等要素的方式构建森林火险综合预报模型,是西南山地区域森林火险综合预报业务化应用的重要发展方向。基于《森林火险气象等级》国家标准(GB/T 36743-2018),本文研究首先构建了重庆市森林火险气象风险预报模型。然后通过融合可燃物因素和人为因素的方式,进一步构建重庆市森林火险综合预报模型。最后利用历史火点数据针对上述两类模型的精度进行对比和分析。研究结果表明:重庆市森林火灾发生次数较多,且呈现出季节性规律;重庆市森林火灾的发生不仅受到气象条件的影响,而且受到地表覆盖和人类活动等多种要素条件的共同影响;与森林火险气象风险预报结果相比,森林火险综合预报结果在空间分布上具有更高的精细程度;森林火险综合预报模型能有效提高森林火险等级预报精度。     

PbO_2复合电极预处理甲苯二胺废水

通过涂覆—热分解法与电沉积法制备了β-PbO_2/α-PbO_2/SnO_2-Sb2O3/Ti复合电极(PbO_2复合电极),采用X射线衍射(XRD)、扫描电子显微镜(SEM)、循环伏安法(CV)、线性极化法(LSV)和加速寿命试验对电极进行表征。将PbO_2复合电极用于处理甲苯二胺(TDA)废水,考察了电解质浓度、电流密度对TDA降解效果的影响。实验结果表明:α-PbO_2呈梭状,β-PbO_2呈花菜状,多层结构的PbO_2电极利于提高电极的稳定性和活性;PbO_2复合电极的析氧电位(1.9 V)明显高于TDA的氧化电位(1.28 V),其使用寿命长达486 d;在电流密度为60 m A/cm2、Na2SO4质量浓度为10 g/L、电解时间为240 min的条件下,对COD为4 791.74 mg/L、TDA质量浓度为486.4mg/L的废水进行处理,TDA去除率高达97.3%,COD去除率可达88.1%。     

一种包埋微生物复合填料的制备及性能评价

采用包埋法制备出一种复合生物填料，测其各项理化性质，并以NO。模拟废气验证其脱硝性能。填料主要由碳酸钙、牛粪堆肥腐殖质、菌剂载体、水泥、轻质珍珠岩、立体网状纤维及脱硝功能微生物等复合而成，粒径书12mm×20mm，自然堆积密度（471±0．8）kg／m2，持水量（49±1．3）％，比表面积3．91m2／g，平均机械强度（427．3±0．2）N，pH为10．5-0．2。填料能长期在潮湿环境中保持良好的粘结强度，并具有营养缓释及pH缓冲能力。包埋脱硝功能微生物复合填料中初期微生物数量5．3×10^5 CFU／g，运行60d后微生物数量达到8．6×10 8 CFU／g，闲置停运30d微生物有所减少，但重启后净化效率基本不变。当进气负荷低于I878mg／（13m3·h），气体停留时间为14．47s时，BF，的去除率高达93．15％。