Synthesis,structure, and adsorption properties of a three-dimensional porous yttrium–organic coordination network

Deprotonation of 4,4′-biphenyldicarboxylic acid (H₂BPDC) with triethylamine followed by the copolymerization with Y(III) in N,N-dimethylformamide (DMF) at room temperature yields a new three-dimensional (3-D) porous metal–organic coordination network, [Y₂(BPDC)₃(DMF)₂(H₂O)₂]_n · (DMF)_n · (H₂O)_n (1). Compound 1 (C_24.50H₁₉N_1.50O₉Y) crystallizes in the triclinic P-1 space group (a = 8.220 (2), b = 13.998 (4), c = 14.212 (4) Å, α = 111.058 (5)°, β = 90.187 (5)°, γ = 94.318 (5)°, V = 1520.9 (7) ų, and Z = 2). X-ray crystallography reveals that 1 consists of a 3-D framework contained open 1-D channels with the dimension of 5 × 10 Å along the crystallographic a axis. The adsorption measurements show that compound 1 can adsorb N₂, Ar and CO₂ into its pores. The adsorption isotherms for MeOH and H₂O were also measured.     

Efficient Preparation and Characterization of Functional Graphene with Versatile Applicability

Graphene, as star versatile materials having extraordinarily high electric conductivity, electron mobility, thermal conductivity, thermal stability, optical transparency, and mechanical strength, has attracted much attention from scientists and engineers in the field of materials, chemistry, physics, energy, and environment in the last decade and achieved fruitful accomplishment. This review discusses preparation strategies, functionality, characterization, and applications for two dimensional nanosheet and quasi-one-dimensional nanoribbon of graphene through direct exfoliation of graphite, chemical vapor deposition of hydrocarbon, laser-induced direct synthesis of graphene, laser etched graphene oxide in the dry state without the use of toxic reducing agent hydrazine, unzipping carbon nanotube, and polycondensation of polycyclic aromatics on the basis of 178 representative references mostly in 2015. The stabilization of graphene oxide prepared in chemical preparation in "top-down" is emphasized. Several vital classic methods of characterizing molecular structure, C/O ratio, defect, morphology, single-or few-layered (2 to 10 layers) structure, porous and hollow structures, including Raman spectroscopy, AFM, SEM, TEM, STM, electron diffraction, X-ray diffraction, and X-ray photoelectron spectroscopy are systematically introduced. Because graphene possesses novel incomparable multifunctionalities, its versatile applications as novel conducting additives, reinforcing filler, separation membrane, sensor, anticorrosive coating, catalyst, electromagnetic shield, lubricant, and flexible electrode materials in electrochemical and electronic devices, including photovoltaic cells, supercapacitors, rechargeable batteries, sensors, field effect transistors, light emitting diodes, separation membranes, adsorbents and absorbents, catalysts, electro-optic modulator, terahertz emitter and detector, and semiconductors, have been mentioned.Especially in the aspect of both high performance and cost-effectiveness, graphene is expected to be even superior to the expensive carbon nanotubes.     

Problems of manufacturing prefabricated drainage filters and filtrating textiles

In its first part the paper deals with the production of jacketted flexible drainage pipes with filtrating textiles, the so called prefafilters. Four possible arrangements of the production line are given, of which most effective solution is the combination of the production line of flexible drainage pipes with the jacketting line in one unit.In part two of the paper, desired properties of the filtrating textile are given. These properties are specified from the aspect of both its workability in the manufacturing of jacketted drainage pipes and its protective efficiency. Furthermore, technical parameters of the filtrating textiles used in Czechoslovakia are given, namely non-woven spunbound textiles (type B), needle-punched textiles of recycled synthetic and natural fibres interlacing (type C1 and C2), and their properties are compared with the traditional frequently used non-woven needle-punched textile from original synthetic material (type A).     

粉煤灰地聚物反应体系下的反应影响因素分析

以粉煤灰基地质聚合物为研究对象,研究了粉煤灰在地聚物反应体系下的反应影响因素。主要研究内容有:反应时间、反应温度和反应碱浓度对反应过程及宏观强度的影响及相关反应机理。结果表明:在反应中后期,粉煤灰反应速率明显下降而此时地聚物的宏观性能反而呈现最大值。以75℃为例,反应时间从24h延长到672h的过程中,反应程度仅从20.8%增加到了32.4%,平均反应速率仅为0.0179%/h,而此时样品的抗压强度则从1.31MPa增加到了7.98 MPa;在地聚物反应体系下,反应产物为无定形的硅铝胶凝体,该物质的致密程度与地聚物宏观性能直接相关;温度的升高可有效提高粉煤灰的反应速率及地聚物的宏观性能,促进无定形胶凝体的形成和硬化。反应24h,75℃下的反应程度和抗压强度可以达到20.8%和1.31 MPa,而同期35℃下的反应程度只能达到7.8%且尚未形成宏观强度;碱浓度的变化不仅可影响反应速率和宏观性能,还可改变粉煤灰在地聚物反应体系下的最终反应程度,在反应温度为75℃和50℃时,10 mol/L体系下672h的反应程度比5 mol/L体系分别高了90%和28.6%。     

Phosphorus in rivers — ecology and management

This paper examines the nature of the risk to riverine ecosystems from artificially enhanced loads of phosphorus, considers the key sources of phosphorus enrichment and ways of controlling them, and provides a framework for developing control strategies. The aquatic plant community is the foundation for a healthy and diverse riverine ecosystem, providing food, shelter and breeding habitats for a wide range of animal species. Phosphorus enrichment in rivers can degrade the plant community by altering the competitive balance between different aquatic plant species, including both higher plants and algae. This has consequences for the whole ecosystem. To promote healthy riverine plant communities and the wide range of animal species dependent on them, phosphorus concentrations need to be reduced to as near to background levels as possible. The risk of adverse effects declines as phosphorus concentrations approach background levels, such that any incremental reduction should be seen as a positive step towards trophic restoration. Pragmatic management targets vary between 0.02 and 0.1 mg l⁻¹ soluble reactive phosphorus, depending on river type, with an interim target of 0.2 mg l⁻¹ for heavily enriched rivers. Continuous point sources of phosphorus, dominated by sewage treatment works, have a highly important influence on levels of bioavailable phosphorus in the water column through the growing season. It is important to tackle point sources comprehensively so that reductions in phosphorus concentrations are maximised during this critical time of year. Diffuse sources of phosphorus, particularly from agriculture, are a major contributor to phosphorus levels in riverine sediments, where it can be utilised by benthic algae and rooted plants. This phosphorus can also be released into the water column by a variety of processes. As point sources are brought under control, the relative contribution from diffuse sources becomes increasingly important. An integrated programme of control, involving proactive action on both point and diffuse sources, will be required in most circumstances to bring phosphorus levels in the water column and sediment down to near background levels.     

上海市排水系统雨天出流的初期效应分析

以上海市苏州河沿岸5个代表性排水系统为研究对象，采用无因次累积负荷体积分数曲线[M（y）曲线]和b参数方法，对上海市排水系统雨天出流的初期效应现象进行了探讨。研究表明，若以30／80标准衡量，5个排水区域都没有初期效应。若以50／50标准判定，合流制系统具有微弱初期效应，分流制系统雨天出流水质变化过程随降雨事件不同而有很大波动，总体上没有初期效应。COD和BOD5比SS更具初期效应。各水质指标的初期效应强度随不透水比例增加而增加，随汇水面积增加而减小。研究成果为雨水存储池等城市面源污染控制设施的规划设计提供了依据．     

电解法深度处理生活垃圾焚烧厂渗滤液研究

采用三元电极对垃圾焚烧厂渗滤液的生化-混凝出水进行电解处理，研究了其处理效果及影响因素。结果表明，在电解反应过程中COD的降解符合三级反应动力学，其t时刻的出水浓度为：Ct=（2kt＋C0^-2）^-0.5；电流、pH值、电解时间、氯离子浓度、进水COD浓度对有机物去除率的影响较大，而极间距、温度和极水比则影响较小。此外，考察了该电极对氮化合物的去除效果。结果表明，在电解过程中亚硝态氮很快被氧化成硝态氮，之后氨氮转化为氮气，总氮基本以硝态氮的形式存在。     

低碳、高氮磷城市污水的化学辅助除磷研究

对于低碳、高氮磷的城市污水，可采用生物脱氮并辅助化学除磷的工艺进行处理，以使氮、磷同时达到排放标准。选择聚合硅酸铁作为混凝剂并将其直接投加到生物反应器中，结果表明，当投加量为12mg／L（以Fe计）时出水中的TP〈0．5mg／L，达到了《城镇污水处理厂污染物排放标准》（GB 18918-2002）的一级A标准。所投加的聚合硅酸铁与进水中TP的物质的量之比同出水TP之间具有很好的相关性，因而在进、出水TP浓度一定的情况下。可据此确定混凝剂的投量。投加了混凝剂后，污泥絮体变得更密实，沉降性能良好。     

In situ structure/function studies in wastewater treatment systems

As an example of the importance and the potential of in situ structure/function studies, nitrifying aggregates from different zones of a lab-scale fluidised bed reactor were analysed by microelectrode measurements of O₂ NH₄⁺, NO₂⁻, and NO₃⁻ and in situ hybridisation targeting the 16S rRNA of the nitrifying bacteria. A shift trom an ammonia oxidising to a nitrite oxidising community is present along the reactor. In the single aggregates an active nitrifying shell of about 100 gm could be related to the maximum abundance of nitrifiers in this zone. Interestingly, the main actors in this system are not representatives of the well-described genera Nitrosomonas and Nitrobacter but some other ammonia oxidisers from the beta subclass of Protcobacteria and a thus far unknown nitrite oxidising population.