Fluorescence detection of phosphate in an aqueous environment by an aluminum-based metal-organic framework with amido functionalized ligands

● A novel Al-MOF was successfully synthesized by a facile solvothermal method. ● Al-MOF showed superior performance for phosphate detection. ● High selectivity and anti-interference for detection were demonstrated. ● The high coordination between Al-O and PO₄³⁻ was the key in fluorescence sensing. The on-site monitoring of phosphate is important for environmental management. Conventional phosphate detection methods are not appropriate to on-site monitoring owing to the use of complicated detection procedures, and the consequent high cost and maintenance requirements of the detection apparatus. Here, a highly sensitive fluorescence-based method for phosphate detection with a wide detection range was developed based on a luminescent aluminum-based metal-organic framework (Al-MOF). The Al-MOF was prepared by introducing amine functional groups to conventional MIL to enhance phosphate binding, and exhibited excellent fluorescence properties that originated from the ligand-to-metal charge transfer (LMCT). The detection limit was as low as 3.25 μmol/L (0.10 mg/L) and the detection range was as wide as 3–350 μmol/L (0.10–10.85 mg/L). Moreover, Al-MOF displayed specific recognition toward phosphate over most anions and metal cations, even for a high concentration of the co-existent ions. The mechanism of phosphate detection was analyzed through the characterization of the combination of Al-MOF and phosphate, and the results indicated the high affinity between Al-O and phosphate inhibited that the LMCT process and recovered the intrinsic fluorescence of NH₂-H₂BDC. The recovery of the developed detection method reached a satisfactory range of 85.1%–111.0%, and the feasibility of on-site phosphate detection was verified using a prototype sensor for tap water and lake water samples. It was demonstrated that the prepared Al-MOF is highly promising for on-site detection of phosphate in an aqueous environment.     

Immobilization of antimony in soil and groundwater using ferro-magnesium bimetallic organic frameworks

Sb(Ⅲ) is often detected in contaminated soil and groundwater. Hence, high-efficiency technology is needed. In this study, bimetallic organic frameworks were used for the first time to immobilize Sb(Ⅲ) from contaminated soil and groundwater. The materials were synthesized by the hydrothermal method. Both ends of the prepared material were hexagonal tip rods,and the length became shorter as the ratio of Fe/Mg decreased. The bimetallic organic framework with a Fe/Mg feeding ratio of 0.5 was the opt...     

SOCIO-ECONOMIC IMPACTS OF RURAL WATER SUPPLES1

ABSTRACT Development of community water systems in rural areas through the Farmers Home Administration, U. S. D. A., has been marked since the initiation of the program in the early 1%O's. System development in Mississippi has been very rapid and now numbers the largest among the states excepting Texas. Concurrent with this growth, however, has been a concern for operational quality and efficiency as well as questions of community impacts. The paper is purposed with describing the results of research conducted relative to these areas and methods currently being employed or considered for dealing with problematic items.     

Optimal Control Models and Elicitation of Attitudes towards Climate Damages

This paper examines the consequences of various attitudes towards climate damages through a family of stochastic optimal control models (RESPONSE): cost-efficiency for a given temperature ceiling; cost-benefit analysis with a pure preference for current climate regime and full cost-benefit analysis. The choice of a given proxy of climate change risks is actually more than a technical option. It is essentially motivated by the degree of distrust regarding the legitimacy of an assessment of climate damages and the possibility of providing in due time reliable and non controversial estimates. Our results demonstrate that (a) for early decades abatement, the difference between various decision-making frameworks appears to matter less than the difference between stochastic and non stochastic approach given the cascade of uncertainty from emissions to damages; (b) in a stochastic approach, the possibility of non-catastrophic singularities in the damage function is sufficient to significantly increase earlier optimal abatements; (c) a window of opportunity for action exists up to 2040: abatements further delayed may induce significant regret in case of bad news about climate response or singularities in damages.     

Two novel sets of UiO-66@ metal oxide/graphene oxide Z-scheme heterojunction: Insight into tetracycline and malathion photodegradation

Nowadays,widespread researches have been focused on the development of effective photocatalysts to remove pollutants of the aquatic system.In accordance with the universal studies,two new sets of UiO-66@metal oxide(including ZnO and TiO_2)/graphene oxide heterojunctions were synthesized for photodegradation of aromatic(tetracycline)and nonaromatic(malathion) pollutants which are challenging cases in the environment.The dosage of the photocatalyst,pH of the solution,the type of metal oxide,and the presence of various scavengers are assayed parameters in this work.In the optimum condition,maximum photodegradation efficiency is achieved in 90 min for tetracycline(81%) and malathion(100%) by the UiO-66@ZnO/graphene oxide.The superior separation of charge carriers by Z-scheme mechanism,excellent electron mobility on layers of graphene oxide and high surface area are factors that enhanced the efficiency.Furthermore,in comparison with pure UiO-66,the band gaps belong to heterojunctions revealed a red shift in the absorption edge,which can be responsible for more expand adsorption of the solar spectrum.Total organic carbon analysis verified the decontamination of these pollutants in the solution.The produced main intermediates during the photocatalytic process were identified and the possible degradation pathway proposed.In general,the superior photocatalytic activity suggests that these designed photocatalysts can be a promising choice for having a clean future.     

Integrated risk assessment framework for transformation products of emerging contaminants: what we know and what we should know

● A better risk assessment can combine the improved non-target analysis method. ● Multi-evidence is advised in molecular determination and risk-based prioritization. ● Combining omics, multi-endpoint EDA, and machine learning to assess product risks. The continuous input of various emerging contaminants (ECs) has inevitably introduced large amounts of transformation products (TPs) in natural and engineering water scenarios. Structurally similar to the precursor species, the TPs are expected to possess comparative, if not more serious, environmental properties and risks. This review summarizes the state-of-the-art knowledge regarding the integrated risk assessment frameworks of TPs of ECs, mainly involving the exposure- and effect-driven analysis. The inadequate information within existing frameworks that was essential and critical for developing a better risk assessment framework was discussed. The main strategic improvements include (1) non-targeted product analysis in both laboratory and field samples, (2) omics-based high-throughput toxicity assessment, (3) multichannel-driven mode of action in conjugation with effect-directed analysis, and (4) machine learning technology. Overall, this review provides a concise but comprehensive insight into the optimized strategy for evaluating the environmental risks and screening the key toxic products from the cocktail mixtures of ECs and their TPs in the global water cycle. This facilitates deciphering the mode of toxicity in complex chemical mixtures and prioritizing the regulated TPs among the unknown products, which have the potential to be considered a class of novel “ECs” of great concern.     

Construction of MOFs-based nanocomposite membranes for emerging organic contaminants abatement in water

● Application of the MOF-composite membranes in adsorption was discussed. ● Recent application of MOFs-membranes for separation was summarized. ● Separation and degradation for emerging organic contaminants were described. Presence of emerging organic contaminants (EOCs) in water is one of the major threats to water safety. In recent decades, an increasing number of studies have investigated new approaches for their effective removal. Among them, metal-organic frameworks (MOFs) have attracted increasing attention since their first development thanks to their tunable metal nodes and versatile, functional linkers. However, whether or not MOFs have a promising future for practical application in emerging contaminants-containing wastewater is debatable. This review summarizes recent studies about the removal of EOCs using MOFs-related material. The synthesis strategies of both MOF particles and composites, including thin-film nanocomposite and mixed matrix membranes, are critically reviewed, as well as various characterization technologies. The application of the MOF-based composite membranes in adsorption, separation (nanofiltration and ultrafiltration), and catalytic degradation are discussed. Overall, literature survey shows that MOFs-based composite could play a crucial role in eliminating EOCs in the future. In particular, modified membranes that realize separation and degradation might be the most promising materials for such application.     

金属有机框架（MOFs）材料电催化还原CO2研究进展

电催化还原CO2转化为清洁能源或有用的化学品被认为是减排CO2的一种有效方式。金属有机框架(MOFs)材料由于分散的金属中心和可调的化学结构等特点而被广泛应用于电催化领域。综述了MOFs材料用于电催化还原CO2的研究进展,对比了近年来MOFs材料及其衍生物电催化CO2化学转化的效率及产物选择性,并对MOFs材料作为电催化材料的应用前景进行了展望。     

含钴基金属有机框架硅橡胶泡沫阻燃特性研究*

为提高硅橡胶泡沫（SiFs）的阻燃性能,采用溶剂法制备钴基金属有机框架材料（Co-MOFs）并用X射线光电子能谱仪（XPS）对其结构进行表征。将制备的材料添加到SiFs中,利用极限氧指数（LOI）、UL-94试验和锥形量热仪（CONE）对SiFs的阻燃性能和抑烟性能进行研究。结果表明:添加1%及以上Co-MOFs时,SiFs阻燃等级达到UL-94-V0级;添加3%Co-MOFs时,SiFs的LOI达30.2%,热释放速率峰值（PHRR）和总热释放量（THR）相比原样分别降低了56.92%和66.73%;添加1%Co-MOFs的SiFs的产烟率峰值（PSPR）和产烟量（TSR）比原样分别降低了82%和85%,Co-MOFs提高了SiFs的阻燃和抑烟性能。     

UiO-66/UiO-66-PYDC的制备及其对UO22+吸附性研究

通过水热法合成了两种锆基有机骨架材料,采用XRD、SEM、IR、TG、EDS、BET等技术对材料的结构和形貌进行了表征,并通过静态吸附实验在不同条件下测试所制材料对UO2+2的吸附性能,考察了时间、温度、初始铀浓度、pH、CO2-3对吸附的影响.结果表明:Ui O-66体系对铀酰离子的吸附以化学吸附为主,通过表面的羧基官能团与铀酰离子结合从而达到吸附的目的.此外,本实验中材料的比表面积对吸附的影响不明显.在初始最佳pH为10.5的条件下,通过热力学模型拟合发现,低浓度下Ui O-66拥有更大的吸附量.随着溶液中初始铀酰离子浓度的升高,Ui O-66-PYDC展现出更好的吸附效果.