Ion Exchange Method for Removal and Separation of Noble Metal Ions

Ion exchange has been widely applied in technology of chemical separation of noble metal ions. This is associated with dissemination of methods using various ion exchange resins which are indispensable in many fields of chemical industry. Due to small amounts of noble elements in nature and constant impoverishment of their natural raw materials, of particular importance are physicochemical methods of their recovery from the second sources e.g. worn out converters of exhausted gases, chemical catalysts, dental alloys, anodic sludges from cooper and nickiel electrorefining as well as waste waters and running off waters from refineries containing trace amount of noble metals. It should be stated that these waste materials are usually pyro- and hydrometallurgically processed. Recovery of noble metals, from such raw materials requires individual approach to each material and application of selective methods for their removal. Moreover, separation of noble metals, particularly platinum metals and gold from geological samples, industrial products, synthetic mixtures along with other elements is a problem of significant importance nowadays. In the paper the research on the applicability of different types of ion exchangers for the separation of noble metals will be presented. The effect of the different parameters on their separation will be also discussed. The examples of the removal of noble metals chlorocomplexes will also be presented in detail

Comparative phylogeography of two sister (congeneric) species of cardiid bivalve: Strong influence of habitat, life history and post-glacial history

International audienceSister (congeneric) species may exhibit disparate patterns of biogeographic genetic structures due to different life histories and habitat preferences. The common cockle Cerastoderma edule and the lagoon cockle Cerastoderma glaucum probably diverged from their common ancestor in the present territory of Sahara around 5 million years ago. Although it is difficult to separate both species morphologically, various genetic markers, both mitochondrial and nuclear, clearly distinguish them. Furthermore, their lifestyles are different, as C. edule has a much less fragmented coastal habitat and a longer duration of pelagic larval stage than C. glaucum. A comparative genetic analysis was conducted on 17 populations of C. edule and 13 populations of C. glaucum using a 506 bp fragment of mitochondrial DNA (COI).We tested the hypothesis that differences in habitat types and life history are reflected in the genetic structure patterns of these two cockles. Indeed substantial differences in population genetic structures between them are revealed. Genetic diversity within C. glaucum populations decreases northwards as a consequence of post-glacial (re)colonization from southern refugia, while C. edule displays an opposite pattern indicating survival in glacial refuges in the northern Atlantic. Among populations within geographic groups, genetic differentiation is low in C. edule, probably as a result of larval dispersal with coastal currents, while it is extremely high in C. glaucum, best explained by the fragmented habitats. Interestingly, long distance divergence is less expressed in C. glaucum than in C. edule, which supports the speculation that migrating birds (frequently observed in lagoons) may occasionally transport the former more often or more efficiently than the latter. The approach applied in this study (e.g., rarefaction procedure, selection of samples of both species from the same regions) enabled a new and reliable comparative analysis of the existing raw datasets

Laser-induced breakdown spectroscopy analysis of copper and nickel in chelating resins for metal recovery in wastewater

Recovery of heavy metals from industrial waste streams is becoming an important challenge due to increasing wastewater production. Chelating resins provide an effective treatment for selective adsorption of metals. Several analytical techniques can be used to assess the adsorption performance, but LIBS offers the unique advantage of in-process continuous monitoring. In this work, LIBS measurements of copper and nickel spectra were performed on single and bi-component resin samples. Single component calibration curves for copper and nickel were obtained with high correlation (R2 = 0.99 and R2 = 0.98 respectively). Bi-component resin measurements reveal good prediction accuracy for nickel and copper concentrations, the mean relative error in concentration prediction being 4.69% and 7.98% respectively. From the calibration curves, the prediction of concentration shows a high correlation with the real values (R2 = 0.99 for copper and 0.98 for nickel).This research was developed in the framework of the projects TEC2016-76021-C2-2-R (AEI/FEDER, UE), PID2019-107270RB-C21/AEI/10.13039/501100011033, CTM2017-87740-R, RTI2018-093310-B-I00 and grant BES-2017-080076, all financed by the Spanish Ministry of Science, Innovation and Universities

The history of rainfall data time-resolution in a wide variety of geographical areas

Collected rainfall records by gauges lead to key forcings in most hydrological studies. Depending on sensor type and recording systems, such data are characterized by different time-resolutions (or temporal aggregations), ta. We present an historical analysis of the time-evolution of ta based on a large database of rain gauge networks operative in many study areas. Globally, ta data were collected for 25,423 rain gauge stations across 32 geo graphic areas, with larger contributions from Australia, USA, Italy and Spain. For very old networks early re cordings were manual with coarse time-resolution, typically daily or sometimes monthly. With a few exceptions, mechanical recordings on paper rolls began in the first half of the 20th century, typically with ta of 1 h or 30 min. Digital registrations started only during the last three decades of the 20th century. This short period limits investigations that require long time-series of sub-daily rainfall data, e.g, analyses of the effects of climate change on short-duration (sub-hourly) heavy rainfall. In addition, in the areas with rainfall data characterized for many years by coarse time-resolutions, annual maximum rainfall depths of short duration can be potentially underestimated and their use would produce errors in the results of successive applications. Currently, only 50% of the stations provide useful data at any time-resolution, that practically means ta = 1 min. However, a sig nificant reduction of these issues can be obtained through the information content of the present database. Finally, we suggest an integration of the database by including additional rain gauge networks to enhance its usefulness particularly in a comparative analysis of the effects of climate change on extreme rainfalls of short duration available in different locations

Screening of Ion Exchange Resins for Hazardous Ni(II) Removal from Aqueous Solutions: Kinetic and Equilibrium Batch Adsorption Method

The development of new, cheaper, and more effective technologies to decrease the amount of wastewater containing heavy metals and to improve the quality is indispensable. Adsorption has become one of the alternative treatment methods. A small number of studies focusing on the batch technique for nickel ion removal by the new generation ion exchangers are described in the literature. In this paper, the Ni(II) removal from aqueous solutions using the ion exchange resins of different types was investigated. The experiments were conducted at different HCl and HCl/HNO3 concentrations, and the initial concentration was 100 mg Ni(II)/L. The investigation of the Ni(II) desorption from the chosen resins were carried out. The Ni(II) removal efficiency and the rate of removal are shown on the kinetic curves and the rate constants as well as kinetic parameters were collected and compared. The isotherm parameters were calculated and Fourier-transform infrared spectroscopy with the attenuated total reflection spectra was performed to determine the nature of adsorption. The experimental results showed that the Ni(II) percentage removal is high and Lewatit MonoPlus TP220 could be an alternative for the treatment of nickel(II) containing wastewaters

Participation research as the answer to the assumptions of the social model of disability?

Społeczny model niepełnosprawności, warunek podmiotowego traktowania uczestników badań społecznych i założenie dostępności badanych osób do procesu badawczego, wynikające z Konwencji o prawach osób niepełnosprawnych, stawiają badaczy przed koniecznością poszukiwania nowych strategii prowadzenia badań, które docierają do świata znaczeń osób badanych. Naprzeciw tym wyzwaniom wychodzi model badań partycypacyjnych, który wydaje się również właściwy dla uchwycenia intersekcjonalności kategorii płci i niepełnosprawności.The social model of disability, the requirement for the subjective treatment of participants in social research and the availability of research subjects to the research process, resulting from the Convention on the Rights of Persons with Disabilities, put researchers before the need to seek new research strategies that grasp the world of meanings of the respondents. The model of participatory research, which seems also appropriate for capturing the intersectionality of the gender and disability, seems to meet these challenges