Ionophore-Based Potassium Selective Fluorescent Organosilica Nano-Optodes Containing Covalently Attached Solvatochromic Dyes

Fluorescent nanoprobes containing ionophores and solvatochromic dyes (SDs) were previously reported as an alternative to chromoionophore-based nano-optodes. However, the small-molecular SDs are prone to leakage and sequestration in complex samples. Here, we chemically attached the SDs to the surface of organosilica nanospheres through copper-catalyzed Click chemistry to prevent dye leakage. The nano-optodes remained well responsive to K+ even after exposure to a large amount of cation-exchange resin, which acted as a sink of the SDs. The potassium nanoprobes exhibited a dynamic range between 1 μM to 10 mM and a good selectivity thanks to valinomycin. Preliminary sensing device based on a nylon filter paper and agarose hydrogel was demonstrated. The results indicate that the covalent anchoring of SDs on nanospheres is promising for developing ionophore-based nanoprobes.

Synthesis of hydrated ferric oxide on cation exchange resin for phosphate and hardness removal in water

In this study, a potential adsorbent was synthesized from iron salt and cation exchange resin (FeOOH@CR) and applied for phosphate adsorption in batch experiments. The characteristics of FeOOH@CR materials before and after phosphate adsorption were determined by FTIR, XRD, and SEM. The factors affecting the adsorption process such as reaction time, solution pH, material dosage, concentration, temperature, and competing ions were tested. Kinetic, thermodynamic and isothermal models of the adsorption process were applied to study the nature of the adsorption process. The properties of phosphate adsorption, effect of competitive ions and material reusability were also examined. Results showed that the adsorption time reached equilibrium after 48 h and the suitable adsorption condition was found at solution pH of 6.5, material dosage of 5 g/L. In addition, the durability of the material after 5 times of regeneration was investigated with the remained adsorption ability of about 55% as compared to the original one.

Determination of the content of rare metals in spent anion-exchange resin SIM202 by methods of neutron-activation and mass-spectrometric analysis

The work is devoted to the development of methods for determining the elemental and isotopic composition of spent ion-exchange resin, industrial waste and environmental objects using an inductively coupled plasma mass spectrometer and analyzing specific samples to determine the content of noble and rare metals in technological materials, industrial waste and natural objects with application of the developed techniques. This article determines the elemental composition of the spent ion-exchange resin SIM202 with the Inductively coupled plasma mass spectrometry (ICP-MS) method and also shows the comparison of the results with neutron activation analysis (NAA). The distribution coefficient of elements in a chromatographic column in ion-exchange resins TAO and SIM202 is given.

Penyisihan Kontaminan dari Air Limbah Hasil Daur Ulang Baterai LiFePO4 (LFP) Menggunakan Penukar Ion Resin Kation Amberlite HPR1100 Na dan Resin Anion Dowex Marathon A

Pada tahun 2025, diperkirakan kebutuhan baterai Li-ion akan mencapai 400.000 ton. Upaya strategis diperlukan untuk mewujudkan pemakaian baterai Li-ion yang berkelanjutan. Setelah siklus pemakaian baterai Li-ion berakhir, baterai Li-ion akan diproses kembali untuk diambil kandungan logam-logam penting yang terkandung di dalam katoda, terutama litium. Secara umum, proses recycle tersebut dilakukan dengan metode hidrometalurgi yang terdiri atas rangkaian leaching dan presipitasi. Namun demikian, dalam proses pemurnian tersebut dihasilkan air limbah yang mengandung beragam logam dengan konsentrasi yang berbeda. Untuk baterai LFP, logam-logam tersebut berasal dari katoda yang mengandung Li, Na, Si, dan PO4. Proses pelindian dan pencucian serbuk katoda membutuhkan air dalam jumlah yang relatif besar. Pengolahan air limbah hasil proses daur ulang baterai diharapkan dapat secara signifikan meningkatkan efisiensi penggunaan air. Pada eksperimen ini, metode adsorpsi batch dengan ion-exchange resin kation Amberlite HPR1100 Na dan resin anion Dowex Marathon A digunakan untuk menghilangkan ion logam dari air limbah artifisial. Pengambilan sampel air limbah yang diolah diambil pada menit ke-3, 6, 10, 20, 30 dan hari ke-3. Berdasarkan pada hasil removal percentage, diperoleh bahwa pengolahan air limbah artifisial metode adsorpsi dengan menggunakan ion-exchange resin kation Amberlite HPR1100 Na dapat mengurangi kadar ion litium dan natrium sampai 100% pada menit ke-20 dengan variasi dosis adsorben 10 g/100 mL, sedangkan penggunaan ion-exchange resin anion Dowex Marathon A dapat mengurangi kadar ion fosfat sampai 100% pada menit ke-30 dengan dosis adsorben 10 g/100 mL. Dengan adsorpsi isotherm didapat model Langmuir lebih sesuai dengan data eksperimen dengan nilai parameter Qm dan KL untuk ion litium sebesar 1,16 mg/g dan 2,57 mg/g, ion natrium sebesar 74,62 mg/g dan 0,04 mg/gL/mg, dan ion fosfat sebesar 208,33 mg/g dan 0,06 mg/g. Selain itu, studi kinetika menunjukkan bahwa model pseudo second-order memiliki kesesuaian data yang lebih baik daripada pseudo first-order.