A Redox-Active Molybdenum Disulfide Filter Capable of Meeting Stringent Hexavalent Chromium Drinking Water Guidelines.

BACKGROUND: Rhenium is a rare and valuable metal coexisting with molybdenum in molybdenite and sulfide copper ores and is hard to separate. Methods such as solvent extraction, ion exchange, adsorption, precipitation, etc. have been used to separate and purify Re(VII), and resin ion exchange has been widely investigated and used owing to its convenient operation and relatively low‐cost. The main challenge comes from the preparation of resins having high performance and stability. In an earlier study, an N‐methylimidazolium functionalized strong basic anion exchange resin was successfully synthesized and used for Cr(IV) extraction. This paper, reports on further synthesis and application of this resin for adsorption and separation of Re(VII) and Mo(VI), especially from copper arsenic filter cake.RESULTS: At pH 6.25, Re(VII) and Mo(VI) can be effectively separated with the N‐methylimidazolium functionalized strong basic anion exchange resin, giving a Re(VII) recovery of up to 93.3%, but only 5.1% for Mo(VI). When using the copper arsenic filter cake sample 89.1% Re(VII) recovery was achieved.CONCLUSION: The N‐methylimidazolium functionalized strong basic anion exchange resin exhibited high selectivity and recovery for Re(VII) in a mixed system. © 2012 Society of Chemical Industry

Four surface drinking water sources were selected to investigate the impact of strong base anion (SBA) exchange resins—as a pretreatment to ultraviolet/hydrogen peroxide (UV/H2O2)—on dissolved organic carbon (DOC), nitrate, UV transmittance, and hydroxyl radical (·OH) scavenging of the water samples. Results demonstrated good efficiency of SBA exchange resins at increasing UV transmittance (up to 75%) and reducing DOC (up to 80%), nitrate (up to 75%), and sulfate (up to 75%) within the ion exchange (IX) conditions applied. Additionally, data confirmed the positive effect of IX treatment at reducing the ·OH scavenging characteristics of the water, especially for high‐DOC/low‐transmittance water sources. Electrical energy per order for removing a probe compound (4‐chlorobenzoic acid) was reduced 20 to 40%, indicating improvement in the efficacy of UV/H2O2 treatment. Study findings demonstrated the potential of using the IX process to improve the quality of water undergoing UV/H2O2 treatment and its subsequent benefits on UV/H2O2 efficacy and electrical energy consumption.

The adsorption of yttrium, neodymium and lanthanum on a strong base anion exchange resin from dilute hydrochloric acid solutions containing ethanol

The elution of platinum and palladium cyanide from strong base anion exchange resins

Improving chloride ion penetration resistance of cement mortar by strong base anion exchange resin

Comparison of different methodologies for the 90Sr determination in environmental samples

Disinfection of viable Pseudomonas stutzeri in ultrapure water with ion exchange resins

N-methylimidazolium functionalized strongly basic anion exchanger: Synthesis, chemical and thermal stability

Sorption of rhenium and uranium by strong base anion exchange resin from solutions with different anion compositions

Phosphate removal from water using an iron oxide impregnated strong base anion exchange resin

The recovery of tungsten (W) from a honeycomb-type spent selective catalytic reduction (SCR) catalyst using an alkaline leaching–ion exchange method was investigated. Spent SCR catalyst mainly consists of TiO2 and other oxides (6.37% W, 1.57% vanadium (V), and 2.81% silicon (Si), etc.). The ground catalyst was leached at the optimal conditions, as follows: NaOH concentration of 0.3 kg/kg of catalyst, pulp density of 3%, leaching temperature of 70 °C, particle size of −74 μm, and leaching time of 30 min. In this study, the leaching rate values of V and W under the above conditions were 87 wt %, and 91 wt %, respectively. The pregnant solution was then passed through a strong base anion exchange resin (Amberlite IRA900). At high pH conditions, the use of strong base anion exchange resin led to selective loading of divalent WO42− from the solution, because the fraction of two adjacent positively-charged sites on the IRA900 resin was higher and separate from the coexisting VO43−. The adsorbed W could then be eluted with 1 M NaCl + 0.5 M NaOH. The final concentrated W solution had 8.4 g/L of W with 98% purity. The application of this process in industry is expected to have an important impact on the recovery of W from secondary sources of these metals.

The effects of different solvents on synthesis of base functional ionic liquid, butyl pyridinium hydroxide ([bPy]OH), from butyl pyridinium bromine ([bPy]Br) were investigated systematically using KOH/NaOH as the base agent and strong base anion exchange resin. The results showed that the yield of [bPy]OH achieved 35% with the molar ratio of 1:1.1 ([bPy]Br to NaOH) using dichloromethane under room temperature. With isopropanol and 8 h of the reaction time, the yield could reach 88% with byproducts. The yield of 97% without byproduct was achieved by using strong base anion exchange resin in column chromatography static reaction for 0.25 h. The yield of carboxyl and pyridine functional ionic liquids based on neutralization method, exchange method and one-step method were compared and the results showed that the one-step method possessed the maximum yield of 88% with 3 h of the reaction time at room temperature.

The extraction of platinum and palladium from a synthetic cyanide heap leach solution with strong base anion exchange resins

A study of the kinetics of adsorption of gold and zinc cyanide onto a strong base anion exchange resin using a mini-column technique

Evaluation of a drop-in waste volume reduction method for liquid investigation derived waste containing per- and polyfluoroalkyl substances