Selective adsorption of cationic dye utilizing poly(methacrylic acid-co-ethylene dimethacrylate) monolith from wastewater

In this study, poly(methacrylic acid-co-ethylene dimethacrylate (poly(MAA-co-EDMA)) monolith was prepared for the selective adsorption of acidic dye, namely methylene blue (MB), from wastewater. The fabrication of the monolith was carried out by photoinitiation polymerization by irradiating a mixture of methacrylic acid (MAA), ethylene dimethacrylate (EDMA), porogenic solvents and an initiator. Batch adsorption assays were performed to examine the impact of monolith dosage and initial dye concentration on the adsorption capacity and efficiency of the monolith towards MB dye molecules. This adsorption kinetic study revealed that MB adsorption on the monolith followed pseudo-second-order model and equilibrium adsorption behavior was best modeled by Langmuir adsorption isotherm indicating a monolayer adsorption with a maximum adsorption capacity of 50.00 mg g-1. Owing to the presence of negative binding sites on the monolith surface, cationic MB molecules are selectively adsorbed from MB/methyl orange (MO) mixture with an adsorption efficiency of 99.54% at equilibrium time. Moreover, the MB adsorbed monolith was regenerated up to four cycles and the percentage removal efficiency of MB on the monolith dropped to 67.64 % after the fourth cycle. Finally, the monolith effectively adsorbed MB from the tap water in presence of competing ions and the maximum adsorptive capacity obtained was 47.62 mg g-1 with 84.5% adsorption efficiency. Hence, poly(MAA-co- EDMA) monolith is an adequate sorbent for the treatment of cationic dyes in the presence of other dyes and competing ions from wastewater.

Start Here When Performing Radiochemical Reactions

Radiation products are present in several fields of knowledge. From the energy field, with nuclear reactors and nuclear batteries, to the medical field, with nuclear medicine and radiation therapy (brachytherapy). Although chemistry works in the same way for radioactive and non-radioactive chemicals, an extra layer of problems is present in the radiochemical counter-part. Reactions can be unpredictable due to several factors. For example, iodine-125 in deposited in a silver wire to create the core of a medical radioactive seed. This core is the sealed forming a radioactive seed that are placed inside the cancer. Several aspects can be discussed in regards to radiation chemistry. For example: are there any competing ions? Each way my reaction is going? Each reaction is more likely to occur? Those are important questions, because, in the case of iodine, a volatile product can be formed causing contamination of laboratory, equipment, personal, and environment. This chapter attempts to create a guideline on how to safely proceed when a new radioactive chemical reaction. It discusses the steps by giving practical examples. The focus is in protecting the operator and the environment. The result can be achieved safely and be reliable contribution to science and society.

Defective Bismuth Oxide as Effective Adsorbent for Arsenic Removal from Water and Wastewater

In this work, we report solid-state synthetized defective Bi2O3 containing Bi(V) sites as effective and recyclable arsenic adsorbent materials. Bi2O3 was extensively characterized, and structure-related adsorption processes are reported. Both As(V) and As(III) species-adsorption processes were investigated in a wide range of concentrations, pH values, and times. The effect of several competing ions was also tested together with the adsorbent recyclability.

Pure and Sb-doped ZrO2 for removal of IO3− from radioactive waste solutions

Radioactive 129I with a long half-life (1.57 × 107 y) and high mobility is a serious radiohazard and one of the top risk radionuclides associated with its accidental and planned releases to nature. The complex speciation chemistry of iodine makes its removal a complicated task, and usually a single method is not able to remove all iodine species. Especially its oxidized form iodate (IO3−) lacks a selective and effective removal method. Here, the granular aggregates of hydrous zirconium oxides with and without antimony doping were tested for IO3− removal and the effects of contact time, competing anions in different concentrations and pH were examined. The materials showed high selectivity for IO3− (Kd over up to 50,000 ml/g) in the presence of competing ions and relatively fast uptake kinetics (eq. < 1 h). However, B(OH)4− and SO42−, as competing ions, lowered the iodate uptake significantly in basic and acidic solution, respectively. The suitability of the materials for practical applications was tested in a series of column experiments where the materials showed remarkably high apparent capacity for the IO3− uptake (3.2–3.5 mmol/g). Graphic abstract

Protein-Based Platform for Purification, Chelation, and Study of Medical Radiometals: Yttrium and Actinium

Actinium-based therapies could revolutionize cancer medicine but remain tantalizing due to the difficulties in studying Ac chemistry. Current efforts focus on small synthetic chelators, limiting radioisotope complexation and purification efficiencies. Here we demonstrate how a recently discovered protein, lanmodulin, can be utilized to efficiently bind, recover, and purify medically-relevant radiometals, actinium(III) and yttrium(III), and probe their chemistry. The stoichiometry, solution behavior, and formation constant of the 228Ac-lanmodulin complex (Ac3LanM, Kd, 865 femtomolar) and its 90Y/natY/natLa analogues were experimentally determined, representing both the first actinium-protein and most stable actinide(III)-protein species to be characterized. Lanmodulin’s unparalleled properties enable the facile purification-recovery of radiometals, even in the presence of >10+10 equivalents of competing ions and at ultra-trace levels: down to 2 femtograms 90Y and 40 attograms 228Ac. The lanmodulin-based approach charts a new course to study elusive isotopes and develop versatile chelating platforms for medical radiometals, both for high-value separations and potentially in vivo applications.

Protein-Based Platform for Purification, Chelation, and Study of Medical Radiometals: Yttrium and Actinium

Actinium-based therapies could revolutionize cancer medicine but remain tantalizing due to the difficulties in studying Ac chemistry. Current efforts focus on small synthetic chelators, limiting radioisotope complexation and purification efficiencies. Here we demonstrate how a recently discovered protein, lanmodulin, can be utilized to efficiently bind, recover, and purify medically-relevant radiometals, actinium(III) and yttrium(III), and probe their chemistry. The stoichiometry, solution behavior, and formation constant of the 228Ac-lanmodulin complex (Ac3LanM, Kd, 865 femtomolar) and its 90Y/natY/natLa analogues were experimentally determined, representing both the first actinium-protein and most stable actinide(III)-protein species to be characterized. Lanmodulin’s unparalleled properties enable the facile purification-recovery of radiometals, even in the presence of >10+10 equivalents of competing ions and at ultra-trace levels: down to 2 femtograms 90Y and 40 attograms 228Ac. The lanmodulin-based approach charts a new course to study elusive isotopes and develop versatile chelating platforms for medical radiometals, both for high-value separations and potentially in vivo applications.

Nanoscale Copper II Oxide An Efficient and Reusable Adsorbent for Removal of Nickel II from Contaminated Water

The present work describes the synthesis of copper(II) oxide nanoparticles (NPs) with high surface area (52.11 m2/g) and its Ni(II) adsorption efficiency from contaminated water at room temperature. Copper (II) oxide NPs are able to remove Ni(II) as 93.6 per cent and 93.7 per cent using 500 ppb & 1000 ppb initial concentration of nickel at near-neutral pH respectively. CuO NPs is very much effective to remove more than 75 per cent nickel over a wide range of pH even in presence of other competing ions like Cd2+, Pb2+, Cr6+, SO42-. Prepared CuO NPs can be used to remove Ni(II) from aqueous solution in real field application.

Ion-capture electrodialysis using multifunctional adsorptive membranes

Technologies that can efficiently purify nontraditional water sources are needed to meet rising global demand for clean water. Water treatment plants typically require a series of costly separation units to achieve desalination and the removal of toxic trace contaminants such as heavy metals and boron. We report a series of robust, selective, and tunable adsorptive membranes that feature porous aromatic framework nanoparticles embedded within ion exchange polymers and demonstrate their use in an efficient, one-step separation strategy termed ion-capture electrodialysis. This process uses electrodialysis configurations with adsorptive membranes to simultaneously desalinate complex water sources and capture diverse target solutes with negligible capture of competing ions. Our methods are applicable to the development of efficient and selective multifunctional separations that use adsorptive membranes.