Phosphonate metal–organic frameworks used as dye removal materials from wastewaters

Abstract

A very intense study class of complex porous materials, metal-organic frameworks (MOFs), composed of diverse central metallic ions attached to organic linkers, was used in this study as adsorbant materials from wastewaters. Phosphonate MOFs were prepared by the reaction of divalent inorganic salts (CoSO 4 Á7H 2 O, NiSO 4 Á6H 2 O, CuSO 4 Á5H 2 O,) with vinyl phosphonic acid in hydrothermal conditions, obtaining cobalt, nickel, and copper vinylphosphonate (CoVP, NiVP, and CuVP). During synthesis the experimental conditions were varied in terms of time, temperature, and pH. The synthesized materials were characterized by Fourier transform infrared, thermogravimetric analysis, scanning electron microscopy, and X-ray crystallography. The efficiency of MOFs as adsorbents was investigated for diverse initial dye concentrations at different pH values and at three temperatures (25, 40, and 55 C). The synthesized materials presented good efficiency in the elimination of anionic as well as cationic type of dyes from aqueous solutions. The highest adsorption capacities were obtained working at optimum solution pH 4.2 for Acid Orange 7 and 10 for Basic Fuchsine, using 1 g/L of MOFs at room temperature (25 C). The adsorption capacities increase in the following order: CuVP < NiVP < CoVP. K E Y W O R D S adsorption, dyes removal, phosphonate metal organic frameworks 1 | INTRODUCTION Industry is a huge source of water pollutants such as toxic materials, rare earth elements, and organic dyes, which are extremely harmful for people, animals, and the environment. [1-4] Worldwide, water pollution become a major environmental problem because of rapid industrialization and urbanization. [5] Pollutants from the leather, plastic, textile, paper, rubber, cosmetic, and food industries can harm environmental protection, living organisms, and global ecosystems if no suitable treatments are available. About 10-15% of commercial dyes formed from the textile industries are let out into the environment every year. [6,7] Organic dyes do not decompose readily under normal conditions because of their stable and complex chemical structures. Most of these dyes are toxic and carcinogenic. [6,8-10] Dyes are mostly stable to light, oxidizing agents, and heat, and are very soluble in water. [11] The direct release of colored wastewater into the environment disturbs its ecological status by causing numerous undesirable changes. [8,11] As regulation has become stricter, significant importance has been given to the treatment of dye-containing wastewaters. [5,12] Therefore, the

The Influence of Boron on the Structure and Properties of Hybrid Compounds Containing Zirconium and Phosphorus

“…The boron changed and improved the properties of the novel synthesized materials. The synthesized hybrids led to obtaining organic–inorganic transition metal networks, which can be regarded as MOFs [ 17 , 18 , 19 , 20 , 21 ], in the case of the present work containing P-O-Zr, Zr-O-Zr, and Zr-O-B bridges. Nevertheless, it should be pointed out that those bridges could only be obtained in the mild conditions used for the sol–gel process.…”

“…Discovering new proton conductors is an area of great interest nowadays because of the potential use of those compounds for different applications, such as in sensors, water electrolysis units, and in other common electrochemical devices. By using the sol–gel process or by grafting on different surfaces, several hybrid compounds could be obtained, such as organic–inorganic networks, including phosphorus containing materials such as phosphonate metal organic frameworks, heterocyclic compounds, materials with flame retardant properties, and grafted materials for further use as new compounds with promising applications in electrochemical devices, as well as in the fields of catalysis, medicine, or agriculture [ 1 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ].…”

IL-Functionalized Mg3Al-LDH as New Efficient Adsorbent for Pd Recovery from Aqueous Solutions

“…The pseudo-first order model is expressed in its linear form, according to the following equation [ 40 , 41 , 42 ]. where: q e and q t represent the amount of Pd(II) adsorbed onto 1 g of adsorbent materials at equilibrium and after the treatment time, t; k 1 represent the rate constant specific for the adsorption process of Pd ions onto studied materials.…”

Fabrication of novel porous ZIF-67/PES composite microspheres and the efficient adsorption of triphenylmethane dyes from water

“…57–59 The maximum FA adsorption capacity of the porous ZIF-67/PES composite microspheres can reach 2176.52 mg g −1 and was the second highest adsorption capacity reported in the literature for adsorption materials. 49,60 At pH < 6.33, the porous ZIF-67/PES composite microspheres had a low adsorption capacity of CV, and its adsorption capacity was only 122.78 mg g −1 (ref. 56, 61 and 62) because the electrostatic repulsion between the cationic dye CV and the positively charged porous ZIF-67/PES microspheres at pH < 6.33 led to poor CV adsorption capacity.…”