Adsorption of aqueous Hg (II) by a novel poly(aniline-co -o -aminophenol)/mesoporous silica SBA-15 composite

Synthesis of Magnetic Short-Channel Mesoporous Silica SBA-15 Modified with a Polypyrrole/Polyaniline Copolymer for the Removal of Mercury Ions from Aqueous Solution

A novel magnetic short-channel mesoporous silica SBA-15 composite adsorbent was prepared by the copolymerization of pyrrole and aniline. The prepared novel nanoadsorbent polypyrrole-polyaniline/CoFe2O4-SBA-15 (PPy-PANI/M-SBA-15) has a significant adsorption effect on heavy metal mercury ions. The batch adsorption experiment was carried out to study the effects of various parameters including solution pH, initial concentration (C 0), adsorbent dose (dosage), temperature (T), and contact time on the adsorption effect. The analysis results of the response surface method (RSM) and central composite design (CCD) show that the importance for adsorption factors is pH > C 0 > T > dosage, and the maximum capacity of PPy-PANI/M-SBA-15 is 346.2 mg/g under the optimal conditions of pH = 6.7, T = 310 K, C 0 = 29.5 mg/L, and a dosage of 0.044 g/L. The pseudo-second-order kinetic model and the Langmuir isotherm model simulate the adsorption behavior of mercury ions. In addition, thermodynamic parameters indicate self-heating and reversible adsorption processes. A covalent bond is formed between the nitrogen-containing functional group and the mercury ions. Excellent magnetic properties and high reproducibility indicate that PPy-PANI/M-SBA-15 has excellent recyclability and environmentally friendly properties and can become a potential heavy metal ion adsorbent in practical applications.

Removal of mercury by adsorption: a review

Due to natural and production activities, mercury contamination has become one of the major environmental problems over the world. Mercury contamination is a serious threat to human health. Among the existing technologies available for mercury pollution control, the adsorption process can get excellent separation effects and has been further studied. This review is attempted to cover a wide range of adsorbents that were developed for the removal of mercury from the year 2011. Various adsorbents, including the latest adsorbents, are presented along with highlighting and discussing the key advancements on their preparation, modification technologies, and strategies. By comparing their adsorption capacities, it is evident from the literature survey that some adsorbents have shown excellent potential for the removal of mercury. However, there is still a need to develop novel, efficient adsorbents with low cost, high stability, and easy production and manufacture for practical utility.

Electric Field-Responsive Mesoporous Suspensions: A Review

This paper briefly reviews the fabrication and electrorheological (ER) characteristics of mesoporous materials and their nanocomposites with conducting polymers under an applied electric field when dispersed in an insulating liquid. Smart fluids of electrically-polarizable particles exhibit a reversible and tunable phase transition from a liquid-like to solid-like state in response to an external electric field of various strengths, and have potential applications in a variety of active control systems. The ER properties of these mesoporous suspensions are explained further according to their dielectric spectra in terms of the flow curve, dynamic moduli, and yield stress.