Polyanilines as New Sorbents for Hydrocarbons Removal from Aqueous Solutions

Abstract

Water remediation from hydrocarbons is crucial to reduce health risks. Numerous costly and, sometimes, sophisticated methods were proposed over the years. Herein, an innovative green procedure for porous polyanilines preparation is reported. Polyaniline (PANI) was synthesized by three different approaches ranging from traditional to more eco-friendly ones. Thermal, optical and morphological features of the resulting materials were investigated along with their surface properties. Finally, PANIs were tested as sorbents for hydrocarbons removal from waterbodies. Although an overall fast and high sorption efficiency is always observed, the effective hydrocarbons abatement performed by ‘green’ PANIs is particularly welcome in the context of environmental protection. Moreover, the sorption efficiency retention after five-run recycling tests suggests potential applications in wastewater remediation.

Solar Light Photoactive Floating Polyaniline/TiO2 Composites for Water Remediation

“…In particular, the band at 1500 cm −1 is assigned to benzene rings of PANI, while that at 1600 cm −1 to quinone rings [14][15][16][17]51]. For all the PANI-modified PUs, no signals specifically attributable to titania are recognized, since in the ATR-FTIR spectrum of PANI many bands below 900 cm −1 are observed (Figure S1).…”

“…Among these approaches, adsorption is one of the most used treatments for the removal of pollutants from the water matrix thanks to its simplicity, low cost, high efficiency, and sustainability [13][14][15][16][17]. In fact, adsorption processes based on the use of environmentally-friendly adsorption materials, such as adsorbents originating from agricultural sources and by-products (fruits, vegetables, foods), agricultural waste and derivatives, biochar, hydroxyapatite, and so forth, represent a new generation of sustainable treatments that pave the way for new scenarios in this sector.…”

“…These processes lead to the formation of peroxides and hydroxyls that, further, take part in the mineralization of organic species. It is also important to note that CPs are good adsorbents for the removal of not only small organic molecules, which can escape the photodegradation process, but also dangerous heavy metals [14][15][16][17]. Among the CPs, polyaniline (PANI) is unique thanks to its ease of synthesis, environmental stability, redox properties and unique doping/dedoping process [40,41].…”

Efficient Day-and-Night NO2 Abatement by Polyaniline/TiO2 Nanocomposites

“…In general, they are employed as adsorbents for the removal of several types of pollutants (dyes [ 43 , 44 ], metals [ 45 , 46 ]) or as photosensitizers [ 47 , 48 , 49 , 50 ]. Among COPs, polyaniline (PANI) occupies a special place for its unique characteristics and, therefore, it can be considered a valid candidate to be used in the fields, where its interesting redox properties related to the presence of imino-quinoid/amino-benzenoid groups can make the difference [ 42 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 ]. So far, concerning NOx, COPs have been largely studied to fabricate gas sensors [ 59 , 60 , 61 ].…”

Efficient and Fast Removal of Oils from Water Surfaces via Highly Oleophilic Polyurethane Composites

“…There are many chemical, physical, and biological methods to remove oils from contaminated water [ 13 ], including oil dispersant [ 14 ], in situ burning [ 15 ], filters [ 16 ], reverse osmosis [ 17 ], gravity separation [ 18 ], electrocoagulation [ 19 ] and electroflotation [ 20 ]. Sorption is probably one of the most used methods because oil sorbents fall into two very broad categories: synthetic, such as polyanilines and polypyrrole-silica polymer composites [ 21 , 22 ], and natural adsorbents, such as bio-based aerogels and natural adsorbents based on sawdust [ 23 , 24 ]. The latter can be further divided into organic and inorganic [ 25 , 26 ].…”