A Dually Charged Membrane for Seawater Utilization: Combining Marine Pollution Remediation and Desalination by Simultaneous Removal of Polluted Dispersed Oil, Surfactants, and Ions

Abstract

Shortage of freshwater and deterioration of the marine environment have a serious effect on the human body and ecological environment. Here, we demonstrated a facile way to prepare a multiple-target superwetting porous material to obtain available water without cumbersome steps. Through the facile immersion and hydrothermal method, a charge-enhanced membrane material combining superwettability, electrostatic interaction, and the steric effect is prepared. Such a material breaks through the limitations of single size sieving and has a universal effect on different kinds of contaminants with accurate wettability manipulation and fluid separation control. The protonation and deprotonation of active carboxyl groups at the novel created solid/liquid interface facilitate the surface wettability and flux transition, which will bring out superior continuous separation and surface lubrication control.

Superhydrophilic and Underwater Superoleophobic Cotton Fabric for Oil–Water Separation and Removal of Heavy-Metal Ion

“…So far, many technologies have been reported for the disposal of oily wastewater, including flotation, centrifuges, oil skimmers, membrane separation, etc . The membrane separation method based on a superwetting surface has been attracting extensive attention in the field of oily wastewater treatment because of its simple operation and high separation efficiency. − Notably, oily wastewater contains other pollutants, such as organic dyes and heavy-metal ions, among which heavy-metal ions are one of the most common and harmful pollutants in water pollution. , Adsorption is one of the most commonly used methods to remove heavy metals because of its simple operation, easy recycling, and low cost. ,− A superhydrophilic membrane with functional groups for heavy-metal ion adsorption could simultaneously remove oil and heavy-metal ions from wastewater, which simplifies the purification process of oily wastewater containing heavy-metal ions and reduces the cost of wastewater treatment. − Wang et al prepared an organic-inorganic composite membrane by the electrospinning technique modified with 3-[(trimethoxysilyl) propyl]-diethylenetriamine to obtain a superhydrophilic and underwater superhydrophobic membrane. The membrane was used to treat artificial emulsified oily wastewater with the desired concentrations of heavy-metal ions Pb­(II), Cr­(III), and Ni­(II); the water flux could reach 1517 ± 53 L·m –2 ·h –1 , and the removal efficiencies of both oil and heavy-metal ions were larger than 99%.…”