Simultaneous Removal of Antibiotics and Heavy Metals with Poly(Aspartic Acid)‐Based Fenton Micromotors

Abstract

The discharge of diverse pollutants has led to a complex water environment and posed a huge health threat to humans and animals. Self-propelled micromotors have recently attracted considerable attention for efficient water remediation due to their strong localized mass transfer effect. However, a single functionalized component is difficult to tackle with multiple contaminants and requires to combine different decontamination effects together. Here, we introduced a multifunctional micromotor to implement the adsorption and degradation roles simultaneously by integrating the poly(aspartic acid) (PASP) adsorbent with a MnO 2based catalyst. The as-prepared micromotors are well propelled in contaminated waters by MnO 2 catalyzing hydrogen peroxide. In addition, the catalytic ramsdellite MnO 2 (R-MnO 2 ) inner layer is decorated with Fe 2 O 3 nanoparticles to improve their catalytic performance, contributing to an excellent degradation ability with 90% tetracycline (TC) removal in 50 minutes by enhanced Fenton-like reactions. Combining the attractive adsorption capability of poly (aspartic acid) (PASP), the composite micromotors offer an efficient removal of heavy metal ions in short time. Moreover, the designed micromotors are able to simultaneously remove antibiotic and heavy metals in mixed contaminants circumstance just in single treatment. This multifunctional micromotor with distinctive decontamination ability exhibits a promising prospective in treating multiple pollutants in the future.

Micromotor‐in‐Sponge Platform for Multicycle Large‐Volume Degradation of Organic Pollutants

“…The solvothermal fabrication method used allows high production rates of CFO nanoparticles with the size under 100 µm. [48] CFO micromotors are located in spherical cavities inside the sponge's structure and their characteristic bubble-recoil motion mechanism not only provides an enhanced in situ pollutant degradation under extremely low fuel concentration (0.13%) when compared to previous micromotor-based degradation approaches, [17,23,34] but also an increased intrasponge pressure that promotes fluid pumping, useful to improve mixing and fluid exchange in wastewater degradation processes. Therefore, the combination of the sponge and CFO micromotors results in a synergistic concept with high performance for organic pollutant degradation.…”

“…[ 8–11 ] During the last decade, these micro‐ and nanodevices have been designed with the aim of eliminating a wide range of pollutants through different physical and chemical processes such as physisorption [ 12–20 ] and biological‐based capture, [ 21 ] degradation, [ 22–38 ] and cell lysis [ 39–42 ] or combination of some of them. [ 17,43,44 ] Among them, degradation processes which include catalysis, [ 23,24,30,45,46 ] photocatalysis [ 25,26,36–38 ] and enzymatic catalysis, [ 27–29 ] are the most widely used mechanisms for the removal of organic pollutants. Particularly, Fenton‐like reactions have been explored as efficient decontaminating processes of AOPs in both bubble propelled platinum [ 23,45 ] or MnO 2 [ 17,43,47 ] microtubes and cobalt ferrite microparticles (CFO), [ 48 ] demonstrating exceptional degradation rates.…”

“…Engineered micro-and nanomotors have been exploited as active microcleaners for environmental purposes, showing an outstanding degradation performance due to the associated fluid mixing, as well as an efficient contaminant sensing. [8][9][10][11] During the last decade, these micro-and nanodevices have been designed with the aim of eliminating a wide range of pollutants through different physical and chemical processes such as physisorption [12][13][14][15][16][17][18][19][20] and biological-based capture, [21] degradation, [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] and cell lysis [39][40][41][42] or combination of some of them. [17,43,44] Among them, degradation processes which include catalysis, [23,24,30,45,46] photocatalysis [25,26,[36]…”

“…[8][9][10][11] During the last decade, these micro-and nanodevices have been designed with the aim of eliminating a wide range of pollutants through different physical and chemical processes such as physisorption [12][13][14][15][16][17][18][19][20] and biological-based capture, [21] degradation, [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] and cell lysis [39][40][41][42] or combination of some of them. [17,43,44] Among them, degradation processes which include catalysis, [23,24,30,45,46] photocatalysis [25,26,[36][37][38] and enzymatic catalysis, …”

“…[17,43,44] Among them, degradation processes which include catalysis, [23,24,30,45,46] photocatalysis [25,26,[36][37][38] and enzymatic catalysis, [27][28][29] are the most widely used mechanisms for the removal of organic pollutants. Particularly, Fenton-like reactions have been explored as efficient decontaminating processes of AOPs in both bubble propelled platinum [23,45] or MnO 2 [17,43,47] microtubes and cobalt ferrite microparticles (CFO), [48] demonstrating exceptional degradation rates. Although some of the nano/micromotors design up to date avoided the use of costly fabrications processes [48][49][50] aiming for mass production to permit the technology transfer of such active microcleaners in real applications, there is still one main concern: how to deploy them safely while keeping high performance to reuse and recover them in order to ensure a green and sustainable degradation process.…”