Versatile Magnetic Mesoporous Carbon Derived Nano‐Adsorbent for Synchronized Toxic Metal Removal and Bacterial Disinfection from Water Matrices

Abstract

Contamination of water resources by toxic metals and opportunistic pathogens remains a serious challenge. The development of nano‐adsorbents with desired features to tackle this problem is a continuously evolving field. Here, magnetic mesoporous carbon nanospheres grafted by antimicrobial polyhexamethylene biguanidine (PHMB) are reported. Detailed mechanistic investigations reveal that the electrostatic stabilizer modified magnetic nanocore interfaced mesoporous shell can be programmatically regulated to tune the size and related morphological properties. The core–shell nano‐adsorbent shows tailorable shell thickness (≈20–55 nm), high surface area (363.47 m2 g−1), pore volume (0.426 cm3 g−1), radially gradient pores (11.26 nm), and abundant biguanidine functionality. Importantly, the nano‐adsorbent has high adsorption capacity for toxic thallium (Tl(I) ions (≈559 mg g−1), excellent disinfection against Staphylococcus aureus and Escherichia coli (>99.99% at 2 and 2.5 µg mL−1), ultrafast disinfection kinetics rate (>99.99% within ≈4 min), and remarkable regeneration capability when exposed to polluted water matrices. The Tl(I) removal is attributed to surface complexation and physical adsorption owing to open ended mesopores, while disinfection relies on contact of terminal biguanidines with phospholipid head groups of membrane. The significance of this work lies in bringing up effective synchronic water purification technology to combat pathogenic microorganisms and toxic metal.

Exploring the Potential of Amino-Functionalized Zeolite Series/H3PO4-Biochar for Environmental Microplastic Removal

“…It was observed that the uptake of PSMMs by AFZ increased from pH values of 1.0 to 7.0 until a sharp fall was observed at pH > 7.0. ,, The plausible reason for the protonation of the surface of AFZ at pH ≤ 7.3 and the possession of a positive zeta potential is the modification of coffee waste (a starting material for AFZ synthesis) with concentrated phosphoric acid. Moreover, at pH > PZC, the solution possessed greater negative charges that improved the uptake of PSMMs by AFZ. − A positive zeta potential shows an increase in the hydrophobic interaction between the target contaminant and adsorbent. In this case, the positive zeta potential increased the hydrophobic interaction between PSMMs and AFZ through π–π interactions, van der Waal interactions, and hydrogen bonding …”

Mesoporous Silica Nanoparticles for the Uptake of Toxic Antimony from Aqueous Matrices

“…However, the mixed solution of Mn and Fe inhibits the removal rate of Sb­(III) ions, and the maximum uptake can reach only up to 0.61 mg·g –1 . This could be due to the competition among Sb­(III) ions and Mn­(II) for adsorption sites, specific ionic potential, and smaller hydrated ionic radius . Therefore, the manganese ion is the competitive ion for MSNs to remove Sb­(III) from aqueous matrices.…”

“…Currently, many technologies have been developed for Sb­(III) removal from wastewater, such as coagulation bioremediation, membrane filtration, electrochemical deposition, and adsorption . Mostly, these approaches require high-end maintenance and energy; however, adsorption is most effective due to its low cost, simplicity, recyclability, and high efficiency. − Many adsorbents have been developed so far for heavy metal ion adsorption from water, and these can be categorized as inorganic, ,, organic, − and biomass-derived. − Activated carbon is a highly effective Sb­(III) adsorbent due to its large surface area and porosity. However, it has been reported that the adsorption capacity of activated carbon decreases with increasing pH, which may limit its effectiveness in certain applications .…”

“…However, their efficiency may be impacted by the presence of competing ions, such as phosphate and sulfate, in water . Recently, nanoscopic adsorbents have been paid increasing attention due to their unique physiochemical properties, particularly a high surface area and a mesoporous framework. ,, Mesoporous silica nanoparticles (MSNs) are chemically inert, have a high surface area and abundant pores, and are decorated with functional groups . However, their application as an adsorbent remains underdeveloped and needs further attention .…”

Highly transparent antibacterial polystyrene/styrene‐butadiene block copolymer/polyhexamethylene guanidine composite

“…To synchronously obtain high optical transparency and antibacterial property, the antibacterial agent should have excellent bactericidal action and comparable refractive index to PS. Polyhexamethylene guanidine (PHMG) is lethal to most bacteria, and the effect takes quickly, [13][14][15][16] which shows a promising potential in water purification, 17 air filtration, 18 and equipment. [19][20][21] The organic PHMG can be rapidly adsorbed to the negatively charged bacterial cell surface.…”