We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Effects of humic acid on Pb2+ adsorption onto polystyrene microplastics from spectroscopic analysis and site energy distribution analysis
Summary
Researchers investigated how humic acid (HA) affects the adsorption of lead ions onto polystyrene microplastics, finding that higher HA concentrations promoted greater lead adsorption by acting as a bridging molecule between the plastic surface and the metal. Spectroscopic analysis confirmed that HA introduced additional adsorption sites and enhanced the surface affinity of the microplastics for lead.
Microplastics (MPs), act as vectors of heavy metal pollutants in the environment, is of practical significance to study the adsorption process and mechanism on heavy metals. In this study, polystyrene microplastics (PSMPs) were used as model MPs to study the adsorption of Pb2+ on PSMPs and the effects of humic acid (HA) on the adsorption process. The results showed that HA promoted the adsorption of Pb2+ on PSMPs, and the higher the concentration of HA, the greater the adsorption of Pb2+. With the increase of pH value and decrease of ionic strength, the adsorption capacity of PSMPs for Pb2+ increased. The scanning electron microscope equipped with the energy dispersive spectroscope (SEM-EDS), fourier transform-infrared spectra (FT-IR) and X-ray photoelectron spectroscopy (XPS) analysis showed that Pb2+ could be adsorbed directly onto PSMPs and also indirectly by HA. The higher KSV values in the PSMPs-HA-Pb2+ system than PSMPs-HA system by fluorescence analysis of HA suggested that HA acted as a bridging role in the adsorption of Pb2+ on PSMPs. The site energy distribution analysis further revealed that HA increased the average site energy μ(E*) and its standard deviation σe* of PSMPs by introducing more adsorption sites, thus enhanced the adsorption affinity of PSMPs. This study provided more thoughts and insights into the adsorption behavior and mechanism of MPs for Pb2+ in aquatic environments.
Sign in to start a discussion.
More Papers Like This
Effect of microplastics on the binding properties of Pb(ii) onto dissolved organic matter: insights from fluorescence spectra and FTIR combined with two-dimensional correlation spectroscopy
Researchers investigated how polystyrene microplastics affect the binding of lead ions to dissolved organic matter, using fluorescence and FTIR spectroscopy to reveal that microplastics promote heavy metal adsorption onto humic acid through altered binding mechanisms.
Enhanced vector transport of microplastics-bound lead ions in organic matter rich water
Researchers evaluated how pristine and aged polyethylene microplastics adsorb Pb2+ ions in water under varying pH, ionic strength, contact time, Pb2+ concentration, and humic acid (HA) concentration, finding that HA enhanced lead adsorption onto aged microplastics and that maximum adsorption occurred around pH 5-6, demonstrating the vector transport potential of microplastics for lead in organic matter-rich waters.
Effects of humic acids on the adsorption of Pb(II) ions onto biofilm-developed microplastics in aqueous ecosystems
Biofilm-coated PVC microplastics adsorbed Pb(II) ions at 3.57 mg/g, nearly double the capacity of virgin PVC at 1.85 mg/g, while humic acid increased Pb adsorption on virgin PVC through complexation but decreased adsorption on biofilm-coated PVC by shielding sorption sites.
Exploring Humic Acid as an Efficient and Selective Adsorbent for Lead Removal in Multi-Metal Coexistence Systems: A Review
This review examines how humic acid, a natural substance found in soil and water, can selectively remove lead from water contaminated with multiple heavy metals. The research explores how to enhance humic acid's ability to capture lead ions specifically, including through chemical activation and pH control. While focused on heavy metals, the work is relevant to microplastics research because microplastics can concentrate and transport lead and other heavy metals, and better lead removal from water could reduce this combined pollution threat.
Influence of Organic Matter and Speciation on the Dynamics of Trace Metal Adsorption on Microplastics in Marine Conditions
Researchers evaluated how dissolved organic matter in the form of humic acid influences the adsorption dynamics of essential and toxic trace metals — including cobalt, copper, nickel, zinc, cadmium, and lead — onto polyethylene and polystyrene microplastics under simulated marine conditions. The study found that humic acid altered metal speciation and reduced adsorption onto microplastic surfaces, demonstrating that natural organic matter substantially modifies the role of microplastics as trace metal vectors in the ocean.