Effect of light irradiation on heavy metal adsorption onto microplastics
Journal
Chemosphere
Journal Volume
285
Date Issued
2021
Author(s)
Abstract
Microplastics are frequently found in many environmental media. Polypropylene (PP) is one of the plastics commonly used, resulting in more and more PP fragments in natural waters. Contaminants, such as lead (Pb), could get adsorbed onto microplastics after the exposure to sunlight, and pose a larger threat to aquatic species. In this study, the oxidative indices of PP pellets after different exposure times to a Xenon lamp were evaluated by Fourier transform infrared (FTIR) and energy-dispersive X-ray spectrometry. The results show that the percentage of oxygen content increased from 2.80 to 20.95 wt% and changes of characteristic peaks of the FTIR pattern, implying that the exposure to the Xenon lamp could initiate oxidation. Due to the changes of functional groups after the exposure to the Xenon lamp for 28 days, the adsorption capacities of the PP pellets were up to 274.4 mg?kg?1, 1.7 to 2.5 times higher than that of the raw PP pellets depending on the solution pHs. The adsorption behavior can be described by a pseudo-second-order model with rate constants of adsorption of 0.00212–0.01404 kg?mg?1?h?1. The increase of adsorption capacity due to changes of the PP pellets after the Xenon lamp exposure increased the potential risk to the aquatic species. ? 2021 Elsevier Ltd
Subjects
Adsorption
Heavy metal
Microplastics
Photodegradation
Polypropylene
Fourier transform infrared spectroscopy
Heavy metals
Microplastic
Pelletizing
Polypropylenes
Rate constants
Xenon
Adsorption capacities
Aquatic species
Fourier transform infra reds
Heavy metal adsorption
Light irradiations
Photo degradation
Polypropylene pellets
Xenon lamps
functional group
lead
oxygen
polypropylene
xenon
heavy metal
plastic
adsorption
FTIR spectroscopy
irradiation
adsorption kinetics
Article
controlled study
energy dispersive X ray spectroscopy
oxidation
photodegradation
radiation exposure
rate constant
sunlight
ultraviolet radiation
weathering
water pollutant
Metals, Heavy
Plastics
Water Pollutants, Chemical
Type
journal article