We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Adsorption and desorption characteristics of heavy metals onto conventional and biodegradable plastics.
Summary
This study compared how conventional polyethylene plastic bags and biodegradable polylactic acid bags adsorb heavy metals like lead and cadmium from water. Both types adsorbed significant amounts of heavy metals, suggesting that biodegradable plastics, before they decompose, can still act as vectors transporting toxic metals through aquatic food chains.
Biodegradable plastics have been widely used to replace conventional plastics to minimize environmental impacts of plastic packaging. However, before biodegradable plastics decompose in the environment, they could pose a threat to terrestrial and aquatic creatures by acting as vectors of contaminants in the food chain. In this study, conventional plastic bags (CPBs) made of polyethylene and biodegradable plastic bags (BPBs) made of polylactic acid were examined for their heavy metal adsorption. Effects of solution pHs and temperatures on adsorption reactions were investigated. Because of a larger BET surface area, presence of oxygen-containing function groups, and smaller crystallinity, the heavy metal adsorption capacities of BPBs are significantly larger than those of CPBs. Among Cu (up to 791.48 mg⋅kg), Ni (up to 60.88 mg⋅kg), Pb (up to 1414.58 mg⋅kg), and Zn (up to 295.17 mg⋅kg), Pb and Ni show the largest and the lowest extents of adsorption onto the plastic bags, respectively. In the different waterbodies in nature, Pb adsorption on the CPBs and the BPBs were 318.09-379.91 and 528.41-764.22 mg⋅kg, respectively. Consequently, Pb was selected as the target contaminant in the desorption experiments. After Pb was adsorbed onto the CPBs and the BPBs, Pb could be completely desorbed and released into simulated digestive systems in 10 h. In conclusion, BPBs could be potential vectors of heavy metals, and their suitability as a substitute for CPBs must be thoroughly investigated and confirmed.
Sign in to start a discussion.
More Papers Like This
Insights into interactions of biodegradable and non-biodegradable microplastics with heavy metals
Researchers found that biodegradable polylactic acid microplastics can adsorb heavy metals like cadmium, copper, and chromium at rates comparable to or exceeding conventional non-biodegradable plastics, suggesting biodegradable microplastics may also serve as carriers of toxic metals in the environment.
Adsorption behavior of heavy metals onto microplastics derived from conventional and biodegradable commercial plastic products
Researchers tested how well different types of microplastics, including both conventional and biodegradable plastics, absorb heavy metals like lead, nickel, copper, zinc, and cadmium from water. They found that all microplastic types could pick up significant amounts of heavy metals, with biodegradable plastics sometimes absorbing even more than conventional ones. This is concerning because microplastics carrying heavy metals could deliver a double dose of contamination to organisms that ingest them.
Biodegradable microplastics adsorb more Cd than conventional microplastic and biofilms enhance their adsorption
Researchers compared how biodegradable polylactic acid and conventional polyethylene microplastics adsorb the heavy metal cadmium, with and without biofilm development from outdoor weathering. They found that pristine PLA adsorbed significantly more cadmium than pristine PE, and that biofilms forming on weathered plastics were responsible for most of the increased cadmium uptake. The study suggests that biodegradable microplastics in agricultural soils may pose a greater risk for heavy metal transport than conventional plastics.
Study on the Adsorption Behavior and Mechanism of Heavy Metals in Aquatic Environment before and after the Aging of Typical Microplastics
Researchers investigated the adsorption behavior and mechanisms of heavy metals by typical microplastics before and after environmental aging, finding that aging significantly alters microplastics' surface properties and capacity to bind metals such as cadmium and lead in aquatic systems.
Microplastics as a vehicle of heavy metals in aquatic environments: A review of adsorption factors, mechanisms, and biological effects
This review summarizes how microplastics in water can absorb and carry toxic heavy metals like lead and cadmium, making them more dangerous to aquatic life than either pollutant alone. Environmental factors such as water acidity, salinity, and organic matter influence how much metal sticks to microplastic surfaces. Since contaminated seafood is a major source of human exposure, understanding these interactions is important for assessing health risks.