Significance of Chlorinated Phenols Adsorption on Plastics and Bioplastics during Water Treatment

Abstract

Microplastics and chlorinated phenols (CPs) are pollutants found ubiquitously in freshwater systems. Meanwhile, bioplastics are attracting much attention as alternatives to conventional plastics, but there is little data about their effect on the behaviour of pollutants. This work therefore investigates the sorption of four CPs (4-chlorophenol—4-CP, 2,4-dichlorophenol—2,4-DCP, 2,4,6-trichlorophenol—2,4,6-TCP and pentachlorophenol—PCP) on three different plastics (polyethylene (PЕg), polypropylene (PP) and polylactic acid (PLA)) using kinetics and isotherm studies. All experiments were carried out in a synthetic water matrix and in spiked Danube river water. In all cases, adsorption kinetics fitted well with the pseudo-second order rate model. Adsorption proceeded through two linear phases, corresponding to transport from the bulk solution to the external surfaces and then into the interior pores of the sorbents. Maximum adsorption capacities calculated with the Langmuir isotherm indicated that whereas adsorption of 4-CP was not significantly affected by the type of plastic present, the adsorption of 2,4-DCP, 2,4,6-TCP and PCP varied greatly, with polypropylene showing the greatest affinity for CPs adsorption. The differences observed between the adsorption behaviour of CPs in the synthetic and natural water matrices suggest further investigation is required into how the different fractions of natural organic matter impact interactions between CPs and plastics.

Sorption of chemical contaminants on degradable and non-degradable microplastics: Recent progress and research trends

“…This line of research has come a long way, focusing on chemical pollutants from a wide range of sources. We have divided the recent progress of the interaction of chemical pollutants and microplastics based on the type of chemical, source or commercial use: Flame retardants (Chen et al, 2019;Xu et al, 2018a;Seidensticker et al, 2018), metals (Besson et al, 2020;Guo et al, 2020aGuo et al, , 2020bWang et al, 2020aWang et al, , 2020bWang et al, 2021;Zhou et al, 2020b;Zon et al, 2020;Zou et al, 2020), PAHs (Li et al, 2020;Lin et al, 2019;Wang et al, 2019;Zhao et al, 2020), PBDEs (Wu et al, 2020a(Wu et al, , 2020bXu et al, 2019), PCBs (Lin et al, 2019;Zhan et al, 2016), PHCs (Qiu et al, 2019;Zhang et al, 2019), Phthalate esters (Liu et al, 2019a(Liu et al, , 2019b(Liu et al, , 2019c, personal care products (Dong et al, 2019;Ho and Leung, 2019;Li et al, 2019;Wu et al, 2020aWu et al, , 2020bZhang et al, 2018aZhang et al, , 2018b, pesticides (Gong et al, 2019;Šunta et al, 2020;Tubić et al, 2019), pharmaceuticals (Guo et al, 2018(Guo et al, , 2019a(Guo et al, , 2019b…”

“…Contrary to nondegradable microplastics, studies investigating the sorption behavior of pollutants onto degradable plastics are very recent and limited. Only eight articles were found in this line of research, encompassing metals (Li et al, 2020;Liao and Yang, 2020), PAHs (Zhao et al, 2020;Zuo et al, 2019), PFASs (Ateia et al, 2020), pesticides (Gong et al, 2019;Tubić et al, 2019), and pharmaceuticals (Fan et al, 2021). Table 1 summarizes sorption capacity and coefficient in degradable polymers.…”

“…The high sorption capacities of the degradable microplastics were many times higher than conventional ones, probably attributed to the presence of oxygen-containing functional groups (carbonyl oxygens), and the sorption rates were faster. Tubić et al (2019) investigated the sorption behavior of four chlorinated phenols, compounds commonly used in multiple pesticides, onto PE, PP, and PLA. In none of the four compounds, PLA exhibited the highest sorption capacity.…”

Effect of Plastics on the Photodegradation Behavior of Chlorophenols

“…Microplastics have unexpected residence times on the ocean surface, and they adsorb 10 5 -10 6 times more organic pollutants than their surroundings (Mato et al, 2001). e most commonly detected pollutants are polycyclic aromatic hydrocarbons (PAHs) (Wang et al, 2019), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT) (Bakir et al, 2016), and chlorophenols (CPs) (Tubić et al, 2019). Because hydrophobic organic pollutants, such as CPs and PCBs, are persis-tent in the environment and act as endocrine disruptors or mutants (Sun et al, 2019), the fates of hydrophobic pollutants adsorbed on microplastics should be clari ed from the view point of risk assessment.…”

“…Because hydrophobic organic pollutants, such as CPs and PCBs, are persis-tent in the environment and act as endocrine disruptors or mutants (Sun et al, 2019), the fates of hydrophobic pollutants adsorbed on microplastics should be clari ed from the view point of risk assessment. e adsorption behavior of hydrophobic organic pollutants, such as CPs, PCBs and PAHs, has been intensively studied, and it is well known that most of these pollutants show the Freundlich or Langmuir adsorption isotherm on microplastic surfaces (Tubić et al, 2019). Photodegradation of any substance in the natural environment is a combination of reactions of all types of photochemical processes depending on the absorption level, radiation wavelength, quantum yield, radiation exposure duration, and physical state of the compound undergoing the transformation (Czaplicka, 2006).…”