The Potential for PE Microplastics to Affect the Removal of Carbamazepine Medical Pollutants from Aqueous Environments by Multiwalled Carbon Nanotubes

Abstract

Microplastics are ubiquitous in aquatic environments and interact with other kinds of pollutants, which affects the migration, transformation, and fate of those other pollutants. In this study, we employ carbamazepine (CBZ) as the contaminant to study the influence of polyethylene (PE) microplastics on the adsorption of CBZ pollutants by multiwalled carbon nanotubes (MCNTs) in aqueous solution. The adsorption capacity of CBZ by MCNTs in the presence of PE microplastics was obviously lower than that by MCNTs alone. The influencing factors, including the dose of microplastics, pH, and CBZ solution concentration, on the adsorption of CBZ by MCNTs and MCNTs−PE were thoroughly investigated. The adsorption rate of CBZ by MCNTs decreased from 97.4% to 90.6% as the PE microplastics dose increased from 2 g/L to 20 g/L. This decrease occurred because the MCNTs were coated on the surface of the PE microplastics, which further decreased the effective adsorption area of the MCNTs. This research provides a framework for revealing the effect of microplastics on the adsorption of pollutants by carbon materials in aqueous environments.

Removal of Polystyrene Microplastics from Aqueous Solution Using the Metal–Organic Framework Material of ZIF-67

“…The current experiment mainly studied the influence mechanism of single key factors on the adsorption of microplastics. Our research showed that the ZIF-67 could effectively absorb different concentrations of PSMPs (5-50 mg/L) in a wide pH range (3)(4)(5)(6)(7)(8)(9)(10), and a temperature ranging from 288 to 308 K. In addition, compared with other technologies for removing PSMPs from water, ZIF-67 showed the superiority including a lower cost and higher treatment efficiency.…”

“…Fluorescent PSMPs (with average diameter of 1.0 µm, 1% w/v) were purchased from the Tianjin Beisiline Chromtech Research Center, (Tianjin, China). The fluorescent PSMPs stock solution was diluted using deionized water, then treated with an ultrasonic device (KQ-100DE, KunShan Ultrasonic Instruments Co., Ltd., Jiangsu, China) for 10 min at 100 W and 20 kHz to obtain the desired PS concentrations (5,10,15,20,25,30,40, and 50 mg/L). The ZIF-67 used in this investigation was prepared through a high-throughput production method [47].…”

“…The PSMP adsorption rates of ZIF-67 (0.4 g/L) were then measured in response to various PSMP concentrations (5,10,15,20,25,30,40, and 50 mg/L). The contact time and temperature were 20 min and 298 K, respectively.…”

“…The effect of reaction time on PSMP adsorption performance was assessed at different contact times (1,5,10,20,30,40,50, and 60 min) at a constant 0.4 g/L ZIF-67 dose. The volume of the PSMP solution (5 mg/L) was 30 mL, with a contact temperature of 298 K.…”

“…These increases in plastic production and consumption will inevitably lead to increases in the discharge of plastic waste. In natural water or soil environments, microplastics (MPs, with size ranging from 1 µm to 5 mm) are generated from the degradation of plastic products through natural processes such as UV photodegradation, mechanical degradation, and hydrolysis [2][3][4][5]. MPs have become extremely conspicuous and have already been detected in personal care products, food (e.g., drinking water, milk, and table salt), and baby products [6][7][8][9].…”