Adsorption modeling, thermodynamics, and DFT simulation of tetracycline onto mesoporous and high-surface-area NaOH-activated macroalgae carbon

Increasing quantities of pharmaceutical pollutants have been found in aquatic ecosystems. The treatment of pharmaceutical pollutants has been a major task that people have been committed to in recent years. The removal of pharmaceutical pollutants can be achieved by adsorption and advanced oxidation processes (AOPs). Compared with other carbon materials, biochar has a strong adsorption capacity and persulfate activation ability, and more importantly, biochar is cheap and easy to obtain; thus, it has higher economic benefits. This study firstly reviews the application of biochar in the removal of drugs (tetracycline (TC), sulfamethoxazole (SMX), acetaminophen (ACT), cephalexin (CPX), levofloxacin (LEV), etc.) through adsorption and persulfate-based AOPs. In addition, we summarize the adsorption mechanism of biochar for various pharmaceutical pollutants and the main attack sites on different pharmaceutical pollutants in persulfate-based AOPs catalyzed by biochar. Finally, the challenges and prospects of biochar with respect to the removal of pharmaceutical pollutants are put forward.

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A Review on Application of Biochar in the Removal of Pharmaceutical Pollutants through Adsorption and Persulfate-Based AOPs

A feasible biochar derived from biogas residue and its application in the efficient adsorption of tetracycline from an aqueous solution.

The recovery of carbon materials from biogas residue (BR) could efficiently promote the efficient utilization of waste and the preparation of novel materials. In this study, a green and feasible reagent of citric acid was introduced and applied in the modification of biogas residue biochar (BRC). The modified biogas residue biochar (CABRC) showed a superior adsorption ability due to its higher specific surface area (approximately 6 times that of the BRC). Additionally, the adsorption capacities of CABRC and BRC for TC were 58.25 mg/g and 20.77 mg/g, respectively, while the TC adsorption performance of CABRC was 2.8 times that of BRC. The adsorption of TC by both BRC and CABRC was primarily controlled by physical adsorption and chemical adsorption (including pore filling, hydrogen bonding, π-π DEA interaction, and electrostatic interaction). Therefore, CABRC should be considered an environmentally friendly material due to its higher adsorption performance, which could expand its application in wastewater treatment. 

A feasible biochar derived from biogas residue and its application in the efficient adsorption of tetracycline from an aqueous solution

Due to the continuous and adverse effects of microplastics on the environment, an increasing number of studies have begun to focus on their migration patterns and removal from aquatic environments. Herein, our study innovatively evaluated the ability of the capacity of ZIF-67, a novel metal–organic framework (MOF) material, to adsorb polystyrene (PS) microplastics (MPs) from aqueous solutions, aiming to explore the potential of MOF materials to remove MPs from wastewater. The adsorption ratio of PSMPs (5 mg/L, 30 mL) by ZIF-67 reached up to 92.1%, and the PSMP adsorption equilibrium was achieved within 20 min at 298 K. The adsorption of PSMPs would be favored at a pH of 8, a PSMPs solution concentration of 5 mg/L, and a temperature of 298 K. Further analyses demonstrated that hydrogen bond interactions, π-π stacking, and electrostatic interactions played a crucial role in the adsorption of PSMPs by ZIF-67 in aqueous solutions. Our findings thus provide insight into novel methods to remove MPs from acidic and weakly alkaline aquatic environments and wastewater.

/pdf/removal-of-polystyrene-microplastics-from-aqueous-solution-1w7rxwea.pdf

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

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.

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

Xiaoyu Sheng

Papers

A feasible biochar derived from biogas residue and its application in the efficient adsorption of tetracycline from an aqueous solution.

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