A Review on the Removal of Carbamazepine from Aqueous Solution by Using Activated Carbon and Biochar

Abstract

Carbamazepine (CBZ), one of the most used pharmaceuticals worldwide and a Contaminant of Emerging Concern, represents a potential risk for the environment and human health. Wastewater treatment plants (WWTPs) are a significant source of CBZ to the environment, polluting the whole water cycle. In this review, the CBZ presence and fate in the urban water cycle are addressed, with a focus on adsorption as a possible solution for its removal. Specifically, the scientific literature on CBZ removal by activated carbon and its possible substitute Biochar, is comprehensively scanned and summed up, in view of increasing the circularity in water treatments. CBZ adsorption onto activated carbon and biochar is analyzed considering several aspects, such as physicochemical characteristics of the adsorbents, operational conditions of the adsorption processes and adsorption kinetics and isotherms models. WWTPs usually show almost no removal of CBZ (even negative), whereas removal is witnessed in drinking water treatment plants through advanced treatments (even >90%). Among these, adsorption is considered one of the preferable methods, being economical and easier to operate. Adsorption capacity of CBZ is influenced by the characteristics of the adsorbent precursors, pyrolysis temperature and modification or activation processes. Among operational conditions, pH shows low influence on the process, as CBZ has no charge in most pH ranges. Differently, increasing temperature and rotational speed favor the adsorption of CBZ. The presence of other micro-contaminants and organic matter decreases the CBZ adsorption due to competition effects. These results, however, concern mainly laboratory-scale studies, hence, full-scale investigations are recommended to take into account the complexity of the real conditions.

Physical-Chemical Characterization of Different Carbon-Based Sorbents for Environmental Applications

“…Regarding biochar, Décima et al reported a wide range of specific surface area (i.e., S BET = 0.9–470.4 m 2 /g) [ 82 ]. Naghdi et al reported a low specific surface area, i.e., S BET = 47.25 m 2 /g, for pinewood biochar produced at 550 °C [ 120 ], while Chen et al reported S BET values equal to 1.82, 7.08, and 64.72 m 2 /g, depending on the pyrolysis temperature, i.e., 200, 300, and 500 °C [ 121 ], respectively.…”

“…The adsorption–desorption isotherms were acquired in a relative pressure ( p / p 0 ) range from 0.01 to 0.99 [ 82 ]. Isotherm analyses were performed using the 3Flex Version 4.05 software.…”

Carbamazepine Removal by Clay-Based Materials Using Adsorption and Photodegradation

“…Activated carbon is one of the common methods for adsorbing organic pollutants in drinking water, including pharmaceutically active compounds. The removal of carbamazepine by carbonbased sorbents was tested at various conditions with relatively high sorption capacities of up to 2 mmol g −1 [32][33][34]. Different clays and organoclay are also used as potential adsorbents for pharmaceutical pollution as a low-cost and effective technique.…”

Use of Typical Wastes as Biochars in Removing Diethyl Phthalate (Det) from Water

“…Several commercially available biochars derived from waste wood are characterized for physical and chemical properties that can signify their relevant environmental applications. Parameters characterized include: physical properties (particle size distribution, specific gravity, density, porosity, surface area), hydraulic properties (hydraulic conductivity and water holding capacity), and chemical and electrochemical properties (organic matter and organic carbon contents, pH, oxidation-reduction potential and electrical conductivity, zeta potential, carbon, nitrogen and hydrogen (CHN) elemental composition, polycyclic aromatic hydrocarbons (PAHs), heavy metals, and leachable PAHs and heavy metals) [28]. A wide range of fixed carbon (0-47.8%), volatile matter (28-74.1%), and ash contents (1.5-65.7%) were observed among tested biochars.…”