Algae-mediated antibiotic wastewater treatment: A critical review

Abstract

The existence of continually increasing concentrations of antibiotics in the environment is a serious potential hazard due to their toxicity and persistence. Unfortunately, conventional treatment techniques, such as those utilized in wastewater treatment plants, are not efficient for the treatment of wastewater containing antibiotic. Recently, algae-based technologies have been found to be a sustainable and promising technique for antibiotic removal. Therefore, this review aims to provide a critical summary of algae-based technologies and their important role in antibiotic wastewater treatment. Algal removal mechanisms including bioadsorption, bioaccumulation, and biodegradation are discussed in detail, with using algae-bacteria consortia for antibiotic treatment, integration of algae with other microorganisms (fungi and multiple algal species), hybrid algae-based treatment and constructed wetlands, and the factors affecting algal antibiotic degradation comprehensively described and assessed. In addition, the use of algae as a precursor for the production of biochar is highlighted, along with the modification of biochar with other materials to improve its antibiotic removal capacity and hybrid algae-based treatment with advanced oxidation processes. Furthermore, recent novel approaches for enhancing antibiotic removal, such as the use of genetic engineering to enhance the antibiotic degradation capacity of algae and the integration of algal antibiotic removal with bioelectrochemical systems are discussed. Finally, some based on the critical review, key future research perspectives are proposed. Overall, this review systematically presents the current progress in algae-mediated antibiotic removal technologies, providing some novel insights for improved alleviation of antibiotic pollution in aquatic environments.

Keywords: ABC; ARGs; Algae-bacteria consortia; Algae-based technology; Antibiotic resistance genes; Antibiotic wastewater treatment; Hybrid system; Removal mechanisms.

Graphical abstract

Fig. 1

Mechanisms involved in the removal of antibiotics by algae. Reprinted with permission from Xiong et al. [21], copyright (2021) Elsevier.

Fig. 2

(a) Processes included in the removal of PPCPs using algae-based techniques, modified from Ref. [56]. (b) Sorption and photodegradation based tetracycline removal during wastewater treatment using algal ponds [60].

Fig. 3

Contaminant removal mechanisms using the algae-fungi consortia. (a) Algae and fungi work together to degrade wastewater: I. Capture or adsorption of suspended solids; II. Reduction by extracellular enzymes secreted by fungi; III. Assimilation of soluble nutrients by algae and fungi. (b) Detailed description of the assimilation of soluble nutrients via microalgae and fungi. Note: Glu indicates glucose; CBB cycle indicates the Calvin-Benson-Bassham cycle. Modified from Ref. [67].

Fig. 4

Factors affecting antibiotic degradation by algae.

Fig. 5

(a) N-doped graphite biochar generated from C-phycocyanin extracted from Spirulina residues for catalytic persulfate activation, organic oxidation and nonradical disinfection, reprinted with permission from Ref. [82], copyright (2019) Elsevier. (b) Potassium hydroxide-modified algae-based biochar for sulfamethoxazole removal, reprinted with permission from Ref. [95], copyright (2021) Elsevier.

Fig. 6

(a) Photodegradation pathway of norfloxacin in water containing both algae and Fe(III), modified from Ref. [49]. (b) Mechanism of catalytic degradation of sulfamethazine by microalgae and monoclinic BiVO₄ under visible-light irradiation, modified from Ref. [106].

Fig. 7

(a) Advanced oxidation processes combined with microalgae for the treatment of recalcitrant wastewater, modified from Ref. [110]. The removal efficiency of (b) amoxicillin and (c) cefradine, via a combined Fenton-algal treatment process, modified from Ref. [111]. (d) UV/algal treatments, modified from Ref. [112].

Fig. 8

(a) Algae utilization as a source of carbon in the MFC anode for electricity production. (b) Live algae utilized as an electron donor to the MFC anode for electricity production. (c) A dual-chamber photosynthetic microbial fuel cell configuration, modified from Ref. [125]. (d) Schematic representation of the microbial fuel cell [126]. (e) Multiple anodic chambers combined an algal raceway pond to form a photosynthetic microbial fuel cell stack, reprinted with permission from Ref. [129], copyright (2019) Elsevier.