Antibiotics are a typical group of pharmaceutical and personal care products (PPCPs) with emerging pollutant effects. The presence of residual antibiotics in the environment is a prominent issue owing to their potential hazards, toxic effects, and persistence. Several treatments have been carried out in aquatic environments in order to eliminate antibiotic residues. Among these, photodegradation is regarded as an environmentally-friendly and efficient option. Indirect photodegradation is the main pathway for the degradation of residual antibiotics in natural water, as opposed to direct photodegradation. Algae, working as photosensitizers, play an important role in the indirect photolysis of residual antibiotics in natural water bodies. They promote this reaction by secreting extracellular organic matters (EOMs) and inducing the generation of active species. In order to provide a thorough understanding of the effects of algae on residual antibiotic degradation in the environment, this paper comprehensively reviews the latest research regarding algae-induced antibiotic photodegradation. The summary of the different pathways and photosensitive mechanisms involved in this process show that EOMs are indispensable to antibiotic photodegradation. The influencing factors of algae-induced photodegradation are also discussed here: these include algae species, antibiotic types, and environmental variables such as light source, ferric ion presence, temperature, and ultrasound treatment. Based on the review of existing literature, this paper also considers several pathways for the future study of algae-induced antibiotic photodegradation.

A double strategy based on the removal of sulfonamide antibiotics by Pleurotus ostreatus and adsorption on spent mushroom substrate was assessed to reclaim contaminated wastewater. P. ostreatus was firstly tested in a liquid medium fortified with five sulfonamides: sulfamethoxazole, sulfadiazine, sulfathiazole, sulfapyridine and sulfamethazine, to evaluate its capacity to remove them and to test for any adverse effects on fungal growth and for any reduction in residual antibiotic activity. P. ostreatus was effective in removing sulfonamides up to 83 to 91% of the applied doses over 14 days. The antibiotic activity of the sulfonamide residues was reduced by 50%. Sulfamethoxazole transformation products by laccase were identified, and the degradation pathway was proposed. In addition, P. ostreatus growth on a semi-solid medium of spent mushroom substrate and malt extract agar was used to develop a biofilter for the removal of sulfonamides from real wastewater. The biofilter was able to remove more than 90% of the sulfonamide concentrations over 24 h by combining adsorption and biodegradation mechanisms.