In this work for disposal of the biologically hard decomposed pollutant Benzo[a]Pyrene (BaP) photooxidation Chlorella kessleri was used. The simulation model system under the different experimental conditions (varying biomass and light intensity) was evaluated. For quantitative analysis of the decrease in BaP, GC/MS technique was used. The highest degradation efficiency was achieved in the case of biomass from the culture of live algae (29%) and light intensity at level of 13.5 W m⁻². When the dry biomass was used, degradation under the same conditions was lower because of lack of enzymatic activity in the system.

Metal-free, low-cost, organic photocatalytic graphitic carbon nitride (g-C₃N₄) has become a promising and impressive material in numerous scientific fields due to its unique physical and chemical properties. As a semiconductor with a suitable band gap of ~2.7 eV, g-C₃N₄ is an active photocatalytic material even after irradiation with visible light. However, information regarding the toxicity of g-C₃N₄ is not extensively documented and there is not a comprehensive understanding of its potential adverse effects on human health or the environment. In this context, the term “toxicity” can be perceived in both a positive and a negative light, depending on whether it serves as a benefit or poses a potential risk. This review shows the applications of g-C₃N₄ in sensorics, electrochemistry, photocatalysis, and biomedical approaches while pointing out the potential risks of its toxicity, especially in human and environmental health. Finally, the future perspective of g-C₃N₄ research is addressed, highlighting the need for a comprehensive understanding of the toxicity of this material to provide safe and effective applications in various fields.