Evaluation of effluent treatment efficiency by fractal analysis Elvira Nafikova, Dmitry Alexandrov, Arina Sidorova, Azalia Aitkulova and Kamilla Chuvashaeva E3S Web Conf., 460 (2023) 08004 Published online: 11 December 2023 DOI: 10.1051/e3sconf/202346008004