Rationale for the Combined Use of Biological Processes and AOPs in Wastewater Treatment Tasks

Vladimir Shtepa,Magdalena Balintova,Stefan Demcak,Mathieu Gautier,Viktoriia Chubur,Yelizaveta Chernysh

doi:10.3390/app11167551

Abstract

This paper aims to form a unified concept of the integrated use of different wastewater treatment methods to form a resistant biological treatment stage of technological systems under the influence of such toxic factors as antibiotics and surfactants. The processes of mechanical treatment, ozonation, UV irradiation, and electrolytic anodic oxidation were implemented in an electrotechnological wastewater treatment facility. Wastewater treatment quality was determined by the concentration of nitrogen compounds in aqueous solutions according to the method of Lurie. Biodiagnostics of the investigated activated sludge via surfactant action was carried out at polyethylene oxide concentrations of 10, 30, and 50 mg/dm3. As a result of experiments on wastewater treatment after aquaculture, an improvement in the reduction of pollutants only by the indicator “nitrate concentration” was determined: by 20% after anodic oxidation, and by 15% after photolysis. At almost all surfactant concentrations studied, the activated sludge was not completely recovered, which was expressed in a decrease in its quantity and in the inability to aggregate flakes of activated sludge. The diameter of the growth retardation of the standard disk with antibiotic (amoxiclav) by the accumulative culture of activated sludge was 17.3 ± 2 mm at a concentration of 4 mg/dm3 and 31.3 ± 3 mm at a concentration of 6 mg/dm3. In the process of studying the state of the activated sludge’s biocenosis under the influence of such toxicants, several regularities were revealed. The directions of using combined approaches of water treatment and wastewater treatment were defined. The structural model of treatment facilities using aerobic and anaerobic bioprocesses together with advanced oxidative technologies was substantiated.

Highlights

Irradiation and the addition of hydrogen peroxide [23]. The comparison with these results is fair because, before reaching the photolysis unit, the aqueous solution passes through an electrolysis unit where, among other things, it is saturated with hydrogen peroxide
It is necessary to take into account the qualitative and quantitative parameters of the operation of the activated sludge biosystem in order to form a dynamic equilibrium in its species diversity for the most effective destruction of organic pollutants
The main technological disadvantages of the systems of physical, chemical, and biological methods of treatment were grouped into a single block diagram

Summary

Introduction

The introduction of various types of toxicants—in particular, antibiotics and surfactants—into aquatic ecosystems is becoming an increasing problem. A global problem in the conservation of aquatic ecosystems is the active pollution of water resources worldwide with pharmaceutical products, including antibiotics, whose concentration in some rivers of the world exceeds the safety limit [1,2]. Up to 90% of antibiotics used will end up in components of the natural environment, such as soil and water bodies. Medicinal drug residues enter rivers from human and animal waste, as well as from suboptimal treatment facilities, including those of pharmaceutical companies [3,4]. Antibiotics can significantly change the biocenosis of water bodies [3]

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