FEATURES OF THE DESIGN AND OPERATION OF MEMBRANE BIOREACTORS IN THE FIELD OF BIOTECHNOLOGY AND WASTEWATER TREATMENT

Abstract

The purpose of the work is to study modern designs of MBRs, rules for their operation, problems that arise during operation, and methods of membrane regeneration. The paper presents modern designs of membrane reactors, the main characteristics and conditions of application of different types of membrane modules. Comparative characteristics of the operation of technological schemes are presented. It has been shown that increased doses of activated sludge (8–12 g/dm3) allow ensuring stable purification quality. The degree of wastewater purification in a membrane bioreactor is BOD – 98.7–99.7%, COD – 80–90%, ammonium nitrogen – 98.5–99.8%, phosphorus – 90–95%. The efficiency of bacteria removal is 99.99%, viruses – 99%. Schemes of conversion of traditional technologies (aerotankssecondary clarifiers) to membrane bioreactor technologies are presented. It is emphasized that reconstruction allows for advantages in construction and operation: compactness of structures; high concentrations of activated sludge; storage of slowly growing microorganisms (nitrifying bacteria). The main stages of MBR operation are determined: system startup and stabilization; ongoing operation (regulation of wastewater and air flow – control of process parameters – membrane cleaning – removal of excess sludge); preventive maintenance and repair; maintenance.An analysis of biofilm fouling and their impact on the operation of membrane bioreactors was conducted. The main factors influencing membrane fouling were identified. The advantages and disadvantages of MBR systems compared to traditional methods were presented. A classification of membrane fouling and methods for their cleaning was provided.