Reliability of operation and failure management of membrane wastewater treatment

The analysis of the long-term performance of a full-scale submerged bioreactor confirms the reliability of operation and the process sustainability in terms of environmental and health protection. The failure mode analysis was used as a problem prevention tool that enabled to identify weak areas of the treatment process and develop actions to prevent their occurrence. The major risk is undoubtly membrane damage or fouling. In full-scale operation, two types of equipment are likely to be the major cause for decrease of membrane permeability – faulty pre-treatment, mainly fine screening and grease removal, and poor activated sludge properties induced by faulty aeration or shock salt and toxic loadings. PLC and SCADA systems are very important and reliable tools for MBR operation, but can be disturbed by some minor malfunctions or unreliable equipment such as communication links. Redundant equipment and adequate SCADA system lead to significant reduction of risk of failure of electromechanical apparatus enabling immediate detection of any breakdown or malfunction.