High operational costs, and energy costs in particular, are often seen as the Achilles heel of MBRs. Energy efficiency in operating MBRs has attracted a great deal of attention, particularly in relation to blowing air and aeration energy efficiency.
According to the great Tom Lehrer: 'Life is like a sewer: what you get out of it depends on what you put in'. In which case, of course, wastewater treatment reflects life. A big selling point of MBRs is the constant and high wastewater quality.