Membrane bioreactors cost analysis

Key words membrane bioreactors, cost analysis, productivity. 

A cost analysis of an extractive membrane bioreactor (EMB) for wastewater treatment has been reported by Freitas dos Santos and Lo Biundo [6.24]. The EMB studied was similar with those reported in Chapter 4. Calculations were carried out for a feed flowrate of 1 m h of wastewater polluted with dichloromethane at a concentration of 1 g l A minimum pollutant removal rate of 99 % and 8000 h of operation per year were considered. As expected, the analysis indicated that the costs are strongly dependent on the pollutant flow entering the bioreactor to be transformed. Two key parameters, namely the total membrane area required and the external mass transfer coefficient, were studied. The results show that the costs and membrane area decrease significantly as the mass transfer coefficient increases from 0.5 x 10 to 2.0 x 10 m-s (these values are typical for large units, while laboratory measured values harbor around 5x10 m-s [624]). Using a mass transfer coefficient of 1.0 x 10 m s the authors calculated the costs and the membrane area required for different wastewater flowrates. These results are shown in Fig. 6.3. 

Membrane bioreactors and membrane reactors can be analysed as whole plants and process units, with the membranes playing the simultaneous role of catalyst support or biocatalyst and separation unit. In this case, the analysis has to be done on the system and all the costs are related to it. 

Yeo K, (2010), Cost Analysis of Membrane Bioreactors to Reverse Osmosis Filters, http //nature.berkeley.edu/classes/esl96/projects/2010flnal/YeoK 2010.pdf. 

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