Energy and cost survey of membrane processes

Limited seawater application — energy consumption is 3—5 times SWRO Requires less pretreatment than RO Not limited by osmotic pressure Not affected by silica fouling 

Feed water hardness 1 ppm silica 1 ppm heavy metals 10ppb chlorine 20 ppb TOC 500 ppb as C 

The SEC of SWRO has dropped from 10 kWh/m to typically 4.0 kWh/m in the last 30 years [3,5,9,12-14] as a result of improvements in membranes, systems design and hardware. The process, however, is still energy intensive. Additional reductions of 10—20% may be achievable when operating with modified staged des ps of membrane arrays [5,6,14] and/or operating in a combined heat and power mode [13]. 

The thermodynamic minimum energy independent of the desalination process is 1.06 kWh/m [5,7,13,14]. The lowest energy consumption achieved in pilot studies 

MF/UF External MBR 2.0-4.0 pre-filtration LandfiU leachate, industrial wastewater, RO 

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