“…Various works for more generalised fixed flowrate problem were also reported for direct reuse/recycle (Dhole et al, 1996;Polley and Polley, 2000;Hallale, 2002;El-Halwagi et al, 2003;Manan et al, 2004;Prakash and Shenoy, 2005;Bandyopadhyay et al, 2006;Foo et al, 2006b;Almutlaq and ElHalwagi, 2007;Foo, 2007;Shenoy and Bandyopadhyay, 2007;Foo, 2008) and for regeneration systems (Ng et al, 2007a;Ng et al, 2008b). Furthermore, the use of combined conceptual-based and mathematical optimisation techniques was also reported for water network synthesis with reuse/recycle, regeneration and total water network (Alva-Argáez et al, 2007;Ng et al, 2007b;Ng et al, 2007c;Ng et al, 2009a;Ng et al, 2009b;Ng et al, 2010). Note that total water network consists of the elements of water reuse/recycle, regeneration (treatment for reuse/recycle), and waste treatment (treatment for final discharge).…”