An iterative method for design of water‐using networks with regeneration recycling

Abstract

in Wiley Online Library (wileyonlinelibrary.com).Both freshwater consumption and wastewater discharge can be reduced significantly when wastewater regeneration recycling is introduced in the design of the water-using networks (WUNs). However, it is often difficult to design the WUNs involving regeneration recycling. This article presents an iterative method to design the WUNs involving regeneration recycling. The final designs can be obtained without iteration for the networks with known regenerated concentrations, and in a few iterations for the networks with known removal ratios of the contaminants. The method proposed can reduce the following parameters simultaneously, the consumptions of freshwater and the regenerated water, and the concentrations of the stream before regeneration, and all of them reflect the cost of the network involving regeneration recycling. The results of a few literature examples show that the designs obtained in this work are comparable to that obtained in the literature. The proposed method is simple and effective.

Analysis of water-using networks with multiple contaminants involving regeneration recycling

“…The results are the same as that obtained by the method of Pan et al (2012). However, no detailed iterative calculations are required to obtain the above values with the method proposed in this paper.…”

“…We can obtain C max R;A from the above equation, and obtain C R;A with the method of Pan et al (2012), as shown in Table 4. It can be seen from Table 4 that C R;A are lower than C max R;A across the regenerated concentration interval [8.39, 20] ppm of contaminant B.…”

“…We take the network obtained by Pan et al (2012) as the base case of this example: the regenerated concentrations for contaminants A, B, and C are (89. 16, 8.39, 121.09) ppm, the flow rate of the regenerated stream F reg;0 is 56.08 t h À 1 , and the flow rate of the regeneration pinch-source stream F B P;0 is 25.92 t h À 1 .…”

“…Meanwhile, when the regenerated concentrations are reduced, consumption of regenerated stream (even freshwater) can be reduced (Feng et al, 2007(Feng et al, , 2008Pan et al, 2012), but regeneration costs are likely to increase. Therefore, it is important to investigate the influences of the regenerated concentrations of contaminants on regenerated stream consumption.…”

“…The introduction of concentration potential concepts simplified the design procedure for multi-contaminant water networks (Liu et al, 2009b). Based on the above insight and concentration potential concepts, Pan et al (2012) developed an iterative procedure for design of the multicontaminant water networks involving regeneration recycling, and Zhao et al (2013) developed an iterative method for design of the regeneration recycling water networks with internal water mains.…”