Design of distributed wastewater treatment networks by combining total mixing influence potential indicator with heuristic rules

This article presents a design method for the following wastewater treatment networks: a treatment process can remove multiple contaminants and/or a contaminant can be removed by multiple treatment processes. The method is developed by improving the numerical indicator of total mixing influence potential (TMIP), which was proposed by Li et al. (2015, AIChE J, 61: 3223-3231) based on the minimum treatment flowrate calculated with pinch-based method. The design procedure presented in this work includes two steps. First, calculate the values of TMIP with pinch method together with a linear programming approach for the processes which can remove multiple contaminants. Based on the TMIP values, the performing order of treatment processes can be identified and the initial network can be built. Secondly, for the situation when a contaminant needs to be removed by multiple processes, a heuristic rule and mass balance have been used to adjust the initial network for obtaining the final result. The proposed method has the advantages of noncomplicated calculation and engineering significance. It can provide the results close to those published in the literature.