Abstract: Wastewater regeneration reuse is an effective way to reduce freshwater consumption of industrial water systems. The post-regeneration (Cr) is a critical factor to reduce freshwater consumption and operating cost. The quality of regenerated water improves continuously with the increase of the depth of treatment. However，the increase in the cost of wastewater treatment and decrease of the regeneration ratio (Ψ) will leads to the reduction of the quantity of regenerated water. In this paper，the post-regeneration (Cr) was related with the operating cost and regeneration ratio (Ψ). An optimal method of regeneration recycling water networks with double outlets regeneration unit was proposed with a case study，using an improved problem table method. Taking freshwater consumption and operating cost into account，the post-regeneration (Cr) was determined with the consideration of freshwater consumption and operating cost. Next，an optimal water network was constructed. Furthermore，a rain drainage regeneration recycling project of a petrochemical enterprise was analyzed via the proposed approach and the comparison between two available schemes was made.

Key words: wastewater, wastewater minimization, regeneration, optimization

摘要： 污水循环回用，提高污水的重复利用率，是实现节水优化的有效途径。再生后浓度是影响污水回用再生系统新鲜水用量、操作费用的关键因素。随着处理深度的增加，再生水的水质不断上升，可匹配的水阱增加，但污水的回用成本不断上涨，再生率也相应下降，可回用水量减少。本文提出双出口再生单元再生后浓度与再生率、回用成本关系的关联模型，并求解具体的案例说明具有双出口再生单元再生循环水网络的优化设计步骤。采用改进的问题表法，确定不同再生后浓度下具有双出口再生单元再生循环水网络的目标值。综合考虑新鲜水量和操作成本，确定最优再生后浓度，并对水网络进行优化。计算实例表明，本文建立的方法是可行的。工业实例分析，石化企业雨排水处理回收利用项目考虑了再生率与再生后浓度关系，比较两种方案的节水量，以便指导方案的选择。

关键词: 废水, 废水最小化, 再生, 优化