Potential of Treated Wastewater Reuse in Industrial Symbiosis: A Case Study of Iranian Industrial Park

Aim: 
This study aims to investigate the feasibility of reusing treated wastewater from the wastewater treatment plant of an industrial park to save fresh water and industrial symbiosis.
Methods: 
This study is descriptive, analytical, and comparative. This study analyzed the chemical, physical, and biological characteristics of treated wastewater from the wastewater treatment plant of Hashtgerd industrial park for 2 years (2022–2023). Then, reuse options of treated wastewater were evaluated using a multi-criteria decision-making process based on the analytic hierarchy process (AHP).
Results: 
Based on the obtained results, the amount of treated wastewater produced in the industrial park is up to1200 m³/d, and by reusing it, significant savings can be made in industrial water use. The average effluent concentrations were 96.25 ± 61.78 mg/l, 46.25 ± 29.91 mg/l, 17.75 ± 10.99 mg/l, and 1635 ± 315.5 mg/l for chemical oxygen demand (COD), biochemical oxygen demand (BOD₅), total suspended solids (TSS), and total dissolved solid (TDS), respectively. This treated wastewater is suitable for some reuse scenario according to the some standards and guidelines. The results of the AHP showed that the best way to treated wastewater reuse is industrial reuse (weight 0.251), which saves a lot of water consumption in industries located in the industrial park.
Conclusion: 
The TDS are higher than the permitted limits for some reuse. Therefore, further treatment may be required for some reuse of treated wastewater from the Hshtgerd industrial park.