Design and Optimization of a Reverse Osmosis System for Reject Water Treatment in a Petrochemical Plant

Industrial wastewater discharge into land and/or surface water bodies has grown to be a serious environmental issue, especially when it endangers aquatic ecosystems and the sustainability of the environment. Therefore, in order to determine the most economical and successful treatment techniques, thorough investigations and evaluations of the wastewater quality released from different industrial sectors are crucial. The production of drinkable water, seawater desalination, and industrial effluent treatment all make extensive use of reverse osmosis (RO), a cutting-edge water purification technology. Reverse osmosis rejects, retentates, or concentrates are the concentrated waste stream produced by this process, which also produces purified water (permeate). The reject stream needs to be properly treated before being released because of the high osmotic pressure and high amounts of organic pollutants. Furthermore, this study's main goal is to make it possible to reuse RO reject water in cooling systems following the proper purification process. In order to do this, the reject stream from the primary RO unit was treated by a secondary RO unit. This system uses RO B085 FR 4040 membranes and functions as a single-pass unit. A thorough feasibility study showed that adding a second RO unit to treat the primary RO reject stream would have several advantages, such as lower raw water consumption, less chemical use in water treatment, better plant equipment protection, environmental sustainability, and increased economic viability. The newly designed Reverse Osmosis system aims to recover approximately 45 m³/h from the 60 m³/h of reject water. To attain the intended treatment efficiency, system characteristics were simulated and operating parameters were optimized using the LANXESS Calculation and Design Software.