Freshwater resources are limited and economically worthwhile with socioeconomic and environmental impact. Due to the extension of cities, industrial extension, and population growth, environmental pollution has become noteworthy. Heavy metals are pollutants that are produced by the industrial factory. Therefore, wastewater should be purified and treated and then be returned to natural water circulation. In this research, the removal of heavy metal Zinc at high concentrations in steel plant and the performance of the integrated system including activated carbon adsorption column (as pretreatment) and reverse osmosis (RO) membrane system under different operating conditions are investigated. The variable parameters studied are pH (4.5, 6.5, 7, and 9), pressure (5, 7, 9, and 11 bar), and Zinc concentration (30, 50, 70 mg/l) to obtain Zinc removal efficiency, turbidity dissolved solids (TDS), electrocoagulation (EC), and turbidity (TU) at constant temperature and flow rate. The results show that the efficiency of the integrated system at 9 bar pressure and the pH of 7.5 is considered to be optimal in terms of water outlet quality. At optimal conditions, the removal efficiency recorded for TDS is 98.1%, 97.4% for EC, 100% for Zinc and the turbidity removal efficiency is 95.3%, which are desirable. Moreover, the efficiency of this system at a high concentration of Zinc is evaluated. According to the results, it can be seen that the integrated system is resistant to probable shocks, high concentration and has a desirable efficiency since the efficiencies of all parameters are almost above 90%.