The Comparative Analysis of Wastewater Treatment Efficiency in Nickel-Chrome and Zinc Electroplating Industries for Pollutant Removal; [تحلیل مقایسه‌ای کارایی فرایندهای تصفیه فاضلاب در صنایع آبکاری نیکل-کروم و روی در حذف آلاینده‌ها]



Naeimi B ; Haddadi M ; Alimohammadi M ; Dehghani M H ; Aghaei M ; Changani F
Source: Iranian Journal of Health and Environment Published:2026

Abstract

Background and Objective: The rapid expansion of industrial and urban activities in recent decades has led to the increased use of electroplating processes and the generation of wastewater containing heavy metals and toxic compounds such as cyanide and phenol. These pollutants can pose significant risks to human health and the environment. This study aims to conduct a quantitative and qualitative assessment of wastewater from electroplating industries and to evaluate its compliance with discharge standards, thereby providing a basis for improving wastewater management and mitigating environmental impacts. Materials and Methods: This cross-sectional study was conducted at two nickel-chromium and zinc electroplating units equipped with on-site treatment systems in Tehran Province. Following an assessment of the electroplating processes and treatment units, grab sampling was performed twice on both raw wastewater and effluent samples. In each sampling event, six samples were collected, resulting in a total of 12 samples. Physical and chemical characteristics were measured, and the performance of the treatment systems in removing pollutants was evaluated. Results: The analytical results indicated that in the effluent from unit 1, the concentrations of COD and nickel, and in the effluent from unit 2, the concentration of zinc, exceeded the established permissible limits. The treatment system in the nickel-chromium electroplating unit exhibited the highest removal efficiency for chromium (100%) as well as for zinc, phosphate, and nickel (94–99%), whereas the removal efficiencies for COD and TSS were estimated at 45% and 69%, respectively. In the zinc electroplating unit, the removal efficiencies for nickel, zinc, COD, and phosphate were approximately 98–99%, while the lowest removal efficiencies were observed for cyanide (50%) and copper (33%). Conclusion: The findings of this study indicated that the concentrations of several parameters in the treated effluents exceeded the permissible limits established by Department of Environment (DoE) of Iran standards, highlighting the urgent need to upgrade treatment processes and improving wastewater management. © 2026 Iranian Association of Environmental Health, and Tehran University of Medical Sciences. Published by Tehran University of Medical Sciences. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International license (https://creativecommons.org/licenses/by-nc/4.0/). Noncommercial uses of the work are permitted, provided the original work is properly cited.