Electrocoagulation as a sustainable treatment strategy for wastewater from the pulpwood

Over centuries, paper became indispensable across civilizations, yet its modern production presents significant environmental challenges. Today, the pulpwood is among the most resource-intensive sectors. The manufacturing process emits pollutants such as sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and carbon dioxide (CO₂), contributing to acid rain and global warming. Wastewater from paper mills often contains organic matter (like lignin), chlorates, chelating agents, and heavy metals, all of which disrupt aquatic ecosystems by raising biochemical oxygen demand (BOD) and promoting eutrophication. Chlorine-based bleaching further introduces toxic organochlorine compounds into the environment. The industry also contributes to soil degradation through effluent disposal practices. Hazardous substances such as mercury, benzene, methanol, and ammonia present significant health and ecological risks. This study investigates the use of electrocoagulation (EC) as a treatment method for wastewater from a pitchboard industry. EC applies an electric current to remove contaminants via coagulation. Experimental results showed that a charge density of 12 C/L for 20 minutes achieved optimal chemical oxygen demand (COD) removal. COD reduction improved with increasing current density and specific chloride concentrations. Aluminum electrodes performed best at 400 mg/L chloride, while graphite electrodes were most effective at 600 mg/L. Mixed electrode pairs, including graphite – iron and graphite – aluminum, also achieved high removal rates, particularly at 600 mg/L chloride. Additionally, the optimal pH for removal was found to be between 6 and 8.These findings highlight electrocoagulation as a promising, sustainable method for treating wastewater from the pulpwood.