E-CORK · Advanced Electrochemical Treatments for Cork Washing Wastewater Remediation towards a Circular Economy

Advanced Electrochemical Treatments for Cork Washing Wastewater Remediation towards a Circular Economy

The difficulties in industrial wastewater treatment and management are exacerbating global water stress, where water regeneration and reuse are crucial. The role of producing industries and industrial wastewater treatment plants in seeking more cost-efficient and environmentally friendly technologies to address this issue is critical, presenting scientific, technological, environmental, and economic challenges. With a production of 162,000 tons per year, Portugal and Spain hold the largest global share of cork production, with cork stoppers for wine and champagne being the "star product." Approximately 90% of the cork stoppers used worldwide are produced in these two countries. The European Cork Federation has established mandatory practices to ensure the quality of natural stoppers, which involve several washing, bleaching, and disinfection steps. These procedures generate large volumes of wastewater, up to 195,000 m3/year, containing non-biodegradable organic matter, hydrogen peroxide used as a disinfectant and as a bleaching agent, and various dissolved salts, posing a serious risk to the environment and human health. The E-CORK project is based on the premise that cork washing wastewaters can be effectively treated by electrochemical advanced oxidation processes. The main goal is to develop an optimized electrochemical treatment line for purifying and reusing cork washing wastewaters, taking advantage of the hydrogen peroxide present in the main effluent (from by-product to reactant). The project not only focuses on treatment performance but also considers its technical, economic, and environmental feasibility. Various advanced electrochemical processes are proposed, including electrocoagulation, electrochemical peroxidation, and photo-assisted electrochemical peroxidation (also known as electro-Fenton and photo-electro-Fenton with external hydrogen peroxide feeding). Through this approach and considering the possibility of reusing the regenerated wastewaters, the E-CORK project aims to transform the cork industry into a circular economy. It takes into account Portugal and Spain's inherent responsibility for promoting cleaner and more cost-efficient technologies that safeguard cork production and aquatic environments, establishing a close link with industrial needs. During the first half of the project's life, electrochemical peroxidation under optimized conditions emerged as the most cost-efficient process for wastewaters with a high organic load. The treatment capitalizes on utilizing hydrogen peroxide, a by-product present in the effluent, as a reactant throughout the process, promoting a more sustainable approach to treatments within the cork processing industry.

Data: CORDIS, © European Union