Recycled copper waste as a green functional material for enhanced bacterial removal in drinking water filtration systems

In rural communities, conventional methods used to disinfect raw water are not only insufficient, but they also generate harmful byproducts. This increases the risk of water-borne diseases, highlighting the necessity of sustainable solutions that effectively reduce bacteria and improve water quality. The goal of this study was to evaluate pathogen removal through the incorporation of copper pipe waste and mesh in the pre-filtration and post-filtration stages. A comparative experimental design with three different treatments was implemented during the study: filtration without copper, copper filtration at the entrance of the filter, and copper filtration at the filter’s outlet. The copper mesh and fragments of copper pipes were placed in strategic points of the sand filters, and were kept in operation for three months. For each treatment, total coliforms and fecal coliforms were analyzed, both from the raw water and the filter effluent. The results showed that the placement of copper in the filter significantly increased the effectiveness of coliform removal in comparison to the copper non-contact filtration system. The sand filter without copper obtained a low average reduction rate of coliforms of 83.04% (0.77 log), indicating moderate microbiological control capacity. However, the coliform removal efficiency with copper contact (prefiltration) was 93.50% (1.19 log), and with copper contact (postfiltration), the coliform removal was 86.15% (0.86 log). In general, copper systems performed better, suggesting a positive effect of copper in bacterial removal. These findings suggest that the application of metallic copper in water disinfection may constitute a sustainable alternative for improving water quality, reducing the necessary dose of chlorine, and preventing water-borne diseases in rural communities.