Water Purification Using Active Charcoal with Microbes and Chelated Iron Soaked into Its Micropores

Abstract

Urbanization in China has led to a significant increase in surface water pollution, posing a threat to the health and safety of residents and hindering sustainable economic development. Individual traditional methods have been used to purify polluted water, including the use of bamboo-derived activated charcoal, microbial material, and zero-valent iron. However, these methods have been found to have certain limitations. This study investigates the effects of an activated charcoal material combined with beneficial microbes and chelated nano-iron in removing nitrates. The experiments were conducted at various scales, including a bench-scale study, and studies of a small river, sewage plant tailwater, and artificially constructed wetlands. The microbes used included Bacillus spp., Lactobacillus spp., and yeasts. During the fermentation process, nano-scale iron powder was added, resulting in the formation of bivalent iron ions under anaerobic conditions. These ions were subsequently chelated by organic acids. Bamboo-derived activated charcoal was then soaked in the fermented liquid, allowing the microbes, chelated iron ions, and organic acids to infiltrate the pores of the activated charcoal. This activated charcoal material, containing microbes and chelated iron ions, demonstrated effective nitrate removal in laboratory experiments and sewage plant tailwater treatment, and water purification in wetlands and rivers. It is important to note that this research solely focused on the removal of nitrates, and further studies are required to confirm its effectiveness in other aspects of water purification.