Shigei, et al (2024) Efficient removal of organic matter and nitrogen from municipal wastewater in multi-module biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More filters for onsite wastewater treatment. Environmental Technology. https://doi.org/10.1080/09593330.2024.2402096

Biochar, a carbon-rich material, is gaining attention as an alternative for onsite wastewater treatment systems (OWTS). A recent study evaluated the effectiveness of multi-module biochar filters (MmBFs) in treating municipal wastewater. The MmBF system, consisting of six modules, was designed to sequentially remove organic matter, nitrogen, and bacteria like E. coli. The first three modules operated under aerobic conditions to promote organic matter oxidation and nitrogen nitrification, while the next two modules, under anoxic conditions, facilitated nitrogen denitrification. The final module used biochar and pine bark for bacterial removal.

Over a 381-day study period, the MmBFs achieved a 95% reduction in chemical oxygen demand (COD) and a 71% reduction in total nitrogen. However, phosphorus removal remained minimal at just 3.4%, indicating the need for system improvements. The filters demonstrated high efficiency in removing E. coli, though the removal rate decreased slightly over time.

While the MmBF system proved effective for COD, nitrogen, and bacterial treatment, further research is necessary to optimize long-term performance, especially for phosphorus and micropollutant removal. Enhancing the system’s design, particularly for phosphorus capture, and further exploration into the microbial activity within the biochar could improve future outcomes. The compact, modular design offers flexibility for OWTS, with potential applications in rural and urban settings alike.