A recent review published in the Journal of Water Process Engineering by Diksha Pandey and colleagues explores the role of 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 in improving constructed wetlands (CWs) for wastewater treatment. Constructed wetlands use plants, substrates, and microorganisms to naturally purify wastewater, offering an environmentally sustainable solution to water pollution.

Biochar, a carbon-rich material derived from the pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More of organic waste, enhances CW performance by increasing pollutant adsorptionBiochar has a remarkable ability to attract and hold onto pollutants, like heavy metals and organic chemicals. This makes it a valuable tool for cleaning up contaminated soil and water.   More, supporting microbial diversity, and facilitating plant-microbe interactions. Its high surface area, porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More, and chemical stability make biochar effective in removing nutrients, heavy metals, and emerging contaminants such as pharmaceuticals and pathogens.

The study highlights biochar’s adaptability, showing how production conditions like feedstockFeedstock refers to the raw organic material used to produce biochar. This can include a wide range of materials, such as wood chips, agricultural residues, and animal manure. More type and pyrolysis temperature influence its efficacy. For instance, biochar derived from agricultural waste efficiently removes nutrients like nitrogen and phosphorus, while iron-modified biochars are particularly effective against heavy metals. Additionally, biochar can support microbial populations, enabling processes like denitrification and contaminant degradation.

Despite its potential, challenges remain. Long-term stability, saturation effects, and the high cost of biochar production require further research to optimize its application. Innovations like integrating biochar with electrochemical systems or using modified biochars for targeted pollutant removal could make CWs even more effective.

The review concludes that biochar-enhanced CWs offer a promising avenue for sustainable wastewater treatment but recommends field-scale studies and economic evaluations to bridge gaps between research and large-scale implementation.

Pandey, et al (2025) Biochar application in constructed wetlands for wastewater treatment: A critical review. Journal of Water Process Engineering. https://doi.org/10.1016/j.jwpe.2024.106713