The use of biochar made from biomass and biosolids as a substrate for green infrastructure: A review

Abstract

Biochar made from biomass and biosolids can be used in substrates suitable for urban green infrastructure, especially green roofs, green parking lots, and green walls. The properties of biochar depend on the feedstock and pyrolysis conditions. Biochar made from different feedstocks, e.g., sludges, biomass, food waste, wood, and plant residues, has different physicochemical properties that affect the availability of nutrients, absorption of pollutants and harmful gases, carbon sequestration, and improvement of pH of amended soil. This paper reviews and summarizes various feedstocks for biochar production, pyrolysis technology and conditions, and physicochemical properties of selected types of biochar. Since biochar has a positive influence on plant growth, fertilizer efficiency, and rainwater capture, showing its use as a stable organic component of the substrate is the main objective of this research paper. Conclusion of the review considers the usage of biochar as a substrate for green infrastructure in pursuance of its characteristics, limiting pollutants concentration, potential benefits and risks for the environment, water sources and occurring climate change. The review is based on the analysis of selected papers on existing research and case studies related to the use of biochar and the evaluation of the impact of biochar on the characteristics of growing medium.