Modified Orange Peels Biochar as a Sustainable Green Biosorbents for Nitrates and Phosphates in Environmental Waters

by Gerald Wachira Mbugua, Otieno Kevin Okoth, Otieno Winstone Ochieng

Published: December 18, 2025 • DOI: 10.51584/IJRIAS.2025.101100076

Abstract

Biomass waste utilization has garnered a lot of interest lately, particularly in the purification of environmental water. Water pollution caused by excessive nitrates has become a significant environmental concern globally. The traditional treatment methods often involve costly and energy-intensive processes. This chapter examines the potential of using modified fruit peels, specifically modified orange peels biochars, as natural bio sorbents for the removal of nitrates and phosphates from environmental waters. Biochar, a charcoal-like material produced by heating biomass in an oxygen limited environment, has emerged as a promising tool for water purification due to its unique properties and environmental advantages. Its microporous structure offers a vast surface area decorated with functional groups, ideal for capturing contaminants such as the phosphates and the nitrates. Biochar's purification power works through a combination of mechanisms. It acts like a sponge, using its porous structure to trap contaminants physically through adsorption. The charged functional groups on its surface also act like magnets, attracting and holding onto unwanted ions through ion exchange. Scientists rely on mathematical models like Langmuir and Freundlich isotherms to fully understand how well biochar will work in a particular situation. These models describe how efficiently biochar removes contaminants at varying concentrations either through monolayer adsorption route on homogenous surfaces as in the case of Langmuir or onto heterogenous surfaces as in the case of Freundlich isotherm, providing valuable insights for optimizing biochar-based water treatment systems.