Recovering Phosphate from Sludge-Incinerated Ash Using Modified Biochar

A study in the Journal of Environmental Chemical Engineering demonstrates that #biochar modified with calcium and magnesium can recover over 80% #phosphate from sludge-incinerated ash. This phosphate-rich biochar effectively improves soil and promotes plant growth, offering sustainable agricultural and nutrient recycling benefits.

June 26, 2024

1–2 minutes

Wang, et al (2024) Recovering phosphate from sludge-incinerated ashAsh is the non-combustible inorganic residue that remains after organic matter, like wood or biomass, is completely burned. It consists mainly of minerals and is different from biochar, which is produced through incomplete combustion. Ash Ash is the residue that remains after the complete More by modified 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 as a soil conditioner and P-fertilizer. *Journal of Environmental Chemical Engineering.* https://doi.org/10.1016/j.jece.2024.113329

In a recent study published in the Journal of Environmental Chemical Engineering, researchers explored an innovative method for recovering phosphate from sludge-incinerated ash (SIA) using modified biochar. This approach not only aims to extract valuable nutrients but also offers potential benefits as a soil conditioner and phosphorus (P) fertilizer.

The study focused on modifying biochar, a carbon-rich product derived from agricultural biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More, to improve its phosphate adsorption capabilities. Typically, biochar has a negatively charged surface, which hinders its ability to absorb phosphate, a nutrient that exists in anionic forms. To address this, the researchers used calcium (Ca2+) and magnesium (Mg2+) to modify the biochar, enhancing its capacity to adsorb phosphate from the acidic leachate of SIA.

The modified biochar demonstrated impressive results, achieving over 80% phosphate adsorption with capacities ranging from 56.20 to 93.76 mg P/g biochar. This high adsorption efficiency indicates that the modified biochar could be an effective tool for phosphate recovery.

Moreover, the study revealed that the phosphate-laden biochar could function as a slow-release P-fertilizer. Pot tests showed that this biochar significantly promoted lettuce growth, improved soil pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More, and enhanced nutrient uptake by plants. These findings suggest that the modified biochar not only recovers phosphate efficiently but also has practical applications in agriculture.

This research highlights a promising pathway for recycling nutrients from waste products, contributing to sustainable agricultural practices and the circular economy.