New Research Transforms Biomass Processing Wastewater Into High-Efficiency Liquid Fertilizer for Sustainable Agriculture

Hydrothermal carbonization byproduct can increase rice yields by 30%. Discover how this liquid waste is becoming a sustainable alternative to synthetic fertilizer.

By: AXL Media

Published: Apr 28, 2026, 9:21 AM EDT

Source: Information for this report was sourced from EurekAlert!

Redefining Waste in the Circular Bioeconomy

The industrial conversion of wet organic matter into solid fuel is yielding a secondary resource that could revolutionize sustainable farming. According to a new review published in the journal Biochar, the liquid byproduct of hydrothermal carbonization, known as process water, is transitioning from a disposal liability to a strategic agricultural asset. While historical focus remained on hydrochar, the solid carbon product, researchers now highlight that the liquid fraction can constitute up to 70 percent of the processed material. This fluid contains high concentrations of organic carbon and essential nutrients, offering a scalable solution for waste management and resource recovery.

The Chemical Composition of Next-Generation Fertilizers

Technical analysis of this process water reveals a complex profile rich in nitrogen, phosphorus, and potassium. These elements are the fundamental building blocks of plant nutrition, and their presence in a liquid state allows for rapid absorption by various crop species. Research synthesized in the review indicates that when the liquid is properly diluted and applied to crops such as rice, nutrient use efficiency improves by 15 to 30 percent. This efficiency gain is a critical metric for farmers looking to maximize output while minimizing the environmental footprint of their chemical inputs.

Integration with Renewable Energy and Mineral Recovery

The utility of hydrothermal process water extends beyond direct soil application into the realms of energy production and mineral extraction. The organic content within the liquid can be funneled into anaerobic digestion systems to generate methane-rich biogas, providing a renewable energy source for industrial operations. Furthermore, innovative recovery techniques such as struvite precipitation allow for the precise extraction of phosphorus and nitrogen. This multi-tiered approach ensures that almost no part of the original feedstock, whether food waste or sewage sludge, is lost to the environment as unutilized waste.