Background

Anaerobic digestion is a widely practiced sequence of processes in which microorganisms break down biodegradable materials in the absence of oxygen used by nearly every major metropolitan area. It is a relatively simple process that also produces large volumes of various reusable by products, including but not limited to stabilized biosolids that can be used as fertilizer and natural biogas which can be used as an energy source. However, this is a relatively fragile microbiological process sensitive to a variety of factors and releases phosphorous and sulfur into the byproducts in potentially harmful ways. Currently, to remove or manage phosphorous and sulfur byproducts is a costly and time-consuming process.

Technology Overview

Inventors have developed a method for sequestering phosphorous and sulfur from wastewater, being especially advantageous for methods where iron- and/or steel-making slags are added. Basic Oxygen Furnace and/or Electric Arc Furnace steel slag particles are widely available as agricultural lime. The process they developed significantly reduces the concentrations of phosphorous or sulfur in the immediate aqueous phase, surrounding moisture, and/or associated gasses. The removal of these compounds enriches the biogas methane content and increases the concentration of phosphorous in the biosolids component used as fertilizer, which is a critical nutrient in fertilizer.

Stage of Development

Proof of concept

Benefits

Saves time and money
Enriches biosolid and biogas by products
More effective waste treatment process
Widely available precursors

Applications

Wastewater treatment plants

CU4299B

Sequestration of Macronutrients from Anaerobic Wastewater Treatment With Iron-and Steel-Making Slags