Patent ID: 8721885

Claim:
A system for removing phosphorous (P) from P-containing wastewater, comprising: a source of the P-containing wastewater, wherein the P-containing wastewater comprises has an initial pH and organic matter; a main filter unit (MFU) in fluid communication with the source of the P-containing wastewater to receive the P-containing wastewater, wherein the MFU is substantially filled with steel slag, wherein the P-containing wastewater passes through the steel slag to form MFU-filtered wastewater from the P-containing wastewater by removing P from the P-containing wastewater, and the MFU-filtered wastewater has a first pH greater than the initial pH; a pH adjusting unit (AU) in fluid communication with the MFU to receive the MFU-filtered wastewater, wherein the AU is predominantly filled with a carbon rich material having microorganisms attached thereto, wherein said microorganisms consume the organic matter in the MFU-filtered wastewater and produce carbon dioxide gas, wherein the MFU-filtered wastewater flows through the carbon rich material and combines with the carbon dioxide gas produced by the microorganisms to form AU-filtered wastewater, and wherein the carbon dioxide gas combines with the MFU-filtered wastewater to lower the first pH of the MFU-filtered wastewater such that the AU-filtered wastewater has a second pH that is lower than the first pH.