Mining phosphorus from waste streams at wastewater treatment plants: a review of enrichment, extraction, and crystallization methods

Two interrelated problems exist: the non-renewability of phosphate rock as a resource and the excess phosphate in the water system lead to eutrophication. Removal and recovery of phosphorus (P) from waste streams at wastewater treatment plants (WWTPs) is one of the promising solutions. This paper reviews strategies for P recovery from waste streams in WWTPs are reviewed, and the main P recovery processes were broken down into three parts: enrichment, extraction, and crystallization. On this basis, the present P recovery technology was summarized and compared. The choice of P recovery technology depends on the process of sewage treatment and sludge treatment. Most P recovery processes can meet the financial requirements since the recent surge in phosphate rock prices. The safety requirements of P recovery products add a high cost to toxic substance removal, so it is necessary to control the discharge of toxic substances such as heavy metals and persistent organic pollutants from the source.

Automated summary

The non-renewability of phosphate rock as a resource and excess phosphate in water systems leading to eutrophication are two interrelated problems. This paper reviews strategies for phosphorus (P) recovery from waste streams in wastewater treatment plants (WWTPs) and breaks down the main P recovery processes into enrichment, extraction, and crystallization. The choice of P recovery technology depends on sewage and sludge treatment processes. Most P recovery processes can meet the financial requirements due to the recent surge in phosphate rock prices. However, the safety requirements for P recovery products add a high cost to toxic substance removal, highlighting the need to control the discharge of toxic substances from the source.