Overview of recent advances in phosphorus recovery for fertilizer production

Abstract

This Mini Review gives an overview of and respective references for the current situation regarding global phosphorus reserves and the legal situation for P recovery using Germany as the model. Apart from the well‐known pilot up to industrial/full scale recovery techniques, emerging chemical and bio‐based P recovery techniques are named without claiming to be all‐encompassing. Special attention is paid to the biological systems for P recovery that reveal ways for use of renewable resources as raw materials. A few chemically based recovery techniques like AirPrex®, (Ostara)PEARL™, AshDec®, and RecoPhos® have already been used to recover P at a rate and quality which allows for its sale as a fertilizer. Many chemically based processes are at the stage of investigation on a pilot or laboratory scale, e.g. P‐RoC, LeachPhos, and Mephrec®. All of the biologically based technologies like P‐Bac are still at an early stage of research and show promising results. Of all recovered materials struvite, calcium phosphate and biological bound phosphorous seem to have the best plant availability. Although there is no ultimate “one fits all” technology, potential P‐recovery plant operators can choose from a wide range of techniques which will best fit local raw material availability, economic and ecological situation.

Using an Environment-Friendly Fertiliser from Sewage Sludge Ash with the Addition of Bacillus megaterium

“…As the treatment of wastewater and management of process by-products are now another major global issue [10], the use of SSA as a fertiliser may also alleviate this dilemma. Some EU countries have already introduced or intend to introduce a mandatory legal obligation to recover P from sewage sludge and slaughterhouse waste [11].…”

Integrated nutrient recovery from source-separated domestic wastewaters for application as fertilisers

“…Phosphorous precipitation Anaerobic digestate can be used for precipitation of struvite, a slow-release phosphate fertiliser. Struvite is currently produced at several decentralised and centralised STPs at a variety of scales [43][44][45] and is probably one of the better known fertiliser products recovered from wastewater. Examples of alternative outlooks for phosphorous recovery through precipitation are the formation of calcium phosphate granules inside UASB reactors during anaerobic treatment of BW [46,47] and electrochemical precipitation as struvite or calcium phosphates [48,49].…”

Exploring resource recovery potentials for the aerobic granular sludge process by mass and energy balances – energy, biopolymer and phosphorous recovery from municipal wastewater

“…21 Efforts to recover P have been recently intensified as various EU member states including Germany, introduced legislation to enforce P recovery from WWTPs in the near future. 22 Currently, fractions of the influent-P are predominantly recovered by two technological solutions, namely chemical P extraction from sludge incineration-ash and as struvite mineral from P-rich side streams in WWTPs that apply biological P removal. 23 Struvite precipitation in WWTPs was discovered almost 60 years ago and its removal served initially the purpose of improving plant operations and especially clogging of pipes and equipment.…”