Phosphate Recovery

Promoting a positive dialogue regarding the recovery and recycling of phosphates from sewage and animal wastes.

Introduction

Phosphorus is a scarce natural resource for which there is intense competition between life forms: both on land and in the aquatic environment. Those organisms that are most successful in scavenging, storing and recycling have a natural advantage. Only modern man, far removed from the process of primary production, has forgotten the importance of conserving and re-using this precious non renewable resource: hundreds of thousands of tonnes of phosphorus are "lost" in human and animal wastes annually.

Phosphorus resources occur in some sedimentary and igneous rocks, collectively known as phosphate rock. Deposits of phosphate rock occur widely in the Earthís crust but high grade reserves, workable for commercial exploitation are geographically limited. Today, the main phosphate producing regions are North Africa, Russia, the United States, South Africa and China, with most of Europe's requirements coming from North Africa (especially Morocco).

Estimates of the Earth's phosphate reserves vary considerably but most commentators expect them to last more than one hundred years at current exploitation rates. Nevertheless, it is certainly true that the highest quality reserves are being depleted rapidly and the way we currently use phosphate does not accord with the principles of sustainability.

The opportunity exists to reverse this trend via the development of effective sewage and animal waste treatment technologies which facilitate the removal of phosphorus from these waste streams into a form suitable for recycling by the phosphate industry. There are compelling reasons for doing this:

phosphate rock resources are limited and declining both in quality and accessibility;

growth in the world population, necessitating increased food production, will lead to an increase in phosphate fertiliser consumption, only partially offset by a declining rate of use in the historically over-fertilised temperate zones;

the pressure to remove heavy metals from all phosphate products (including fertilisers) derived from natural phosphate rock will lead to increasing raw material prices and escalating disposal costs whereas recovered phosphate would be comparatively metal-free;

Nutrient enrichment of surface waters is a universal problem and, increasingly, water quality legislation will require the removal of phosphorus from sewage treatment works effluent. Where phosphorus removal is required by law, phosphorus recovery from sewage may be an economically attractive alternative. Animal wastes also offer a potentially large source of phosphates for recovery. The technology of phosphate recovery is relatively straightforward and the economics can be positive: as well as the value of the recovered phosphorus there can be significant savings in both sewage treatment costs and in the disposal of the residual sewage sludge.

It is hoped that this site, devoted to phosphorus recovery, will help to stimulate interest in the prospect of conserving and recovering this important resource.

CEEP logo This site developed and maintained by Eva Valsami-Jones

The site is sponsored by CEEP (Centre Europeen d'Etudes des Polyphosphates, a sector group of CEFIC, the European Chemical Industry Council).