Enhanced biological phosphorus removal (EBPR) is a
sewage treatment
Sewage treatment (or domestic wastewater treatment, municipal wastewater treatment) is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable for discharge to the surrounding envir ...
configuration applied to
activated sludge systems for the removal of
phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid .
The phosphate or orthophosphate ion is derived from phospho ...
.
The common element in EBPR implementations is the presence of an
anaerobic tank (
nitrate
Nitrate is a polyatomic ion
A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zer ...
and
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...
are absent) prior to the
aeration tank. Under these conditions a group of
heterotroph
A heterotroph (; ) is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. In the food chain, heterotrophs are primary, secondary and tertiary consumers, but ...
ic
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
, called
polyphosphate-accumulating organisms (PAO) are selectively enriched in the bacterial community within the activated sludge. In the subsequent aerobic phase, these bacteria can accumulate large quantities of
polyphosphate within their
cells and the removal of phosphorus is said to be ''enhanced''.
Generally speaking, all bacteria contain a fraction (1-2%) of
phosphorus
Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...
in their
biomass
Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bi ...
due to its presence in cellular components, such as
membrane phospholipid
Phospholipids, are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue (usually a glycerol molecule). Marine phospholipids typ ...
s and
DNA. Therefore, as bacteria in a wastewater treatment plant consume nutrients in the wastewater, they grow and phosphorus is incorporated into the bacterial biomass. When PAOs grow they not only consume phosphorus for cellular components but also accumulate large quantities of polyphosphate within their cells. Thus, the phosphorus fraction of phosphorus accumulating biomass is 5-7%. In mixed bacterial cultures the phosphorus content will be maximal 3 - 4 % on total organic mass. If additional chemical precipitation takes place, for example to reach discharge limits, the P-content could be higher, but that is not affected by EBPR. This biomass is then separated from the treated (purified) water at end of the process and the phosphorus is thus removed. Thus if PAOs are selectively enriched by the EBPR configuration, considerably more phosphorus is removed, compared to the relatively poor phosphorus removal in conventional activated sludge systems.
See also
*
List of waste-water treatment technologies
This page consists of a list of wastewater treatment technologies:
See also
*Agricultural wastewater treatment
*Industrial wastewater treatment
*List of solid waste treatment technologies
* Waste treatment technologies
*Water purification
*Sewa ...
References
Further reading
*
External links
Handbook Biological Waste Water Treatment- Principles, Configuration and Model
EPBR Metagenomics: The Solution to Pollution is Biotechnological Revolution- A Review from the Science Creative Quarterly
Website of the Technische Universität Darmstadt and the CEEP about Phosphorus Recovery
{{DEFAULTSORT:Enhanced Biological Phosphorus Removal
Biotechnology
Waste treatment technology