Search results
Results from the WOW.Com Content Network
Maintaining optimal pH is important for the removal of phosphorus from water. Phosphorus is most effectively removed at the neutral pH range, when the insoluble aluminum hydroxide is present. This hydroxide functions as a Lewis acid , [ 5 ] creating a flocculation environment similar to conventional wastewater treatment.
The yield of PAOs (Polyphosphate Accumulating Organisms) is reduced between 70 and 80% under aerobic conditions. Even though the phosphorus can be removed upstream of the aeration tank by chemical precipitation (adding metal ions such as: calcium, aluminum or iron), the biological phosphorus removal is more economic due to the saving of chemicals.
[24] [25] Phosphorus recovery methods from wastewater or sludge can be categorized by the origin of the used matter (wastewater, sludge liquor, digested or non-digested sludge, ash) or by the type of recovery processes (precipitation, wet-chemical extraction and precipitation, thermal treatment). [26]
In Northern Ireland, phosphorus enrichment of lakes due to agriculture is a significant problem. [30] Locally available laterite—a low-grade bauxite rich in iron and aluminum—is used in acid solution, followed by precipitation to remove phosphorus and heavy metals at several sewage treatment facilities. [30]
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.
Aluminium sulfate is used in water purification and for chemical phosphorus removal from wastewater. It causes suspended impurities to coagulate into larger particles and then settle to the bottom of the container (or be filtered out) more easily. This process is called coagulation or flocculation.
Their roots penetrate microscopic scale pores in the soil matrix and can cycle 100 L of water per day per tree. These trees act almost like a pump and treat remediation system. [5] Willows have been successfully used as “vegetation filters” for nutrient (e.g. nitrogen and phosphorus) removal from municipal wastewater [6] and polluted ...
The most studied example of this phenomenon is in polyphosphate-accumulating bacteria (PAB) found in a type of wastewater processing known as enhanced biological phosphorus removal (EBPR), however phosphate hyperaccumulation has been found to occur in other conditions such as soil and marine environments, as well as in non-bacterial organisms ...