% Molybdate reactive phosphorus of total phosphorus in urban wastewater influents and effluents in County Cork agglomerations >2000 P.E
Abstract
Phosphorus is a key nutrient in freshwater ecosystems as it is well known to cause severe
water quality problems when enrichment with phosphorus occurs, a phenomenon known as
eutrophication. Legislative measures are in place to control or limit the amount of
phosphorus discharged, and there are several physical, chemical and biological treatment
processes used to remove or reduce phosphorus prior to discharge. Whether or not rural
developments are granted planning permission in Ireland is often contingent on the levels
of phosphorus in the receiving waters it is proposed to discharge treated effluent to.
Several forms of phosphorus exist in environmental monitoring; the most often encountered
is the inorganic form usually known as orthophosphate. However, there are other names
used for this inorganic form, depending on the method of analysis, such as soluble reactive
phosphorus (SRP), molybdate reactive phosphorus (MRP), dissolved reactive phosphorus
(DRP), leading to confusion and misinterpretation of results. The presentation of analytical
data also leads to confusion when the results’ form is not clearly expressed.
Average wastewater influent total phosphorus levels for County Cork’s wastewater
treatment plants vary considerably. Average phosphorus loadings were in the range 2.3 to
14.2 mg/1 TP-P, although a more reliable upper end of the range for average influent TP-P
in Cork is Ballincollig with 11.6 mg/1 TP-P. Average influent MRP ranged from 1.6 mg/1
to 7.6mg/l PO4-P. Average MRP% of the total phosphorus ranged from 43.5% to 68 %.
Disregarding effluents where phosphorus removal measures are required under the Urban
Waste Water Treatment Regulations, 2001, average effluent concentrations of total
phosphorus ranged from l.lmg/1 at Kanturk to 6.4mg/l TP-P at Ballincollig. Average
effluent concentrations of MRP ranged from 0.9 to 4.6mg/l PO4-P. The range of % MRP of
the total phosphorus was greater in plants where phosphorus removal technologies were
employed, 34.4% to 91.7%. Plants without additional phosphorus removal had a narrower
range, 62.4% to 87.1%.
Collections
- Theses - Science ITS [171]
The following license files are associated with this item: