Premium
Orthophosphate concentrations in the River Thames: reductions in the past decade
Author(s) -
Kinniburgh J. H.,
Barnett M.
Publication year - 2010
Publication title -
water and environment journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 37
eISSN - 1747-6593
pISSN - 1747-6585
DOI - 10.1111/j.1747-6593.2008.00161.x
Subject(s) - eutrophication , environmental science , phosphorus , effluent , sewage treatment , limiting , sewage , chlorophyll a , environmental engineering , hydrology (agriculture) , nutrient , chemistry , ecology , geology , engineering , biology , mechanical engineering , biochemistry , geotechnical engineering , organic chemistry
Ten years ago plans were made to reduce the phosphorus load from sewage‐treatment works' effluents into the River Thames. This was driven by the EC Urban Wastewater Treatment Directive in relation to sensitive areas (eutrophic). Modelling work identified the most significant loads to tackle first. Phosphorus removal had been commissioned at 36 works by 2003. The orthophosphate load to the River Thames from these works has reduced from 5755 to 688 kg P/day. The impact of the improvement programme on the quality of the river was assessed by comparing pre‐ and post‐investment data. Orthophosphate concentrations in the river have reduced from between about 0.5 and 2 mg P/L to 0.2 and 0.4 mg P/L. These observations match the model predictions. Chlorophyll a concentrations in the river have also reduced. This was unexpected given that the orthophosphate concentrations still exceed the values thought to be limiting for algal growth.