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Influence of Salinity on Duckweed Growth and Duckweed Based Wastewater Treatment System

Research output: Contribution to journalArticle

  • Sena Peace Hounkpe Wendeou
  • Martin Pepin Aina
  • Martin Crapper
  • Edmond Adjovi
  • M Daouda

Related Edinburgh Organisations

Original languageEnglish
Pages (from-to)993-999
Number of pages7
Journaljournal of water resource and protection
Early online date29 Oct 2013
Publication statusPublished - 2013


The growth of duckweed (Spirodela polyrrhiza) was investigated in an outdoor batch system under 15 different conduc- tivities ranging from 200 μS/cm to 3000 μS/cm with average 110 μmol/m2 daylight intensity. The growth was per- formed in an anaerobically treated domestic wastewater using an initial plants population of 50 fronds. Increase in Rela- tive Growth Rate—RGR—(in terms of fresh weight and number of fronds) had a significant non-linear (polynomial) relationship with the conductivity. The maximum RGR related to fresh weight of 0.176 was observed at the conductivi- ity of 1200 μS/cm while the maximum RGR related to fronds number was 0.193 at the conductivity of 800 μS/cm. The optimum range for duckweeds growth was found to be between conductivities of 600 μS/cm and 1400 μS/cm. The maximal rates of removal of COD of 14.5 mg/day, 24PO of 0.65 mg/day, NTK of 15.68 mg/day, faecal coliforms of 100% and turbidity of 80.8% were observed in this range. The COD and 24PO removal rates were highly correlated to the growth rate, with the correlation factor of up to 0.783 and, then to the conductivity. The NTK reduction was posi- tively related to the conductivity.

ID: 10797595