Feasibility of Typha latifolia for high salinity effluent treatment in constructed wetlands for integration in resource management systems

Int J Phytoremediation. 2014;16(4):334-46. doi: 10.1080/15226514.2013.773284.

Abstract

High salinity wastewaters have limited treatment options due to the occurrence of salt inhibition in conventional biological treatments. Using recirculating marine aquaculture effluents as a case study, this work explored the use of Constructed Wetlands as a treatment option for nutrient and salt loads reduction. Three different substrates were tested for nutrient adsorption, of which expanded clay performed better. This substrate adsorbed 0.31 mg kg(-1) of NH4(+)-N and 5.60 mg kg(-1) of PO4(3-)-P and 6.9 mg kg(-1) dissolved salts after 7 days of contact. Microcosms with Typha latifolia planted in expanded clay and irrigated with aquaculture wastewater (salinity 2.4%, 7 days hydraulic retention time, for 4 weeks), were able to remove 94% NH(4+)-N (inlet 0.25 +/- 0.13 mg L(-1)), 78% NO2(-)-N (inlet 0.78 +/- 0.62 mg L(-1)), 46% NO3(-)-N (inlet 18.83 +/- 8.93 mg L(-1)) whereas PO4(3-)-P was not detected (inlet 1.41 +/- 0.21 mg L(-1)). Maximum salinity reductions of 52% were observed. Despite some growth inhibition, plants remained viable, with 94% survival rate. Daily treatment dynamics studies revealed rapid PO4(3-)-P adsorption, unbalancing the N:P ratio and possibly affecting plant development. An integrated treatment approach, coupled with biomass valorization, is suggested to provide optimal resource management possibilities.

MeSH terms

  • Aquaculture
  • Biodegradation, Environmental
  • Feasibility Studies
  • Nitrogen / metabolism
  • Phosphorus / metabolism
  • Salinity
  • Sodium Chloride / metabolism
  • Typhaceae / growth & development
  • Typhaceae / metabolism*
  • Waste Disposal, Fluid / methods*
  • Wastewater / analysis
  • Water Purification / methods*
  • Wetlands

Substances

  • Waste Water
  • Phosphorus
  • Sodium Chloride
  • Nitrogen