Phosphorus retention and release by sediments in the eutrophic Mai Po Marshes, Hong Kong.

摘要: Abstract This study examined the phosphorus retention and release characteristics of sediments in eutrophic Mai Po Marshes Hong Kong. Results chemical fractionation show that sum inorganic P pools exceeded 50% total sediment content, with redox-sensitive iron-bound (Fe(OOH) ≈ P) being dominant fraction. Given considerable average Fe(OOH) ≈ P concentration 912 μg g−1, demonstrated a great potential to bioavailable under low redox potentials. was further supported by high mean anaerobic flux 31.8 mg m−2 d−1 recorded cores, indicating role bottom as net source. Although had appreciable Langmuir adsorption maxima (1642–3582 mg kg−1), zero equilibrium concentrations (0.02–0.51 mg L−1) obtained suggest sorption processes would contribute sustaining conditions overlying water column even reduction external load. Concerted efforts should be made reduce internal loading P, especially reducing conditions, complement implementation discharge policy for Deep Bay effective eutrophication abatement long-term quality improvement Marshes.