Comparison of effects of plant and biofilm bacterial community parameters on removal performances of pollutants in floating island systems

Abstract

This study focused on a comparison of the role that plant and biofilm bacterial community parameters played in mediating removals of pollutants in the floating island microcosms mono-cultured with different macrophytes. The greater removals of BOD5, COD, total phosphorus and NH4–N were observed in floating microcosms planted with Alternanthera philoxeroides or Cyperus alternifolius, respectively. The microcosms planted with Scirpus validus exhibited the greatest removals of total nitrogen, and those planted with Canna generalis showed a great removal of NO3–N. The above-ground biomass was positively related to the removal of the NO3–N, while the translocation factor for nitrogen was positively related to total nitrogen and phosphorus, the translocation factor for phosphorus was positively related to the removals of total phosphorus and NO3–N, respectively. Nevertheless, bacterial community parameters such as the ribotype number and diversity index were not correlated with the removals of pollutants.