[The role of submerged group ecological media box in repairing black and odorous water body].

As a conventional technology, the ecological floating bed has been widely used to repair waste water body. However, it can only repair the surface oxygen-enriched water, and has limited ability to repair the lower anoxic water. To meet the needs of the restoration of black and odorous water body, we designed a submersible ecological media box (submerged group) and compared it with traditional ecological floating bed (floating bed group). Water quality of black and odorous water before and after the restoration was examined, with the growth status of aquatic plants and the accumulation ability of N and P being investigated. The results showed that with the prolongation of repairing time, the removal rate of each pollutant increased gradually in both treatments. The removal ability of the submerged group for TN, NH4+-N, TP was better than that of the floating bed group, but its ability to remove CODMn was slightly inferior than that of the floating bed group. Plants (Vallisneria natans) in the submerged group grew better than that in the floating bed group (Acorus cala-mus), with similar patterns of the absorption and accumulation capacity and removal rate of TN and TP. In addition, the plasma membrane permeability and malondialdehyde content of V. natans were lower than that of A. calamus and the chlorophyll content of A. calamus was higher than that of V. natans, indicating that V. natans is more suitable for planting in black and odorous water bodies. Thus, the submersible ecological media box is a new in-situ integrated remediation device, which is more suitable to repair the black and odorous water.