Bioactive multilayer covering remediation method for contaminated sediment

Abstract

The invention discloses a bioactive multilayer covering remediation method for contaminated sediments. Bioactive multilayer covering with a synergistic effect of river sand and natural zeolite for fixing high-efficiency nitrifying bacteria and denitrifying bacteria is adopted for reducing the amount of contaminants released towards a water body in the sediments and controlling the eutrophication of the water body. The method comprises the steps of: using the river sand and the biozeolite as covering materials, inoculating highly-effective strain bacteria solution obtained through screening into liquid culture medium, adding enriched nitrifying bacteria and denitrifying bacteria liquid into sterilized eutrophic raw water, pouring turbid raw water into a container containing a certain amount of zeolite after the raw water becomes turbid, forming a biofilm, controlling the concentration of dissolved oxygen (DO) to be 2-3mg / L through an aeration device to accelerate biofilm formation, and after three days of continuous aeration for biofilm formation, using continuous water to wash away bacteria which are adsorbed on the surfaces of fillers. The prepared biozeolite and the clean river sand evenly cover the sediments in a multilayer covering way of laying the biozeolite at a lower layer and the river sand at an upper layer. Therefore, a bioactive multilayer covering technique is used for realizing the in-situ remediation of the contaminated sediments.

Description

technical field [0001] The invention belongs to the technical field of water treatment, and in particular relates to a technology for repairing polluted sediments by using biologically active multi-layer covering, and is especially suitable for repairing sediments in rivers, lakes and reservoirs with serious endogenous nitrogen and phosphorus loads. Background technique [0002] Eutrophication of water body is a difficult problem in water pollution control, and has become one of the most important environmental problems in the world. Sediment is the "source" or "sink" of N and P in the water body, and the concentration of N and P is the main limiting factor for the eutrophication of the water body. When exogenous N and P are effectively controlled, controlling the release of endogenous N and P in sediments will be an effective measure to control water eutrophication. The current methods to reduce the endogenous release of polluted sediments include natural attenuation, dred...

AI Technical Summary

Problems solved by technology

The main problems of the dredging method are the pollution of the water body caused by sediment resuspension, the secondary pollution caused by the sediment transportation and treatment process, the high cost, and the destruction of the biological community structure of the water body, etc.

The covering method is a research hotspot in the world today. It has developed from the traditional thick physical masking layer to the current thin active covering layer. There are problems in the thin-layer active covering method: the active covering material will lose its ability to absorb and saturate pollutants, and its long-term Effectiveness needs to be improved; in practice, uneven coverage leaves part of the sediment uncovered, resulting in direct release of sediment pollutants to water bodies and benthic bioturbation that promotes the release of sediment pollutants

Images