Active coverage system for in-situ control of surface water bottom sediment nitrogen and phosphorus release and method

Abstract

The invention provides an active bottom sediment coverage system for in-situ control of bottom sediment nitrogen and phosphorus release. The active bottom sediment coverage system structurally comprises a geotechnical cloth layer I, a zirconium modified zeolite coverage layer, a geotechnical cloth layer II, a mixture coverage layer and a geotechnical cloth layer III from top to bottom, the mixture coverage layer comprises hydroxyapatite particles, calcite particles and calcium modified zeolite particles with the weight ratio of 1:(1-1000):(1-1000), and the zirconium modified zeolite coverage layer comprises zirconium modified zeolite particles. The invention further provides a method of the active bottom sediment coverage system for in-situ control of bottom sediment nitrogen and phosphorus release. By the aid of the geotechnical cloth layers, structural integrity of bottom sediment coverage material layers can be effectively prevented from being damaged by external conditions, and loss of active coverage materials in the active bottom sediment coverage system is prevented. By taking the advantage that bottom sediment nitrogen and phosphorus release is respectively controlled by the coverage materials such as calcite, hydroxyapatite, calcium modified zeolite and zirconium modified zeolite, bottom sediment nitrogen and phosphorus release can be effectively and simultaneously controlled, nitrogen and phosphorus in bottom sediment are rapidly and efficiently fixed, and the active bottom sediment coverage system is suitable for wide popularization.

Description

technical field [0001] The invention relates to the technical field of controlling the release of nitrogen and phosphorus from surface water polluted sediments, in particular to an active covering system and method for simultaneously controlling the release of nitrogen and phosphorus from sediments. Background technique [0002] Water eutrophication is one of the most serious water environmental problems facing the world today. Nitrogen and phosphorus are two key nutrients that cause water eutrophication. Sediment is an important part of surface water bodies. Nitrogen and phosphorus imported from external sources into the water body will be deposited in the sediment through a series of physical and chemical processes. When the external environmental conditions change, the nitrogen and phosphorus originally deposited in the sediment can be released again and become the endogenous source of nitrogen and phosphorus pollution in the overlying water body. Therefore, controllin...

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Problems solved by technology

However, this sediment active overburden system constructed of a single calcite material has obvious defects: (1) Calcite usually fixes phosphorus slowly in water, which causes the sediment active overburden system constructed of calcite to inhibit The efficiency of phosphorus release in mud is not very ideal; (2) The thickness of the sediment active covering system constructed by a single calcite is often relatively thin, and it is easily affected by water erosion, wind waves, aquatic animal disturbance, etc., which leads to this sediment activity. The integrity of the overall structure of the overburden system is easily damaged by external conditions such as water flow, wind waves, and aquatic animals, thereby reducing the effect of this active sediment overlay system on controlling the release of phosphorus in the sediment.

Although the method reported in the Chinese patent document CN201210246668.5 can overcome the defects of a single calcite covering system, the method reported in the Chinese document method CN201210246668.5 cannot effectively control the release of sediment nitrogen

At present, there are no reports at home and abroad on the use of geotextiles to wrap apatite, calcite, calcium-modified zeolite, and zirconium-modified zeolite as a covering system while controlling the release of nitrogen and phosphorus from sediments.

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