Method for treating black and odorous bottom mud by combining in-situ injection of calcium nitrate and ecological restoration

Abstract

The invention discloses a method for treating black and odorous bottom mud by combining in-situ injection of calcium nitrate and ecological restoration, which comprises the following steps: injecting5-10kg of liquid calcium nitrate solution into each square meter by using a shipborne target type dosing device, and ensuring that the depth of the liquid calcium nitrate solution injected into the bottom mud is generally 15-20cm; planting submerged plants and emergent aquatic plants in the bottom mud within 4 weeks after the liquid calcium nitrate is injected; harvesting the submerged plants at the length of 10 cm at the end of spring or summer, cutting off the upper parts of the emergent aquatic plants in winter, and remaining rhizomes. The method can treat the black and odorous riverway quickly and effectively, can improve the black and odorous sediment environment fundamentally, is low in cost, low in energy consumption and small in disturbance to the environment, is beneficial to restoring the ecological landscape of the riverway, and can restore the ecological function of the riverway fundamentally.

Description

technical field [0001] The invention relates to the technical field of river bottom mud treatment, in particular to a method for treating black and odorous bottom mud by combining in-situ injection of calcium nitrate and ecological restoration. Background technique [0002] With the rapid development of my country's economy, the acceleration of urbanization and the increase of urban population, the discharge of industrial wastewater and domestic sewage is increasing. Due to poor management of environmental protection, a large amount of sewage without effective treatment is directly discharged into rivers, greatly Exceeding the environmental capacity of the river, the self-purification ability of the river itself is reduced and the pollutants cannot be degraded. The river ecosystem degrades, causing many urban rivers to be in a black and odorous state for a long time. Sediment is an important part of the natural water ecosystem. , is an important link in the material cycle of w...

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Problems solved by technology

[0004] Black and odorous river sediment treatment technology can be divided into ex-situ treatment and in-situ treatment. Ex-situ treatment of sediment mainly refers to sediment dredging technology; in-situ treatment includes in-situ physical restoration, in-situ chemical restoration and in-situ biological restoration technology ;Compared with the ex-situ treatment technology, the in-situ sediment treatment technology can avoid the secondary pollution caused by the dredging and transfer process of the sediment, and the engineering cost is relatively small. The in-situ chemical restoration of the sediment is an efficient method of sediment restoration Adding calcium nitrate is a commonly used method for in-situ chemical treatment of black and odorous sediments. By adding calcium nitrate, it eliminates black and odorous sediments, inhibits the release of phosphorus in sediments, and promotes the degradation of organic matter in sediments. The restoration effect of black and odorous water bodies and sediments is only temporary, and the restoration of the damaged water ecosystem is the long-term effective control measure for black and odorous rivers and black and odorous sediments

Phytoremediation is a widely used, environmentally friendly and cost-effective treatment technology. Aquatic plants have good enrichment and degradation capabilities for pollutants in black and odorous water bodies and sediments. The cycle is long, and at the same time, if the aquatic plants cannot be salvaged and harvested in time in the later stage, it is easy to cause the plants to rot and cause secondary pollution. Therefore, we propose a method of combining in-situ injection of calcium nitrate and ecological restoration to treat black and odorous sediment

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