Surface improvement system and method for in-situ remediation of contaminated benthic sediments

In-situ remediation system for incorporating stabilizers into benthic sediments using a rotating spreader and a disturbance-mixing wheel

This technology is a surface improvement system designed for in-situ remediation of contaminated benthic sediments without dredging. It consists of a stabilizer spreader that disperses stabilizers underwater over the target area, and a disturbance and mixing unit that mixes the stabilizers with the contaminated sediments to induce bioturbation.

Existing monitored natural recovery requires isolating the target water body, which is difficult to apply in land-scarce regions like Korea. Environmental dredging is time-consuming and costly due to the processing, recycling, and post-management of the excavated contaminated sediments. In-situ treatment methods using geotextile membranes are limited by their effectiveness being restricted to the surface layer and the difficulty of handling and installing the textiles.

This technology features multiple spreader pipes that rotate radially around a supply pipe divided into channels by distribution vanes, with an angle adjustment unit that modifies the deployment angle and rotation speed to control the spreading range. The blades of the disturbance and mixing wheel attached to the rotating shaft have adjustable lengths via fixing holes to match sediment thickness, and feature curved ends. A curved, open-bottom barrier structure isolates the work area, while cameras, turbidity meters, and flow sensors allow for real-time monitoring. It can be applied to ports and coastal areas contaminated with heavy metals and organic matter, inland rivers and lake beds, and waterways near industrial complexes, providing immediate remediation without the costs of dredging and disposal, while containing turbidity within the work zone.

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Key Features:

• A stabilizer spreader that disperses stabilizers underwater over the target area, and a disturbance and mixing unit that mixes them with contaminated sediments to induce bioturbation
• A stabilizer supply pipe that guides the stabilizer from the storage unit and is divided into multiple internal channels via distribution vanes
• Stabilizer spreader pipes arranged radially around the supply pipe that rotate and allow for adjustment of the spreading range via an angle adjustment unit
• Blades spaced circumferentially along the rim, with lengths adjustable via multiple fixing holes to match sediment thickness, and featuring curved ends

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This invention was developed with support from the Ministry of Environment for the development of in-situ remediation technology for contaminated sediments using eco-friendly, high-efficiency stabilizer injection and the ecological functions of benthic organisms.

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