[Energy people are watching, click on the upper right corner to add 'Follow'] Ecological Restoration Network News: 1. Research Background 1. Strategic Demand. The overall situation of heavy metal pollution in farmland is not optimistic ✧ The Ministry of Environmental Protection a

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Ecological Restoration Network News: 1. Research background

1. Strategic demand for the overall situation of heavy metal pollution in farmland soil is not optimistic ✧ The Ministry of Environmental Protection and the Ministry of Land and Resources issued the "National Soil Pollution Status Survey Bulletin" in 2014, which clearly stated that the national soil location exceeds the standard rate of arable land is 19.4%, and the main pollutants are cadmium, nickel, copper, arsenic, etc.; ✧ The latest statistics of the Ministry of Land and Resources show that more than 12% of the 1.826 billion mu of arable land area in the country are polluted by heavy metals.

2. In-situ repair of technology development trends is the basic idea of ​​heavy metal repair in farmland soil. It is necessary to improve repair efficiency, shorten the repair cycle and improve the long-term stability of the repair effect.

3. Problems and challenges. Crop roots absorb pore water heavy metals are the main cause of heavy metal pollution in agricultural products. It is very important to remove or reduce heavy metals with excessive soil pore water.

4. Solution ideas

electric repair and environmental protection. Heavy metals are enriched on the electrode surface through electromigration , lacking a complete set of devices for separation of heavy metals. EKG (Electrokinetic Geosynthetics) electrodes have both conductivity and water conductivity (gravity + electroosmotic) functions, and have the potential to synchronously dehydrate and remove heavy metals!

2. Technical principles and device development

1. Technical principles

✧ Cationes and anions in soil pore water migrate to EKG electric repair module (cathode) and EKG electric repair module ( anode ) under the action of electromigration and electrodialysis respectively. , enter the liquid collection tank ✧ Liquid in the liquid collection tank flows into the liquid collection tank through the peristaltic pump to achieve the purpose of separation of heavy metals and soil

2. Device development

✧ Develop anti-blocking, easy-to-plug EKG electric repair module ✧ Soil pore water storage module that can be automatically collected and guided to store ✧ Assembled heavy metal in situ electric water reflux and remove complete set of devices

3. Test and debug

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4. Field demonstration

1, on-site layout

2, experimental design

✧Electric repair Mix the farmland soil with irrigation water evenly (irrigate 28.5L/m2 in the farmland soil with a water content of about 25%, and the depth of water accumulation on the soil surface after mixing is about 7mm), drain all the overlying water after 1 day, and perform electric repair, use intermittent power-up, loading voltage 100V, and processing for 48h, of which the electric repair time is 24h.

✧ Edge-Electric Repair mixes the farmland soil with FeCl3 leaching liquid evenly (soaks 28.5L/m2 in the farmland soil with a water content of about 25%, and the depth of the soil surface effusion is about 7mm after stirring). After the overlay is discharged after 1 day, electric repair is carried out, and intermittent power is used, loading voltage is 100V, and the processing is 48h, of which the electric repair time is 24h.

V. Conclusion and Prospect

Conclusion

✧Electric repair can promote the migration of heavy metal Cd in soil pore water

✧48h treatment, the removal rate of total Cd in rice soil reaches 30%

✧After electric repair, the pH of each section of the soil is uniform, the rapid-acting nitrogen decreases, and the rapid-acting phosphorus decreases greatly. The prospect of rapid-acting phosphorus is large.

✧Research and development of devices suitable for mechanized operations

✧Screen low-cost environmentally friendly leaching agent ✧Electric drainage treatment and recycling

Original title: Tang Xianqiang: In-situ electric water reflux repair technology and field demonstration

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