Fixing heavy metals in sludge and reducing pollution to soil using heavy metal stabilizers

The heavy metal stabilizers were added to sludge contained in used plastic containers, through artificially watering or naturally rain falling, the fertilizer components flowed out with leaching water and fertilized plants but the heavy metals retained in the sludge within container. The leaching experiments and the pot experiments with Laetuca satiuali and Ipomoea aquatic showed that the positive effects of the mixture of the sludge and K₂SO₄ on plant production and reduction of heavy metal contents in plants were significant. Metals-bound sludge could be collected easily after treatment to prevent the secondary pollution, provided that the heavy metals were fixed within the container and reduced obviously the leaching of heavy metals to soil. This equipment meets requirements of safe agricultural utilization of the sludge. Besides, this method permits the plastic waste recycled and realized with a low cost.