CHLORINE AND HEAVY METAL CONTAINING WASTE TREATMENT METHOD

PROBLEM TO BE SOLVED: To provide a treatment method for effectively dechlorinating and cleaning dust with a few amount of cleaning water. SOLUTION: Cleaning water is added to dust to slurry the dust and a soluble component in the dust is eluted to carry out a solid-liquid separation of a slurry. The ratio of 60% or more of supernatant water is circulated as the cleaning water to dehydrate and clean a precipitate. Fresh water is added as the cleaning water and cleaning discharging water is circulated as cleaning water of an elusion step. The soluble component in the dust is made to effectively circulate by a full amount of cleaning water of 10-100 times by weight of the dust to give the precipitate in which the soluble component of Cl, etc. is well removed. A using amount of fresh water can be diminished because 60% or more of supernatant water is circulated to the elusion step. The soluble component is well removed by dehydrating and cleaning the precipitate. Because fresh water is used as the cleaning water, a chlorine content remaining in a cake dehydrated is well cleaned and removed to give a high dechlorinating and cleaning effect. The considerably few amount of fresh water of 0.1-4.0 times of dust is sufficient. COPYRIGHT: (C)2007,JPO&INPIT