CLEANING CLASSIFICATION PROCESSING METHOD OF CONTAMINATED SOIL

To provide a cleaning classification processing method of contaminated soil capable of performing cleaning classifying of a contaminated soil with good efficiency.SOLUTION: The method contains: a first step S1 of adding a water W1 to a contaminated soil 100, classifying by wet sieving 11 for separating a coarse grain fraction 102 and further classifying for a slurry of a sand 101 into a sand fraction 104 and a fine grain fraction 103; a second step S2 of cleaning of a sand fraction 104 classified in the first step S1; and a third step S3 of coagulation sedimentation of the fine grain fraction 103 classified in the first step S1 for separating into a sedimented sludge 105 and a treatment water W2, dehydrating the sedimented sludge 105 for separating into a concentrated residue 106 and a treatment water W3; in the first step S1, a cation addition step S12 of adding a cation I to the contaminated soil 100 is conducted.SELECTED DRAWING: Figure 1 【課題】汚染土壌の洗浄分級処理を効率よく行うことができる汚染土壌の洗浄分級処理方法を提供する。【解決手段】汚染土壌１００に水Ｗ１を添加し、湿式ふるい１１分級処理して粗粒子分１０２を分離したスラリー状の土砂１０１を砂分１０４と細粒子分１０３とにさらに分級処理する第１工程Ｓ１と、第１工程Ｓ１で分級処理した砂分１０４を洗浄処理する第２工程Ｓ２と、第１工程Ｓ１で分級処理した細粒子分１０３を凝集沈殿させて沈殿汚泥１０５と処理水Ｗ２とに分離し、沈殿汚泥１０５を脱水処理して濃縮残渣１０６と処理水Ｗ３とに分離する第３工程Ｓ３と、を有し、第１工程Ｓ１では、汚染土壌１００に陽イオンＩを添加する陽イオン添加工程Ｓ１２を行う。【選択図】図１