The effluent from fixed double chamber anion bed in a power plant has high level hardness

which has over-standard.The reasons like raw water leaking into the anion bed

alkali being polluted and cation resin leaking into the anion bed were excluded.The field test data show the deep failure of cation bed during its repetitive commissioning is the actual cause.Then when the water from the cation bed flows into the alkaline resin layer

the hardness will deposit on the anion bed and slowly release when the anion bed runs.Thus

the acid and alkali immersion methods were employed to regenerate the anion resin.After that

the effluent from fixed double chamber anion bed met all standard requirements.