| 摘要 |
<p>PURPOSE:To clarify waste water to an extent that it can be recycled for the desulfurization of waste water by passing the gypsum-process flue gas desulfurization waste water through the dialyzer consisting of four electrification chambers built up of anion-cation exchange membranes and monovalent anion-cation selectively permeable membranes to obtain divalent anion and cation concentrated solution by double decomposition, separation, and concentration. CONSTITUTION:The lime 9 is added to the desulfurization waste water 8, and then the waste water is sent to the sedimentation apparatus 2 to separate the sludge 11 consisting of heavy metals and gypsum. The supernatant liquor 21 is sent into the electric dialyzer 22 of four electrification chambers built up of anion-cation exchange membranes and monovalent anion-cation selectively permeable membranes, where two kinds of divalent anion and cation concentrated liquors are formed by double decomposition, separation, and concentration. Then, the divalent anion concentrated liquor is taken out and sent to the polythionic acid decomposer 25 to oxidize and decompose polythionic acid present to sulfuric acid ion and then sent to the NH3 recovery apparatus 26 to recover the NH3 33. Then, the liquor is sent to gypsum crystallized 27 where it is mixed with divalent cation concentrated liquor 24 and the gypsum 28 is recovered. The supernatant liquor 29 is sent back to the desulfurization waste water 8.</p> |
