Purifying waste water containing heavy metal complexes comprises precipitation, ultraviolet irradiation, catalytic oxidation and ion exchange

摘要

Process for purifying waste water containing heavy metal complexes comprises: (a) removing heavy metal ions by adding a precipitant to convert the complexes to sparingly soluble products and separating these in a filter press; (b) removing residual complexes or free complexing agent by UV irradiation and catalytic oxidation in a fixed bed reactor after adding acid and oxidizing agent; and (c) removing residual heavy metal ions by ion exchange. Process for purifying waste water containing heavy metal complexes comprises: (a) removing heavy metal ions by adding a precipitant to convert the water-soluble complexes to sparingly soluble products in a precipitation vessel (1) and separating these products in a filter press (3); (b) b) removing residual complexes or free complexing agent by UV irradiation and oxidation on a solid catalyst in a fixed bed reactor (9) at up to 95 deg C after adding acid (to give a pH of up to 6.5) and oxidizing agent in a mixer (5); (c) removing residual heavy metal ions by ion exchange and discharging the purified water. An Independent claim is also included for apparatus for carrying out the above process, comprising a precipitation vessel (1), a filter press (3), an intermediate container (4), a mixer (5), a UV reactor (8), a fixed bed reactor (9), a recycle system (20) and an ion exchanger (10).