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Table 2: Content of metals in waste waters.

Paste Chemical element Electrode 19/9 29/9 29/12/3 A Cr, mg${\text{L}}^{-1}$ 101.3 31.76 47.1 Ni, mg${\text{L}}^{-1}$ 107.77 49.84 56.07 Fe, mg${\text{L}}^{-1}$ 397.2 206.56 245.17 B Cr, mg${\text{L}}^{-1}$ 55.31 45.45 46.55 Ni, mg${\text{L}}^{-1}$ 61.05 78.49 58.56 Fe, mg${\text{L}}^{-1}$ 299.23 305.02 279.92 C Cr, mg${\text{L}}^{-1}$ 11.35 12.71 19.71 Ni, mg${\text{L}}^{-1}$ 12.46 22.43 28.03 Fe, mg${\text{L}}^{-1}$ 101.83 166.51 219.59 Electrochemical treatment Cr, mg${\text{L}}^{-1}$ 254.64 346.64 318.71 Ni, mg${\text{L}}^{-1}$ 170.07 244.2 225.51 Fe, mg${\text{L}}^{-1}$ 482.14 515.93 506.27