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. 2023 Dec 8;31(2):2419–2436. doi: 10.1007/s11356-023-31102-6

Table 3.

The isotherm constants for the adsorption of Eu(III) ions onto Phy/B mixtures

Phy/B Phy/B
100/0 75/25 50/50 25/75 0/100 100/0 75/25 50/50 25/75 0/100
pH 4.5, L:S 100:1 pH 7.0, L:S 100:1
Freundlich isotherm
  1/n 0.2127 0.2306 0.2431 0.2705 0.3133 0.2282 0.2476 0.2571 0.2885 0.4141
  KF 1.341 2.389 4.374 7.994 17.97 2.541 5.813 10.61 15.07 17.34
  R2 0.9711 0.9737 0.9877 0.9654 0.9076 0.9848 0.9161 0.9612 0.9608 0.9891
  SSE 0.37 1.86 2.03 6.03 19.61 1.38 20.44 12.30 10.49 7.35
  χ2 0.29 1.60 1.78 3.95 7.72 1.85 7.58 3.07 7.01 3.41
Langmuir isotherm
  q 3.50 6.60 13.62 16.42 19.16 7.20 12.14 19.33 20.37 20.56
  qL 3.512 6.649 13.68 16.48 19.80 7.24 12.41 19.38 20.46 21.22
  KL 0.2537 0.3684 0.5203 9.661 27.38 2.821 3.658 3.784 6.315 7.291
  R2 0.9499 0.9635 0.9373 0.9474 0.9884 0.9297 0.9747 0.9674 0.9607 0.9729
  SSE 0.77 1.10 1.43 1.49 1.95 6.44 2.49 6.26 10.56 8.35
  χ2 2.71 0.75 7.96 1.27 0.64 2.79 2.14 2.94 3.42 5.10
Dubinin-Raduskevich isotherm
  qD 0.0400 0.0810 0.1580 0.2010 0.5660 0.0810 0.1331 0.3210 0.4650 0.9980
  β·10−3 1.677 1.849 1.923 1.409 1.796 1.724 1.299 1.672 1.74 1.807
  E 17.26 16.44 16.12 18.84 16.68 17.03 19.62 17.29 16.95 16.63
  R2 0.9890 0.9929 0.9767 0.9838 0.9276 0.9932 0.9633 0.9856 0.9806 0.9909
  SSE 0.22 0.51 2.21 3.19 2.87 0.61 2.33 4.90 5.17 3.15
  χ2 0.40 0.46 0.98 2.35 3.73 1.03 2.38 2.88 2.32 2.31
Sips isotherm
  qS 4.892 8.883 16.67 20.09 31.12 12.67 12.67 23.69 27.23 59.39
  KS 0.4069 0.3816 0.5053 0.9750 1.451 0.2721 1.007 1.168 1.563 0.4178
  mS 0.3869 0.4318 0.3909 0.5867 0.3614 0.3293 0.5262 0.5037 0.5187 0.4996
  R2 0.9909 0.9961 0.9935 0.9853 0.9697 0.9919 0.9946 0.9962 0.9893 0.9902
  SSE 0.19 0.27 0.82 1.56 8.30 0.73 0.77 1.83 5.60 4.66
  χ2 0.18 0.28 0.92 1.59 4.32 1.19 1.13 2.30 2.91 2.66
pH 4.5, L:S 500:1 pH 7.0, L:S 500:1
Freundlich isotherm
  1/n 0.1964 0.2567 0.3281 0.1991 0.1316 0.1994 0.2059 0.2274 0.2114 0.2183
  KF 0.4725 5.3825 8.977 15.37 25.47 0.5155 9.671 14.776 21.07 26.13
  R2 0.9299 0.9807 0.9807 0.9664 0.9013 0.9441 0.9739 0.9659 0.9645 0.9219
  SSE 0.0974 6.46 11.72 12.49 293.6 0.1014 5.38 7.56 12.24 156.3
  χ2 0.163 5.31 3.11 4.02 1.63 0.1823 6.15 5.40 3.65 1.93
Langmuir isotherm
  q 7.90 17.9 27.5 36.8 44.00 19.5 26.00 41.80 52.50 61.0
  qL 7.973 17.95 27.71 37.15 40.47 20.56 27.70 42.33 53.26 61.45
  KL 0.084 0.2958 0.4557 0.537 21.18 0.1089 0.1060 0.6917 1.129 1.587
  R2 0.9366 0.9711 0.9870 0.9624 0.9815 0.9488 0.9611 0.9617 0.9629 0.9482
  SSE 4.74 1.09 2.19 2.70 31.96 2.347 1.88 2.65 2.88 143.8
  χ2 0.304 1.64 2.67 3.71 1.24 0.0126 1.23 2.80 2.87 1.559
Dubinin-Raduskevich isotherm
  qD 0.1030 0.237 0.351 0.391 0.4110 0.2470 0.258 0.481 0.586 0.7090
  β·10−3 1.361 1.934 1.923 1.408 1.231 2.11 1.472 1.76 1.541 1.562
  E 14.05 16.07 16.12 18.44 20.18 15.31 18.43 16.83 18.03 17.92
  R2 0.9909 0.9935 0.9767 0.9829 0.9879 0.9844 0.9705 0.9891 0.9851 0.9820
  SSE 0.676 1.67 2.14 4.43 13.26 0.545 1.54 2.70 3.53 34.06
  χ2 0.054 0.872 1.23 2.44 0.634 0.231 1.11 1.13 1.79 0.543
Sips isotherm
  qS 10.76 23.68 30.39 41.25 45.21 25.79 37.15 49.21 58.14 77.56
  KS 0.0631 0.2603 0.4561 0.8075 18.99 0.1961 0.2877 0.5274 0.9594 0.6555
  mS 0.3307 0.5017 0.6408 0.4226 0.8174 0.3785 0.4612 0.4613 0.4722 0.4047
  R2 0.9928 0.9973 0.9931 0.9881 0.9811 0.9944 0.9748 0.9947 0.9967 0.9865
  SSE 1.87 0.68 1.48 1.09 1.957 0.466 1.51 1.88 4.16 0.4614
  χ2 0.154 0.452 0.841 0.772 0.233 0.152 0.57 1.23 1.81 0.0629

KF ((mg/g)·(L/mg)1/n); qL (mg/g); KL (L/mg); qD (mmol/g); β (mol2/J2); E (kJ/mol); qS (mg/g); KS (L/mg)m