Annex 1: Effluents of an Italian tannery
(Source: Clonfero, 1990; values refer to 800 kg raw hides).
|
Pressing cycle |
Water m3 |
Water (% total) |
COD mg/l |
COD kg |
COD % on total |
BOD 5 mg/l |
SS mg/l |
SS Kg |
SS. % on total |
Chrome mg/l |
S in mg/l |
pH |
|
Salt Washing |
10.00 |
7.51 |
8,800 |
167.2 |
6.220 |
4.200 |
3.340 |
63.46 |
4.88 |
|
|
6.9 |
|
First Washing |
5.00 |
1.97 |
2,000 |
10.0 |
0.370 |
|
730 |
3.65 |
0.28 |
|
|
7.2 |
|
Sec. Washing |
5.00 |
1.97 |
1,850 |
9.2 |
0.340 |
|
970 |
4.85 |
0.37 |
|
|
7.1 |
|
Soaking |
19.00 |
7.51 |
17,240 |
327.5 |
12.200 |
7.500 |
5.420 |
102.98 |
7.93 |
|
138 |
12.6 |
|
Liming |
19.00 |
7.51 |
60,400 |
1147.6 |
42.750 |
24.500 |
42.900 |
815.10 |
62.70 |
|
3.200 |
12.6 |
|
Washing |
32.00 |
12.66 |
8,200 |
262.4 |
9.770 |
|
3.580 |
114.56 |
8.80 |
|
420 |
11.9 |
|
Fleshing |
2.00 |
0.97 |
2,000 |
4.0 |
0.140 |
|
|
|
|
|
|
8.4 |
|
Tot. beamh. |
101.00 |
39.92 |
19,089 |
1928.0 |
71.820 |
|
10.936 |
1104.60 |
85.00 |
|
761(av) |
|
|
First Washing |
12.00 |
4.74 |
7,000 |
34.0 |
3.120 |
|
1.920 |
23.040 |
1.80 |
|
300 |
11.5 |
|
Sec. Washing |
50.00 |
19.78 |
1,250 |
62.5 |
2.320 |
|
770 |
38.500 |
2.96 |
|
8 |
10.5 |
|
Deliming & Bating |
10.00 |
3.95 |
19,700 |
197.0 |
7.330 |
14,300 |
3.790 |
37.900 |
2.90 |
|
|
7.0 |
|
Washing |
34.40 |
13.61 |
6,900 |
237.3 |
8.840 |
|
1.070 |
36.800 |
2.83 |
|
|
7.2 |
|
Pickling & Pretanning |
10.00 |
3.95 |
5,350 |
53.5 |
1.990 |
1,450 |
1.590 |
15.900 |
1.22 |
1.380 |
|
2.6 |
|
Tanning |
10.00 |
3.95 |
4,550 |
45.5 |
1.690 |
740 |
1.240 |
12.400 |
0.95 |
3.120 |
|
3.8 |
|
Pressing |
1.00 |
0.39 |
5,500 |
5.5 |
0.200 |
|
1.200 |
1.200 |
0.09 |
1.850 |
|
3.9 |
|
Total tanning |
127.40 |
50.37 |
5,379 |
685.3 |
25.830 |
|
1.300 |
165.740 |
12.90 |
367 (av) |
31 (av) |
|
|
|
|
|
(av) |
|
|
|
(av) |
|
Total: |
46.85 kg |
4 kg |
|
|
Retanning (chrome) |
4.15 |
1.64 |
4,700 |
19.5 |
0.720 |
|
870 |
3.610 |
|
480 |
|
4.0 |
|
Neutralization |
4.02 |
1.59 |
2,520 |
10.1 |
0.370 |
|
1.500 |
6.030 |
|
|
|
6.0 |
|
Fatliquoring & Dyeing |
5.75 |
2.27 |
6,220 |
35.8 |
1.330 |
|
2.700 |
15.520 |
|
|
|
3.4 |
|
Total grain side process |
13.92 |
5.50 |
4,697 |
65.4 |
2.430 |
|
1.800 |
25.160 |
1.90 |
143 (av) |
|
|
|
|
|
|
|
|
|
|
(av) |
Total: |
1.99 kg |
1.99 kg |
|
|
|
Retanning (Cr) |
1.37 |
0.54 |
1,200 |
1.6 |
0.061 |
|
540 |
0.740 |
|
250 |
|
3.5 |
|
Washing |
0.95 |
0.37 |
1,000 |
1.0 |
0.035 |
|
270 |
0.256 |
|
55 |
|
4.6 |
|
Neutralization |
2.06 |
0.84 |
560 |
1.1 |
0.042 |
|
420 |
0.865 |
|
|
|
6.6 |
|
Washing |
3.44 |
1.36 |
150 |
0.5 |
0.020 |
|
170 |
0.584 |
|
|
|
6.1 |
|
Retanning |
0.68 |
0.27 |
230 |
0.2 |
0.005 |
|
50 |
0.034 |
|
|
|
5.9 |
|
Fatliquoring |
0.68 |
0.27 |
170 |
0.1 |
0.004 |
|
240 |
0.163 |
|
|
|
4.2 |
|
Dyeing |
1.20 |
0.47 |
950 |
1.1 |
0.042 |
|
120 |
0.144 |
|
|
|
3.4 |
|
Total crust process |
10.38 |
4.09 |
544 |
5.7 |
0.210 |
|
280 |
2.786 |
0.20 |
37 (av) |
|
|
|
|
|
|
(av) |
|
|
|
average |
|
Total: |
0.39 kg |
|
|
|
General |
252.70 |
100.00 |
10,600 |
2684.4 |
100.000 |
5,160 |
5,100 |
1298.3 |
100.00 |
195 (av) |
319 (av) |
|
|
Total |
|
|
(av) |
|
|
|
average |
|
|
49.23 kg |
80.85 kg |
|
