Table 6: Variables selected for residual aluminium using multilayer perceptrons (MLPs).

RoundVariablesCorrelation coefficient (C)

1Water temperature0.76
2Aluminium dose/raw water KMnO40.86
3Silicates in raw water0.88
4Surface level of Lake Humaljärvi0.88
5Hardness of raw water0.88
6Turbidity of raw water0.89
7Aluminium dose0.90
8pH of raw water0.91
9KMnO4 of raw water0.89
10Aluminium feed0.91