Byproduct material

Particle-size fraction

P removal

p-value*

Average

Variance

mm

%

Red mud iron filter cake

<2

98

0.009

<0.001

<6

56

0.004

<0.001

<12.5

28

0.221

<0.001

Water treatment residual

<2

94

0.118

0.496

<6

57

0.052

<0.001

<12.5

10

0.280

<0.001