Table 1.

Chemical composition of the sediments

Parameter	Unit	Sample no. 1 Ca(OH)2 + NaOH conventional treatment	Sample no. 2 Ca(OH)2 + NaOH + TMT	Sample no. 3 Ca(OH)2 + NaOH + DMDTC	Sample no. 4 Ca(OH)2 + NaOH + Na2CS3
Co	g/kg	$0.20\pm 0.03$	$0.15\pm 0.02$	$0.10\pm 0.02$	$0.19\pm 0.03$
Cr	g/kg	$14.0\pm 2.1$	$13.9\pm 2.1$	$9.8\pm 1.5$	$14.7\pm 2.2$
Cu	g/kg	$31.6\pm 4.7$	$31.0\pm 4.7$	$23.6\pm 3.5$	$39.8\pm 6.0$
Ni	g/kg	$43.2\pm 6.5$	$41.3\pm 6.2$	$30.5\pm 4.6$	$42.5\pm 6.4$
Pb	g/kg	$31.3\pm 4.7$	$33.1\pm 5.0$	$24.3\pm 3.6$	$28.2\pm 4.2$
Cd	g/kg	$17.5\pm 2.6$	$17.1\pm 2.6$	$12.2\pm 1.8$	$18.7\pm 2.8$