The Migration and Transformation of Heavy Metals in Sewage Sludge during Hydrothermal Carbonization Combined with Combustion

Table 4

Concentrations of HMs in the combustion residual (mg/kg).

Samples	Cr	Mn	Ni	Cu	Zn	As	Cd	Pb
SS	156.50±5.56	1160.75±65.87	88.61±4.89	382.20±15.67	1448.33±70.45	62.36±2.56	3.35±0.08	111.87±3.32
SS-220-1h	200.90±6.78	1338.55±77.34	126.63±7.45	580.82±18.56	2026.21±68.62	62.58±2.03	4.62±0.10	168.50±5.25
SS-220-2h	182.66±6.68	1345.87±72.56	118.05±6.45	505.83±12.05	1950.73±55.24	44.65±1.89	4.66±0.11	147.99±3.98
SS-220-3h	187.80±8.56	1425.18±65.45	125.41±5.23	531.88±10.78	2010.28±69.46	41.61±1.01	4.63±0.09	152.88±4.23
SS-250-1h	184.07±10.56	1350.55±75.78	118.88±6.54	531.64±11.34	1964.51±51.67	41.36±1.56	4.55±0.13	152.55±4.01
SS-280-1h	219.89±11.45	1356.32±68.67	124.50±5.45	580.29±15.67	1972.96±75.34	38.39±1.12	4.69±0.08	153.34±4.23