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

Table 1

Physicochemical characteristic of SS before and after HTC.

Samples	Ultimate analysis/wt.%					Proximate analysis/wt.%				HHV^2)	Moisture content of SR^3) (wt.%)	pH (WL)	-N; (mg/L); (WL)
										(kJ/kg)
SS	20.13	4.61	4.68	1.73	12.41	9.54	39.66	3.90	46.90	10.11	-	ND	ND
SS-220-1h	23.87	3.45	3.49	1.12	7.71	1.95	32.74	6.90	58.41	10.31	64.90	8.70	1734
SS-220-2h	23.21	3.06	2.95	1.44	5.57	1.86	28.86	7.37	61.91	9.78	62.50	8.90	1773
SS-220-3h	23.65	3.14	2.82	1.82	5.28	1.59	29.37	7.34	61.70	10.06	59.35	9.00	1825
SS-250-1h	25.26	2.93	2.32	1.36	1.85	1.54	26.61	7.11	64.74	10.67	52.30	9.20	2005
SS-280-1h	26.69	2.64	2.16	0.87	0.28	1.34	25.07	7.47	66.02	11.28	48.50	9.50	2245

¹⁾O(%)=100%-(C%+N%+H%+S+%M%+A%); ad-air dry basis.
²⁾HHV, higher heating value. Calculated was according to Channiwala and Parikh [25].
³⁾Moisture content of SR after filtration and before drying.