Enhanced short chain fatty acids production from waste activated sludge conditioning with typical agricultural residues: carbon source composition regulates community functions

Table 1 Performance of semi-continuous reactors for CS, RS, LES, ABS, and BL

Parameter	Stage 1 SRT = 10 d					Stage 2 SRT = 8 d					Stage 3 SRT = 5 d
Parameter	CS	RS	LES	ABS	BL	CS	RS	LES	ABS	BL	CS	RS	LES	ABS	BL
OLR^a	2.1				1.4	2.6				1.8	4.2				2.8
SCFAs^b	8743.1	9044.2	5576.4	5880.4	2918.6	9942.7	10,491.8	6271.9	6601.6	3508.6	9039.0	9247.2	4859.0	4899.0	2880.1
Product yield^c	416.3	430.7	265.5	280.0	208.5	473.5	499.6	298.7	314.4	250.6	430.4	440.3	231.4	233.3	137.1
Acetate^d	38.2	39.1	41.7	47.5	47.3	43.2	45.5	54.6	54.1	51.3	48.1	46.0	52.2	58.9	53.5
Propionate^d	25.3	22.5	21.1	18.4	13.2	31.8	26.3	24.1	20.2	15.4	25.8	22.3	22.5	20.1	16.3
Other SCFAs^d	36.5	38.4	37.2	34.1	39.5	25.0	28.2	21.3	25.7	34.3	26.1	31.7	25.3	21.0	30.2
Soluble chemical oxygen demand (SCOD)^e	13,428.1	14,039.2	9742.8	9961.8	3778.9	12,361.2	12,528.5	9233.9	8761.2	3461.5	11,340.3	12,263.1	8545.5	8025.3	3749.3
Soluble carbohydrate^b	430.1	495.1	232.1	299.6	70.4	343.8	362.4	246.5	229.8	63.9	353.6	323.5	184.2	190.5	48.1
Soluble protein^b	2893.1	2852.9	2033.2	1881.4	553.2	2554.3	2338.5	1708.6	1544.3	433.3	2405.2	2179.2	1578.8	1284.7	372.7
NH₄ ⁺-N^e	508.5	521.2	354.2	350.6	130.4	455.0	488.5	247.5	298.5	106.6	525.6	490.3	232.8	217.3	76.1
PO₄ ³⁻-P^e	161.4	161.3	130.1	103.9	42.7	134.8	159.5	103.2	85.2	35.3	145.7	163.2	112.3	82.5	33.4
Total suspended solids (TSS) decrease^f	9.8	10.1	8.3	6.6	3.3	9.2	8.9	8.3	7.2	2.9	8.1	8.5	7.4	6.1	2.8
Volatile suspended solids (VSS) removal^f	9.2	9.1	7.3	6.2	2.9	8.6	8.5	7.6	5.8	2.5	7.5	7.8	6.9	5.2	2.4

All numbers were the average values of all valid data
^aUnit is kgVSS/m³/d; ^bunit is mgCOD/L; ^cunit is mgCOD/gVSS; ^dpercentage of specific VFA in total SCFAs, %; ^eunit is mg/L; ^fthe decrease amount of TSS and VSS, unit is g/L

ISSN: 2731-3654