Lactic acid fermentation of food waste in a semicontinuous SBR system: influence of the influent composition and hydraulic retention time

Figures & data

Table 1. Physico-chemical features of the synthetic FW used in this study.

Property	Parameter	Value
Solid content	TS (% wet based)	17.08 ± 0.08
	VS (% wet based)	16.41 ± 0.08
	VS (% TS)	96.08 ± 0.01
Composition	Total COD (g/kg)	152.9 ± 6.09
	Total carbohydrates (g/kg)	64.98 ± 2.65
	Total protein (g/kg)	11.43
	Ammonia (mg/L)	7.90 ± 2.00
Physical properties	pH	4.72
	Conductivity (mS/cm)	4.21
	Salinity (g/kg)	2.10

Table 2. Reactor phases and SBR cycle.

Phase	Reactor configuration	Duration (days)	HRT (days)	Volume in/out (mL)	Feeding time	Fermentation time	Settling time	Discharge
–	Batch	5	–	–	–	–	–	–
I	SBR	42	5	160	10 min	22 h 40 min	1 h	10 min
II	SBR	73	4	200
III	SBR	27	2	400

Figure 1. pH profile of the influent and effluent during the experimental time.

Figure 2. Composition variation of the influent during the experimental run.

Figure 3. Composition variation of the effluent during the experimental run.

Figure 4. Daily variation of the production of LA and ethanol and carbohydrate utilization.

Figure 5. Influence of the HRT in the production yields of (a) LA and (b) ethanol.

Data availability

The data will be provided on request to the corresponding author.