The relationship between volatile fatty acids accumulation and microbial community succession triggered by excess sludge alkaline fermentation

Li, Xiangkun; Liu, Gaige; Liu, Shuli; Ma, Kaili; Meng, Lingwei

doi:10.1016/j.jenvman.2018.06.002

Cited by 61 publications

(12 citation statements)

References 47 publications

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“…Although some studies indicate that higher VFA production could be obtained under alkaline conditions than under acidic conditions (Lee et al 2014; Garcia-Aguirre et al 2017), in this study, the results showed that the VFA production under pH 10 was not as high as what could be expected, reaching a similar VFA production and distribution of individual VFAs to the obtained at pH 6.0 (see Table 3). As stated in Table 3, the sCOD was higher in the fermenter working at pH 10 than in the fermenter working at lower pH, because hydrolysis was favored at the alkaline pH (Li et al 2018; Liu et al 2018; Zou et al 2018). In alkaline pH, a strong repulsion exists between extracellular polymeric substances (EPS) followed by release of carbohydrate and protein from internal cell to the environment (Yu et al 2008; Feng et al 2014; Yuan et al 2015).…”

Section: Resultsmentioning

confidence: 99%

Volatile fatty acid production from mesophilic acidogenic fermentation of organic fraction of municipal solid waste and food waste under acidic and alkaline pH

Cheah

Vidal-Antich

Dosta

et al. 2019

Environ Sci Pollut Res

116

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This study is focused on the effects of pH on the production of volatile fatty acids (VFAs) and their distribution through the acidogenic fermentation of source-sorted organic fraction of municipal solid waste (OFMSW) from a mechanical-biological treatment (MBT) plant, and food waste (FW) from a university canteen. In semi-continuous lab-scale digesters using OFMSW at a hydraulic retention time (HRT) of 3.5 days under acidic conditions (pH 6.0), the VFA concentration in the effluent increased to 9.8–11.5 g L−1 (VS content of the feedstock between 4.2 and 5.2% w/w), while its individual VFA profiling was similar to the influent which was already pre-fermented (namely, C2 35–41%, C3 18–22%, C4 17–21%, and C5 9–12%). When working with the same conditions but using FW as feedstock, an effluent with a VFA concentration up to 11.5 g VFA L−1 (FW with a VS content of 5.5% w/w) and a stable distribution of C2 and C4 acids (up to 60.3% and 12.9%, respectively) but with very low quantities of C3 and C5 acids (lower than 1.8 and 2.7%, respectively) was obtained. Anaerobic batch tests using FW revealed that alkaline pH near 9 could lead to higher VFA production with high acetic acid content when compared to pH 6. In the semi-continuous fermenters working at alkaline conditions (pH 9.5–10) using OFMSW and FW, an enhanced solubilization of organic matter was registered with respect to the fermenters working under acidic conditions. This fact was not reflected in a higher VFA production when using OFMSW as feedstock, probably due to free ammonia inhibition, since OFMSW was mixed in the MBT plant with supernatant from anaerobic digestion of this biowaste. However, when using FW, alkaline conditions lead to an enhanced VFA production with respect to the reactor working under acidic conditions, being acetic acid the predominant product, which represented up to 91% of the VFA spectrum obtained.Electronic supplementary materialThe online version of this article (10.1007/s11356-019-05394-6) contains supplementary material, which is available to authorized users.

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Section: Resultsmentioning

confidence: 99%

Volatile fatty acid production from mesophilic acidogenic fermentation of organic fraction of municipal solid waste and food waste under acidic and alkaline pH

Cheah

Vidal-Antich

Dosta

et al. 2019

Environ Sci Pollut Res

116

View full text Add to dashboard Cite

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“…However, this process is highly energy consuming and requires the occupation of large land quantities with possible GHG formation (Lawal-Akinlami, Palaniyandi, 2017). Similar disposal problems are encountered with other organic waste produced in urban areas, especially wastewater sludge generated from biological wastewater treatment processes (Li et al, 2018). Some of the most common processes applied for biological sludge disposal are composting or anaerobic digestion.…”

Section: Introductionmentioning

confidence: 86%

An urban biorefinery for food waste and biological sludge conversion into polyhydroxyalkanoates and biogas

et al. 2020

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“…Another crucial parameter investigated in this work is pH. It is well known from literature that in anaerobic processes the pH affects the hydrolysis and fermentation rate, substrate solubilisation and methanogenic activity (Chen et al, 2007;Li et al, 2018;Maspolim et al, 2015). Generally, at relatively low reaction time methanogenic bacteria do not show remarkable activity and VFA can be accumulated without being consumed.…”

Section: Effect Of Initial Ph On the Urban Waste Fermentation In Batch Testsmentioning

confidence: 99%

Optimization of urban waste fermentation for volatile fatty acids production

et al. 2019

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The problem of waste disposal has recently focused on practices for waste recycling and bio-resources valorization. Organic waste produced in urban context together with biological sludge produced in wastewater treatment plants (WWTPs) can be used as renewable feedstock for the production of building blocks of different products, from biopolymers to methyl esters. This paper deals with the optimization of the fermentation process in order to transform urban organic waste (a mixture of pre-treated food waste and biological sludge) into added-value volatile fatty acid (VFA) rich stream, useful for biological processes within a biorefinery technology chain. Different temperatures, pH, hydraulic retention times (HRTs) and organic loading rates (OLRs) were tested both in batch and continuous trials. Batch tests showed the best working conditions at 37°C and pH 9, using the bio-waste feedstock thermally pretreated (76 h at 72°C). These conditions were applied in continuous process, where higher HRT (6.0 d) and lower OLR [7.7 kg VS/(m 3 d)] gave the best performances in terms of process yield and maximum VFA level achieved: 0.77 COD VFA /VS (0) and 39 g COD VFA /L. An optimized fermentation process is crucial in a biorefinery perspective since it has to give a final stream of constant composition or tailored products suitable for further applications.

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The relationship between volatile fatty acids accumulation and microbial community succession triggered by excess sludge alkaline fermentation

Cited by 61 publications

References 47 publications

Volatile fatty acid production from mesophilic acidogenic fermentation of organic fraction of municipal solid waste and food waste under acidic and alkaline pH

Volatile fatty acid production from mesophilic acidogenic fermentation of organic fraction of municipal solid waste and food waste under acidic and alkaline pH

An urban biorefinery for food waste and biological sludge conversion into polyhydroxyalkanoates and biogas

Optimization of urban waste fermentation for volatile fatty acids production

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