Effect of mixture ratio and organic loading rate during anaerobic co-digestion of olive mill wastewater and agro-industrial wastes

This study evaluated the performance of a plug-flow reactor (PFR) for high-rate anaerobic co-digestion of complex agro-industrial wastes and used cooking oil or animal fat. The PFR was successfully operated up to an organic loading rate (OLR) of 21 g L−1 d−1, yielding biogas at 0.35 L g−1 chemical oxygen demand (COD) influent. During the study period, supernatant COD at the PFR effluent remained between 4 and 7 g L−1, with negligible volatile fatty acids’ concentrations (<500 mg L−1) and no presence of foaming incidents. The biomass concentration inside the PFR, expressed as total suspended solids, remained between 30 and 60 g L−1. Moreover, the above-mentioned anaerobic digestion technology has been currently scaled-up at 50 m3 PFR, while a full-scale facility of 240 kW-el is under construction in the region of north-eastern Greece.

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Anaerobic Treatment of Polyethylene Terephthalate (PET) Wastewater from Lab to Full Scale

Water Science & Technology ◽

10.2166/wst.1999.0426 ◽

1999 ◽

Vol 40 (8) ◽

pp. 229-236 ◽

Cited By ~ 4

Author(s):

F. Fdz-Polanco ◽

M. D. Hidalgo ◽

M. Fdz-Polanco ◽

P. A. García Encina

Keyword(s):

Polyethylene Terephthalate ◽

Loading Rate ◽

Treatment Plant ◽

Textile Wastewater ◽

Anaerobic Treatment ◽

Cod Removal ◽

Organic Loading Rate ◽

Foam Formation ◽

Organic Loading ◽

Start Up

In the last decade Polyethylene Terephthalate (PET) production is growing. The wastewater of the “Catalana de Polimers” factory in Barcelona (Spain) has two main streams of similar flow rate, esterification (COD=30,000 mg/l) and textile (COD=4000 mg/l). In order to assess the anaerobic treatment viability, discontinuous and continuous experiments were carried out. Discontinuous biodegradability tests indicated that anaerobic biodegradability was 90 and 75% for esterification and textile wastewater. The textile stream revealed some tendency to foam formation and inhibitory effects. Nutrients, micronutrients and alkali limitations and dosage were determined. A continuous lab-scale UASB reactor was able to treat a mixture of 50% (v) esterification/textile wastewater with stable behaviour at organic loading rate larger than 12 g COD/l.d (0.3 g COD/g VSS.d) with COD removal efficiency greater than 90%. The start-up period was very short and the recuperation after overloading accidents was quite fast, in spite of the wash-out of solids. From the laboratory information an industrial treatment plant was designed and built, during the start-up period COD removal efficiencies larger than 90% and organic loading rate of 0.6 kg COD/kg VSS.d (5 kg COD/m3.d) have been reached.

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Performance of an anaerobic baffled reactor (ABR) as a hydrolysis-acidogenesis unit in treating landfill leachate mixed with municipal sewage

Water Science & Technology ◽

10.2166/wst.2000.0253 ◽

2000 ◽

Vol 42 (12) ◽

pp. 115-121 ◽

Cited By ~ 13

Author(s):

B. Wang ◽

Y. Shen

Keyword(s):

Landfill Leachate ◽

Loading Rate ◽

Granular Sludge ◽

Operational Performance ◽

Municipal Sewage ◽

Organic Loading Rate ◽

Stable Operation ◽

Organic Loading ◽

Anaerobic Baffled Reactor ◽

Biological Treatability

A study on the performance of an Anaerobic Baffled Reactor(ABR) as a hydrolysis-acidogenesis unit in treating the mixed wastewater of landfill leachate and municipal sewage in different volumetric ratios was carried out. The results showed that ABR substantially improved the biological treatability of the mixed wastewater by increasing its BOD5/COD ratio to 0.4–0.6 from the initial values of 0.15–0.3. The formation of bar-shaped granular sludge of 0.5–5 mm both in diameter and length with an SVI of 7.5–14.2 ml/g was observed in all compartments of the ABR when the organic loading rate reached 4.71 kgCOD/m3 · d. The effects of the ratios of NH4+-N/COD and COD/TP in mixed wastewater on the operational performance were also studied, from which it was found that a reasonable NH4+-N/COD ratio should be lower than 0.02, and the phosphorus supplement was needed when the volumetric ratio was higher than 4:6 for stable operation of ABR.

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