Thermophilic anaerobic digestion of sewage sludge with high solids content

2014 ◽  
Vol 69 (9) ◽  
pp. 1949-1955 ◽  
Author(s):  
Feng Wang ◽  
Taira Hidaka ◽  
Tsutomu Uchida ◽  
Jun Tsumori
Keyword(s):  
Sewage Sludge ◽  
Stable State ◽  
Methane Yield ◽  
High Solids ◽  
Removal Ratio ◽  
Treatment Performance ◽  
Thermophilic Anaerobic Digestion ◽  
Vs Removal ◽  
Solids Content ◽  
High Solids Content

The treatment performance of thermophilic anaerobic digestion (AD) of sewage sludge with high solids content was investigated with two laboratory-scale thermophilic anaerobic reactors (R1 and R2) with a feeding of pre-centrifuged sewage sludge. Reactor R1 was fed with sludge of 3.7% total solids (TS). The volatile solids (VS) removal ratio and methane yield in the stable state were 54.9% and 0.29 NL CH4/g VSadded, respectively. For reactor R2, when the TS content of fed sludge was 7.4%, the VS removal ratio and methane yield in the stable state were 73.2% and 0.38 NL CH4/g VSadded, respectively. When the TS content was increased to 9.5%, the VS removal ratio and methane yield slightly decreased to 69.3% and 0.32 NL CH4/g VSadded, respectively, but the reactor was stably operated. An increase of ammonia concentration was observed, but it was in the safe range without severe inhibition on the methane production. The result indicated that thermophilic AD could support sewage sludge with high TS content (9.5%) without abrupt deterioration of the treatment performance. The high-solids AD process is an economical method for centralized sewage sludge treatment with lower transport cost.

Deep Shaft High Rate Aerobic Digestion: Laboratory and Pilot Plant Performance

1981 ◽  
Vol 16 (1) ◽  
pp. 71-90 ◽  
Author(s):  
F. Tran ◽  
D. Gannon
Keyword(s):  
Retention Time ◽  
Oxygen Transfer ◽  
Pilot Plant ◽  
High Rate ◽  
Plant Performance ◽  
High Solids ◽  
Aerobic Digestion ◽  
Volatile Solids ◽  
Solids Content ◽  
High Solids Content

Abstract The Deep Shaft process, originating from ICI Ltd. in the U.K., has been further developed by C-I-L Inc., Eco-Technology Division into an extremely energy efficient, high rate biological treatment process for industrial and municipal wastewaters. The Deep Shaft is essentially an air-lift reactor, sunk deep in the ground (100 - 160 m): the resulting high hydrostatic pressure together with very efficient mixing in the shaft provide extremely high oxygen transfer efficiencies (O.T.E.) of up to 90% vs 4 to 20% in other aerators. This high O.T.E. suggests real potential for Deep Shaft technology in the aerobic digestion of sludges and animal wastes: with conventional aerobic digesters an O.T.E. over 8% is extremely difficult to achieve. This paper describes laboratory and pilot plant Deep Shaft aerobic digester (DSAD) studies carried out at Eco-Research's Pointe Claire, Quebec laboratories, and at the Paris, Ontario pilot Deep Shaft digester. An economic pre-evaluation indicated that DSAD had the greatest potential for treating high solids content primary or secondary sludge (3-7% total solids) in the high mesophilic and thermophilic temperature range (25-60°C) i.e. in cases where conventional digesters would experience severe limitations of oxygen transfer. Laboratory and pilot plant studies have accordingly concentrated on high solids content sludge digestion as a function of temperature. Laboratory scale daily draw and fill DSAD runs with a 5% solids sludge at 33°C with a 3 day retention time have achieved 34% volatile solids reduction and a stabilized sludge exhibiting a specific oxygen uptake rate (S.O.U.R.) of less than 1 mgO2/gVSS/hour, measured at 20°C. This digestion rate is about four times faster than the best conventional digesters. Using Eco-Research's Paris, Ontario pilot scale DSAD (a 160 m deep 8 cm diameter u-tube), a 40% reduction in total volatile solids, (or 73% reduction of biodegradable VS) and a final SOUR of 1.2 mg02/gVSS/hour have been achieved for a 4.6% solids sludge in 4 days at 33°C, with loading rates of up to 7.9 kg VSS/m3-day. Laboratory runs at thermophilic temperatures (up to 60°C) have demonstrated that a stabilized sludge (24-41% VSS reduction) can be produced in retention time of 2 days or less, with a resulting loading rate exceeding 10 kg VSS/m3-day.

Effects of experimental parameters on methane production and volatile solids removal from tomato and pepper plant wastes

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 4763-4780
Author(s):  
Saraí Camarena-Martínez ◽  
Juan H. Martínez-Martínez ◽  
Adriana Saldaña-Robles ◽  
Hector G. Nuñez-Palenius ◽  
Rogelio Costilla-Salazar ◽  
...  
Keyword(s):  
Methane Production ◽  
Methane Yield ◽  
Pepper Plant ◽  
Limited Information ◽  
Total Solids ◽  
Volatile Solids ◽  
Vs Removal ◽  
Solids Content ◽  
Solids Removal ◽  
Positive Effect

In Mexico, protected agriculture generates large amounts of tomato and pepper plants residues (TPW and PPW, respectively). Given the limited information on methane production from anaerobic digestion of these wastes, this study aimed to determine the effects of the substrate/inoculum (S/I) ratio, temperature, and total solids content on methane production and volatile solids (VS) removal by two subsequent batch experiments (Experiments A and B). Experiment A was performed to evaluate the substrate/inoculum ratios of 0.5, 1.0, and 2.0 at room temperature (22 ± 4.5 °C). Based on the best methane yield from experiment A, a new experiment was established (Experiment B) using only tomato wastes, where temperature was kept at 29 °C and 39 °C. The total solids content was analyzed depending on the S/I ratio used. For both substrates, an S/I ratio of 0.5 was the most appropriate for methane production. The temperature had a positive effect on volatile solids removal and methane yield. In contrast, the total solids content (% TS) only had a positive effect on methane production. To the authors’ knowledge, this is the first study evaluating the effect of the S/I ratio on methane production from tomato and pepper plant wastes.

Polymerization of high-solids-content acrylic latexes using a nonionic polymerizable surfactant

2002 ◽  
Vol 40 (10) ◽  
pp. 1552-1559 ◽  
Author(s):  
E. Aramendia ◽  
M. J. Barandiaran ◽  
J. Grade ◽  
T. Blease ◽  
J. M. Asua
Keyword(s):  
High Solids ◽  
Polymerizable Surfactant ◽  
Solids Content ◽  
Acrylic Latexes ◽  
High Solids Content
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