scholarly journals Energy sustainability of two parallel sewage sludge-to-energy pathways: Effect of sludge volatile solids content on net energy efficiency

2012 ◽  
Vol 38 (2) ◽  
Author(s):  
Yucheng Cao ◽  
Artur Pawłowski
2017 ◽  
Vol 126 ◽  
pp. 342-350 ◽  
Author(s):  
Wenbo Yu ◽  
Jiakuan Yang ◽  
Shuangyi Tao ◽  
Yafei Shi ◽  
Jiangwei Yu ◽  
...  

1981 ◽  
Vol 16 (1) ◽  
pp. 71-90 ◽  
Author(s):  
F. Tran ◽  
D. Gannon

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.


1991 ◽  
Vol 23 (10-12) ◽  
pp. 2011-2018 ◽  
Author(s):  
T. Murakami ◽  
K. Sasabe ◽  
K. Sasaki ◽  
T. Kawashima

The possible volume reduction and stabilization of the sewage sludge associated with the melting process are expected to be greater than with the incineration process. In addition, melted slag can be utilized. However, since the melting process requires a very high temperature to melt inorganics (ash) in the sludge, the technologies to minimize energy consumption, to establish system operation and to prolong durability of facilities should be developed. This paper discusses the auxiliary fuel consumption as follows.(1)Preparation of a model that provides the auxiliary fuel consumption of the melting system on the basis of the mass and heat balances.(2)Evaluation of the auxiliary fuel consumption in the above model using the cake moisture content, the volatile solids of the cake, the dried cake moisture content and the melting temperature as parameters.(3)Examination of the operational conditions for an energy saving melting system based on the results of (1) and (2) above.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shahryar Habibi

Purpose The purpose of this study is to design a zero-energy home, which is known to be capable of balancing its own energy production and consumption close to zero. Development of low-energy homes and zero-net energy houses (ZEHs) is vital to move toward energy efficiency and sustainability in the built environment. To achieve zero or low energy targets in homes, it is essential to use the design process that minimizes the need for active mechanical systems. Design/methodology/approach The methodology discussed in this paper consists of an interfacing building information modeling (BIM) tool and a simulation software to determine the potential influence of phase change materials on designing zero-net energy homes. Findings BIM plays a key role in advancing methods for architects and designers to communicate through a common software platform, analyze energy performance through all stages of the design and construction process and make decisions for improving energy efficiency in the built environment. Originality/value This paper reviews the literature relevant to the role of BIM in helping energy simulation for the performance of residential homes to more advanced levels and in modeling the integrated design process of ZEHs.


2019 ◽  
Vol 12 (2) ◽  
pp. 131-140 ◽  
Author(s):  
Józef CIUŁA ◽  
Krzysztof GASKA ◽  
Łukasz ILJUCZONEK ◽  
Agnieszka GENEROWICZ ◽  
Viktor KOVAL

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 ◽  
...  

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.


Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 231 ◽  
Author(s):  
Renata Xavier Alberico Freitas ◽  
Lara Aguiar Borges ◽  
Handray Fernandes de Souza ◽  
Fernando Colen ◽  
Alex Sander Rodrigues Cangussu ◽  
...  

The generation of large volumes of waste by industrial processes has become an object of study because of the necessity to characterize the composition of residues in order to suggest appropriate treatments and to minimize adverse environmental impacts. We performed analyses of total fixed and volatile solids, moisture, and chemical oxygen demand (COD). We found high organic matter content. We also measured physicochemical characteristics, including corrosivity, reactivity, and toxicity. Sewage sludge showed levels of chloride and sodium above the maximum allowed limits. These data suggest the potential for anaerobic digestion as a treatment option for sewage sludge and for its use as a biofertilizer.


2019 ◽  
Vol 37 (5) ◽  
pp. 542-550 ◽  
Author(s):  
Irena Wojnowska-Baryła ◽  
Dorota Kulikowska ◽  
Katarzyna Bernat ◽  
Sławomir Kasiński ◽  
Magdalena Zaborowska ◽  
...  

Autoclaving of unsorted municipal solid waste is one of the solutions in waste management that maximises the amount of waste for recycling. After autoclaving, however, a large part of the waste is composed of unstabilised biodegradable fractions (organic remaining fraction, ORF), which may comprise up to 30% of autoclaved waste and cannot be landfilled without further stabilisation. Thus, the aim of this study was to investigate the effectiveness of aerobic stabilisation in a passively aerated reactor of organic remaining fraction after full-scale autoclaving of unsorted municipal solid waste. The organic remaining fraction had a volatile solids content of ca. 70%, a 4-day respiration activity test (AT4) of ca. 26 g O2 kg–1 total solids and a 21-day gas formation test (GP21) of ca. 235 dm3 kg–1 total solids. Stabilisation was conducted in a 550 L reactor with passive aeration (Stage I) and a periodically turned windrow (Stage II). The feedstocks consisted entirely of organic remaining fraction, or of organic remaining fraction with 10% inoculum (ORF + I). Inoculum constituted product of stabilisation of organic remaining fraction. During stabilisation of organic remaining fraction and ORF + I, thermophilic conditions were achieved, and the decreases of volatile solids, AT4 and GP21 could be described by 1 order kinetic models. The rate constants of volatile solids removal (kVS) were 0.033 and 0.068 d–1 for organic remaining fraction and ORF + I, respectively, and the thermophilic phase was shorter with ORF + I (25 days vs. 45 days). The decrease in GP21 corresponded to volatile solids decrease, but AT4 decreased sharply during the first 10 days of waste stabilisation in the reactor, indicating that the content of highly biodegradable organic matter decreased during this time.


2004 ◽  
Vol 49 (10) ◽  
pp. 147-154 ◽  
Author(s):  
J.-Y. Wang ◽  
O. Stabnikova ◽  
S.T.-L. Tay ◽  
V. Ivanov ◽  
J.-H. Tay

Biotechnology for intensive aerobic bioconversion of sewage sludge and food waste into fertilizer was developed. The wastes were treated in a closed reactor under controlled aeration, stirring, pH, and temperature at 60¡C, after addition of starter bacterial culture Bacillus thermoamylovorans. The biodegradation of sewage sludge was studied by decrease of volatile solids (VS), content of organic carbon and autofluorescence of coenzyme F420. The degradation of anaerobic biomass was faster than biodegradation of total organic matter. The best fertilizer was obtained when sewage sludge was thermally pre-treated, mixed with food waste, chalk, and artificial bulking agent. The content of volatile solid and the content of organic carbon decreased at 24.8% and 13.5% of total solids, respectively, during ten days of bioconversion. The fertilizer was a powder with moisture content of 5%. It was stable, and not toxic for the germination of plant seeds. Addition of 1.0 to 1.5% of this fertilizer to the subsoil increased the growth of different plants tested by 113 to 164%. The biotechnology can be applied in larger scale for the recycling of sewage sludge and food wastes in Singapore.


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