scholarly journals Description of a Decentralized Small Scale Digester for Treating Organic Wastes

Environments ◽  
2020 ◽  
Vol 7 (10) ◽  
pp. 78
Author(s):  
Rubén González ◽  
Daniel Blanco ◽  
Judith González-Arias ◽  
José García-Cascallana ◽  
Xiomar Gómez
Keyword(s):  
Organic Loading Rate ◽  
Small Scale ◽  
Complex Nature ◽  
Fed Batch ◽  
Batch Mode ◽  
Commercial Unit ◽  
Start Up ◽  
Volatile Solids ◽  
Vegetable Wastes ◽  
Feeding Substrate

This manuscript deals with the detailed design of a small digestion prototype intended as a commercial unit fully operational to cover the demand for decentralized treatment of wastes. These plants are highly affected by the complex nature of wastes giving rise to different operating problems that should be considered in detail. This paper describes the design and start-up strategy of a small-scale digestion plant with a volume of 8 m3 designed to operate with a hydrolysis pretreatment unit. The plant was designed to treat fruit and vegetable wastes as substrates derived from a local processing food factory. The performance of the plant during fed-batch operation was reported. The strategy of inoculating the reactor only to a third of its original volume and subsequently increasing the volume of the reactor by using the fed-batch mode was inadequate. The acid pH of the feeding substrate resulted in the application of a low organic loading rate with a volumetric variation of just 19.7 L/d. The performance of the plant was evaluated at non-steady state conditions and resulted in excessive destruction of volatile solids due to the low nitrogen content of the feeding substrate. The prototype reported a specific methane production of 232 L/kg volatile solids despite the low feeding rate supplemented.

Equalizing growth in high-throughput small scale cultivations via precultures operated in fed-batch mode

2009 ◽  
Vol 103 (6) ◽  
pp. 1095-1102 ◽  
Author(s):  
Robert Huber ◽  
Marco Scheidle ◽  
Barbara Dittrich ◽  
Doris Klee ◽  
Jochen Büchs
Keyword(s):  
High Throughput ◽  
Small Scale ◽  
Fed Batch ◽  
Batch Mode

scholarly journals High-throughput screening ofHansenula polymorphaclones in the batch compared with the controlled-release fed-batch mode on a small scale

2010 ◽  
Vol 10 (1) ◽  
pp. 83-92 ◽  
Author(s):  
Marco Scheidle ◽  
Markus Jeude ◽  
Barbara Dittrich ◽  
Sylvia Denter ◽  
Frank Kensy ◽  
...  
Keyword(s):  
Controlled Release ◽  
High Throughput ◽  
High Throughput Screening ◽  
Small Scale ◽  
Fed Batch ◽  
Batch Mode

Treatment of Sago Wastewater using Hybrid Anaerobic Reactor

2006 ◽  
Vol 41 (1) ◽  
pp. 56-62 ◽  
Author(s):  
J. Rajesh Banu ◽  
Sudalyandi Kaliappan ◽  
Dieter Beck
Keyword(s):  
Loading Rate ◽  
Low Cost ◽  
High Strength ◽  
Organic Loading Rate ◽  
Hybrid Reactor ◽  
Small Scale ◽  
Anaerobic Sludge ◽  
Organic Loading ◽  
Volatile Solids ◽  
Anaerobic Sludge Blanket

Abstract Sago, tapioca starch, is manufactured by over 800 small-scale units located in the Salem district of the State of Tamilnadu, South India. These units generate large quantities of high-strength wastewater requiring elaborate treatment prior to disposal. The present study is an attempt to treat the sago wastewater using a hybrid reactor, which combines the advantages of both fixed-film and up-flow anaerobic sludge blanket systems. A hybrid reactor with a volume of 5.9 L was operated at organic loading rates varying from 10.4 to 24.6 kg COD/m3d. After 120 d of start-up, an appreciable decrease in COD and efficient removal of solids were evident. The COD removal varied from 91 to 83%. While the removal of total solids was in the range of 56 to 63%, that of volatile solids varied from 67 to 72%. The methane production during the study period was in the range of 0.11 to 0.14 L CH4/g COD-d and the percentage was from 55 to 67%. The ideal organic loading rate (OLR) was determined on the basis of tolerance of the reactor towards higher organic loading rate and it was found to be 23.4 kg COD/m3d. The findings of the study open new possibilities for the design of low-cost and compact on-site treatment systems with very short retention periods.

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

1999 ◽  
Vol 40 (8) ◽  
pp. 229-236 ◽  
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.

scholarly journals Screening for optimal protease producing Bacillus licheniformis strains with polymer-based controlled-release fed-batch microtiter plates

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Tobias Habicher ◽  
Tobias Klein ◽  
Jacqueline Becker ◽  
Andreas Daub ◽  
Jochen Büchs
Keyword(s):  
Controlled Release ◽  
Bacillus Licheniformis ◽  
Protease Activity ◽  
Microtiter Plate ◽  
Fed Batch ◽  
Batch Mode ◽  
Screening Process ◽  
Microtiter Plates ◽  
Batch Fermenter ◽  
Production Conditions

Abstract Background Substrate-limited fed-batch conditions have the favorable effect of preventing overflow metabolism, catabolite repression, oxygen limitation or inhibition caused by elevated substrate or osmotic concentrations. Due to these favorable effects, fed-batch mode is predominantly used in industrial production processes. In contrast, screening processes are usually performed in microtiter plates operated in batch mode. This leads to a different physiological state of the production organism in early screening and can misguide the selection of potential production strains. To close the gap between screening and production conditions, new techniques to enable fed-batch mode in microtiter plates have been described. One of these systems is the ready-to-use and disposable polymer-based controlled-release fed-batch microtiter plate (fed-batch MTP). In this work, the fed-batch MTP was applied to establish a glucose-limited fed-batch screening procedure for industrially relevant protease producing Bacillus licheniformis strains. Results To achieve equal initial growth conditions for different clones with the fed-batch MTP, a two-step batch preculture procedure was developed. Based on this preculture procedure, the standard deviation of the protease activity of glucose-limited fed-batch main culture cultivations in the fed-batch MTP was ± 10%. The determination of the number of replicates revealed that a minimum of 6 parallel cultivations were necessary to identify clones with a statistically significant increased or decreased protease activity. The developed glucose-limited fed-batch screening procedure was applied to 13 industrially-relevant clones from two B. licheniformis strain lineages. It was found that 12 out of 13 clones (92%) were classified similarly as in a lab-scale fed-batch fermenter process operated under glucose-limited conditions. When the microtiter plate screening process was performed in batch mode, only 5 out of 13 clones (38%) were classified similarly as in the lab-scale fed-batch fermenter process. Conclusion The glucose-limited fed-batch screening process outperformed the usual batch screening process in terms of the predictability of the clone performance under glucose-limited fed-batch fermenter conditions. These results highlight that the implementation of glucose-limited fed-batch conditions already in microtiter plate scale is crucial to increase the precision of identifying improved protease producing B. licheniformis strains. Hence, the fed-batch MTP represents an efficient high-throughput screening tool that aims at closing the gap between screening and production conditions.

scholarly journals Batch and Semi-Continuous Anaerobic Digestion of Industrial Solid Citrus Waste for the Production of Bioenergy

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 648
Author(s):  
Erik Samuel Rosas-Mendoza ◽  
Andrea Alvarado-Vallejo ◽  
Norma Alejandra Vallejo-Cantú ◽  
Raúl Snell-Castro ◽  
Sergio Martínez-Hernández ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Oxygen Demand ◽  
Continuous Mode ◽  
Citrus Industry ◽  
Batch Mode ◽  
Volatile Solids ◽  
Working Volume ◽  
Plant Level ◽  
Citrus Waste ◽  
Mesophilic Conditions

The aim of this paper is to describe a study of the anaerobic digestion of industrial citrus solid waste (ISCW) in both batch and semi-continuous modes for the production of bioenergy without the elimination of D-limonene. The study was conducted at the pilot plant level in an anaerobic reactor with a working volume of 220 L under mesophilic conditions of 35 ± 2 °C. Cattle manure (CM) was used as the inoculum. Three batches were studied. The first batch had a CM/ISCW ratio of 90/10, and Batches 2 and 3 had CM/ISCW ratios of 80/20 and 70/30, respectively. In the semi-continuous mode an OLR of approximately 8 g total chemical oxygen demand (COD)/Ld (4.43 gVS/Ld) was used. The results showed that 49%, 44%, and 60% of volatile solids were removed in the batch mode, and 35% was removed in the semi-continuous mode. In the batch mode, 0.322, 0.382, and 0.316 LCH4 were obtained at STP/gVSremoved. A total of 24.4 L/d (34% methane) was measured in the semi-continuous mode. Bioenergy potentials of 3.97, 5.66, and 8.79 kWh were obtained for the respective batches, and 0.09 kWh was calculated in the semi-continuous mode. The citrus industry could produce 37 GWh per season. A ton of processed oranges has a bioenergy potential of 162 kWh, which is equivalent to 49 kWh of available electricity ($3.90).

Optimized Large Scale Synthesis of Phosphorothioate Oligonucleotides on PS-PEG Supports

1997 ◽  
Vol 52 (1) ◽  
pp. 110-116
Author(s):  
Michael Gerster ◽  
Martin Maier ◽  
Nils Clausen ◽  
Jens Schewitz ◽  
Ernst Bayer
Keyword(s):  
Gel Electrophoresis ◽  
Continuous Flow ◽  
Large Scale ◽  
Electrospray Mass Spectrometry ◽  
Small Scale ◽  
Batch Mode ◽  
Crucial Step ◽  
Capillary Gel Electrophoresis ◽  
Phosphoramidite Chemistry ◽  
Large Scale Synthesis

Sulphurization is a crucial step during synthesis of phosphorothioate oligonucleotides. Insufficient reaction leads to inhomogeneous products with phosphodiester defects and subsequently to destabilization of the oligomers in biological media. To achieve a maximum extent of sulphur incorporation, various sulphurizing agents have been investigated. Solely, the use of Beaucage reagent provided satisfactory results on PS-PEG supports. Based on our investigations in small scale synthesis (1 μmol) with continuous-flow technique, upscaling to the 0.1-0.25 mmolar range has been achieved using a peptide synthesizer. The syntheses were performed in batch mode with standard phosphoramidite chemistry. Additionally, large scale synthesis of a phosphodiester oligonucleotide has been carried out on PS-PEG with optimized protocols and compared to small scale synthesis on different supports. Products were analysed by 31P NMR, capillary gel electrophoresis and electrospray mass spectrometry. An extent of sulphurization of 99% and coupling effiencies of more than 99% were obtained and the products proved to have similar purity compared to small scale syntheses on CPG

scholarly journals A Study on the Sustainability of Microfinance Institutions in Serving the Low-Income Group in Malaysia

2021 ◽  
Vol 8 (Special Issue) ◽  
pp. 339-353
Author(s):  
Nur Harena Redzuan ◽  
Amir Abidin Bashir
Keyword(s):  
Low Income ◽  
Income Group ◽  
Small Scale ◽  
Microfinance Institutions ◽  
Poverty Eradication ◽  
The People ◽  
Start Up ◽  
Low Income Groups ◽  
The Government ◽  
The Impact

A microfinance scheme was introduced in Malaysia in the year 1987 as one of the alternatives to poverty eradication strategies in the country by the government. Since then, several institutions have created to carry out the agenda of providing small loans to the low-income group to start up their small-scale business to generate more sources of income to support their household consumption. However, for a certain reason, the people still do not find microfinance an important tool to uplift their economic positions. Most of the low-income groups are still unaware of this golden opportunity tailored for them. Besides, the sustainability of these subsidized microfinance systems implemented by Malaysia had not been appropriately studied. This study explores the attractiveness of the products offered by microfinance institutions and emphasizes the option that the participants must start utilizing the product. This research also explores microfinance facilities that contain conventional finance element which is prohibited in Islamic trade. The study also discusses the measures and actions taken by microfinance institutions in serving the low-income group in Malaysia. This paper employs a qualitative method through interviews and content analysis. The report, journal publications, and other related documents were also analyzed in achieving the objectives. The study provides the impact that it may pave the way to an indistinct understanding of how Islamic microfinance institutions sustain their operations.

A Study on the Temperature Calibration for a Small Electrical Resistance Furnace

2010 ◽  
Author(s):  
Un Bong Baek ◽  
Hae Moo Lee ◽  
Yun-Hee Lee ◽  
Seung Hoon Nahm
Keyword(s):  
Electrical Resistance ◽  
Power Plants ◽  
Low Cycle Fatigue ◽  
Small Scale ◽  
Temperature Calibration ◽  
Cycle Fatigue ◽  
Resistance Furnace ◽  
Small Space ◽  
Start Up ◽  
Electrical Resistance Furnace

A severe thermal stress occurs during start up/shutdown transients in thick walled components of high temperature power plants. Thus, a precise consideration of this issue is very important. Many researchers have studied low-cycle fatigue at high temperatures and small box-type electrical resistance furnaces have been developed for small-sized fatigue specimens. However, these small-scale electrical resistance furnaces need precise temperature calibrations because temperature control is difficult in a small space. Thus, a method for the temperature calibration of a box-type electrical resistance furnace is investigated and calibration procedures are proposed in this study.

scholarly journals The feasibility of trace element supplementation for stable operation of wheat stillage-fed biogas tank reactors

2011 ◽  
Vol 64 (2) ◽  
pp. 320-325 ◽  
Author(s):  
J. Gustavsson ◽  
B. H. Svensson ◽  
A. Karlsson
Keyword(s):  
Trace Element ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Biogas Production ◽  
Organic Loading Rate ◽  
Stable Operation ◽  
Organic Loading ◽  
Process Stability ◽  
Volatile Solids ◽  
High Sulfate

The aim of this study was to investigate the effect of trace element supplementation on operation of wheat stillage-fed biogas tank reactors. The stillage used was a residue from bio-ethanol production, containing high levels of sulfate. In biogas production, high sulfate content has been associated with poor process stability in terms of low methane production and accumulation of process intermediates. However, the results of the present study show that this problem can be overcome by trace element supplementations. Four lab-scale wheat stillage-fed biogas tank reactors were operated for 345 days at a hydraulic retention time of 20 days (37 °C). It was concluded that daily supplementation with Co (0.5 mg L−1), Ni (0.2 mg L−1) and Fe (0.5 g L−1) were required for maintaining process stability at the organic loading rate of 4.0 g volatile solids L−1 day−1.

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