scholarly journals Bio-methanization of organic fraction from municipal solid waste: temperature effects

2013 ◽  
Vol 15 (2) ◽  
pp. 99-106 ◽  
Author(s):  
J. Fernández-Rodríguez ◽  
M. Pérez ◽  
L.I. Romero
Keyword(s):  
Temperature Effects ◽  
Operating Time ◽  
Batch Reactors ◽  
Organic Fraction ◽  
Digestion Process ◽  
Temperature Ranges ◽  
Rate Of Hydrolysis ◽  
Dry Anaerobic Digestion ◽  
Two Temperature ◽  
Methanogenic Phase

The main objective of this study was to analyse the development of dry anaerobic digestion process of OFMSW in batch reactors under two temperature ranges, thermophilic (55°C) and mesophilic (35°C). The experimental results lead to the conclusion that the thermophilic range has a greater rate of hydrolysis and is therefore more effective to degrade wastes, shortening the overall operating time. For example, the hydrolytic step in the thermophilic (T) process lasted an average of 8 days versus 14 days in the mesophilic (M) range. The methanogenic phase lasted for 18 and 29 days in the T and M processes, respectively. The mesophilic range showed higher removal of the organic effluent but with greater uptime requirements. Moreover, the thermophilic range showed greater productivities than the mesophilic range, and the productivities were approximately doubled in terms of the produced biogas from a given amount of consumed organic matter.

scholarly journals Anaerobic Digestion Process for the Treatment of Sisdole Landfill Leachate in Nepal

2020 ◽  
Vol 55 (4) ◽  
Author(s):  
Bikash Adhikari ◽  
Shilpa Koirala
Keyword(s):  
Anaerobic Digestion ◽  
Removal Efficiency ◽  
Landfill Leachate ◽  
Waste Treatment ◽  
Batch Reactor ◽  
Batch Reactors ◽  
Leachate Treatment ◽  
Anaerobic Digestion Process ◽  
Digestion Process ◽  
Solids Concentration

Along with the population, organic waste has been rising significantly in recent years. The resulting uncontrollable waste loads and conventional methods of waste treatment have begun to cause chaos at the landfill sites. This study evaluates the performance of an anaerobic digestion process using batch reactors for the treatment of landfill leachate collected from the Sisdole landfill site in Nuwakot, Nepal. A lab-scale anaerobic batch reactor was set up in Kathmandu University, Nepal. Using an anaerobic digestion process, COD values of the leachate decreased from 2230 mg/l to 1125 mg/l (removal efficiency of ~50%), whereas total solids concentration decreased from 1925 to 925 mg/L under a retention time of 10 days. In addition, Monod’s model was established to design an Anaerobic Sequential Batch Reactor to achieve better performance, resulting in 85% removal efficiency for the leachate treatment. Overall, this study analyzed the anaerobic digestion process on the landfill leachate of Sisdole, and modeled the process to identify the conditions required for increasing the efficiency of treatment of Sisdole landfill leachate.

Deposition Effects on the Ultimate Strength of Tungsten Alloy

2014 ◽  
Vol 887-888 ◽  
pp. 857-860
Author(s):  
Ying Ge Xu ◽  
Ze Wei Wu
Keyword(s):  
Mechanical Properties ◽  
Ultimate Strength ◽  
Temperature Effects ◽  
Tensile Tests ◽  
Tungsten Alloy ◽  
Fracture Modes ◽  
Fracture Surfaces ◽  
Temperature Ranges

The temperature effects on the ultimate strength of 93WNiFe alloy have been investigated systematically through tensile tests, fracture surfaces and microstructure. The temperature ranges from 10 to 900 degrees. The results show that the ultimate strength decreases with the increase of temperature, and there is a platform in 300 to 600 degrees .The deposition has been observed in fracture surfaces from 500 to 600 degrees. The fracture modes influence the ultimate strength,deposition can improve mechanical properties of W-W and W-M interfaces, it is the cause of the ultimate strength platform.

Anaerobic digestion of co-mingled municipal solid waste and sewage sludge

1998 ◽  
Vol 38 (2) ◽  
pp. 127-132 ◽  
Author(s):  
N. Hamzawi ◽  
K. J. Kennedy ◽  
D. D. McLean
Keyword(s):  
Sewage Sludge ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Biogas Production ◽  
Empirical Models ◽  
Organic Fraction ◽  
Primary Sludge ◽  
Digestion Process ◽  
Solids Concentration ◽  
Anaerobic Biodegradability

This study evaluated the technical feasibility of the anaerobic co-digestion process in the context of typical North American solid waste. Using biological activity tests, an optimal mixture was identified with 25% organic fraction of municipal solid waste (OFMSW) and 75% sewage sludge (65% raw primary sludge (RAW), 35% thickened WAS (TWAS)) based on biogas production. Also, based on the rate of biogas production, the most anaerobically biodegradable components of the OFMSW were paper and grass. The TWAS and the newspaper were found to be the least biodegradable components. Lab-scale testing indicated that alkaline pretreatment increased the biodegradability of the sewage sludge/OFMSW mixture the most, as compared to the untreated control. Thermochemically pretreated feedstocks inhibited anaerobic biodegradability as compared to the control, whereas the anaerobic biodegradability of thermally pretreated feed was not found to be significantly different from that of the control. Empirical models were developed based on alkaline dose, feed total solids concentration and particle size for biogas production and removal of TS and VS. All three experimental factors were found to be significant with respect to the response variables studied.

A computational investigation of laminar shock/wave boundary layer interactions

2013 ◽  
Vol 117 (1187) ◽  
pp. 27-56 ◽  
Author(s):  
N. R. Deepak ◽  
S. L. Gai ◽  
A. J. Neely
Keyword(s):  
High Temperature ◽  
Temperature Effects ◽  
Specific Enthalpy ◽  
Computational Investigation ◽  
Computational Fluid Dynamics Cfd ◽  
Interaction Regions ◽  
Wave Boundary ◽  
Grid Independence ◽  
Two Temperature ◽  
Flow Separation And Reattachment

AbstractHypersonic laminar flow past a compression corner has been numerically investigated using time-accurate computational fluid dynamics (CFD) approach. Two flow conditions were considered relevant to high and low enthalpy conditions with a total specific enthalpy of 19MJ/kg and 2·8MJ/kg. The Mach number and unit Reynolds number per metre were 7·5, 9·1 and 3·10 × 105and 32·2 × 105respectively. These free stream conditions provided attached, incipiently separated and fully separated flows for ramp angles between θw= 5° to 24°. A grid independence study has been carried out to estimate the sensitivity of heat flux and skin friction in the strong interaction regions of the flow. The investigation was carried out assuming the flow to be laminar throughout and high temperature effects such as thermal and chemical nonequilibrium are studied using Park’s two temperature model with finite rate chemistry. A critical comparison has been made with existing steady state computational and experimental data and the study has highlighted the importance of high temperature effects on the flow separation and reattachment.

scholarly journals Effect of Two Temperatures on Reflection Coefficient in Micropolar Thermoelastic with and without Energy Dissipation Media

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Rajneesh Kumar ◽  
K. D. Sharma ◽  
S. K. Garg
Keyword(s):  
Energy Dissipation ◽  
Temperature Effects ◽  
Plane Waves ◽  
Angle Of Incidence ◽  
Amplitude Ratios ◽  
Reflected Waves ◽  
Two Temperatures ◽  
Thermally Conducting ◽  
Without Energy Dissipation ◽  
Two Temperature

The reflection of plane waves at the free surface of thermally conducting micropolar elastic medium with two temperatures is studied. The theory of thermoelasticity with and without energy dissipation is used to investigate the problem. The expressions for amplitudes ratios of reflected waves at different angles of incident wave are obtained. Dissipation of energy and two-temperature effects on these amplitude ratios with angle of incidence are depicted graphically. Some special and particular cases are also deduced.

Sign in / Sign up

Export Citation Format

Share Document